Control device, radiation imaging system, method of operating control device, and program

Abstract

To provide a control device that optimizes the selection of a lighting field in imaging with automatic exposure control.SOLUTION: A control device comprises: a setting section that sets a detection region used for automatic exposure control of radiation using information from a radiation detection section that detects radiation; and a determination section that determines candidate regions that are not to be used for automatic exposure control among the set detection regions using a radiation image of a subject acquired in the past. The setting section sets the detection region again on the basis of the candidates.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a control device, a radiation imaging system, a method for operating a control device, and a program. [Background technology]

[0002] In recent years, studies have been conducted to increase the number of functions of radiation detectors used in the medical field to detect radiation such as X-rays. One such study is to equip radiation detectors with a function to monitor radiation irradiation. This function would enable, for example, detection of the timing at which radiation irradiation from a radiation generating unit starts, detection of the timing at which radiation irradiation should be stopped, and detection of the radiation dose or cumulative radiation dose.

[0003] Furthermore, automatic exposure control (AEC) can be performed by detecting the cumulative dose of radiation that has passed through the subject and stopping the radiation irradiation from the radiation generating unit when the detected cumulative dose reaches a threshold dose. In order to detect the radiation dose and implement the AEC function, it is known to place a radiation detection area (detection field) that measures radiation and is used for automatic exposure control inside the radiation detector. When multiple detection fields for automatic exposure control are placed in the radiation detector, the detection field to be used for automatic exposure control is selected depending on the patient's condition and the area to be imaged when performing imaging using automatic exposure control.

[0004] Generally, imaging procedures that include information such as the imaging area, imaging position, and radiation detector to be used include default imaging field setting information based on these information, as well as logical operation information for determining when to stop irradiation based on the radiation dose detected in the imaging field.

[0005] Patent Document 1 describes a radiation imaging system that displays a patient's contour based on the patient's height, size, and other statistically acquired dimensional data, and allows an operator to select a measurement field to be used for automatic exposure control. The radiation imaging system described in Patent Document 1 allows the operator to select a measurement field appropriate for the patient's size and overall physique. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-139619 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the method described in Patent Document 1, when an operator selects an irradiation field, an irradiation field that should not be selected may be selected. For example, if an irradiation field that straddles various parts of the body, such as bones, organs, or fat, which have different X-ray absorption rates, is selected, the time until irradiation of radiation at the desired dose is stopped may differ from the time that should have been set.

[0008] Therefore, one object of one embodiment of the present disclosure is to provide a control device that optimizes the selection of the light collection field in imaging under automatic exposure control. [Means for solving the problem]

[0009] A control device according to one embodiment of the present disclosure includes a setting unit that sets a detection area to be used for automatic exposure control of radiation using information from a radiation detection unit that detects radiation, and a determination unit that determines candidate areas from the set detection area that will not be used for the automatic exposure control using radiation images of a subject that have been captured in the past, and the setting unit re-sets the detection area based on the candidate areas. [Effects of the Invention]

[0010] According to one embodiment of the present disclosure, it is possible to optimize the selection of the light collection field in automatic exposure control imaging. [Brief explanation of the drawings]

[0011] [Figure 1] 1 shows a schematic configuration of a radiation imaging system according to a first embodiment. [Figure 2] 2 shows the hardware and software configurations of a control device according to the first embodiment. [Figure 3] 3 shows an example of the arrangement of the light measurement fields according to the first embodiment. [Figure 4] 10 shows an example of a setting screen for a measurement field according to the first embodiment. [Figure 5A] 10 is a flowchart showing the procedure of a process for optimizing the selection of the measurement field according to the first embodiment. [Figure 5B] 10 is a flowchart showing the procedure of a process for optimizing the selection of the measurement field according to the first embodiment. [Figure 6] 10 shows an example of an optimization result of the selection of the measurement field presented in the second embodiment. [Figure 7] 10 is a flowchart showing the procedure of a process for optimizing the selection of the measurement field according to the second embodiment. [Figure 8] 11 is a flowchart showing the procedure of a process for optimizing the selection of the measurement field according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, and relative positions of components described in the following embodiments are arbitrary and can be changed depending on the configuration of an apparatus to which the present disclosure is applied or various conditions. In addition, the same reference numerals are used between drawings to indicate identical or functionally similar elements.

[0013] In the following embodiments, the term "radiation" can include, in addition to X-rays, for example, α-rays, β-rays, γ-rays, particle rays, and cosmic rays. Furthermore, the regions with different radiation absorption rates below may be referred to as regions with different radiation absorption differences. Here, the radiation absorption difference refers to the difference in the amount of radiation incident on the radiation imaging device based on the radiation absorption rate.

[0014] [First embodiment] Hereinafter, a radiation imaging system, a control device, and an operation method of the control device according to the first embodiment of the present disclosure will be described with reference to Figs. 1 to 5B. Fig. 1 is a schematic diagram showing an example of a schematic configuration of a radiation imaging system 100 according to this embodiment. The radiation imaging system 100 is provided with a control device 110, a display unit 112, an operation unit 113, a radiation generation unit 114, a radiation detector 115, a RIS 130, a PACS 140, and an HIS 150. Here, RIS is an abbreviation for Radiology Information Systems. PACS is an abbreviation for Picture Archiving and Communication Systems (image server). HIS is an abbreviation for Hospital Information Systems.

[0015] The control device 110 functions as an example of an imaging control device. The control device 110 is connected to the display unit 112, the operation unit 113, and the radiation generation unit 114 via wired connections, and to the radiation detector 115 via wired or wireless connections, and communicates with each device to control its operation. Here, wired communication can be performed via a LAN (Local Area Network) such as Ethernet (registered trademark), but communication may also be performed using other wired communication methods. Wireless communication may be performed using, for example, a circuit board equipped with an antenna and a communication IC, etc. The circuit board equipped with a communication IC, etc. can perform communication processing of a protocol based on the wireless LAN via the antenna.

