Photographing support device, operation method for photographing support device, and operation program for photographing support device

Abstract

To provide an imaging support device capable of reducing unnecessary exposure to a subject, an operation method of the imaging support device, and an operation program of the imaging support device.SOLUTION: A CPU of a console includes a first acquisition part, a second acquisition part, a specification part, and an extraction part. The first acquisition part acquires designation information on a measurement object portion for bone density of a subject. The second acquisition part acquires an optical image acquired by imaging the subject undergoing radiography with a camera. The specification part specifies a region of the measurement object portion in the optical image on the basis of the designation information. The extraction part extracts a region in a radiograph corresponding to the region of the measurement object portion as a measurement region for the bone density on the basis of correspondence information between a pixel of the radiograph and a pixel of the optical image.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The technology of the present disclosure relates to a photography support device, an operation method for a photography support device, and an operation program for a photography support device. [Background technology]

[0002] Dual-energy X-ray absorptiometry (DEXA) is a method that takes advantage of the difference in radiation absorption between bone tissue and soft tissue, for example, by irradiating a subject with two types of radiation with different energies to obtain two radiological images and measuring the subject's bone density. This DEXA method can contribute to the diagnosis and treatment of osteoporosis, which is a major cause of bedriddenness.

[0003] Conventionally, in radiography using the DEXA method, a pre-radiography is performed in which a subject is irradiated with a low dose of radiation prior to the actual radiography for measuring bone density. Then, using the radiographic image obtained in the pre-radiography, an operator such as a diagnostic radiologist manually specifies a bone density measurement region (for example, a region surrounding the femoral neck or lumbar vertebrae). Therefore, Patent Document 1 proposes a technology that reduces the burden on the operator by automatically extracting a bone density measurement region from the radiographic image obtained in the pre-radiography. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-217227 Summary of the Invention [Problem to be solved by the invention]

[0005] Both the conventional method in which an operator manually specifies a bone density measurement region using a radiographic image obtained in a pre-radiography and the method described in Patent Document 1 in which a bone density measurement region is automatically extracted from a radiographic image obtained in a pre-radiography are based on the premise that a pre-radiography is performed by irradiating radiation. Therefore, both methods still expose the subject to unnecessary radiation exposure in addition to the actual radiography.

[0006] One embodiment of the technique of the present disclosure provides a photography support device, an operation method for the photography support device, and an operation program for the photography support device, which are capable of reducing unnecessary exposure to a subject. [Means for solving the problem]

[0007] The imaging support device disclosed herein is an imaging support device that supports radiography to obtain radiographic images for measuring the bone density of a subject, and is equipped with a processor. The processor acquires designation information for the area to be measured for bone density, acquires an optical image obtained by photographing the subject undergoing radiography with a camera, identifies the area of ​​the area to be measured in the optical image based on the designation information, and extracts the area in the radiographic image corresponding to the area to be measured as the bone density measurement area based on the correspondence between the pixels of the radiographic image and the pixels of the optical image.

[0008] The processor preferably identifies the region of the measurement target portion by performing a semantic segmentation process for identifying objects on the optical image.

[0009] If the area of ​​the region of the measurement target part identified by the semantic segmentation process is less than a predetermined threshold, the processor preferably determines that the positioning of the subject is inappropriate and outputs information according to the determination result.

[0010] It is preferable that the processor performs a feature point extraction process on the optical image to extract feature points, and identifies the region of the measurement target portion based on the feature points.

[0011] When radiography is performed again on a subject that has previously been radiographed, it is preferable that the processor controls the display to superimpose the previous optical image obtained during the previous radiography on the current optical image during preparation for radiography before the radiography.

[0012] It is preferable that the apparatus has a position adjustment support function that supports adjustment of the position of the radiation source that irradiates radiation during preparation for radiography, and further that the radiation source is provided with a light source that irradiates position indication light that indicates the position of the radiation source, and that the processor, during preparation for radiography, causes the light source to emit the position indication light, photographs the subject irradiated with the position indication light with a camera, acquires an optical image, and controls the display to superimpose a mark that is affixed to an area of ​​the measurement target portion identified based on the optical image and indicates a target point for the position of the radiation source on the optical image, thereby realizing the position adjustment support function.

[0013] The operating method of the imaging support device disclosed herein is a method for operating an imaging support device that supports radiography to obtain radiographic images for measuring the bone density of a subject, and includes obtaining specified information for the area to be measured for bone density, obtaining an optical image obtained by photographing the subject undergoing radiography with a camera, identifying the area of ​​the area to be measured in the optical image based on the specified information, and extracting an area in the radiographic image corresponding to the area of ​​the area to be measured as a bone density measurement area based on the correspondence between the pixels of the radiographic image and the pixels of the optical image.

[0014] The operating program of the imaging support device disclosed herein is an operating program of an imaging support device that supports radiography to obtain radiographic images for measuring the bone density of a subject, and causes a computer to perform processing including obtaining specified information for the area to be measured for bone density, obtaining an optical image obtained by photographing the subject undergoing radiography with a camera, identifying the area of ​​the area to be measured in the optical image based on the specified information, and extracting the area in the radiographic image corresponding to the area of ​​the area to be measured as the bone density measurement area based on the correspondence between the pixels of the radiographic image and the pixels of the optical image. [Effects of the Invention]

[0015] According to the technology of the present disclosure, it is possible to provide a photography support device, an operation method for a photography support device, and an operation program for a photography support device that are capable of reducing unnecessary exposure to a subject. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a diagram illustrating a radiography system. [Figure 2] FIG. 1 is a diagram showing radiation seen from the craniocaudal direction of a subject. [Figure 3] FIG. 1 is a diagram showing how an optical image is captured by a camera. [Figure 4] 1A and 1B are diagrams illustrating how radiation is captured and how a radiation image is generated. [Figure 5] FIG. 2 is a diagram illustrating the internal configuration of a radiation image detector. [Figure 6] FIG. 2 is a block diagram showing the configuration of a console. [Figure 7] FIG. 2 is a block diagram showing a processing unit of a CPU of the console. [Figure 8] FIG. 10 is a diagram illustrating processing by an identification unit. [Figure 9] FIG. 10 is a diagram illustrating the processing of an extraction unit and a calculation unit. [Figure 10] FIG. 10 is a diagram showing a measurement result display screen. [Figure 11] 10 is a flowchart showing a processing procedure of the console. [Figure 12] 10 is a flowchart showing a processing procedure of the console. [Figure 13] 10A and 10B are diagrams illustrating a second embodiment in which it is determined whether the positioning of a subject is appropriate or not based on the area of ​​the region of the measurement target portion. [Figure 14] 14A and 14B show the processing of the determination unit, where FIG. 14A shows the case where the area of ​​the region to be measured is equal to or greater than the threshold, and FIG. 14B shows the case where the area of ​​the region to be measured is less than the threshold. [Figure 15]FIG. 10 is a diagram showing the processing of the determination unit, and is a diagram showing another example of a case where it is determined that the positioning of the subject is inappropriate. [Figure 16] FIG. 10 is a diagram showing an information display screen when the area of ​​the region to be measured is less than a threshold value. [Figure 17] 10A and 10B are diagrams illustrating a state in which a feature point extraction process for extracting feature points is performed on an optical image. [Figure 18] FIG. 10 is a diagram showing how a region of a measurement target part is specified based on feature points. [Figure 19] FIG. 10 is a diagram showing how a region of a measurement target part is specified based on feature points. [Figure 20] 10A and 10B are diagrams illustrating a fourth embodiment in which control is performed to display a past optical image superimposed on a current optical image on a display. [Figure 21] FIG. 10 is a diagram showing an information display screen on which a past optical image is displayed superimposed on a current optical image. [Figure 22] FIG. 10 is a diagram showing a light source that emits position indication light that indicates the position of a radiation source. [Figure 23] FIG. 10 is a diagram illustrating an overview of a position adjustment support function that supports the position adjustment of a radiation source. [Figure 24] FIG. 10 is a diagram showing an information display screen on which a mark indicating a target point for the position of a radiation source is superimposed on an optical image obtained by photographing an object irradiated with position indication light using a camera. DETAILED DESCRIPTION OF THE INVENTION

