Radiation management device, radiation setting method, and radiation setting computer program product

Abstract

This invention relates to a radiation dose management device, a radiation dose setting method, and a radiation dose setting computer program product. The radiation dose management device includes: a ratio acquisition unit that acquires a ratio between a first reference value for radiation dose specified for a case where a first part of a subject is photographed in a still image manner under irradiation and a second reference value for radiation dose specified for a case where the first part is photographed in a moving image manner under irradiation; and a first setting unit that sets a fourth reference value for radiation dose specified for a case where the second part is photographed in a moving image manner, based on a third reference value for radiation dose specified for a case where the second part is photographed in a still image manner and the ratio.

Description

Technical Field

[0001] This invention relates to a radiation dose management device, a radiation dose setting method, and a radiation dose setting computer program product. Background Technology

[0002] To optimize the radiation dose received by patients, the use of a Diagnostic Reference Level (DRL) is recommended. The DRL specifies the radiation dose (DRL value) for patients of standard body type, for example, based on the medical device being examined, the examination site, etc. In radiation dose management devices, radiation dose management for radiographic imaging is performed by comparing the patient's radiation dose with the DRL value (e.g., Patent Document 1).

[0003] Existing technical documents

[0004] Patent Document 1: Japanese Patent Application Publication No. 2020-044332 Summary of the Invention

[0005] In radiographic imaging, specifically in general radiography that captures still images, radiation dose management is performed as described above by comparing the patient's radiation dose with the DRL (Radiation Dose Level). Similarly, in motion radiography, which captures multiple frames of moving images, radiation dose management is desired to optimize the patient's radiation dose, much like in general radiography. However, motion radiography is a relatively new technique currently transitioning from clinical research to practical application in healthcare settings, and methods for radiation dose management, including the setting of the DRL, have not yet been established.

[0006] The purpose of this invention is to provide a radiation dose management device, a radiation dose setting method, and a radiation dose setting computer program product capable of setting radiation doses suitable for dynamic photography.

[0007] The radiation dose management device involved in this invention comprises:

[0008] The ratio acquisition unit acquires the ratio of a first reference value for radiation dose specified when photographing a first part of the subject in a still image manner for exposure to radiation, to a second reference value for radiation dose specified when photographing the first part of the subject in a moving image manner for exposure to radiation; and

[0009] The first setting unit sets a fourth reference value for the radiation dose when photographing the second part in the form of a moving image, based on a third reference value for the radiation dose when photographing the second part in the form of a still image and the aforementioned ratio.

[0010] The radiation dose setting method involved in this invention is used in radiation dose management devices.

[0011] Calculate the ratio of a first reference value for radiation dose specified for a still image of a first part of the subject exposed to radiation, to a second reference value for radiation dose specified for a moving image of the first part of the subject exposed to radiation.

[0012] A fourth reference value for the radiation dose when the second part is photographed in the manner of a still image is set based on a third reference value for the radiation dose and the aforementioned ratio.

[0013] The radiation dose setting computer program product involved in this invention enables the computer of the radiation dose management device to execute:

[0014] The process of determining the ratio of a first reference value for radiation dose specified for photographing a first part of the subject in a still image manner, and a second reference value for radiation dose specified for photographing a first part of the subject in a moving image manner; and

[0015] The processing involves setting a fourth reference value for the radiation dose when photographing the second part in a dynamic image manner, based on a third reference value for the radiation dose when photographing the second part in a still image manner and the aforementioned ratio.

[0016] According to the present invention, it is possible to set a radiation dose suitable for radiation dose management in motion photography. Attached Figure Description

[0017] Figure 1 This is a diagram illustrating an example of the structure of a radiation image processing system according to an embodiment of the present invention.

[0018] Figure 2 This is a block diagram illustrating an example of the functional structure of the photographic control unit in a radiographic imaging system that constitutes a radiographic image processing system.

[0019] Figure 3 This is a block diagram illustrating an example of the functional structure of a radiographic control device constituting a radiographic image processing system.

[0020] Figure 4 This is a block diagram illustrating an example of the functional structure of a radiation image analysis device constituting a radiation image processing system.

[0021] Figure 5 This is a block diagram illustrating an example (Example 1) of the functional structure of a radiation dose management device constituting a radiation image processing system.

[0022] Figure 6 This means that in Figure 5 The diagram shows the DRL (Drone Level at Incident Surface) values ​​for dynamic photography, set based on the DRL values ​​for general photography in the radiation management device shown.

[0023] Figure 7 This means that in Figure 5 The diagram shows the DRL (Drone Level of Incident Surface) for dynamic photography set in the radiation management device based on the DRL (Drone Level of Incident Surface) set for general photography facilities.

[0024] Figure 8 Is Figure 5 The charts displayed in the radiation dose management device shown are for comparison purposes. Figure 6 and Figure 7 The graph shows the DRL values ​​and the radiation dose received by the patient.

[0025] Figure 9 This is a block diagram illustrating another example (Example 2) of the functional structure of the radiation dose management device constituting a radiation image processing system.

[0026] Figure 10 This is a graph illustrating the DRL (radiation dose index) values ​​set according to the child's age in a head CT scan.

[0027] Figure 11 Is Figure 9 The charts displayed in the radiation dose management device shown are for comparison purposes. Figure 10 The graph shows the DRL values ​​and the radiation dose received by the patient.

[0028] Figure 12 This is a graph showing the DRL (radiation dose to incident surface) value in general radiography and the DRL value (radiation dose index) in chest CT scans set according to the child's age. Detailed Implementation

[0029] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0030] <Structure of a Radiation Image Processing System>

[0031] Figure 1 This is a diagram illustrating the radiation image processing system 100 of this embodiment. The radiation image processing system 100 includes a radiation image imaging system 10, a radiation imaging control device (control console device) 20, a radiation image analysis device 30, an image management device 40, a client terminal 50, a radiation dose management device 60, and a medical device 70.

[0032] exist Figure 1 In the example shown, the radiographic imaging system 10 is located in the imaging room, and the radiographic imaging control device 20 is located in the operating room. Alternatively, the radiographic imaging system 10 and the radiographic imaging control device 20 could also be structures mounted in a mobile cart, such as a mobile clinic vehicle.

[0033] The radiographic imaging system 10, radiographic imaging control device 20, radiographic image analysis device 30, image management device 40, client terminal 50, and radiation dose management device 60 are interconnected via a communication network N. The communication network N may be, for example, a communication network conforming to the DICOM (Digital Image and Communications in Medicine) standard.

[0034] In addition, including Figure 1 The medical device 70, which includes a radiographic imaging system 10 and a radiographic imaging control device 20 as illustrated, is also connected to the communication network N. The medical device 70 includes X-ray CT (Computed Tomography) devices that capture tomographic images, and general X-ray imaging devices that capture still images. In this embodiment, radiographic imaging, which is the object of radiation dose management, is... Figure 1 The illustrated examples include dynamic imaging in the radiographic imaging system 10 and the radiographic imaging control device 20, and imaging in the medical device 70.

[0035] Furthermore, although the illustration is omitted, a radiation information terminal, which serves as a radiation information system, is connected to the communication network N and sends information related to radiation examinations, such as patient examination report information, to the radiation image processing system 100. Examples of radiation information terminals include RIS (Radiology Information System).

[0036] The radiographic imaging system 10, under the control of the radiographic imaging control device 20, performs radiographic imaging of dynamic images (hereinafter referred to as dynamic images), i.e., radiographic dynamic imaging (hereinafter referred to as dynamic imaging). The radiographic imaging control device 20 controls the radiographic imaging system 10 based on examination report information, etc., sent from the radiographic information terminal. The dynamic images generated by the radiographic imaging system 10 are processed in the radiographic imaging control device 20 and sent to the radiographic image analysis device 30. The radiographic image analysis device 30 performs dynamic analysis on the dynamic images. The dynamic images and the results of the dynamic analysis are sent to the image management device 40, which is a medical image management system, for management. The image management device 40 may be, for example, a PACS (Picture Archiving and Communication System). The dynamic images and the results of the dynamic analysis are sent to the client terminal 50 for review by doctors and other medical professionals.