[0016] There are no particular limitations on the frequency band, standard, or method of wireless communication, and a proximity wireless communication method such as NFC (Near Field Communication) or Bluetooth (registered trademark) may be used. Furthermore, a method such as UWB (Ultra-Wide Band) may be used for wireless communication. Furthermore, wireless communication may be performed using a communication method appropriately selected from a plurality of methods.

[0017] The control device 110 is also connected to the RIS 130, PACS 140, and HIS 150 via a network 120. The control device 110 can exchange radiographic images, patient information, radiography orders, and the like with these systems.

[0018] The display unit 112 displays imaging examination information, captured radiographic images, various types of information, etc. The operation unit 113 accepts input information from an operator. In this embodiment, the display unit 112 may be configured using any monitor (e.g., a liquid crystal display, etc.). The operation unit 113 may also be configured using a keyboard, a pointing device (e.g., a mouse, etc.), a touch panel, etc.

[0019] The radiation generating unit 114 is provided with a radiation tube that generates radiation. The radiation generating unit 114 functions as an example of a radiation generating device that irradiates radiation onto a patient 1000, who is a subject. In this embodiment, as shown in FIG. 1, an example will be described in which the radiation generating unit 114 is installed in a room where radiation imaging is performed, and the spatial range into which the radiation generating unit 114 irradiates radiation is limited to a certain range. However, a portable radiation generating unit may also be used.

[0020] The radiation detector 115 functions as an example of a radiation imaging device that generates a radiation image based on radiation irradiated from the radiation generating unit 114. The radiation detector 115 can be installed in a room or on a desk depending on the spatial range to which the radiation generating unit 114 irradiates radiation.

[0021] 3, the radiation detector 115 has an AEC function for performing automatic exposure control, and is provided with one or more radiation detection areas (light collection fields) 301 for measuring radiation. The AEC measures the dose of radiation that has passed through the subject in one or more preselected light collection fields 301, and controls to stop irradiation of radiation when the measured dose reaches a predetermined dose.

[0022] The radiation detector 115 can transmit a radiographic image generated based on the detected radiation to the control device 110. The control device 110 can perform image processing on the radiographic image acquired from the radiation detector 115 and display the image on the display unit 112.

[0023] Note that, although the radiation imaging system 100 according to this embodiment will be described as including the RIS 130, the PACS 140, and the HIS 150, the radiation imaging system 100 may not include at least some of these. Furthermore, while Fig. 1 shows an example in which the radiation generating unit 114 and the radiation detector 115 are present as the radiation generating unit and the radiation detector, the combination of the radiation generating unit and the radiation detector is not limited to this. For example, the radiation imaging system 100 may include an additional combination of the radiation generating unit and the radiation detector.

[0024] Next, an example of the configuration of the control device 110 according to this embodiment will be described with reference to Figures 2(a) and 2(b). First, Figure 2(a) is a schematic diagram showing an example of the hardware configuration of the control device 110. The control device 110 is provided with a CPU 201, a RAM 202, a ROM 203, an external memory 204, and a communication I / F unit 205, and these components are connected to each other via a bus 206.

[0025] The CPU (Central Processing Unit) 201 is an example of a processing device that comprehensively controls the operation of the control device 110. The CPU controls each component (RAM 202 to communication I / F unit 205) shown in FIG. 2(a) via a bus 206.

[0026] RAM (Random Access Memory) 202 is an example of writable memory. RAM is the main memory of CPU 201 and functions as a work area, etc. When executing processing, CPU 201 loads necessary computer programs 2031, basic data, etc. from ROM 203 into RAM 202, and executes the computer programs 2031, etc. to realize various functional operations.

[0027] A ROM (Read Only Memory) 203 stores a computer program 2031, basic data, etc., required for the CPU 201 to execute processing. The computer program 2031 may be stored in an external memory 204.

[0028] The external memory 204 is a large-capacity storage device, and can be realized using a storage medium such as a hard disk drive or an IC (Integrated Circuit) memory. The external memory 204 stores, for example, various types of data and information required when the CPU 201 performs processing using the computer program 2031, etc. The external memory 204 can also store, for example, various types of data and information obtained when the CPU 201 performs processing using the computer program 2031, etc.

[0029] The communication I / F (interface) unit 205 is an interface used for communication between the control device 110 and the outside. The bus 206 connects the CPU 201, the RAM 202, the ROM 203, the external memory 204, and the communication I / F unit 205 so that they can communicate with each other.

[0030] The control device 110 according to this embodiment is provided as an embedded device dedicated to the radiation imaging system 100, but may also be realized by a general-purpose information processing device such as a PC (personal computer) equipped with a processor and memory. Here, the general-purpose information processing device may be a desktop PC, a notebook PC, a tablet PC (portable information terminal), or the like. Furthermore, the control device 110 may be configured as a cloud-based computer in which some of the components are located in an external device.

[0031] 2(b) is a functional block diagram showing the software configuration of the control device 110 according to this embodiment. The control device 110 includes a control unit 211, a communication unit 212, an image acquisition unit 213, a storage unit 214, a setting unit 215, and a determination unit 216.

[0032] Each function is realized by the CPU 201 expanding a computer program 2031 stored in the ROM 203 into the RAM 202 and executing it. However, the processor that realizes each function is not limited to a CPU, and may be, for example, a GPU (Graphical Processing Unit) or an FPGA (Field-Programmable Gate Array). Furthermore, each function may be configured by a circuit that performs a specific function, such as an ASIC (Application Specific Integrated Circuit).