[0017] [First embodiment] As an example, as shown in FIG. 1, a radiography system 2 is a system that performs radiography of a subject H using radiation R such as X-rays or gamma rays in order to measure the bone density of the subject H, and is composed of a radiography apparatus 10 and a radiation generation apparatus 11. The radiography apparatus 10 has a supine position imaging table 12, a radiation image detector 13, and a console 14. The radiation generation apparatus 11 has a radiation source 15, a radiation source control device 16, a tube voltage generator 17, and an exposure switch 18. A camera 19 is attached to the radiation source 15.

[0018] The supine position radiography table 12 is an imaging table for radiography of a subject H in a supine position. The top plate of the supine position radiography table 12 has a size that allows an adult male to comfortably assume a supine position.

[0019] A radiological image detector 13 is built into the top plate of the supine position imaging table 12. The radiological image detector 13 is sized to cover substantially the entire surface of the top plate of the supine position imaging table 12 (see also FIG. 2). The radiological image detector 13 detects a radiological image 30 (see FIG. 4) corresponding to radiation R that has passed through the subject H. The radiological image detector 13 is connected to the console 14 by wire or wirelessly so as to be able to communicate with it.

[0020] The radiation image detector 13 has a first detection panel 41 and a second detection panel 43 (both see FIG. 5 ) in which a plurality of pixels that accumulate charges according to radiation R are arranged in a two-dimensional matrix. The first detection panel 41 and the second detection panel 43 are also called FPDs (Flat Panel Detectors). When irradiation of radiation R begins, the first detection panel 41 and the second detection panel 43 start an accumulation operation to accumulate charges in the pixels. When irradiation of radiation R ends, the first detection panel 41 and the second detection panel 43 start a readout operation to read out the charges accumulated in the pixels as electrical signals.

[0021] The console 14 is, for example, a desktop personal computer and is an example of an "imaging support device" according to the technology of the present disclosure. The console 14 has a display 20 that displays various screens and an input device 21 that includes a keyboard, a mouse, etc. and receives operation instructions from an operator such as a diagnostic radiologist. The console 14 transmits various signals to the radiological image detector 13. The console 14 also receives radiological images 30 from the radiological image detector 13. The console 14 displays the radiological images 30 on the display 20. The display 20 is an example of a "display" according to the technology of the present disclosure. The console 14 may also be a notebook personal computer, a tablet terminal, etc.

[0022] The radiation source 15 is connected to the supine position imaging table 12 via a C-arm or the like (not shown). The distance between the radiation source 15 and the top of the supine position imaging table 12, and therefore the source to image receptor distance (SID), which is the distance from the point of generation of the radiation R to the detection surface of the radiation image detector 13, is fixed. On the other hand, the radiation source 15 is movable in the craniocaudal direction of the subject H (in the direction of the long side of the supine position imaging table 12) as indicated by the double arrow. The radiation source 15 is also movable in the left-right direction of the subject H (in the direction of the short side of the supine position imaging table 12), which is perpendicular to the plane of the drawing. The position of the radiation source 15 in the craniocaudal and left-right directions of the subject H is detected by, for example, a linear encoder.

[0023] The radiation source 15 has a radiation tube 22 and an irradiation field limiter 23. The radiation tube 22 is provided with a filament, a target, a grid electrode, etc. (all not shown). A voltage is applied between the filament, which is the cathode, and the target, which is the anode. The voltage applied between this filament and the target is called the tube voltage. The filament emits thermoelectrons toward the target in accordance with the applied tube voltage. The target emits radiation R due to collisions of the thermoelectrons from the filament. The grid electrode is disposed between the filament and the target. The grid electrode changes the flow rate of thermoelectrons from the filament toward the target in accordance with the applied voltage. The flow rate of thermoelectrons from the filament toward the target is called the tube current.

[0024] The irradiation field limiter 23 is also called a collimator, and limits the irradiation field of the radiation R emitted from the radiation tube 22. The irradiation field limiter 23 is configured, for example, such that four shielding plates made of lead or the like that block the radiation R are arranged on each side of a rectangle, and a rectangular exit opening that transmits the radiation R is formed in the center. The irradiation field limiter 23 changes the size of the exit opening by changing the position of each shielding plate, thereby changing the irradiation field of the radiation R.

[0025] The irradiation field limiter 23 narrows the irradiation width of the radiation R in the cranial-caudal direction of the subject H in order to narrow the range of the irradiation angle of the radiation R in the cranial-caudal direction of the subject H. On the other hand, as shown in FIG. 2 as an example, the irradiation field limiter 23 does not narrow the irradiation width of the radiation R in the left-right direction of the subject H, but sets it to about the width of the radiological image detector 13.

[0026] A tube voltage generator 17 and an exposure switch 18 are connected to the radiation source controller 16. The radiation source controller 16 controls the operation of the radiation source 15 in response to various instruction signals from the exposure switch 18. The exposure switch 18 is operated when an operator instructs the radiation source 15 to start irradiating radiation R.

[0027] The radiation source control device 16 is set with radiation R irradiation conditions 63 (see FIG. 6). The irradiation conditions 63 include the tube voltage and tube current to be applied to the radiation tube 22, and the irradiation time of radiation R (see FIG. 6). When an instruction to start irradiating radiation R is given by operating the irradiation switch 18, the radiation source control device 16 operates the tube voltage generator 17 in accordance with the set irradiation conditions 63, causing the radiation tube 22 to irradiate radiation R. After the start of irradiation of radiation R, when the irradiation time set in the irradiation conditions 63 has elapsed, the radiation source control device 16 stops the irradiation of radiation R from the radiation tube 22. The tube voltage generator 17 generates a tube voltage by boosting the input voltage using a transformer. The tube voltage generated by the tube voltage generator 17 is supplied to the radiation tube 22 via a voltage cable (not shown).