[0037] In this embodiment, motion photography refers to repeatedly irradiating (pulsed irradiation) a subject with pulsed radiation (e.g., X-rays) at a predetermined frame rate to obtain a moving image composed of multiple frames. Furthermore, a moving image refers to a moving image composed of a series of frames obtained through motion photography. Additionally, motion analysis refers to the analytical processing performed on the moving image, which includes not only analyzing the movement of the subject based on the moving image, but also analyzing the moving image to emphasize or reduce (remove) predetermined structures.

[0038] The radiographic imaging system 10, the radiographic imaging control device 20, and the radiographic image analysis device 30 are all computers with processors and memory. They achieve predetermined functions by reading the program stored in the memory and executing it.

[0039] [Radiation Imaging System]

[0040] like Figure 1 As shown, the radiographic imaging system 10 includes a imaging control unit 11, a radiographic irradiation unit 12, an imaging stage 13, a radiographic detection unit 14, a display unit 15, and a sound output unit 16.

[0041] The imaging control unit 11 obtains setting information related to dynamic imaging settings from the radiography control device 20. Based on the setting information, the imaging control unit 11 sets the imaging conditions for dynamic imaging, and controls the radiation irradiation unit 12 to irradiate the patient M (subject) with radiation to perform imaging. The imaging control unit 11 is composed of a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), etc.

[0042] The setting information relates to the settings for performing dynamic imaging on patient M. For example, the setting information may include at least one of several dynamic analyses that the radiographic image analysis device 30 can perform on the dynamic image. In the case of a combination of multiple dynamic analyses, the setting information may also include information related to that combination. In the radiographic imaging control device 20, described later, the setting information is set by the operator of the radiographic image processing system 100, such as a radiographic technician.

[0043] Photography conditions include, for example, the location of the photograph, the direction of the photograph, the patient M's position, physique, state, age, and gender. The photographic location may include, for example, the chest or legs. Regarding the patient M's physique, values ​​such as weight, height, BMI (Body Mass Index), and body thickness can be used, and categories based on ranges such as large, medium, small, underweight, average, or overweight can also be used. The patient M's state includes breathing patterns such as holding their breath or deep breathing. The patient M's age can be specified numerically or as a range-based category such as child or adult. The patient M's gender can also be identified based on physical characteristics.

[0044] In addition, imaging conditions include radiation-related conditions such as the type of inspection, tube voltage, tube current, imaging time, current-time product, distance, pulse rate, pulse width, pulse interval, number of frames per imaging session, and radiation dose per unit time under radiation irradiation. Distance is the distance from the radiation irradiation unit 12 (radiation source) to the radiation detection unit 14 (Focus Film Distance: FFD; or Source Image receptor Distance: SID). Pulse rate is the number of radiation irradiations per second, consistent with the frame rate of the image data. Pulse width is the radiation irradiation time for each radiation irradiation. Pulse interval is the time from the start of one radiation irradiation to the start of the next radiation irradiation, consistent with the time interval between multiple image data (frame interval).

[0045] These photographic conditions can be automatically determined by the photographic control unit 11 of the radiographic imaging system 10 based on the setting information.

[0046] The radiation irradiation unit 12 is positioned opposite the radiation detection unit 14 fixed to the imaging stage 13. The radiation irradiation unit 12 irradiates radiation according to the operation of the irradiation indicator switch 11a connected to the imaging control unit 11.

[0047] Specifically, the radiation irradiation unit 12 applies a voltage to the radiation source (tube lamp) corresponding to the preset imaging conditions according to the operation of the irradiation indicator switch 11a, and generates radiation (e.g., X-rays) of a radiation amount corresponding to the applied voltage.

[0048] The radiation irradiation unit 12 generates radiation in a form corresponding to the generated radiation image (still image, moving image, etc.). For example, in the case of a still image, radiation irradiation is performed only once when the irradiation indicator switch 11a is pressed once. In the case of a moving image, pulsed radiation irradiation is performed continuously from the pressing of the irradiation indicator switch 11a (photography start indication) until the pressing is released (photography end indication).

[0049] The radiation detection unit 14 is composed of a semiconductor image sensor such as an FPD (Flat Panel Detector) and generates digital data of a radiation image. The radiation detection unit 14 has a substrate in which multiple detection elements (pixels) are arranged in a matrix. Each pixel on the substrate detects incident radiation, converts it into an electrical signal corresponding to the intensity of the detected radiation, and accumulates it. Each pixel on the substrate is configured, for example, to have a switching unit such as a TFT (Thin Film Transistor).

[0050] The radiation detection unit 14, based on the image reading conditions input from the radiation imaging control device 20, controls the switching units of each pixel to read the accumulated electrical signals in each pixel and outputs the intensity information of each pixel to the image generation unit 113. Image reading conditions include, for example, frame rate, frame interval, pixel size, and image size (matrix size). The frame rate is the number of frames acquired per second, consistent 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, consistent with the pulse interval.

[0051] The photography control unit 11 and the radiation detection unit 14 are interconnected and exchange synchronization signals to synchronize the radiation irradiation action and the image reading action.

[0052] In this way, under the control of the imaging control unit 11, the radiation irradiation unit 12 irradiates radiation, and the radiation detection unit 14 generates image data based on the detected radiation intensity, thereby performing dynamic imaging of radiation images.

[0053] During dynamic photography of the patient, the display unit 15 and the sound output unit 16 provide instructions to the patient M regarding the appropriate posture (photographic position), body condition, and respiratory status. The display unit 15 is, for example, a CRT (Cathode Ray Tube), a Liquid Crystal Display (LCD), or an Electroluminescent (EL) display. The sound output unit 16 is, for example, a speaker. The sound output unit 16 provides instructions to the patient M regarding body condition, respiratory status, etc., for example, through automated voice prompts. The display unit 15 and the sound output unit 16 can each provide the same instructions to the patient M, or only one of them can provide the instructions.

[0054] Figure 2 This is a block diagram illustrating an example of the functional structure of the imaging control unit 11 in the radiographic imaging system 10 that constitutes the radiographic image processing system 100. The imaging control unit 11 includes a setting information acquisition unit 111, an imaging condition determination unit 112, an image generation unit 113, and a storage unit 114.

[0055] The setting information acquisition unit 111 acquires setting information from the radiography control device 20.

[0056] The imaging condition determination unit 112 determines the imaging conditions for performing dynamic imaging of patient M based on the setting information. Information indicating the correspondence between various dynamic analyses and imaging conditions suitable for each dynamic analysis is pre-stored in the storage unit 114. Additionally, information indicating the correspondence between combinations of various dynamic analyses and imaging conditions suitable for those combinations is also pre-stored in the storage unit 114. The imaging condition determination unit 112 reads the correspondence information from the storage unit 114 regarding the dynamic analysis or combination of dynamic analyses indicated by the setting information and compares it with the setting information, thereby determining the imaging conditions.

[0057] Furthermore, in situations such as screening and emergency care, dynamic analysis that can be set as configuration information may sometimes not be possible. In such cases, the imaging condition determination unit 112 determines the imaging conditions by having the operator select at least one imaging condition from a plurality of predefined imaging conditions. Additionally, the imaging condition determination unit 112 allows the operator to select examination form information and determines the imaging conditions based on the selected examination form information. Thus, if dynamic analysis cannot be set before dynamic imaging, it is set after dynamic imaging under the operator-selected imaging conditions, and dynamic analysis in the radiographic image analysis device 30 is executed.

[0058] The image generation unit 113 performs dynamic photography on the patient M based on the determined photographic conditions, generating multiple frames of radiation images. Specifically, the image generation unit 113 controls the operation of the radiation irradiation unit 12 and the radiation detection unit 14 based on the photographic conditions, and obtains intensity information related to the intensity of radiation passing through the subject from the radiation detection unit 14 for each pixel, thereby generating image data.

[0059] As described above, the storage unit 114 stores in advance information indicating the correspondence between various dynamic resolutions and photographic conditions suitable for various dynamic resolutions, and information indicating the correspondence between combinations of various dynamic resolutions and photographic conditions suitable for those combinations.

[0060] [Radiation control device]

[0061] The radiography control device 20 is, for example, a PC (Personal Computer), workstation, or other computer. The radiography control device 20 can be used as... Figure 1 The example shown is a desktop computer, but it can also be a portable computer, such as a laptop, a tablet, etc.

[0062] The radiography control device 20 receives the inspection form information from the radiography information terminal and sends it to the radiography system 10, thereby controlling the dynamic imaging of the radiography system 10.