[0033] The control unit 211 determines whether various setting information is set in the radiation imaging system 100, creates and edits various setting information, controls operation from the operation unit 113, and controls display on the display unit 112. The control unit 211 also determines whether to stop irradiation of radiation using the AEC function, generates an irradiation stop signal, and so on.

[0034] The communication unit 212 communicates with the radiation generation unit 114 and the radiation detector 115, and acquires various types of information, such as information about the radiation detector 115. The communication unit 212 also communicates with the RIS 130, the PACS 140, the HIS 150, and the like, and can acquire various types of information, images, and the like.

[0035] The image acquisition unit 213 acquires a radiographic image from the radiation detector 115. The radiographic image data acquired from the radiation detector 115 may be data formed as an image, or may be data for forming an image. When the image acquisition unit 213 acquires data for forming an image from the radiation detector 115, it may form and acquire a radiographic image based on the data using any known method.

[0036] The storage unit 214 stores various setting information and patient information of the radiation imaging system 100, various information acquired by the communication unit 212, and radiation images acquired by the image acquisition unit 213, etc.

[0037] The setting unit 215 sets and acquires information on the irradiation field used for automatic exposure control included in the imaging procedure. The information on the imaging procedure may be automatically acquired from, for example, an imaging order related to radiography, or may be input by the operator via the operation unit 113. The information on the imaging procedure may also be information on the imaging procedure acquired from an imaging order or the like that has been modified by the operator.

[0038] The determination unit 216 determines whether a measurement field to be used for automatic exposure control is selected between regions with different radiation absorption rates, or whether a measurement field different from the imaging region is selected. In this embodiment, the determination unit 216 determines whether a measurement field to be used for automatic exposure control is selected between regions with different radiation absorption rates, for example, between bone and soft tissue such as fat.

[0039] The above-described functional blocks are merely examples, and the control device 110 may have a configuration that does not include some of the above-described functional blocks. Also, the control device 110 may have a configuration that includes additional functional blocks.

[0040] Next, a measurement field setting screen used for automatic exposure control will be described with reference to Figures 4(a) and 4(b). Figure 4(a) shows an example of a measurement field setting screen for imaging using automatic exposure control, which the control device 110 causes to be displayed on the display unit 112. A measurement field setting screen 401 displays a previous radiation image 402, a measurement field area button 403, a cancel button 404, and a confirm button 405.

[0041] The control unit 211 selects, from the radiation images stored in the storage unit 214, a radiation image relating to the patient information and imaging area that match the patient information of the patient to be imaged and the imaging area included in the imaging procedure, and displays it on the irradiation field setting screen 401 as a past radiation image 402.

[0042] The control unit 211 also acquires configuration information of the radiation detection field in the radiation detector 115, which is included in the information about the radiation detector 115 acquired by the communication unit 212 from the radiation detector 115 having the AEC function. Based on the configuration information of the radiation detection field in the radiation detector 115, the control unit 211 displays a measurement field area button 403, which represents the number and position of the measurement field, superimposed on the measurement field setting screen 401. Note that by displaying the measurement field area button 403 in a pressed state, the control unit 211 can display the measurement field in question so as to indicate that the measurement field in question has been selected as the measurement field to be used for imaging under automatic exposure control. Note that the display mode indicating the selection state of the measurement field is not limited to this. For example, the measurement field area button 403 of the selected measurement field may be displayed in a color or brightness different from that of the other areas, or may be blinking.

[0043] To cancel the setting of the measurement field, the operator presses the cancel button 404 to close the measurement field setting screen 401. On the other hand, when the operator presses the enter button 405, the setting unit 215 applies the measurement field information selected by the measurement field area button 403 as the measurement field setting for the imaging procedure.

[0044] FIG. 4B shows an example of a state in which multiple irradiation field area buttons 403 are selected on the irradiation field setting screen 401. The irradiation field area button 403 may be selected not only by the operator selecting each irradiation field, but also by any other method. For example, a selection method in which the operator selects vertices of a polygon of multiple irradiation field areas to select all irradiation field areas within the polygon formed by connecting the selected vertices may be used. Alternatively, a method in which a region matching the imaging region in the previous radiation image 402 is automatically selected based on information about the imaging region included in the imaging procedure may be used. The control unit 211 selects the irradiation field area button 403 using such a selection method, and the setting unit 215 sets the irradiation field based on the irradiation field information corresponding to the irradiation field area button 403 selected when the confirm button 405 is pressed.

[0045] Next, a process for optimizing the selection of the measurement field according to this embodiment will be described with reference to Figures 5A and 5B. Figures 5A and 5B are flowcharts showing a process for optimizing the selection of the measurement field in automatic exposure control imaging by the radiation imaging system 100 according to this embodiment based on information on logical operations included in the imaging procedure.

[0046] First, in step S501, the control unit 211 causes the display unit 112 to display the measurement field setting screen 401.

[0047] Next, in step S502, the control unit 211 acquires information about the imaging procedure for performing automatic exposure control imaging from the setting unit 215. As described above, the setting unit 215 may automatically acquire the information about the imaging procedure from an imaging order for radiography or the like, or may acquire it via the operation unit 113. The setting unit 215 may also acquire an imaging procedure that has been automatically acquired from an imaging order or the like and that has been modified by the operator. The information about the imaging procedure may include, for example, the imaging region, the type of radiation detector used, the radiation field used for automatic exposure control, parameters for calculating the dose threshold, and information about calculations related to stopping radiation irradiation. However, the information about the imaging procedure is not limited to these, and may include additional information, or may not include some of this information.

[0048] In step S503, the control unit 211 acquires information about the radiation detector 115 used for imaging under automatic exposure control from the communication unit 212. The information about the radiation detector 115 may include, for example, the identification information and type of the radiation detector 115, and the location of the radiation detection region 301 that can be used as the radiation measurement field.