[0028] The irradiation of radiation R may be terminated by an auto exposure control (AEC) function. The AEC function detects the dose of radiation R during irradiation of radiation R, and stops the irradiation of radiation R from the radiation tube 22 when the cumulative dose, which is the integrated value of the detected dose, reaches a preset target dose. In this case, the first detection panel 41 and the second detection panel 43 of the radiation image detector 13 start a readout operation when the cumulative dose of radiation R reaches the target dose.

[0029] The camera 19 is a digital camera that captures a digital optical image 25 (see FIG. 3 ). The camera 19 is attached to the center of the tip of the irradiation field limiter 23 of the radiation source 15. The camera 19 is communicably connected to the console 14 via a wire or wirelessly. The camera 19 captures an image of the subject H lying supine on the supine position imaging table 12 for radiography in accordance with an imaging instruction from the console 14. The instruction to capture the optical image 25 to the camera 19 via the console 14 is given by an operator, for example, after guiding the subject H from a waiting room to a radiography room and having the subject H lie supine on the supine position imaging table 12. The camera 19 transmits the captured optical image 25 to the console 14. The camera 19 may be built into the irradiation field limiter 23. The camera 19 may also be attached to the ceiling or wall of the radiography room, rather than to the radiation source 15.

[0030] 3 shows an example of how the camera 19 captures an image of the subject H lying supine on the supine position imaging table 12 in response to an operator's imaging instructions. In this case, the radiation source 15, and therefore the camera 19, are located at a home position, which is the center position of the long and short sides of the supine position imaging table 12. At this home position, the camera 19 has a field of view (FOV) that allows it to capture a complete image of the entire body of the subject H lying supine on the supine position imaging table 12 and the entire radiation image detector 13 built into the top plate of the supine position imaging table 12. An optical image 25 captured by the camera 19 in this manner captures the entire body of the subject H lying supine on the supine position imaging table 12 and the entire radiation image detector 13 built into the top plate of the supine position imaging table 12.

[0031] As an example, as shown in FIG. 4, during radiography, the radiation source 15, and in turn the radiation tube 22, are moved in the craniocaudal direction from the toes to the parietal region of the subject H under the control of the radiation source control device 16. During this process, the radiation tube 22 irradiates the subject H with radiation R in pulses a total of 10 times under the control of the radiation source control device 16. The radiation image detector 13 outputs a fragmentary radiation image 30A each time radiation R is irradiated. By stitching together these fragmentary radiation images 30A, a single radiation image 30 covering the entire skeleton of the subject H can be obtained. Conversely to the example, the radiation source 15 (radiation tube 22) may be moved from the parietal region to the toes of the subject H. It is also possible to pinpoint an image of a specific region, such as the femoral neck, rather than the entire body (see the fifth embodiment).

[0032] As an example, as shown in Fig. 5, the radiological image detector 13 includes a housing 35. The housing 35 houses a first radiation detection section 36, a radiation limiting plate 37, a second radiation detection section 38, a first circuit section 39, and a second circuit section 40. The first radiation detection section 36, the radiation limiting plate 37, and the second radiation detection section 38 are stacked in this order when viewed from the front side of the housing 35 where radiation R is incident. In other words, the radiological image detector 13 is a stacked type. Specifically, the radiological image detector 13 is a product called "CALNEO Dual" (manufactured by FUJIFILM Corporation), etc.

[0033] The first radiation detection unit 36 ​​is composed of a first detection panel 41 and a first scintillator 42. The second radiation detection unit 38 is composed of a second detection panel 43 and a second scintillator 44. The first detection panel 41 and the first scintillator 42 are stacked in this order when viewed from the front side of the housing 35. In addition, the second detection panel 43 and the second scintillator 44 are stacked in this order when viewed from the front side of the housing 35.

[0034] The first scintillator 42 and the second scintillator 44 contain phosphors and convert incident radiation R into visible light and emit it. The first scintillator 42 and the second scintillator 44 contain different phosphors. The first scintillator 42 contains, for example, CsI:Tl (thallium-activated cesium iodide) as a phosphor. The second scintillator 44 contains, for example, GOS (Gd2O2S:Tb, terbium-activated gadolinium oxysulfide) as a phosphor.

[0035] The first detection panel 41 and the second detection panel 43 detect visible light emitted from the first scintillator 42 and the second scintillator 44 and convert it into an electrical signal. As described above, the first detection panel 41 and the second detection panel 43 have a plurality of pixels arranged in a two-dimensional matrix. As is well known, the pixel has a photoelectric conversion unit that generates and accumulates electric charges (electron-hole pairs) in response to incident visible light, and a switching element such as a TFT (Thin Film Transistor) that controls the accumulation of electric charges in the photoelectric conversion unit and the readout of electric charges from the photoelectric conversion unit.

[0036] The first circuit section 39 controls the driving of switching elements and the like of the first detection panel 41, and generates a first radiographic image 30_1 based on the electrical signals output from the first detection panel 41. Similarly, the second circuit section 40 controls the driving of switching elements and the like of the second detection panel 43, and generates a second radiographic image 30_2 based on the electrical signals output from the second detection panel 43. That is, in the radiography shown in FIG. 4 , two radiographic images, a first radiographic image 30_1 and a second radiographic image 30_2, are generated as a single radiographic image 30 that covers the entire skeleton of the subject H. In the following description, the first radiographic image 30_1 and the second radiographic image 30_2 will be collectively referred to as the radiographic image 30. Note that the first detection panel 41 and the first scintillator 42 may be stacked in this order when viewed from the front side of the housing 35. The same applies to the second detection panel 43 and the second scintillator 44. Furthermore, the radiation image detector 13 may be a direct conversion type that directly converts the radiation R into an electrical signal, rather than an indirect conversion type that converts the radiation R, which has been converted into visible light by the first scintillator 42 and the second scintillator 44 in this example, into an electrical signal.

[0037] The radiation limiting plate 37 limits the dose of radiation R that passes through the first radiation detection unit 36 ​​and is irradiated to the second radiation detection unit 38. The radiation limiting plate 37 is made of, for example, copper, tin, or the like. Because the radiation R is absorbed by the radiation limiting plate 37 and the first radiation detection unit 36, the second radiation detection unit 38 is irradiated with a lower dose of radiation R than the first radiation detection unit 36. Furthermore, the radiation limiting plate 37 absorbs a large amount of low-energy components (also referred to as soft-ray components) of the radiation R. Therefore, the second radiation detection unit 38 is irradiated with radiation R whose energy distribution is biased toward high-energy components (also referred to as hard-ray components). In other words, according to the radiological image detector 13, a single irradiation of radiation R can achieve the same effect as irradiating two types of radiation R with different energy distributions.