[0063] The examination report information includes various details related to the upcoming radiography, such as respiratory instructions, patient information, examination information, imaging information, and data attributes. Examination information includes the examination ID, the body part being examined (e.g., chest, abdomen, lungs, heart), and the type of analysis (e.g., ventilation analysis, pulmonary blood flow analysis, maximum ventilation measurement). For example, this examination report information is generated when a physician or other personnel request radiographic imaging of patient M from the X-ray image processing system 100.

[0064] Furthermore, the radiography control device 20 generates setting information indicating at least one of a variety of dynamic analyses that the radiography image analysis device 30 can perform, based on operator input. In the case of a combination of multiple dynamic analyses, the radiography control device 20 generates setting information indicating the combination of multiple dynamic analyses. The operator can identify which dynamic analysis is being combined, for example, by referring to the contents of the examination form, and perform the input operation to generate the setting information accordingly. Alternatively, the operator can also identify which dynamic analysis is being combined based on information received from a doctor or other means.

[0065] Figure 3 This is a block diagram illustrating an example of the functional structure of the radiography control device 20 constituting the radiography image processing system 100. The radiography control device 20 includes a control unit 21, a storage unit 22, an operation unit 23, a display unit 24, and a communication unit 25. The various components of the radiography control device 20 are interconnected via a bus 26.

[0066] The radiography control device 20 outputs the setting conditions set by the operator and other personnel, as well as the checklist information obtained in advance from the radiography information terminal, to the radiography system 10, thereby controlling the radiography processing of the radiography system 10. The radiography control device 20 can also, for example, display dynamic images generated by the radiography system 10 for operator confirmation.

[0067] The control unit 21 consists of a CPU and RAM, etc. In the control unit 21, the CPU responds to the operation of the operation unit 23, reads the system program and various processing programs stored in the storage unit 22 and expands them into the RAM, and controls the operation of each part of the radiography control device 20 based on the expanded program.

[0068] The storage unit 22 is composed of a non-volatile semiconductor memory, a hard disk, or the like. The storage unit 22 stores various programs executed by the control unit 21, parameters required for program execution, and data such as processing results (e.g., dynamic images). Various programs are stored in the form of readable program code, and the control unit 21 executes actions according to that program code sequentially.

[0069] In addition, the storage unit 22 stores image reading conditions for performing dynamic imaging. Furthermore, the storage unit 22 stores examination form information sent from the radiology information terminal. When the radiology control device 20 controls the dynamic imaging of the radiology imaging system 10, it reads the image reading conditions and examination form information corresponding to the patient M from the storage unit 22 and sends them.

[0070] The operation unit 23 is an operating device such as a keyboard, mouse, or trackball with cursor keys, numeric input keys, and various function keys, as well as a touch panel. The operation unit 23 generates indication signals based on the operator's input and outputs them to the control unit 21.

[0071] The display unit 24 is composed of display devices such as CRT, liquid crystal display, and organic EL display. The display unit 24 displays input instructions from the operation unit 23 and image data (moving images, etc.) generated by the radiographic imaging system 10, according to the display signals input from the control unit 21.

[0072] The communication unit 25 performs data transmission and reception with the radiographic imaging system 10, the radiographic image analysis device 30, etc.

[0073] [Radiation Image Analysis Device]

[0074] The radiation image analysis device 30 is, for example, a computer such as a PC or workstation. The radiation image analysis device 30 can be a desktop computer or a portable computer, such as a laptop computer or a tablet computer.

[0075] The radiation image analysis device 30 performs dynamic analysis on moving images captured by the radiation image imaging system 10 based on setting information set in the radiation imaging control device 20.

[0076] Figure 4 This is a block diagram illustrating an example of the functional structure of the radiation image analysis device 30 constituting the radiation image processing system 100. The radiation image analysis device 30 includes a control unit 31, a storage unit 32, an operation unit 33, a display unit 34, and a communication unit 35. The various components of the radiation image analysis device 30 are connected via a bus 36.

[0077] The control unit 31 consists of a CPU and RAM, etc. In the control unit 31, the CPU responds to the operation of the operation unit 33, reads the system program and various processing programs stored in the storage unit 32 and expands them into the RAM, and executes the action control and dynamic analysis of each part of the radiographic image analysis device 30 based on the expanded program.

[0078] The control unit 31 acquires a dynamic image of multiple frames of radiation images generated by the radiation imaging system 10 and the radiation imaging control device 20, performs dynamic analysis on the dynamic image based on setting information, and obtains the analysis result. The control unit 31 performs the analysis, for example, based on signal changes in the multiple frame images.

[0079] The control unit 31 can perform various dynamic analysis modes, such as blood flow analysis mode, ventilation analysis mode, adhesion analysis mode, diaphragmatic movement analysis mode, and orthopedic correlation measurement mode. Each mode is briefly explained below.

[0080] Blood flow analysis mode is a mode that visualizes signal changes in the lung fields that are synchronized with the heartbeat.

[0081] The ventilation analysis mode is a mode that extracts the temporal signal changes in a specific time band and visualizes the lung tissue activity during breathing.

[0082] Adhesion analysis mode is a mode that visualizes the degree of adhesion of tissues.

[0083] The diaphragm movement analysis model is a model that tracks the up-and-down movement of the diaphragm that accompanies respiration.

[0084] Orthopedic correlation measurement mode is a mode that measures the positional changes of specified bones in, for example, the limbs, and displays the trajectory of movement.

[0085] The storage unit 32 is composed of a non-volatile semiconductor memory, a hard disk, or the like. The storage unit 32 stores various programs executed by the control unit 31, parameters required for program execution, and data such as processing results (moving images, analysis results, etc.). Various programs are stored in the form of readable program code, and the control unit 31 executes actions according to that program code sequentially.

[0086] In addition, the storage unit 32 stores patient information, examination information, and list information indicating status (e.g., progress status such as receiving, dynamic analysis in progress, analysis completed, etc.) related to each dynamic image generated by the radiographic imaging system 10.

[0087] The operation unit 33 is an operation device such as a keyboard, mouse, or trackball with cursor keys, numeric input keys, and various function keys, or a touch panel. The operation unit 33 generates indication signals based on the operator's input and outputs them to the control unit 31. Alternatively, the operation unit 33 may also have a touch panel on the display screen of the display unit 34. In this case, the indication signals input via the touch panel are output to the control unit 31.

[0088] The display unit 34 is composed of display devices such as CRT, liquid crystal display, and organic EL display. The display unit 34 displays input instructions from the operation unit 33 and data (moving images, analysis results, etc.) generated by the radiographic imaging system 10, according to the display signals input from the control unit 31.

[0089] The communication unit 35 performs data transmission and reception with the radiography control device 20 and the image management device 40, etc.

[0090] [Image management device, client terminal]

[0091] The image management device 40 and the client terminal 50 are, for example, computers such as PCs and workstations. The image management device 40 and the client terminal 50 can be desktop computers or portable computers, such as laptops or tablets. Since the image management device 40 and the client terminal 50 can be any known image management device or client terminal, detailed descriptions are omitted here.

[0092] <Example 1>

[0093] [Radiation Dosage Management Device]

[0094] In this embodiment, the radiation dose management device 60 is, for example, a computer such as a PC or workstation. The radiation dose management device 60 can be a desktop computer or a portable computer, such as a laptop computer or a tablet computer.

[0095] The radiation dose management device 60 records and manages radiation dose information associated with the imaging of still and moving radiographic images. Specifically, the radiation dose management device 60 has a recording function for recording radiation dose information and a management function for managing radiation dose information. In the recording function, information including radiation dose information associated with the imaging of radiographic images is recorded and accumulated for each individual patient. In the management function, the radiation dose information is managed by comparing the accumulated radiation dose information for each individual patient with a set diagnostic reference level.

[0096] Here, for general photography, diagnostic reference levels are specified for the examination site, but for dynamic photography that takes pictures of moving images, it is difficult to manage radiation doses because no diagnostic reference levels are specified.

[0097] Therefore, in this embodiment, the radiation dose management device 60 also includes a setting function (proportion acquisition unit 611, first setting unit 612, and first calibration unit 613) for setting a diagnostic reference level for a dynamic image imaging device that has not been set with a diagnostic reference level. Regarding the setting function (proportion acquisition unit 611, first setting unit 612, and first calibration unit 613), refer to... Figure 5 The following will explain.