[0049] In step S504, the control unit 211 acquires patient information from the storage unit 214. Note that the patient information may be input in advance by the operator, or may be acquired from an imaging order or the like.

[0050] In step S505, the control unit 211 acquires radiation images (past radiation images) previously captured of the patient whose patient information was acquired in step S504 from the storage unit 214. The past radiation images stored in the storage unit 214 may be radiation images obtained by imaging previously performed using the control unit 211, or may be past radiation images acquired from the PACS 140 or the like.

[0051] In step S506, the control unit 211 determines whether or not a past radiation image 402 of the patient exists based on the results acquired from the storage unit 214 in steps S504 and S505.

[0052] If it is determined that the past radiation image 402 exists (step S506; Yes), the process proceeds to step S507. On the other hand, if it is determined that the past radiation image 402 does not exist (step S506; No), the process proceeds to step S508.

[0053] In step S507, the control unit 211 superimposes and displays the past radiation image 402 acquired in step S505 on the measurement field setting screen 401. At this time, if there are multiple past radiation images 402 acquired in step S505, the control unit 211 may select the one with the most recent imaging date and time as the past radiation image to be superimposed and displayed on the measurement field setting screen 401. The control unit 211 may also select the past radiation image to be displayed based on other criteria.

[0054] In step S508, the control unit 211 displays the measurement field area button 403 on the measurement field setting screen 401 based on the information on the radiation detection area section 301 that can be used as the measurement field located on the radiation detector 115 obtained in step S503.

[0055] In step S509, the control unit 211 selects the irradiation field region button 403. The selection at this time may be made based on a default irradiation field setting that is set in advance for the imaging procedure, or may be made using any of the selection methods described above with reference to FIG. 4(b).

[0056] In step S510, the control unit 211 determines whether the past radiation image 402 is superimposed on the measurement field setting screen 401. If it is determined that the past radiation image 402 is superimposed (step S510; Yes), the process proceeds to step S511. On the other hand, if it is determined that the past radiation image 402 is not superimposed (step S510; No), the process ends.

[0057] In step S511, the determination unit 216 determines whether or not a measurement field area has been selected among areas with different radiation absorption rates, based on the past radiation image 402 superimposed and displayed in step S507 and the information on the measurement field area button 403 selected in step S509. In relation to this, the determination unit 216 can determine that a measurement field area corresponding to an area with different radiation absorption rates is a candidate area not to be used in automatic exposure control. If it is determined that an area with different radiation absorption rates has been selected (step S511; Yes), the process proceeds to step S512. On the other hand, if it is determined that an area with different radiation absorption rates has not been selected (step S511; No), the process ends.

[0058] In this case, the condition for determining whether a region with a different radiation absorption rate has been selected may be, for example, whether a region other than the region of interest (such as a lung field) identified by region recognition has been selected as the radiation measurement field region. Region recognition may be performed on the past radiation image 402 by any known method, and may be performed by, for example, a method of identifying a region of interest by referring to brightness information or contrast information of the past radiation image 402. The method of region recognition may be, for example, a rule-based method based on information about body tissues, or a method using machine learning.

[0059] Furthermore, the condition for determining whether a region with a different radiation absorption rate has been selected may be whether the selected irradiation field region overlaps regions with a different radiation absorption rate at a rate equal to or greater than a certain rate, based on the histogram information of the past radiation image 402. For example, if the histogram information of the pixel values ​​of the region selected as the irradiation field region contains pixel values ​​other than the imaging region at a rate equal to or greater than a predetermined rate, the determination unit 216 can determine the region as a region with a different radiation absorption rate. Note that the pixel values ​​determined as the pixel values ​​of the imaging region may be set in advance for each imaging region, or may be found from the histogram information of the past radiation image 402.

[0060] In step S512, the control unit 211 determines whether the setting of the logical operation used for automatic exposure control, which is included in the information on the imaging procedure, is "AND" or "OR." Here, the logical operation used for automatic exposure control, more specifically, refers to the logical operation used in threshold processing related to the termination of radiation irradiation by automatic exposure control. If it is determined that the logical operation set for the imaging procedure is "AND," the process proceeds to step S513. On the other hand, if the logical operation set for the imaging procedure is "OR," the process proceeds to step S514.

[0061] The logical operations set for the imaging procedure here generally include "AND (logical product)" and "OR (logical sum)." "AND (logical product)" is a setting that determines that irradiation should be stopped when the radiation dose reaches a threshold in all selected irradiation field areas. On the other hand, "OR (logical sum)" is a setting that determines that irradiation should be stopped when the radiation dose reaches a threshold in any selected irradiation field areas.

[0062] If the logical operation set for the imaging procedure is "AND," and a region with a different radiation absorption rate is selected as the irradiation field region, the automatic exposure control will not determine that irradiation should be stopped even for a radiation field that should not be selected until the radiation dose reaches a threshold. Therefore, in step S513, the setting unit 215 deselects the irradiation field region button 403 corresponding to the region with a different radiation absorption rate and updates the setting of the irradiation field region information used for automatic exposure control included in the imaging procedure. Note that the setting unit 215 can identify the irradiation field region button 403 corresponding to the region with a different radiation absorption rate based on the determination result of the determination unit 216 in step S511.

[0063] On the other hand, if the logical operation set for the imaging procedure in step S512 is "OR," even when areas with different radiation absorption rates are selected, the automatic exposure control determines that irradiation should be stopped when the radiation dose reaches a threshold in any of the measurement fields. Therefore, even in measurement fields that should not be selected, irradiation can be stopped by the automatic exposure control without waiting for the radiation dose to reach a threshold. Therefore, if the logical operation set for the imaging procedure in step S512 is "OR," radiation imaging can be performed without the setting unit 215 updating the setting of the information on the measurement field.