[0038] The first radiographic image 30_1 and the second radiographic image 30_2 show both bony tissues such as the ribs and spine and soft tissues such as the lungs and stomach. However, the energy of radiation R that is easily absorbed by these bony tissues and soft tissues is different. Therefore, the pixel values ​​of the bony tissues shown in the first radiographic image 30_1 and the second radiographic image 30_2 are different. The pixel values ​​of the soft tissues shown in the first radiographic image 30_1 and the second radiographic image 30_2 are also different.

[0039] The radiation image detector 13 may have a single radiation detection unit built in. In this case, for example, two radiation tubes 22 that irradiate two types of radiation R with different energies are provided in the radiation source 15. The two types of radiation R with different energies are then irradiated twice from the two radiation tubes 22, and the radiation R is detected by the radiation image detector 13 each time, thereby acquiring a first radiation image 30_1 and a second radiation image 30_2.

[0040] 6, the console 14 includes, in addition to the display 20 and input device 21, a storage 55, a memory 56, a CPU (Central Processing Unit) 57, and a communication I / F (Interface) 58. The display 20, input device 21, storage 55, memory 56, CPU 57, and communication I / F 58 are interconnected via a bus line (not shown). The storage 55, memory 56, CPU 57, and bus line are an example of a "computer" according to the technology of the present disclosure.

[0041] The storage 55 is a hard disk drive that is built into the computer that constitutes the console 14 or that is connected via a cable or network. The storage 55 stores control programs such as an operating system, various application programs, and various data associated with these programs. Note that a solid state drive may be used instead of a hard disk drive.

[0042] The memory 56 is a work memory for the CPU 57 to execute processing. The CPU 57 loads programs stored in the storage 55 into the memory 56 and executes processing in accordance with the programs. In this way, the CPU 57 comprehensively controls each part of the computer. The CPU 57 is an example of a "processor" according to the technology of the present disclosure. The memory 56 may be built into the CPU 57. The communication I / F 58 controls the transmission of various information to and from external devices such as the radiation image detector 13.

[0043] The CPU 57 receives an imaging order 61 from a Radiology Information System (RIS) 60 via the communication I / F 58. The imaging order 61 registers a subject ID (Identification Data) 131 (see FIG. 20 ) for identifying the subject H, instructions on the body part to be measured for bone density from a doctor or the like of the department who issued the imaging order 61, and the like. The CPU 57 displays the imaging order 61 on the display 20 in response to an operator's operation via the input device 21. The operator checks the contents of the imaging order 61 through the display 20.

[0044] The CPU 57 displays bone density measurement target regions on the display 20 in a selectable format. Measurement target regions include the right thigh and lumbar vertebrae as shown, as well as the right shin, left shin, left thigh, pelvis, thoracic vertebrae, and head. The operator operates the input device 21 to select a measurement target region from multiple measurement target regions that matches the measurement target region specified in the radiography order 61. This inputs measurement target region specification information 62 to the CPU 57. The limbs may also be included in the measurement target regions.

[0045] The storage 55 stores irradiation conditions 63. The CPU 57 reads out the irradiation conditions 63 from the storage 55 and transmits the read irradiation conditions 63 to the radiation source control device 16 via the communication I / F 58. As described above, the irradiation conditions 63 are the tube voltage and tube current applied to the radiation tube 22, and the irradiation time of the radiation R. Instead of the tube current and irradiation time, the irradiation condition 63 may be the product of the tube current and irradiation time.

[0046] Although not shown in the drawings, when an instruction to start irradiation of radiation R is given to the radiation source control device 16 via the irradiation switch 18, the CPU 57 receives an irradiation start signal from the radiation source control device 16, indicating that irradiation of radiation R will start. Upon receiving the irradiation start signal, the CPU 57 transmits a synchronization signal 64 indicating that irradiation of radiation R will start to the radiation image detector 13. Furthermore, the CPU 57 receives an irradiation end signal from the radiation source control device 16, indicating that irradiation of radiation R has ended. Upon receiving the irradiation end signal, the CPU 57 transmits a synchronization signal 64 indicating that irradiation of radiation R has ended to the radiation image detector 13.

[0047] When receiving a synchronization signal 64 from the console 14 indicating that irradiation of radiation R has started, the radiological image detector 13 causes the first detection panel 41 and the second detection panel 43 to start an accumulation operation. When receiving a synchronization signal 64 from the console 14 indicating that irradiation of radiation R has ended, the radiological image detector 13 causes the first detection panel 41 and the second detection panel 43 to start a readout operation. The radiological image detector 13 may have a function to detect the start and end of irradiation of radiation R. Then, when the start of irradiation of radiation R is detected using this function, the first detection panel 41 and the second detection panel 43 may start an accumulation operation, and when the end of irradiation of radiation R is detected, the first detection panel 41 and the second detection panel 43 may start a readout operation.

[0048] The CPU 57 receives the radiographic image 30 from the radiographic image detector 13 via the communication I / F 58. The CPU 57 performs various image processing on the radiographic image 30, and then displays the radiographic image 30 on the display 20 for viewing by the operator. The CPU 57 also measures the bone density of the measurement target site designated by the designation information 62 based on the radiographic image 30, and displays the measurement results on the display 20 for viewing by the operator.

[0049] Although not shown in the drawing, the CPU 57 transmits a shooting instruction to the camera 19 via the communication I / F 58. The CPU 57 receives the optical image 25 captured by the camera 19 in response to this shooting instruction.

[0050] As an example, as shown in FIG. 7, an operating program 70 is stored in the storage 55. The operating program 70 is an application program for causing a computer to function as a photography support device. In other words, the operating program 70 is an example of an "operating program for a photography support device" according to the technology of the present disclosure. The storage 55 also stores a semantic segmentation (hereinafter referred to as SS) model 71, correspondence relationship information 72, and the like.

[0051] When the operating program 70 is started, the CPU 57, in cooperation with the memory 56 and the like, functions as a first acquisition unit 75, a second acquisition unit 76, a third acquisition unit 77, an identification unit 78, an extraction unit 79, a calculation unit 80, and a display control unit 81.

[0052] The first acquisition unit 75 acquires designation information 62 of the measurement target region designated through the input device 21, and outputs the designation information 62 to the identification unit 78. The second acquisition unit 76 acquires an optical image 25 from the camera 19. The second acquisition unit 76 outputs the optical image 25 to the identification unit 78. The third acquisition unit 77 acquires a radiological image 30 from the radiological image detector 13. The third acquisition unit 77 outputs the radiological image 30 to the calculation unit 80 and the display control unit 81.