[0098] Figure 5 This is a block diagram illustrating an example (Example 1) of the functional structure of the radiation dose management device 60 constituting the radiation image processing system 100. The radiation dose management device 60 includes a control unit 61, a storage unit 62, an operation unit 63, a display unit 64, and a communication unit 65. The various components of the radiation dose management device 60 are connected via a bus 66.

[0099] The control unit 61 consists of a CPU and RAM, etc. In the control unit 61, the CPU responds to the operation of the operation unit 63, reads the system program and various processing programs stored in the storage unit 62 and expands them into the RAM, and executes the operation control and radiation management of each part of the radiation dose management device 60 based on the expanded program.

[0100] The control unit 61 includes a proportional acquisition unit 611, a first setting unit 612, and a first calibration unit 613. Furthermore, the following first diagnostic reference levels L1 to fifth diagnostic reference levels L5 are examples of the first to fifth reference values, respectively.

[0101] The ratio acquisition unit 611, for example, reads a first diagnostic reference level L1 and a second diagnostic reference level L2 stored in the storage unit 62. The first diagnostic reference level L1 is a diagnostic reference level for radiation dose specified for situations where radiation is irradiated and a predetermined area (an example of the first area) of the subject is photographed in still image mode. The second diagnostic reference level L2 is a diagnostic reference level for radiation dose specified for situations where radiation is irradiated and a predetermined area is photographed in moving image mode. Furthermore, the ratio acquisition unit 611 acquires the ratio R = L2 / L1.

[0102] Alternatively, the ratio acquisition unit 611 can use the fifth diagnostic reference level L5 instead of the first diagnostic reference level L1 to calculate the ratio R = L2 / L5. The fifth diagnostic reference level L5 is a diagnostic reference level for radiation dose specified for cases where radiation is irradiated and a predetermined part of the subject is photographed in a still image manner; it is a diagnostic reference level specified independently by the imaging facility.

[0103] The first setting unit 612, for example, reads the third diagnostic reference level L3 stored in the storage unit 62. The third diagnostic reference level L3 is a diagnostic reference level for radiation dose when a still image is taken of a target area (an example of the second area) that is different from the predetermined area. Then, based on the third diagnostic reference level L3 and the ratio R, the first setting unit 612 sets a fourth diagnostic reference level L4 for radiation dose management in the case of taking a moving image of the target area. Specifically, the fourth diagnostic reference level L4 = L3 × R. Here, the target area is a area different from the predetermined area, but it can also be the same as the predetermined area.

[0104] The first correction unit 613 corrects the fourth diagnostic reference level L4 based on the target site (e.g., the thickness of the target site). Additionally, when the target site is the chest, the first correction unit 613 can also correct the fourth diagnostic reference level L4 based on the respiratory status of the subject.

[0105] The storage unit 62 is composed of a non-volatile semiconductor memory, a hard disk, or the like. The storage unit 62 stores various programs executed by the control unit 61 (e.g., a radiation dose setting program for executing a radiation dose setting method), parameters required for program execution, etc. These programs are stored in the form of readable program code, and the control unit 61 executes actions according to this program code sequentially.

[0106] In addition, the storage unit 62 stores radiation dose information of the radiation dose during imaging of still images and moving images received from the radiography control device 20. For example, the storage unit 62 stores still images and moving images received from the radiography control device 20 in association with the corresponding radiation dose information. Furthermore, the storage unit 62 can also store radiation dose information of the patient irradiated outside of the imaging of still images and moving images.

[0107] In addition, the storage unit 62 also stores the first diagnostic reference level L1 to the fifth diagnostic reference level L5, the ratio R, etc. The first diagnostic reference level L1 is, for example, the diagnostic reference level (DRL value) for each examination item (e.g., the imaging site, the patient's age, etc.) specified in DRLs2020 for general radiography.

[0108] The operation unit 63 is an operating device such as a keyboard, mouse, or trackball with cursor keys, numeric input keys, and various function keys, or a touch panel. The operation unit 63 generates instruction signals based on the operator's input and outputs them to the control unit 61. Alternatively, the operation unit 63 may also have a touch panel on the display screen of the display unit 64; in this case, instruction signals input via the touch panel are output to the control unit 61.

[0109] The display unit 64 is composed of display devices such as CRT, liquid crystal display, and organic EL display. The display unit 64 displays input instructions from the operation unit 63, data from the radiation dose management device 60, etc., according to the display signal input from the control unit 61.

[0110] The communications unit 65 performs data transmission and reception with the radiography control device 20 and the image management device 40, etc.

[0111] exist Figure 1 In the example shown, the radiation dose management device 60 is a separate device from the radiography control device 20 and the image management device 40, but it may not be a separate device, or it may be included in the radiography control device 20, the image management device 40, etc.

[0112] [Radiation Dosage Setting Method in Example 1]

[0113] (Example 1)

[0114] Reference Figure 6 This explains the method for setting a diagnostic reference level in the radiation dose management device 60 for dynamic photography where no diagnostic reference level has been set. Figure 6 This means that in Figure 5 The diagram shows the DRL (Dose Level Reduction) of dynamic imaging, set based on the DRL of general imaging in the radiation dose management device 60. Furthermore, since the DRL is used here as the DRL, the example is given. However, other radiation doses can also be used as the DRL, such as area radiation (DAP: Dose-Area Product).

[0115] like Figure 6 As shown, for general photography, the incident surface radiation recorded in the columns "front of the chest (less than 100kV)" to "front of the pelvis" is defined as the DRL value.

[0116] In general radiography, the incident surface radiation dose for "frontal chest (100kV or above)" is defined as "0.3mGy" (first diagnostic reference level L1). However, in dynamic radiography within a radiographic imaging system 10 and radiographic control device 20 at a certain facility, the incident surface radiation dose for "frontal chest (100kV or above)" is set as "0.45mGy" (second diagnostic reference level L2). In this case, the scaling factor 611 of the control unit 61 calculates the scaling factor R = L2 / L1. In this example, the scaling factor R = 1.5.

[0117] Furthermore, the first setting unit 612 of the control unit 61 uses a ratio R to multiply the DRL values ​​(third diagnostic reference level L3) of each column specified for general radiography with the ratio R, thereby setting the DRL values ​​(fourth diagnostic reference level L4) of each column in motion radiography. For example, in "frontal chest (less than 100kV)", the DRL value of general radiography is "0.4mGy", so multiplying by the ratio R=1.5, the DRL value of motion radiography becomes "0.6mGy".

[0118] As described above, the control unit 61 sets the fourth diagnostic reference level L4 as a diagnostic reference level for dynamic photography where no diagnostic reference level has been set.

[0119] As explained above, in this embodiment, the radiation dose management device 60 includes a ratio acquisition unit 611 and a first setting unit 612. Here, a first diagnostic reference level L1 for radiation dose is set for the case where radiation is irradiated and a predetermined part of the subject is photographed in still image mode (general photography), and a second diagnostic reference level L2 for radiation dose is set for the case where radiation is irradiated and a predetermined part is photographed in moving image mode (moving photography). The ratio acquisition unit 611 acquires the ratio R = L2 / L1 between the first diagnostic reference level L1 and the second diagnostic reference level L2. The first setting unit 612 sets a fourth diagnostic reference level L4 for radiation dose when the subject part is photographed in moving image mode, based on the third diagnostic reference level L3 for radiation dose when the subject part is photographed in still image mode (general photography) and the ratio R set by the ratio acquisition unit. Specifically, the first setting unit 612 sets a fourth diagnostic reference level L4 for radiation dose management in the case of taking pictures of the object part in a dynamic image manner by multiplying the third diagnostic reference level L3 by a ratio R.

[0120] The radiation dose management device 60 has the above-described structure, so it is possible to set a diagnostic reference level for radiation dose management suitable for dynamic imaging.

[0121] (Example 2)

[0122] exist Figure 6 In the example shown, the prescribed DRL value (Diagnostic Reference Level 1 L1) is used directly for general photography. However, depending on the photography facility, sometimes the prescribed DRL value (Diagnostic Reference Level 1 L1) for general photography is not used directly, but the photography facility's own DRL value (Diagnostic Reference Level 5 L5) is used instead.