[0064] However, if the region with different radiation absorption rates includes a region with low radiation absorption rate, the radiation dose may reach the threshold in the region with different radiation absorption rate before the region of the imaging region. In this case, automatic exposure control may determine to stop irradiation before an appropriate dose of radiation for imaging the imaging region is irradiated. Therefore, in step S514, the control unit 211 displays a warning on the display unit 112 to alert the user that a region that should not have been selected has been selected as the irradiation field.

[0065] The content of the warning may be set arbitrarily according to a desired configuration. For example, the warning may be a message asking the operator whether or not to change the irradiation field region button 403 of the region with a different radiation absorption rate to a non-selected state, or a message prompting the operator to update the irradiation field region button 403. This completes the processing of the flowchart in FIG. 5.

[0066] As described above, the radiation imaging system 100 according to this embodiment includes the radiation detector 115 and the control device 110. The radiation detector 115 includes a radiation detection section (radiation detection region section 301) that detects radiation in order to perform automatic exposure control, and functions as an example of a radiation imaging device that detects radiation.

[0067] The control device 110 includes a setting unit 215 and a determination unit 216. The setting unit 215 functions as an example of a setting unit that sets a detection area to be used for automatic exposure control of radiation using information from a radiation detection unit that detects radiation. Here, the above-mentioned irradiation field area may be an example of a detection area. Furthermore, the determination unit 216 functions as an example of a determination unit that determines, using a radiation image of a subject captured in the past, candidate areas not to be used for automatic exposure control from among the detection areas set by the setting unit 215. Here, the setting unit 215 resets the detection area based on the candidate areas not to be used for automatic exposure control determined by the determination unit 216. Note that resetting the detection area does not have to involve changing the detection area.

[0068] The setting unit 215 can reset the detection area based on candidate areas not used in automatic exposure control and information on calculations related to automatic exposure control. More specifically, the setting unit 215 can remove the candidate from the detection area when the information on the calculations related to automatic exposure control indicates a logical product, and can not remove the candidate from the detection area when the information on the calculations related to automatic exposure control indicates a logical sum. Note that the information on the calculations related to automatic exposure control may be information indicating a calculation used in threshold processing related to stopping radiation irradiation by automatic exposure control.

[0069] With this configuration, when a measurement field that should not be selected as a measurement field for automatic exposure control is selected, the radiation imaging system 100 according to this embodiment can determine candidate regions not to be used for automatic exposure control using previously captured radiation images of the subject. Therefore, the selection of measurement fields to be used for automatic exposure control can be optimized based on the candidate regions not to be used for automatic exposure control. Furthermore, the radiation imaging system 100 according to this embodiment can optimize the selection of measurement fields to be used for automatic exposure control with respect to candidate regions not to be used for automatic exposure control, based on information about calculations included in the imaging procedure. This allows the desired time until radiation irradiation is stopped at a dose that is a threshold in automatic exposure control, thereby enabling an appropriate dose of radiation to be irradiated to the patient.

[0070] The determination unit 216 can determine, as a candidate for an area not to be used in automatic exposure control, an area corresponding to an area with a different radiation absorption rate in a previously captured radiographic image of the subject. In this regard, the determination unit 216 can identify an area with a different radiation absorption rate by performing part recognition or histogram analysis on a previously captured radiographic image of the subject.

[0071] With this configuration, the detection area is reset based on the area corresponding to the area with a different radiation absorption rate, so that the detection area used for automatic exposure control can be more appropriately selected for the desired imaging target, and therefore the termination of radiation irradiation by automatic exposure control can be more appropriately controlled for the desired imaging target.

[0072] The control device 110 further includes a control unit 211. The control unit 211 can function as an example of a display control unit that displays the detection unit area set using information from the radiation detection unit and a radiation image of the subject previously captured on the display unit 112. With this configuration, the operator can easily determine whether or not the detection unit area set using information from the radiation detection unit is appropriate as the detection unit area to be used for radiation imaging of the subject, by checking the display on the display unit 112.

[0073] In this embodiment, when the logical operation set for the imaging technique is "OR", a warning is displayed in step S514, but the processing of step S514 may be omitted. Also, processing similar to the processing of step S514 may be performed before step S513. In relation to this, the control unit 211 can cause the display unit 112 to display a warning regarding the detection area used for automatic exposure control.

[0074] Furthermore, the function of displaying a warning may be controlled to be enabled or disabled as appropriate. For example, the control unit 211 may determine whether to enable or disable the function of displaying a warning based on patient information such as the imaging region and the patient's physique, and may perform warning processing in step S514 or the like when the function is enabled. Therefore, the display of the warning can be executed according to at least one of the imaging region and the patient information. Note that information on the imaging region can be acquired from information on the imaging procedure, etc.

[0075] Furthermore, in this embodiment, the logical operations "AND" and "OR" have been described as examples of operations set for the imaging procedure. In contrast, the operations set for the imaging procedure, more specifically, the operations used for threshold processing related to the termination of radiation irradiation by automatic exposure control, may include "AVG (average)." Here, "AVG" is a setting that determines the termination of irradiation when the average value of the dose in the selected irradiation field region reaches a threshold.

[0076] When the calculation set for the imaging technique is "AVG," the same processing as when the calculation is "AND" can be performed. Therefore, when the control unit 211 determines in step S512 that the setting of the calculation used for automatic exposure control is "AVG," the processing proceeds to step S513, and the processing of step S513 described above is performed. Note that, in this case, the warning described above may also be displayed before the processing of step S513.