[0053] The identification unit 78 performs SS processing on the optical image 25 to identify an object using the SS model 71, thereby identifying an area SA (see FIG. 8) of the measurement target portion in the optical image 25. The identification unit 78 outputs to the extraction unit 79 identified area information 85, which is information on the identified area SA of the measurement target portion.

[0054] The extraction unit 79 extracts, as a bone density measurement area EA (see FIG. 9 ), an area in the radiographic image 30 that corresponds to the area SA of the identified measurement site, based on the correspondence relationship information 72 and the identified area information 85. The extraction unit 79 outputs extracted area information 86, which is information on the extracted bone density measurement area EA, to the calculation unit 80.

[0055] The calculation unit 80 calculates the bone density of the measurement area EA represented by the extraction area information 86 in the radiological image 30 using, for example, a method described in JP 2018-192056 A. The calculation unit 80 outputs bone density information 87, which is information about the calculated bone density, to the display control unit 81.

[0056] The display control unit 81 controls the display of various screens on the display 20. The various screens include a screen for displaying the radiography order 61, a screen for specifying the measurement target region, and a measurement result display screen 95 (see FIG. 10) showing the measurement results of bone density. Although not shown, in addition to these processing units 75 to 81, the CPU 57 also includes a reception unit (see FIG. 20) that receives the radiography order 61 from the RIS 60, an image processing unit that performs various image processing on the radiographic image 30, and a setting unit that sets the irradiation conditions 63 in the radiation source control device 16.

[0057] In the following, an example will be described in which the right thigh and lumbar vertebrae are designated as the measurement target regions.

[0058] 8, as an example, the identification unit 78 inputs the optical image 25 to the SS model 71 and causes the SS model 71 to output an SS image 90. The SS model 71 is a machine learning model trained to identify, on a pixel-by-pixel basis, the regions MTA of all measurement target parts (right shin, left shin, right thigh, left thigh, pelvis, thoracic vertebrae, and head) of the subject H appearing in the optical image 25, and is configured, for example, by a convolutional neural network.

[0059] The identification unit 78 identifies, in the SS image 90, the region MTA of the measurement target region designated by the designation information 62, among the regions MTA of each measurement target region identified by the SS model 71, as the region SA of the measurement target region. In this case, the designated measurement target region is the right thigh and lumbar vertebrae, and therefore the identification unit 78 identifies the region MTA of the right thigh and lumbar vertebrae as the region SA of the measurement target region. Then, coordinate information of pixels OI(X, Y) (see FIG. 9) constituting the region MTA of the right thigh and lumbar vertebrae is output to the extraction unit 79 as identified region information 85. The X axis is the direction along the short side of the supine position imaging table 12, and the Y axis is the direction along the long side of the supine position imaging table 12.

[0060] As an example, as shown in FIG. 9, the correspondence information 72 includes a function F that converts pixels OI(X,Y) in an optical image 25 captured by the camera 19 at the home position shown in FIG. 3 into pixels RI(x,y) in a radiographic image 30. The extraction unit 79 extracts a bone density measurement area EA by converting each pixel OI(X,Y) in an area SA of the measurement target site in the specific area information 85 into a pixel RI(x,y) using this function F. The extracted area information 86 is coordinate information of the pixels RI(x,y) in the bone density measurement area EA thus extracted, in this case the area of ​​the right thigh and lumbar vertebrae. The x-axis is the direction along the short side of the supine position imaging table 12, and the y-axis is the direction along the long side of the supine position imaging table 12.

[0061] 9, the calculation unit 80 calculates the bone density of the right thigh and lumbar vertebrae based on extracted region information 86 indicating the region SA of the right thigh and lumbar vertebrae. The unit of bone density is g / cm. 2 is.

[0062] As an example, as shown in FIG. 10, a measurement result display screen 95 displays a cutout image 96, detailed information 97, and a graph 98 for each measurement site. The cutout image 96 is an image of the measurement site cut out from the radiation image 30. The detailed information 97 displays the measurement site, bone density, bone density comparison with the same age, and bone density comparison with young adults. The bone density comparison with the same age is a comparison between subject H and the average bone density of other subjects H of the same age. The bone density comparison with young adults is a comparison with the average bone density of adults aged 20 to 44. The graph 98 has age on the horizontal axis and bone density and young adult comparison on the vertical axis. A point 99 indicating the bone density of subject H is plotted on the graph 98.

[0063] A save button 100, a print button 101, and a close button 102 are provided at the bottom of the measurement result display screen 95. When the save button 100 is selected, the bone density measurement results are stored in the storage 55. The bone density measurement results stored in the storage 55 are registered, for example, in an electronic medical record of an electronic medical record system connected to the console 14 via a network. When the print button 101 is selected, the content displayed on the measurement result display screen 95 is printed on paper media. The paper media is distributed to the subject H. When the close button 102 is selected, the measurement result display screen 95 is closed.

[0064] Next, the operation of the above configuration will be described with reference to the flowcharts shown in Figures 11 and 12 as an example. Prior to radiography, the operator performs radiography preparation work. The radiography preparation work includes designating the region to be measured for bone density, setting the irradiation conditions 63 for radiation R, and positioning the subject H (adjusting the position and posture relative to the radiographic image detector 13 and radiation source 15), etc.

[0065] In the console 14, the operating program 70 is started, causing the CPU 57 to function as a first acquisition unit 75, a second acquisition unit 76, a third acquisition unit 77, an identification unit 78, an extraction unit 79, a calculation unit 80, and a display control unit 81. First, as shown in FIG. 11 , the operator operates the console 14 to designate a region to be measured for bone density according to the subject H to be radiographed. As a result, the first acquisition unit 75 acquires designation information 62 (step ST100). The designation information 62 is output from the first acquisition unit 75 to the identification unit 78.

[0066] The operator operates the console 14 to set the irradiation conditions 63 for the radiation R. Thereafter, the operator guides the subject H from the waiting room to the radiography room. The operator positions the subject H by having the subject H lie supine on the supine position radiography table 12. After the positioning of the subject H is complete, the operator operates the console 14 to issue an instruction to capture an optical image 25 (YES in step ST110). The instruction to capture is transmitted from the console 14 to the camera 19 (step ST120). As a result, the optical image 25 is captured by the camera 19, as shown in FIG. 3.

[0067] The optical image 25 from the camera 19 is acquired by the second acquisition unit 76 (step ST130). The optical image 25 is output from the second acquisition unit 76 to the identification unit 78.

[0068] 8, in the identification unit 78, SS processing using the SS model 71 is performed on the optical image 25, and an SS image 90 in which the area MTA of each measurement target part is identified is output. Then, of the areas MTA of each measurement target part, the area MTA of the measurement target part designated by the designation information 62 is identified as the area SA of the measurement target part (step ST140). Identified area information 85, which is coordinate information of the area SA of the measurement target part, is output from the identification unit 78 to the extraction unit 79.