[0123] In this case, when setting a diagnostic reference level for motion photography where no diagnostic reference level is specified, the DRL value specific to the photography facility (5th diagnostic reference level L5) is used instead of the DRL value (first diagnostic reference level L1) prescribed for general photography. (Refer to...) Figure 7 This section explains how to set a diagnostic reference level for dynamic photography in this case where no diagnostic reference level has been set. Figure 7 This means that in Figure 5 The diagram shows the DRL (Drone Level of Incident Surface) for dynamic photography set in the radiation management device 60 based on the DRL (Drone Level of Incident Surface) set in the facility for general photography.

[0124] This setting example is basically the same as the setting example 1 described above. Here, in general radiography, the incident surface radiation dose for "frontal chest (100kV or above)" is defined as "0.2mGy" by the radiographic facility itself as the DRL value (Fifth Diagnostic Reference Level L5). Furthermore, in dynamic radiography within the radiographic imaging system 10 and radiographic control device 20 provided in this facility, the incident surface radiation dose for "frontal chest (100kV or above)" is set as "0.30mGy" as the DRL value (Second Diagnostic Reference Level L2). In this case, the scaling factor 611 of the control unit 61 calculates the scaling factor R = L2 / L5. In this example, the scaling factor R = 1.5.

[0125] Furthermore, the first setting unit 612 of the control unit 61 uses a ratio R=1.5 to multiply the DRL values ​​(fifth diagnostic reference level L5) of each column set for general radiography by the ratio R=1.5, thereby setting the DRL values ​​(fourth diagnostic reference level L4) of each column in dynamic radiography. For example, in "frontal chest (less than 100kV)", the DRL value of general radiography is "0.3mGy", so multiplying by the ratio R=1.5, the DRL value of the radiographic imaging device becomes "0.45mGy".

[0126] As described above, the control unit 61 sets the fourth diagnostic reference level L4 as the diagnostic reference level for dynamic photography where no diagnostic reference level has been set.

[0127] Furthermore, the radiation dose management device 60 manages the patient's radiation dose information using a diagnostic reference level set as described above.

[0128] Specifically, when the radiographic imaging system 10 and the radiographic imaging control device 20 capture still images and moving images, the control unit 21 of the radiographic imaging control device 20 calculates the incident surface radiation dose during imaging based on the actual imaging conditions, i.e., the imaging implementation conditions. For example, the control unit 21 calculates the incident surface radiation dose based on factors such as the type of examination, FFD (or SID), tube voltage, current-time product, frame rate, imaging time, patient position, patient physique, patient condition, patient age, and patient gender.

[0129] Furthermore, the control unit 21 of the radiography control device 20, via the communication unit 25, associates with the captured still images and moving images, and transmits information such as the photography implementation conditions and the radiation dose at the incident surface to the radiography image analysis device 30, the image management device 40, and the radiation dose management device 60. Additionally, the radiation dose management device 60 can also obtain still images, moving images, photography implementation conditions, and the radiation dose at the incident surface from the radiography control device 20, the image management device 40, etc., according to its operation.

[0130] The control unit 61 of the radiation dose management device 60 stores and accumulates still images, moving images, photographic implementation conditions, incident surface radiation dose, etc., which are sent or acquired in the storage unit 62. For patients subject to radiation dose management, the display unit 24 displays information comparing the set diagnostic reference level with the incident surface radiation dose.

[0131] Here, Figure 8 Is Figure 5 The charts displayed in the radiation dose management device 60 for comparison are for comparison purposes. Figure 6 and Figure 7 The graph shows the DRL values ​​and the radiation dose received by the patient.

[0132] In this way, the control unit 61 displays a graph on the display unit 24 comparing the set diagnostic reference level with the radiation dose received by patients subject to radiation dose management, thereby providing radiation dose management information to the operator of the radiation dose management device 60. Alternatively, the control unit 61 can also display the radiation dose received by multiple patients using a histogram for each examination item, thereby providing the operator of the radiation dose management device 60 with information for reassessing the currently set diagnostic reference level. Furthermore, the control unit 61 can also calculate the permissible number of still images and moving images (frames) and imaging time based on the set diagnostic reference level and the patient's radiation dose, and provide the calculated results to the radiography control device 20.

[0133] (Example 3)

[0134] In the above-mentioned setting examples 1 and 2, the influence of each part was not considered, but the influence of each part can be considered when setting the diagnostic reference level.

[0135] For example, the amount of radiation transmitted through the chest varies depending on the respiratory state, so it is preferable to adjust the diagnostic reference level according to the respiratory state. Specifically, the amount of radiation transmitted during inhalation is higher than that during exhalation, so the diagnostic reference level can be set lower. For example, in a frontal chest X-ray for health diagnosis, the image is taken during inhalation, so the diagnostic reference level can be set lower.

[0136] In this example configuration, the control unit 61 includes a first correction unit 613, which corrects the DRL value (fourth diagnostic reference level L4) using a correction factor α for a frontal chest radiograph taken during inspiration. For example, the correction factor α is set to 0.9 in this case. Figure 6 In the “Examination of the front of the chest (above 100kV)” shown, the DRL value (Diagnostic Reference Level 4, L4) for dynamic radiography is “0.30”, so it is multiplied by the correction factor α=0.9, and “0.27” is set as the corrected DRL value.

[0137] Furthermore, X-ray transmittance varies with body thickness, so the DRL value (fourth diagnostic reference level L4) can also be corrected based on body thickness. For example, the lateral aspect of the lumbar spine is thicker than other areas, so the first correction unit 613 of the control unit 61 also uses a correction factor α to correct the DRL value (fourth diagnostic reference level L4) for imaging the lateral aspect of the lumbar spine. When the correction factor α is set to, for example, 1.3 in this case, in... Figure 6 In the “lumbar spine lateral view” shown, the DRL value (diagnostic reference level 4, L4) for dynamic radiography is “13.5”, so it is multiplied by the correction factor α=1.3, and “17.55” is set as the corrected DRL value.

[0138] As described above, the control unit 61 corrects the fourth diagnostic reference level L4 based on the location.

[0139] (Example 4)

[0140] In the above-described Example 1, the target part (an example of the second part) is a part that is different from the predetermined part (an example of the first part), but the target part can also be the same as the predetermined part.

[0141] In this setting example, the ratio acquisition unit 611 also acquires the ratio R=L2 / L1 based on the first diagnostic reference level L1 and the second diagnostic reference level L2, just like in the setting example 1 above.

[0142] Furthermore, in this setting example, the first setting unit 612 also reads, for example, the third diagnostic reference level L3 stored in the storage unit 62. However, this third diagnostic reference level L3 is a value set independently by the photographic apparatus for the case of photographing the object part, which is the same part as the predetermined part, in the form of still image (general photography), and is a different value from the first diagnostic reference level L1. Furthermore, the first setting unit 612 sets a fourth diagnostic reference level L4 (=L3×R) for the radiation dose management used in the case of photographing the object part in the form of moving image, based on the third diagnostic reference level L3 and the ratio R.

[0143] For example, in general radiography, the incident surface radiation dose for "frontal chest (100kV or higher)" is defined as "0.3mGy" (first diagnostic reference level L1). Furthermore, in dynamic radiography within the radiographic imaging system 10 and the radiographic control device 20, the incident surface radiation dose for "frontal chest (100kV or higher)" is defined as "0.45mGy" (second diagnostic reference level L2). In this case, the scaling factor 611 of the control unit 61 calculates the scaling factor R = L2 / L1. In this example, the scaling factor R = 1.5.

[0144] The first setting unit 612 of the control unit 61 sets the DRL value (third diagnostic reference level L3) for general radiography (100kV or above) by multiplying it by the aforementioned ratio R. For example, for "frontal chest (100kV or above)," the DRL value (third diagnostic reference level L3) for general radiography is set to "0.2mGy." The first setting unit 612 multiplies "0.2mGy" by the aforementioned ratio R=1.5 to obtain the DRL value (fourth diagnostic reference level L4) for dynamic radiography of "frontal chest (100kV or above)" and sets it to "0.3mGy."

[0145] As described above, the control unit 61 also sets the fourth diagnostic reference level L4 as a diagnostic reference level unique to the photography facility for dynamic photography that has a specified diagnostic reference level.

[0146] Furthermore, in the above, the fourth diagnostic reference level L4 is set as the radiation dose value for radiation dose management, but it can also be set as the radiation dose value for the imaging conditions of motion photography.