[0077] [Second embodiment] In the first embodiment, an example was described in which a radiation imaging system optimizes the selection of a radiation field based on calculation information included in an imaging procedure when a radiation field that should not have been selected is selected in automatic exposure control imaging. In contrast, in a second embodiment of the present disclosure, an example is described in which the result of optimizing the selection of a radiation field is presented. Hereinafter, the radiation imaging system according to this embodiment will be described with reference to FIGS. 6 and 7.

[0078] The configuration of the radiation imaging system according to this embodiment is the same as that of the radiation imaging system according to the first embodiment, and therefore the same reference numerals are used and the description thereof will be omitted. The radiation imaging system according to this embodiment will be described below, focusing on the differences from the radiation imaging system according to the first embodiment.

[0079] Fig. 6 shows an example of the results of optimizing the selection of the measurement field presented on the measurement field setting screen 401. The measurement field setting screen 401 shown in Fig. 6 displays a measurement field exclusion candidate area button 601 in addition to the past radiation image 402 and the like described in the first embodiment.

[0080] The irradiation field exclusion candidate region button 601 is a button that displays, as a candidate for deselection, the irradiation field region button 403 corresponding to a region determined by the determination unit 216 to have a different radiation absorption rate. In this case, the irradiation field exclusion candidate region button 601 can be displayed so as to be distinguishable from both the selected and unselected states of the irradiation field region button 403. For example, the irradiation field exclusion candidate region button 601 may be displayed in a color or transparency different from that of the selected or unselected irradiation field region button 403, or may be displayed in a flashing manner.

[0081] Next, the processing procedure for optimizing the selection of the irradiation field according to this embodiment will be described with reference to Fig. 7. Fig. 7 is a flowchart showing the processing procedure according to this embodiment. With regard to the processing procedure according to this embodiment, the same processes as those in Figs. 5A and 5B according to the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. Note that, since the processes of steps S501 to S512 according to this embodiment are the same as those in the first embodiment, the processes shown in Fig. 5A (steps S501 to S509) are omitted in Fig. 7.

[0082] The processing in steps S510 to S512 is the same as the processing in steps S510 to S512 according to the first embodiment, and therefore description thereof will be omitted. If it is determined in step S512 that the logical operation set for the imaging procedure is "AND," the processing proceeds to step S701. On the other hand, if the logical operation set for the imaging procedure in step S512 is "OR," the processing ends.

[0083] In step S701, the control unit 211 updates the measurement field area button 403, for which the area with a different radiation absorption rate determined in step S511 has been selected, to the measurement field exclusion candidate area button 601, and displays it on the measurement field setting screen 401. This allows the operator to confirm the results of optimizing the selection of the measurement field. Also, in step S701, the control unit 211 may change the selection state of the measurement field area button 403 or the measurement field exclusion candidate area button 601 in response to an input by the operator via the operation unit 113.

[0084] When the process of step S701 is completed, the process proceeds to step S513. In the process of step S513, the setting unit 215 updates the setting of the information on the irradiation field area used for automatic exposure control included in the imaging procedure by deselecting the irradiation field area button 403 corresponding to the irradiation field exclusion candidate area button 601. This completes the processes of the flowchart in FIG.

[0085] As described above, the control unit 211 according to this embodiment can further display, on the display unit 112, candidate areas not to be used in automatic exposure control, which have been determined by the determination unit 216. As described above, in this embodiment, the results of optimizing the selection of the measurement fields are presented, allowing the operator to confirm the results of optimizing the selection of the measurement fields.

[0086] Furthermore, the setting unit 215 can reset the detection area in response to an instruction from the operator for a candidate area not to be used for automatic exposure control. This allows the operator to fine-tune the selection of the measurement area and set the optimal measurement area to be used for automatic exposure control imaging.

[0087] The control unit 211 can display candidate areas not to be used for automatic exposure control on the display unit 112, distinguishing them from both areas to be used for automatic exposure control and areas not to be used for automatic exposure control. This allows the operator to more easily check the candidate areas not to be used for automatic exposure control by checking the display on the display unit 112, and easily determine whether or not the candidate areas are appropriate as detection unit areas to be used for radiographic imaging of the subject.

[0088] In this embodiment, the processing of step S514 is omitted, but as in the first embodiment, the processing of step S514 may be performed if the logical operation is determined to be "OR" in step S512. Also, in step S701, when the irradiation field exclusion candidate region button 601 is displayed, a warning similar to that in step S514 may be displayed. Also, as described in the first embodiment, the function of displaying the warning may be controlled to be enabled or disabled as appropriate.

[0089] Also in this embodiment, the calculations related to automatic exposure control may include "AVG (average)." The processing when the calculation is determined to be "AVG" in step S512 may be the same as the processing when the calculation is determined to be "AND."

[0090] [Third embodiment] In a third embodiment of the present disclosure, an example will be described in which a radiation imaging system optimizes selection of an irradiation field in imaging under automatic exposure control based on information on an imaging region included in an imaging procedure. Hereinafter, the radiation imaging system according to this embodiment will be described with reference to FIG.

[0091] The configuration of the radiation imaging system according to this embodiment is the same as that of the radiation imaging system according to the first embodiment, and therefore the same reference numerals are used and the description thereof will be omitted. The radiation imaging system according to this embodiment will be described below, focusing on the differences from the radiation imaging system according to the first embodiment.

[0092] Fig. 8 is a flowchart showing the procedure for optimizing the selection of the measurement field according to this embodiment. Regarding the procedure for the process according to this embodiment, the same processes as those in Figs. 5A and 5B according to the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. Note that, since the processes in steps S501 to S510 according to this embodiment are the same as those in the first embodiment, the processes shown in Fig. 5A (steps S501 to S509) are omitted in Fig. 8.