[0069] 9, the extraction unit 79 extracts an area in the radiographic image 30 corresponding to the area SA of the measurement target site as a bone density measurement area EA based on the correspondence relationship information 72 and the specific area information 85 (step ST150). Extraction area information 86, which is coordinate information of the bone density measurement area EA, is output from the extraction unit 79 to the calculation unit 80.

[0070] The operator instructs the subject H to take a breath and hold it. Thereafter, the operator operates the irradiation switch 18 to instruct the radiation source 15 to start irradiating the radiation R. As a result, the radiation source 15 irradiates the radiation R toward the subject H.

[0071] The radiation R that has passed through the subject H reaches the radiation image detector 13. The radiation R is then detected by the radiation image detector 13 as a radiation image 30. The radiation image 30 is output from the radiation image detector 13 to the console 14. As shown in FIG. 12 , in the console 14, the third acquisition unit 77 acquires the radiation image 30 (step ST200). The radiation image 30 is subjected to various image processing, and then output to the calculation unit 80 and the display control unit 81.

[0072] 9, the calculation unit 80 calculates the bone mineral density of the measurement area EA (step ST210). The bone mineral density information 87 obtained in this way is output from the calculation unit 80 to the display control unit 81.

[0073] As shown in FIG. 10, under the control of the display control unit 81, the measurement result display screen 95 is displayed on the display 20, and the measurement results of bone density are made available for viewing by the operator (step ST220).

[0074] As described above, the CPU 57 of the console 14 includes a first acquisition unit 75, a second acquisition unit 76, an identification unit 78, and an extraction unit 79. The first acquisition unit 75 acquires designation information 62 of a measurement target region of the subject H for bone density. The second acquisition unit 76 acquires an optical image 25 obtained by capturing an image of the subject H undergoing radiography with the camera 19. The identification unit 78 identifies an area SA of the measurement target region in the optical image 25 based on the designation information 62. The extraction unit 79 extracts an area in the radiographic image 30 corresponding to the area SA of the measurement target region as a bone density measurement region EA based on correspondence relationship information 72 between pixels RI(x, y) of the radiographic image 30 and pixels OI(X, Y) of the optical image 25.

[0075] In this way, with the technology of the present disclosure, the bone density measurement area EA is extracted based on the optical image 25. Therefore, there is no need to perform pre-imaging by irradiating with radiation R to define the bone density measurement area EA, as in the past. This makes it possible to reduce unnecessary exposure to the subject H. Furthermore, the time required for radiography can be shortened, and stress on the subject H due to prolonged constraints can be reduced.

[0076] The identification unit 78 identifies the area SA of the measurement target part by performing SS processing for identifying an object on the optical image 25. Therefore, the area SA of the measurement target part can be identified by the simple process of inputting the optical image 25 into the SS model 71.

[0077] [Second embodiment] As an example, as shown in FIG. 13, the CPU 57 of the console 14 of the second embodiment functions as a determination unit 110 in addition to each processing unit 75 to 81 of the first embodiment (all but the second acquisition unit 76 and the display control unit 81 are not shown).

[0078] The determination unit 110 receives input of specific area information 85 from the identification unit 78. The determination unit 110 compares the area (number of pixels) of the area SA of the measurement target portion represented by the specific area information 85 with a preset threshold value TH. The determination unit 110 determines whether the positioning of the subject H is appropriate or not depending on whether the area of ​​the area SA of the measurement target portion is equal to or greater than the threshold value TH. The determination unit 110 outputs a determination result 111 indicating whether the positioning of the subject H is appropriate or not to the display control unit 81.

[0079] In the second embodiment, the second acquisition unit 76 sequentially acquires the optical images 25 output at a predetermined frame rate from the camera 19. The second acquisition unit 76 outputs the optical images 25 to the display control unit 81.

[0080] 14A, when the area of ​​area SA of the measurement target part is equal to or greater than threshold value TH, determination unit 110 outputs determination result 111 indicating that the positioning of subject H is appropriate. On the other hand, when the area of ​​area SA of the measurement target part is less than threshold value TH, determination unit 110 outputs determination result 111 indicating that the positioning of subject H is inappropriate (inappropriate). FIG. 14B illustrates an example in which the measurement target part is the right thigh, and the hand of subject H is covering the right thigh.

[0081] Fig. 15 shows another example of a case where the determining unit 110 determines that the positioning of the subject H is inappropriate. Fig. 15 illustrates a case where the measurement target part is the right thigh, as in Fig. 14, and the left thigh of the subject H overlaps the right thigh.

[0082] 16, an information display screen 115 is displayed on the display 20 under the control of the display control unit 81. The information display screen 115 has a display area 116 for specified information 62 and a display area 117 for irradiation conditions 63. In the display area 116, sets of specified information 62 input up to that point, subject ID 131 (P0001, P0002, etc.), and the name of subject H are displayed side by side. The specified information 62 currently being used for radiography is displayed in a different color from the other specified information 62, as indicated by hatching. In the display area 117, the tube voltage, tube current, and irradiation time of the irradiation conditions 63 are displayed in an adjustable state.

[0083] The information display screen 115 also has a display area 118 for the optical image 25 and a display area 119 for information corresponding to the determination result 111. The display control unit 81 displays the optical image 25 output from the camera 19 at a predetermined frame rate in the display area 118 while sequentially updating the optical image 25. In other words, the optical image 25 displayed in the display area 118 is a live view image (moving image).

[0084] 16 shows the information display screen 115 in the case of FIG. 14B in which the subject H's hand is covering the right thigh and the determination unit 110 has determined that the positioning of the subject H is inappropriate. In this case, an exclamation mark 120 and a message 121 indicating that the positioning of the subject H is inappropriate are displayed in the display area 119. In this case, the operator instructs the subject H to remove his hand from the right thigh. Although not shown in the figure, if the determination unit 110 has determined that the positioning of the subject H is appropriate, the display area 119 may display, for example, a circle and a message indicating that the positioning of the subject H is appropriate.

[0085] As described above, in the second embodiment, the determination unit 110 determines that the positioning of the subject H is inappropriate if the area of ​​the region SA of the measurement target site is less than the preset threshold value TH. The display control unit 81 outputs information corresponding to the determination result 111 by displaying an exclamation mark 120 and a message 121 in the display region 119. This makes it possible to easily determine whether the positioning of the subject H is appropriate without requiring the operator to do anything. This can prevent radiography from being performed with the subject H inappropriately positioned, resulting in an imaging failure and subject H being exposed to unnecessary radiation. This also increases the likelihood of obtaining a radiographic image 30 suitable for diagnosis.

[0086] Although the right thigh is exemplified as the measurement target part, other measurement target parts, such as the left thigh, right shin, or left shin, may be used. Furthermore, multiple thresholds TH may be set according to the attributes of subject H, such as gender, age, and body type.