[0147] <Example 2>

[0148] [Radiation Dosage Management Device]

[0149] In this embodiment, the radiation dose management device 60 can also be a computer such as a PC or workstation. The radiation dose management device 60 can be a desktop computer or a portable computer, such as a laptop or tablet. That is, the radiation dose management device 60 in this embodiment can have the same structure as the radiation dose management device 60 described in Embodiment 1. Therefore, the same reference numerals are used for structures equivalent to the radiation dose management device 60 described in Embodiment 1, and the following description will follow.

[0150] As also described in Example 1, the radiation dose management device 60 has a recording function for recording radiation dose information and a management function for managing radiation dose information, and records and manages radiation dose information associated with the photography of radiation images.

[0151] In radiographic imaging, particularly in general imaging of still images, radiation dose management is performed by comparing the patient's radiation exposure to the DRL (Diagnostic Reference Level) value, as explained in the background section above. However, in general radiography, DRL values ​​are not predefined based on the examination items (e.g., the location of the examination, the patient's age, etc.), making radiation dose management in radiographic imaging difficult. Furthermore, the same applies to other types of radiographic imaging, such as X-ray CT scans, where DRL values ​​are not predefined based on the examination items, further complicating radiation dose management.

[0152] Therefore, in this embodiment, the radiation dose management device 60 also includes a setting function (second setting unit 621 and second calibration unit 622) for setting diagnostic reference levels for examination items for which no diagnostic reference level has been set. Regarding the setting function (second setting unit 621 and second calibration unit 622), see [reference]. Figure 9 The following will explain.

[0153] Figure 9 This is a block diagram illustrating another example (Embodiment 2) of the functional structure of the radiation dose management device 60 constituting the radiation image processing system 100. The radiation dose management device 60, like in Embodiment 1, includes a control unit 61, a storage unit 62, an operation unit 63, a display unit 64, and a communication unit 65. All the components of the radiation dose management device 60 are connected via a bus 66.

[0154] The control unit 61 consists of a CPU and RAM, etc. In the control unit 61, the CPU reads the system program and various processing programs stored in the storage unit 62 according to the operation of the operation unit 63 and expands them into the RAM. Based on the expanded program, it executes the operation control and radiation management of each part of the radiation dose management device 60.

[0155] The control unit 61 includes a second setting unit 621 and a second calibration unit 622. Furthermore, the following sixth diagnostic reference level L6 to eighth diagnostic reference level L8 are examples of the sixth reference value to the eighth reference value, respectively.

[0156] The second setting unit 621, for cases where radiation is irradiated onto a subject area in a radiographic imaging device to image the subject area, calculates a seventh diagnostic reference level L7 for radiation dose corresponding to the subject's age, based on a sixth diagnostic reference level L6 for radiation dose defined by age and the subject's age. Specifically, the second setting unit 621 uses the sixth diagnostic reference level L6 for age-defined radiation dose as a value corresponding to the median, minimum, or maximum age in the age division to calculate the seventh diagnostic reference level L7. Then, the second setting unit 621 sets the calculated seventh diagnostic reference level L7 as the value used for radiation dose management when the subject area is imaged using a radiographic imaging device.

[0157] Alternatively, the second setting unit 621 can use the eighth diagnostic reference level L8 instead of the sixth diagnostic reference level L6 to calculate the seventh diagnostic reference level L7. The eighth diagnostic reference level L8 is a diagnostic reference level for radiation doses defined according to age, specifically for cases where a radiographic imaging device different from the aforementioned radiographic imaging device is used to image the object's body part.

[0158] The second correction unit 622 corrects the seventh diagnostic reference level L7 based on the target body part (e.g., the thickness of the target body part). Additionally, when the target body part is the chest, the second correction unit 622 can also correct the seventh diagnostic reference level L7 based on the respiratory status of the subject.

[0159] The storage unit 62 is composed of a non-volatile semiconductor memory, a hard disk, or the like. The storage unit 62 stores various programs executed by the control unit 61 (e.g., a radiation dose setting program for executing a radiation dose setting method), parameters required for program execution, etc. These programs are stored in the form of readable program code, and the control unit 61 executes actions according to this program code sequentially.

[0160] Additionally, the storage unit 62 stores radiation dose information from the radiation images received from the radiography control device 20 and the medical device 70, including the radiation dose information received during imaging. For example, the storage unit 62 stores the radiation images received from the radiography control device 20 and the medical device 70 in association with the corresponding radiation dose information. Furthermore, the storage unit 62 can also store radiation dose information for radiation exposure received by the patient outside of the radiography imaging process.

[0161] In addition, the storage unit 62 also stores the 6th diagnostic reference level L6 to the 8th diagnostic reference level L8, etc. The 6th diagnostic reference level L6 and the 8th diagnostic reference level L8 are, for example, diagnostic reference levels (DRL values) specified in DRLs2020.

[0162] The operation unit 63 is an operation device including a keyboard, mouse, or trackball, as well as a touch panel, which are equipped with cursor keys, numeric input keys, and various function keys. The operation unit 63 generates instruction signals based on the operator's input and outputs them to the control unit 61. Alternatively, the operation unit 63 may also have a touch panel on the display screen of the display unit 64. In this case, the instruction signals input via the touch panel are output to the control unit 61.

[0163] The display unit 64 is composed of display devices such as a CRT, a liquid crystal display, or an organic EL display. The display unit 64 displays input instructions from the operation unit 63, data from the radiation dose management device 60, etc., according to the display signals input from the control unit 61.

[0164] The communications unit 65 performs data transmission and reception with the radiography control device 20, the image management device 40, and the medical device 70.

[0165] exist Figure 1 In the example shown, the radiation dose management device 60 is a separate device from the radiography control device 20, the image management device 40, and the medical device 70. However, the radiation dose management device 60 may not be a separate device, but may be included in the radiography control device 20, the image management device 40, the medical device 70, etc.

[0166] [Radiation Dosage Setting Method in Example 2]

[0167] (Example 5)

[0168] Figure 10 This is a diagram illustrating the DRL values ​​set for different ages in children during head CT scans. Furthermore, in Figure 10 In CT, CTDIvol (Computed Tomography Dose Index volume), used as the DRL value, is one of the indicators of the amount of radiation irradiated in CT.

[0169] In radiographic imaging devices that take radiographic images, there are also devices like X-ray CT scanners that specify DRL values ​​(Diagnostic Reference Level 6, L6) based on age ranges defined for children. Figure 10In the example shown, the DRL value (Diagnostic Reference Level 6, L6) is specified as follows: 30 mGy for children under 1 year old, 40 mGy for children aged 1 to under 5 years old, 55 mGy for children aged 5 to under 10 years old, and 60 mGy for children aged 10 to under 15 years old. However, regarding DRL values ​​for children, it is more appropriate to set age-appropriate DRL values ​​by gradually changing them according to age rather than changing them in stages based on age.

[0170] Therefore, in this setting example, the control unit 61 processes the DRL value (6th Diagnostic Reference Level L6) defined for each age division as the value for the intermediate age of each division (however, the interval of less than 1 year old is processed as the value for 1 year old). Then, the control unit 61 uses the DRL value (6th Diagnostic Reference Level L6) set for the intermediate age to calculate the DRL value (7th Diagnostic Reference Level L7) for each age. For example, the control unit 61 uses 30mGy set for 1 year old and 40mGy set for 3 years old as the DRL value for 2 years old (7th Diagnostic Reference Level L7), and calculates the DRL value = 35 according to the formula [30 + (40-30) × (2-1) / (3-1)]. In the control unit 61, as for the DRL value for 2 years old (7th Diagnostic Reference Level L7), the control unit 61 calculates the DRL value = 35 using the formula [30 + (40-30) × (2-1) / (3-1)]. Figure 10 The DRL values ​​(Diagnostic Reference Level 7, L7) for 4-year-olds and 5-year-olds shown were calculated in the same way as above, yielding DRL values ​​of 43.3 and 46.7 respectively. The control unit 61 also calculated the DRL values ​​(Diagnostic Reference Level 7, L7) for the age group divided into 5-year-olds and under 10-year-olds using the same method.

[0171] As described above, the control unit 61 uses the DRL value (6th diagnostic reference level L6) defined according to age, and sets the 7th diagnostic reference level L7 to be an appropriate diagnostic reference level for age.