[0093] The processing in step S510 is the same as the processing in step S510 according to the first embodiment, and therefore description thereof will be omitted. If it is determined in step S510 that the past radiation image 402 is superimposed and displayed (step S510; Yes), the processing proceeds to step S801. On the other hand, if it is determined that the past radiation image 402 is not superimposed and displayed (step S510; No), the processing ends.

[0094] In step S801, the determination unit 216 determines whether a measurement field area different from the imaging region is selected. Specifically, the determination unit 216 makes the determination based on the information on the imaging region included in the information on the imaging procedure acquired in step S502, the past radiation image 402 superimposed and displayed in step S507, and the information on the measurement field area button 403 selected in step S509.

[0095] In this case, the condition for determining whether a measurement field area other than the imaging region has been selected may be, for example, whether an area other than a specific organ or skeletal part, which is the imaging region, has been selected as the measurement field area. For example, the determination unit 216 refers to the past radiation image 402 and determines whether an area in the past radiation image 402 corresponding to the selected measurement field area button 403 depicts an area other than a specific organ or skeletal part, which is the imaging region. Note that the region depicted in the past radiation image 402 may be identified using, for example, a rule-based method based on information about body tissues or a method using machine learning. Furthermore, the condition for determining whether a measurement field area other than the imaging region has been selected is not limited to this example and may be set according to a desired configuration.

[0096] If it is determined that a measurement field in a region different from the imaging region has been selected (step S801; Yes), the process proceeds to step S802. On the other hand, if it is determined that a measurement field in a region different from the imaging region has not been selected (step S801; No), the process ends.

[0097] In step S802, the control unit 211 updates the measurement field area button 403 determined in step S801 to correspond to an area different from the imaging region to the measurement field exclusion candidate area button 601, and displays it. This process allows the operator to confirm the results of optimizing the selection of the measurement field. The display mode of the measurement field exclusion candidate area button 601 may be the same as the display mode of the measurement field exclusion candidate area button 601 according to the second embodiment. In addition, in step S802, the control unit 211 may change the selection state of the measurement field area button 403 or the measurement field exclusion candidate area button 601 in response to an input by the operator via the operation unit 113.

[0098] In step S803, the setting unit 215 updates the setting of the information on the irradiation field area used for automatic exposure control included in the imaging procedure by deselecting the irradiation field area button 403 corresponding to the irradiation field exclusion candidate area button 601. This completes the processes in the flowchart of FIG.

[0099] As described above, in this embodiment, the determination unit 216 determines candidate regions not to be used in automatic exposure control using previously captured radiographic images of the subject and information indicating the imaging region to be imaged. More specifically, the determination unit 216 determines, as the candidate region, a region corresponding to a region different from the imaging region in the previously captured radiographic images of the subject. Therefore, in the radiation imaging system 100 according to this embodiment, when a radiation field that should not have been selected in the selection of radiation fields for imaging under automatic exposure control is selected, the selection of radiation fields to be used in automatic exposure control can be optimized based on information about the imaging region included in the imaging procedure. This allows the desired time until radiation irradiation is stopped at the dose that is the threshold in automatic exposure control, thereby enabling the patient to be irradiated with an appropriate dose of radiation.

[0100] The process of optimizing the selection of the measurement area according to this embodiment may include the process of determining the calculation related to the automatic exposure control in step S512, as described in the first and second embodiments. In this case, the process of step S512 can be performed before the process of step S802. In this configuration, the setting unit 215 can reset the detection area based on the candidate areas not used in automatic exposure control and the information on the calculation related to automatic exposure control.

[0101] Furthermore, similarly to the first embodiment, if the calculation is determined to be "OR" in step S512, the processing of step S514 may be performed. Furthermore, when the irradiation field exclusion candidate region button 601 is displayed in step S802, a warning similar to that of step S514 may be displayed. Note that the function of displaying the warning may be controlled to be enabled or disabled as appropriate, as described in the first embodiment.

[0102] Furthermore, the calculation may include “AVG (average).” The process when the calculation is determined to be “AVG” in step S512 may be the same as the process when the calculation is determined to be “AND.”

[0103] [Other embodiments] The present disclosure can also be realized by providing a program that implements one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that implements one or more functions. A computer may have one or more processors or circuits, and may include multiple separate computers or a network of multiple separate processors or circuits to read and execute computer-executable instructions.

[0104] The processor or circuitry may include a central processing unit (CPU), a microprocessing unit (MPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), or a field programmable gateway (FPGA). The processor or circuitry may also include a digital signal processor (DSP), a data flow processor (DFP), or a neural processing unit (NPU).