[0087] Instead of or in addition to notifying the subject H that the positioning is inappropriate through the information display screen 115, the subject H may be notified by voice. Alternatively, the subject H may be notified by an indicator such as a warning lamp.

[0088] [Third embodiment] In the first embodiment, the area SA of the measurement target portion is identified by performing SS processing on the optical image 25, but the present invention is not limited to this.

[0089] As an example, as shown in FIG. 17 , the identification unit 78 of the third embodiment performs feature point extraction processing 125 on the optical image 25 instead of SS processing. The feature point extraction processing 125 is processing that extracts feature points 126 of the subject H captured in the optical image 25 using a well-known image recognition technique or a machine learning model. The feature points 126 are, from top to bottom, the left and right eye socket points, the left and right external auditory canal points, the left and right shoulder joint points, the left and right hip joint points, the left and right knee joint points, and the left and right ankle joint points. As is well known, the eye socket is a depression that holds the eyeball, and the eye socket point is the center point of the depression. The external auditory canal is what is commonly known as the ear hole, and the external auditory canal point is the center point of the ear hole. The shoulder joint point is the connection point between the scapula and the humerus. The hip joint point is the connection point between the ilium and the femur. The knee joint point is the connection point between the femur and the tibia. The ankle joint point is the connection point between the tibia and the talus.

[0090] 18 and 19 , after the feature point extraction process 125, the identification unit 78 performs an area identification process 127 on the optical image 25. The area identification process 127 is a process for identifying an area SA of the measurement target portion based on the feature points 126 while referring to the identification reference information 128.

[0091] FIG. 18 shows a case where the measurement target site is the right thigh. In this case, the identification reference information 128 specifies that the area enclosed by a 40-degree line L1 passing through the right hip joint, a 90-degree line L2 passing through the right knee joint, and a body surface contour line L3 is the right thigh area. The identification unit 78 draws the 40-degree line L1 passing through the right hip joint and the 90-degree line L2 passing through the right knee joint. The identification unit 78 also extracts the body surface contour of the subject H using a well-known image recognition technique or a machine learning model. The identification unit 78 identifies the area enclosed by the lines L1, L2, and the body surface contour line L3 as the right thigh area SA. The identification unit 78 then outputs coordinate information of the pixels OI(X, Y) constituting the right thigh area SA to the extraction unit 79 as identification area information 85. The angles "40°" and "90°" are angles relative to the Y axis of the optical image 25.

[0092] FIG. 19 shows a case where the measurement target site is the lumbar vertebrae. In this case, the identification reference information 128 specifies that the rectangular region RA, including a line L4 connecting the left and right hip joints and a line L5 parallel to and equal in length to line L4, has its short side width multiplied by 0.55 and its long side width multiplied by 0.4, to be the lumbar vertebrae region. Here, line L5 is a line passing through point TPP, the end of a line L7 connecting the midpoint of line L4 and the midpoint of line L6 connecting the left and right shoulder joints, multiplied by 0.8. The identification unit 78 draws lines L4 and L5, and identifies the rectangular region RA, resulting from the line L4 and line L5, with its short side width multiplied by 0.55 and its long side width multiplied by 0.4, as the lumbar vertebrae region SA. The coordinate information of pixels OI(X, Y) constituting the lumbar vertebrae region SA is then output to the extraction unit 79 as identification region information 85. The values ​​"0.55x", "0.4x", and "0.8x" are statistically determined from past data of an unspecified number of subjects H. The values ​​may be changed depending on the attributes of subject H, such as gender, age, and body type.

[0093] As described above, in the third embodiment, the identification unit 78 performs the feature point extraction process 125 on the optical image 25 to extract the feature points 126, and identifies the area SA of the measurement target portion based on the feature points 126. This method also makes it possible to identify the area SA of the measurement target portion. When performing the SS process on the optical image 25, it is necessary to prepare the SS model 71, but the third embodiment eliminates this hassle.

[0094] If the measurement target part is the head, the identification unit 78 identifies the area SA of the head using the left and right eye socket points and the left and right external auditory canal points. If the measurement target part is the pelvis, the identification unit 78 identifies the area SA of the pelvis using the hip joint points. If the measurement target part is the left and right shins, the identification unit 78 identifies the areas SA of the left and right shins using the left and right knee joint points and the left and right ankle joint points.

[0095] [Fourth embodiment] As an example, as shown in FIG. 20, the CPU 57 of the console 14 of the fourth embodiment functions as a reception unit 130 in addition to each processing unit 75 to 81 of the first embodiment (all but the second acquisition unit 76 and the display control unit 81 are not shown).

[0096] The reception unit 130 receives an imaging order 61 from the RIS 60. The reception unit 130 outputs a subject ID 131 included in the imaging order 61 to a past image database (hereinafter referred to as DB (Data Base)) 132. The past image DB 132 stores a pair of the subject ID 131 of a subject H previously radiographed by the radiation imaging system 2, and a past image 25P which is a past optical image 25 obtained by photographing the subject H with the subject ID 131 with the camera 19 during the past radiation imaging. The past image 25P is a single still image photographed with the camera 19 in response to an imaging instruction during the most recent radiation imaging.

[0097] The past image DB 132 receives the subject ID 131 from the reception unit 130, reads out the past image 25P corresponding to the subject ID 131, and transmits the read out past image 25P to the reception unit 130. The reception unit 130 outputs the past image 25P to the display control unit 81. If the subject ID 131 from the reception unit 130 has not been registered, the past image DB 132 transmits to the reception unit 130 a message that the subject ID 131 has not been registered.

[0098] Here, in the fourth embodiment, similarly to the third embodiment, the second acquisition unit 76 sequentially acquires the optical images 25 output from the camera 19 at a predetermined frame rate. The second acquisition unit 76 outputs the optical images 25 to the display control unit 81.

[0099] 21, during preparation for radiography before radiography, the display control unit 81 displays a current optical image 25 of a moving image and a past image 25P of a still image in a superimposed manner in the display area 118 of the information display screen 115. As indicated by the dashed line, the past image 25P is displayed with a transparency of, for example, 50%. If the reception unit 130 receives information that the subject ID 131 is not registered, a dialog box containing a message indicating that there is no past image 25P is displayed as a pop-up on the information display screen 115.

[0100] 21 illustrates an example in which the position of subject H in the current optical image 25 is different from the position of subject H in the previous image 25P by a threshold value or more. In this case, an exclamation mark 120 and a message 121 indicating that the positioning of subject H is inappropriate are displayed in the display area 119, as in the second embodiment.

[0101] Whether the distance between the position of subject H in the current optical image 25 and the position of subject H in the previous image 25P is equal to or greater than a threshold value is determined, for example, as follows: That is, the feature point extraction process 125 described in the third embodiment is performed on each of the current optical image 25 and the previous image 25P. Then, the distance between the feature point 126 in the current optical image 25 and the feature point 126 in the previous image 25P is calculated, and the calculated distance is compared with a preset threshold value.