[0172] exist Figure 10 In the example shown, the control unit 61 processes the DRL value (6th Diagnostic Reference Level L6) defined for each age segment as the value for the median age of each segment. However, the control unit 61 may also process the DRL value (6th Diagnostic Reference Level L6) defined for each age segment as the value for the minimum or maximum age, and perform the same calculations as described above to obtain the respective DRL value (7th Diagnostic Reference Level L7).

[0173] In addition, Figure 10The example shown depicts the head as the target body part, but for the chest, abdomen, etc., there are also DRL values ​​(6th Diagnostic Reference Level L6) corresponding to the child's age. Therefore, even when the target body part is the chest, abdomen, etc., the control unit 61 performs the same calculation as described above and sets an appropriate DRL value (7th Diagnostic Reference Level L7) for the age.

[0174] Additionally, for those by Figure 1 The dynamic imaging performed by the radiographic imaging system 10 and the radiographic imaging control device 20 shown is also configured as follows: Figure 10 As shown, the DRL value (6th Diagnostic Reference Level L6) is defined according to the child's age. In this case, the control unit 61 also performs the same calculation as above and sets an appropriate DRL value (7th Diagnostic Reference Level L7) for the age.

[0175] As explained above, in this embodiment, the radiation dose management device 60 includes a second setting unit 621. The second setting unit 621 calculates a seventh diagnostic reference level L7 for the radiation dose of the subject based on a sixth diagnostic reference level L6 defined by age and the subject's age, for cases where the subject area is photographed by radiation in a radiographic imaging device. Then, the second setting unit 621 sets the calculated seventh diagnostic reference level L7 as the value used in radiation dose management when the subject area is photographed by a radiographic imaging device.

[0176] The radiation dose management device 60 has the above-described structure, so it is possible to set a diagnostic reference level for radiation dose management suitable for radiographic imaging.

[0177] Furthermore, the radiation dose management device 60 uses a diagnostic reference level set as described above to manage the patient's radiation dose information.

[0178] For example, when an X-ray CT device in medical device 70 takes a radiographic image, the control unit of the X-ray CT device calculates the radiation dose index during the imaging based on the imaging conditions.

[0179] Furthermore, the control unit of the X-ray CT apparatus, via its communication unit, associates with the radiographic images and sends information such as imaging conditions and radiation dose parameters to the image management unit 40 and the radiation dose management unit 60. Additionally, the radiation dose management unit 60 can also obtain radiographic images and information such as imaging conditions and radiation dose parameters from the X-ray CT apparatus and the image management unit 40, depending on its operation.

[0180] The control unit 61 of the radiation dose management device 60 stores and accumulates the transmitted or acquired radiation images, imaging conditions, radiation dose indicators, etc., in the storage unit 62. For patients subject to radiation dose management, the display unit 24 displays information comparing the set diagnostic reference level with the radiation dose indicators.

[0181] Here, Figure 11 Is Figure 9 The charts displayed in the radiation dose management device 60 for comparison are for comparison purposes. Figure 10 The graph shows the DRL values ​​and the radiation dose received by the patient. Figure 11 In this study, since the patient was 2 years old, the DRL value of the CT scan of the head of a 2-year-old child was compared with the radiation dose received by the 2-year-old patient.

[0182] In this way, the control unit 61 displays a graph on the display unit 24 comparing the set diagnostic reference level with the radiation dose received by patients subject to radiation dose management, thereby providing radiation dose management information to the operator of the radiation dose management device 60. Alternatively, the control unit 61 can also display a histogram of the radiation dose received by multiple patients for each examination item, thereby providing the operator of the radiation dose management device 60 with information to reassess the currently set diagnostic reference level. Furthermore, the control unit 61 can also calculate the permissible number of radiographic images (frames) and imaging time based on the set diagnostic reference level and the patient's radiation dose, and provide the calculated results to the radiographic control device 20 and the medical device 70.

[0183] (Example 6)

[0184] Figure 12 This is a graph showing the DRL (radiation dose to incident surface) value in general radiography and the DRL value (radiation dose index) in chest CT scans set according to the child's age.

[0185] In general photography, there are situations where the DRL value is not specified depending on the inspection items. For example, in Figure 12 In the general photography shown, the chest area of ​​a child (5 years old) is specified, but the chest area of ​​a child (10 years old) is not specified.

[0186] Therefore, in this setting example, the control unit 61 sets the DRL value (7th Diagnostic Reference Level L7) of an unspecified examination item based on the DRL value (8th Diagnostic Reference Level L8) specified for a medical device that is different from the radiographic imaging device of the object.

[0187] For example, in Figure 12In the example shown, the DRL value (Diagnostic Reference Level 7 L7) for a child's chest (10 years old) in a general radiograph is set, while the DRL value (Diagnostic Reference Level 8 L8) for a chest CT scan is set according to the child's age.

[0188] For CT scans, such as Figure 12 As shown, a DRL value of 13 mGy is defined for children aged 5 to under 10 years old, and a DRL value of 13 mGy is defined for children aged 10 to under 15 years old. The control unit 61 processes the DRL value for 5-year-olds to 13 mGy and the DRL value for 10-year-olds to 13 mGy based on these DRL values, and calculates the ratio (13 / 13) of the latter's DRL value to the former's DRL value. In this example, the ratio becomes 1.

[0189] Furthermore, the control unit 61 sets the DRL value of 0.2mGy for the child's chest (5 years old) to 0.2mGy by multiplying the calculated ratio by the DRL value of 0.2mGy for the child's chest (10 years old).

[0190] As described above, the control unit 61 uses the DRL value (8th Diagnostic Reference Level L8) specified for medical devices that are different from the radiographic imaging device of the subject, and sets an appropriate DRL value (7th Diagnostic Reference Level L7) for unspecified examination items.

[0191] also, Figure 12 The example shown is just one example. For instance, for examinations not specified above, an appropriate DRL value (DRL level 7, L7) can be set using the DRL value (Diagnostic Reference Level 8) specified for medical devices different from the radiographic equipment used on the subject.

[0192] For example, in the case of Figure 1 In the dynamic imaging performed by the radiographic imaging system 10 and radiographic imaging control device 20 shown, a DRL value is specified for the chest of a child (5 years old), but no DRL value is specified for the chest of a child (10 years old). In this case, similarly to the above, an appropriate DRL value (7th diagnostic reference level L7) can be set for the chest of a child (10 years old) using the DRL value set according to the child's age in the chest CT (8th diagnostic reference level L8).

[0193] (Example 7)

[0194] In the above-mentioned setting examples 5 and 6, the influence of each part was not considered, but the influence of each part can be considered when setting the diagnostic reference level.

[0195] For example, since the amount of radiation transmitted through the chest varies depending on the respiratory state, it is preferable to adjust the diagnostic reference level according to the respiratory state. Specifically, the amount of radiation transmitted through imaging during inhalation increases compared to imaging during exhalation, so the diagnostic reference level can be set lower. For example, in a frontal chest X-ray for health diagnosis, imaging is performed during inhalation, so the diagnostic reference level can be set lower.

[0196] In this example setting, the control unit 61 has a second correction unit 622, which corrects the DRL value (7th Diagnostic Reference Level L7) using a correction factor α for a frontal chest radiograph taken during inspiration. For example, the correction factor α is set to 0.9 in this case. Figure 12 In the “Children’s Chest (5 years old)” shown, the DRL value (Diagnostic Reference Level 7, L7) is “0.2”. Therefore, when taking a frontal chest photograph while inhaling, multiply it by the correction factor α=0.9 and set “0.18” as the corrected DRL value.

[0197] Furthermore, the X-ray transmittance varies depending on body thickness, so the DRL value (7th Diagnostic Reference Level L7) can also be corrected based on body thickness. For example, the lateral aspect of the lumbar spine is thicker than other areas, so the second correction unit 622 of the control unit 61 also uses a correction factor α to correct the DRL value (7th Diagnostic Reference Level L7) for imaging the lateral aspect of the lumbar spine. When the correction factor α is set to, for example, 1.3 in this case, in... Figure 12 In the “lumbar spine side view” shown, the DRL value (7th diagnostic reference level L7) is “9.0”, so it is multiplied by the correction factor α=1.3, and “11.7” is set as the corrected DRL value.

[0198] As described above, the control unit 61 corrects the location to become the 7th diagnostic reference level L7.