[0105] The above disclosure includes the following configurations, methods, and programs. (Configuration 1) a setting unit that sets a detection area used for automatic exposure control of radiation using information from a radiation detection unit that detects radiation; a determination unit that determines candidates for areas not to be used in the automatic exposure control from among the set detection areas using radiation images of the subject captured in the past; Equipped with The setting unit resets the detection area based on the candidate. (Configuration 2) 2. The control device according to configuration 1, wherein the setting unit resets the detection area based on the candidate and information on calculations related to the automatic exposure control. (Configuration 3) The setting unit If the information of the calculation related to the automatic exposure control indicates a logical product or an average, the candidate is removed from the detection area; 3. The control device according to configuration 2, wherein when the information of the calculation related to the automatic exposure control indicates a logical sum, the candidate is not removed from the detection area. (Configuration 4) 4. The control device according to any one of configurations 1 to 3, wherein the determining unit determines, as the candidate, an area corresponding to an area having a different radiation absorption rate in the previously captured radiographic image of the subject. (Configuration 5) 5. The control device according to configuration 4, wherein the determining unit identifies regions with different radiation absorption rates by performing part recognition or histogram analysis on the previously captured radiation image of the subject. (Configuration 6) 2. The control device according to configuration 1, wherein the determining unit determines the candidate by using the previously captured radiation image of the subject and information indicating an imaging region to be imaged. (Configuration 7) 7. The control device according to configuration 6, wherein the determining unit determines, as the candidate, a region corresponding to a region different from the imaging region in the previously captured radiation image of the subject. (Configuration 8) 8. The control device according to configuration 6 or 7, wherein the setting unit resets the detection area based on the candidate and information on the calculation related to the automatic exposure control. (Configuration 9) The setting unit If the information of the calculation related to the automatic exposure control indicates a logical product or an average, the candidate is removed from the detection area; 9. The control device according to configuration 8, wherein when the information of the calculation related to the automatic exposure control indicates a logical sum, the candidate is not removed from the detection area. (Configuration 10) 10. The control device according to any one of configurations 1 to 9, further comprising a display control unit that displays, on a display unit, a detection unit area that is set using information from the radiation detection unit and the radiation image of the subject that was previously captured. (Configuration 11) 11. The control device according to configuration 10, wherein the display control unit further displays the candidates on the display unit. (Configuration 12) 12. The control device according to claim 11, wherein the display control unit displays the candidates on the display unit in a manner that distinguishes them from both an area used for the automatic exposure control and an area not used for the automatic exposure control. (Configuration 13) 10. The control device according to any one of configurations 1 to 9, further comprising a display control unit that causes a warning regarding a detection area used for automatic exposure control to be displayed on a display unit. (Configuration 14) 14. The control device according to configuration 13, wherein the display of the warning is executed in accordance with at least one of the imaging region and patient information. (Configuration 15) 15. The control device according to any one of configurations 1 to 14, wherein the setting unit resets the detection area in response to an instruction from an operator regarding the candidate. (Configuration 16) a radiation imaging device that detects radiation and includes a radiation detection unit that detects radiation for performing automatic exposure control; A control device according to any one of configurations 1 to 15; A radiation imaging system comprising: (Method 1) setting a detection area to be used for automatic exposure control of radiation using information from a radiation detection unit that detects radiation; determining candidates for areas not to be used in the automatic exposure control from among the set detection areas using radiation images of the subject captured in the past; resetting the detection area based on the candidate; A method of operating a control device, comprising: (Program 1) A program that, when executed by a computer, causes the computer to perform each step of the control device operation method described in Method 1.

[0106] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above embodiments. Inventions modified within the scope of the present disclosure and inventions equivalent to the present disclosure are also included in the present disclosure. Furthermore, the above-described embodiments and modifications can be combined as appropriate within the scope of the present disclosure. [Explanation of symbols]

[0107] 100: Radiation imaging system 110: Control device 215: Setting section 216: Judgment section

Claims

1. a setting unit that sets a detection area used for automatic exposure control of radiation using information from a radiation detection unit that detects radiation; a determination unit that determines candidates for areas not to be used in the automatic exposure control from among the set detection areas using radiation images of the subject captured in the past; Equipped with The setting unit resets the detection area based on the candidate.

2. The control device according to claim 1 , wherein the setting unit resets the detection area based on the candidate and information on the calculation related to the automatic exposure control.

3. The setting unit If the information of the calculation related to the automatic exposure control indicates a logical product or an average, the candidate is removed from the detection area; The control device according to claim 2 , wherein when the information of the calculation related to the automatic exposure control indicates a logical sum, the candidate is not removed from the detection area.

4. The control device according to claim 1 , wherein the determining unit determines, as the candidate, an area corresponding to an area having a different radiation absorption rate in the previously captured radiographic image of the subject.

5. The control device according to claim 4 , wherein the determining unit identifies the region having a different radiation absorption rate by performing part recognition or histogram analysis on the previously captured radiographic image of the subject.

6. The control device according to claim 1 , wherein the determining unit determines the candidate by using the previously captured radiographic image of the subject and information indicating an imaging region to be imaged.

7. The control device according to claim 6 , wherein the determining unit determines, as the candidate, a region corresponding to a region different from the imaging portion in the previously captured radiation image of the subject.

8. The control device according to claim 6 , wherein the setting unit resets the detection area based on the candidate and information on the calculation related to the automatic exposure control.

9. The setting unit If the information of the calculation related to the automatic exposure control indicates a logical product or an average, the candidate is removed from the detection area; The control device according to claim 8 , wherein when the information of the calculation related to the automatic exposure control indicates a logical sum, the candidate is not removed from the detection area.

10. The control device according to claim 1 , further comprising a display control unit that causes a detection unit area set using information from the radiation detection unit and the previously captured radiation image of the subject to be displayed on a display unit.

11. The control device according to claim 10 , wherein the display control unit further causes the display unit to display the candidates.

12. The control device according to claim 11 , wherein the display control unit causes the display unit to display the candidates in a manner that distinguishes them from both an area used for the automatic exposure control and an area not used for the automatic exposure control.

13. The control device according to claim 1 , further comprising a display control unit that causes a warning regarding the detection area used for automatic exposure control to be displayed on the display unit.

14. The control device according to claim 13 , wherein the warning display is executed in accordance with at least one of an imaging region and patient information.

15. The control device according to claim 1 , wherein the setting unit resets the detection area in response to an instruction from an operator regarding the candidate.

16. a radiation imaging device that detects radiation and includes a radiation detection unit that detects radiation for performing automatic exposure control; A control device according to any one of claims 1 to 15; A radiation imaging system comprising:

17. setting a detection area to be used for automatic exposure control of radiation using information from a radiation detection unit that detects radiation; determining candidates for areas not to be used in the automatic exposure control from among the set detection areas using radiation images of the subject captured in the past; resetting the detection area based on the candidate; A method of operating a control device, comprising:

18. A program that, when executed by a computer, causes the computer to perform each step of the method for operating a control device according to claim 17.

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