[0199] Furthermore, in the aforementioned setup examples 5 and 6, the seventh diagnostic reference level L7 for the radiation dose to the subject is calculated based on the DRL value specified for each age range. However, if the item is divided by a numerical range, it could be an item other than age. For example, a numerical setting related to radiation exposure, such as tube voltage, could also be used.

[0200] In addition, the following notes are provided in response to the above explanation.

[0201] (Note 1)

[0202] A radiation dose management device includes a second setting unit that, for cases where radiation is irradiated in a radiographic imaging device and a subject area is photographed, calculates a seventh reference value for the radiation dose of the subject based on a sixth reference value for the radiation dose specified for each division of an item divided by numerical range, and the numerical value of the subject in the item, and sets this seventh reference value as the value used in radiation dose management when the subject area is photographed by the radiographic imaging device.

[0203] (Note 2)

[0204] According to the radiation dose management device described in Appendix 1, wherein,

[0205] The second setting unit uses the sixth reference value of the division as a value corresponding to the median, minimum or maximum value of the numerical range in the division, and calculates the seventh reference value.

[0206] (Note 3)

[0207] According to the radiation dose management device described in Appendix 2, wherein,

[0208] The radiation dose management device includes a second correction unit that corrects the seventh reference value based on the target location.

[0209] (Note 4)

[0210] According to the radiation dose management device described in Appendix 3, wherein...

[0211] The second correction unit corrects the seventh reference value based on the thickness of the object part.

[0212] (Note 5)

[0213] According to the radiation dose management device described in Appendix 1, wherein,

[0214] The radiation dose management device includes a second correction unit that, when the target area is the chest, corrects the seventh reference value based on the respiratory status of the subject.

[0215] (Note 6)

[0216] According to the radiation dose management device described in Appendix 1, wherein,

[0217] The second setting unit calculates the seventh reference value by replacing the sixth reference value with an eighth reference value for each defined radiation dose, specifically for cases where the object part is photographed by a radiographic imaging device different from the radiographic imaging device.

[0218] (Note 7)

[0219] According to the radiation dose management device described in Appendix 1, wherein,

[0220] The item is either the subject's age or a numerical setting related to the radiation exposure.

[0221] (Note 8)

[0222] A method for setting radiation dose, wherein,

[0223] In a radiation dose management device, for cases where radiation is irradiated in a radiographic imaging device and a subject area is photographed, a 7th reference value for the radiation dose of the subject is calculated based on a 6th reference value for the radiation dose specified for each division of an item divided by numerical range, and the numerical value of the subject in the item, and is set as the value used in radiation dose management when the subject area is photographed by the radiographic imaging device.

[0224] (Note 9)

[0225] A radiation dose setting computer program product, which is executed by the computer of a radiation dose management device:

[0226] In the case of irradiating a subject with radiation in a radiographic imaging device and photographing a part of the subject, a seventh reference value for the radiation dose of the subject is calculated based on a sixth reference value for the radiation dose specified for each division of an item divided by numerical range, and the numerical value of the subject in the item, and is set as the value used in radiation dose management when the subject part is photographed by the radiographic imaging device.

[0227] The above embodiments are merely examples illustrating specific implementations of the invention and should not be used to limit the scope of the invention. That is, the invention can be implemented in various ways without departing from its spirit or main features.

[0228] [Explanation of Symbols]

[0229] 10: Radiographic imaging system; 11: Imaging control unit; 12: Radiation irradiation unit; 13: Imaging stage; 14: Radiation detection unit; 15: Display unit; 16: Sound output unit; 20: Radiographic imaging control device; 30: Radiographic image analysis device; 40: Image management device; 50: Client terminal; 60: Radiation dose management device; 61: Control unit; 62: Storage unit; 63: Operation unit; 64: Display unit; 65: Communication unit; 66: Bus; 70: Medical device; 100: Radiographic image processing system; 611: Proportion acquisition unit; 612: First setting unit; 613: First calibration unit; 621: Second setting unit; 622: Second calibration unit.

Claims

1. A radiation dose management device, comprising: The ratio acquisition unit acquires the ratio of a first reference value for radiation dose specified when photographing a first part of the subject in a still image manner for exposure to radiation, to a second reference value for radiation dose specified when photographing the first part of the subject in a moving image manner for exposure to radiation; and The first setting unit sets a fourth reference value for the radiation dose when photographing the second part in the form of a moving image, based on a third reference value for the radiation dose when photographing the second part in the form of a still image and the aforementioned ratio.

2. The radiation dose management device according to claim 1, wherein, The second part is a part that is different from the first part. The third reference value is a value specified for the case where the second part is photographed in still image mode.

3. The radiation dose management device according to claim 1, wherein, The second part is the same as the first part. The third reference value is a value set for the case where the second part is photographed in still image mode, and is a value different from the first reference value.

4. The radiation dose management device according to claim 1, wherein, The ratio acquisition unit uses a fifth reference value, which is determined by the photographic facility alone for the case of photographing the first part in the form of a still image, instead of the first reference value, to calculate the ratio.

5. The radiation dose management device according to claim 1, wherein, The radiation dose management device includes a first calibration unit that calibrates the fourth reference value based on the second part.

6. The radiation dose management device according to claim 5, wherein, The first correction unit corrects the fourth reference value based on the thickness of the second part.

7. The radiation dose management device according to claim 1, wherein, The radiation dose management device includes a first correction unit that, when the second site is the chest, corrects the fourth reference value based on the respiratory status of the subject.

8. A method for setting radiation dose, wherein, In radiation dose management devices, Calculate the ratio of a first reference value for radiation dose specified for a still image of a first part of the subject exposed to radiation, to a second reference value for radiation dose specified for a moving image of the first part of the subject exposed to radiation. A fourth reference value for the radiation dose when the second part is photographed in the manner of a still image is set based on a third reference value for the radiation dose and the aforementioned ratio.

9. The method for setting the radiation dose according to claim 8, wherein, The second part is a part that is different from the first part. The third reference value is a value specified for the case where the second part is photographed in still image mode.

10. The method for setting the radiation dose according to claim 8, wherein, The second part is the same as the first part. The third reference value is a value set for the case where the second part is photographed in still image mode, and is a value different from the first reference value.

11. The method for setting the radiation dose according to claim 8, wherein, The ratio is determined by replacing the first reference value with a fifth reference value for the radiation dose specified by the photographic facility itself for the case of photographing the first part in the manner of a still image.

12. The method for setting the radiation dose according to claim 8, wherein, The fourth reference value is corrected based on the second part.

13. The method for setting the radiation dose according to claim 12, wherein, The fourth reference value is corrected based on the thickness of the second part.

14. The method for setting the radiation dose according to claim 8, wherein, In the case where the second site is the chest, the fourth reference value is corrected based on the respiratory status of the subject.

15. A radiation dose setting computer program product, which causes the computer of a radiation dose management device to execute: The ratio is obtained by processing the data to determine the ratio between a first reference value for radiation dose specified for a still image of the first part of the subject under radiation exposure and a second reference value for radiation dose specified for a moving image of the first part of the subject under radiation exposure; and The first setting process sets a fourth reference value for the radiation dose when the second part is photographed in the manner of a moving image, based on a third reference value for the radiation dose when the second part is photographed in the manner of a still image and the aforementioned ratio.

16. The radiation dose setting computer program product according to claim 15, wherein, The second part is a part that is different from the first part. The third reference value is a value specified for the case where the second part is photographed in still image mode.

17. The radiation dose setting computer program product according to claim 15, wherein, The second part is the same as the first part. The third reference value is a value set for the case where the second part is photographed in still image mode, and is a value different from the first reference value.

18. The radiation dose setting computer program product according to claim 15, wherein, In the process of obtaining the ratio, the ratio is obtained by replacing the first reference value with a fifth reference value of radiation dose that is determined by the photographic facility alone for the case of photographing the first part in the manner of a still image.

19. The radiation dose setting computer program product according to claim 15, wherein, The computer performs a first correction process to correct the fourth reference value based on the second part.

20. The radiation dose setting computer program product according to claim 19, wherein, In the first correction process, the fourth reference value is corrected based on the thickness of the second part.

21. The radiation dose setting computer program product according to claim 15, wherein, The computer performs a first correction process to correct the fourth reference value based on the subject's respiratory status when the second site is the chest.

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