[0102] As described above, in the fourth embodiment, when radiation imaging is to be performed again on the subject H who has previously been radiographed, the display control unit 81 performs control so that, during preparation for radiography before radiography, the previous image 25P, which is the optical image 25 obtained during the previous radiography, is superimposed on the current optical image 25 and displayed on the display 20. This allows the operator to easily check how much the current position of the subject H has deviated from the position of the subject H during the previous radiography. The operator can instruct the subject H to correct the positioning to eliminate the deviation from the position during the previous radiography, and can easily align the current position of the subject H with the position during the previous radiography.

[0103] As shown in Fig. 1, the irradiation width of the radiation R in the craniocaudal direction of the subject H is narrowed by the irradiation field limiter 23, but as shown in Fig. 2, the irradiation width of the radiation R in the left-right direction of the subject H is not narrowed by the irradiation field limiter 23. Therefore, if the current position of the subject H deviates left-right from the position at which the subject H was previously radiographed, the irradiation angle of the radiation R with respect to the subject H will change between the past and present, resulting in a loss of reproducibility in bone density measurements. However, according to the fourth embodiment, the current position of the subject H can be aligned with the position at which the subject H was previously radiographed, as described above, thereby ensuring reproducibility in bone density measurements.

[0104] Instead of or in addition to notifying the subject H that the positioning is inappropriate through the information display screen 115, the subject H may be notified by voice. Alternatively, the subject H may be notified by an indicator such as a warning lamp.

[0105] [Fifth embodiment] In the fifth embodiment described below, a position adjustment support function is executed to support the position adjustment of the radiation source 140 during preparation for radiography before radiography.

[0106] As an example, as shown in FIG. 22 , a radiation source 140 according to the fifth embodiment includes an irradiation field limiter 141 and a light source 142 and a mirror 143 disposed therein. The light source 142 is, for example, a semiconductor laser and is attached to the inner side surface of the irradiation field limiter 141. The light source 142 emits position indication light PL that indicates the position of the radiation source 140, more specifically, the irradiation center of the radiation R. The mirror 143 is provided in the center of the inner space of the irradiation field limiter 141 and reflects the position indication light PL emitted from the light source 142 downward. When emitting the radiation R, the mirror 143 moves out of the irradiation path of the radiation R so as not to interfere with the emission of the radiation R. The light intensity of the position indication light PL complies with the Japanese Industrial Standards regulations to prevent injury if the light accidentally enters the eyes of the subject H.

[0107] As an example, as shown in FIG. 23, the CPU 57 of the console 14 of the fifth embodiment functions as a light source control unit 145 in addition to each processing unit 75 to 81 of the first embodiment (all but the second acquisition unit 76, the identification unit 78, and the display control unit 81 are not shown).

[0108] The light source control unit 145 controls the operation of the light source 142. More specifically, the light source control unit 145 controls the light source 142 to turn on and off the position indication light PL in response to an instruction from the operator via the input device 21.

[0109] Here, in the fifth embodiment, as in the second and fourth embodiments, the second acquisition unit 76 sequentially acquires optical images 25 output from the camera 19 at a predetermined frame rate. The second acquisition unit 76 outputs the optical images 25 to the display control unit 81. When position indication light PL is irradiated from the light source 142 under the control of the light source control unit 145, the position indication light PL appears in the optical image 25 together with the subject H. The second acquisition unit 76 acquires the optical image 25 obtained by photographing the subject H irradiated with the position indication light PL using the camera 19. In addition to the optical image 25 from the second acquisition unit 76, the display control unit 81 also receives input of identified region information 85 from the identification unit 78.

[0110] 23 illustrates an example in which the measurement target portion is the femoral neck, and the femoral neck is imaged with pinpoint accuracy. In this case, the area SA of the measurement target portion is an area surrounding the femoral neck 152, including the femur 146, greater trochanter 147, femoral head 148, acetabulum 149, ilium 150, and ischium 151. The center point of the measurement target portion area SA coincides with the center point of the femoral neck 152. The center point of the measurement target portion area SA, and therefore the center point of the femoral neck 152, is the target point TP of the position of the radiation source 140.

[0111] 24, the display controller 81 displays a cross-shaped mark 155 indicating the target point TP superimposed on the optical image 25 in the display area 118. By aligning the position indicator light PL with the center of the mark 155, the position of the radiation source 140 is adjusted to a position directly above the target point TP.

[0112] 24 illustrates an example in which the position indication light PL and mark 155, i.e., the position between radiation source 140 and target point TP, deviates by more than the threshold value. In this case, an exclamation mark 120 and a message 156 indicating that the position of radiation source 140 is deviated from target point TP are displayed in display region 119.

[0113] Whether the positional deviation between the position indication light PL and the mark 155 is equal to or greater than a threshold value is determined, for example, as follows: First, using a well-known image recognition technique, the position indication light PL is extracted from the optical image 25. Then, the distance between the position indication light PL and the mark 155 is calculated, and the calculated distance is compared with a preset threshold value.

[0114] As described above, in the fifth embodiment, the radiation source 140 is provided with a light source 142 that emits position indication light PL that indicates the position of the radiation source 140. The light source control unit 145 causes the light source 142 to emit the position indication light PL when preparing to capture an image. The second acquisition unit 76 acquires an optical image 25 obtained by using the camera 19 to capture an image of the subject H irradiated with the position indication light PL. The display control unit 81 controls the display 20 to superimpose a mark 155 on the optical image 25. The mark 155 is affixed to the area SA of the measurement site identified by the identification unit 78 based on the optical image 25. The mark 155 indicates the target point TP of the position of the radiation source 140. This realizes a position adjustment assistance function that assists in adjusting the position of the radiation source 140.

[0115] The position adjustment support function makes it easy to align the position of the radiation source 140 with the target point TP. Conventionally, pre-exposure has been performed to align the position of the radiation source 140 with the target point TP, but this position adjustment support function eliminates the need for such work. In addition, it becomes possible to further reduce unnecessary radiation exposure to the subject H.

[0116] The measurement target site is not limited to the exemplary femoral neck 152, but may be, for example, the lumbar vertebrae. When the measurement target site is the lumbar vertebrae, the target point TP is, for example, the center point between the lumbar vertebrae L2 and L3.

[0117] Instead of or in addition to notifying the user through the information display screen 115 that the position of the radiation source 140 has deviated from the target point TP, the user may be notified by voice or by an indicator such as a warning lamp.

[0118] In the second and fourth embodiments, if it is determined that the positioning of the subject H is inappropriate, the radiation source 15 may be prohibited from emitting radiation R. Similarly, in the fifth embodiment, if the position of the radiation source 140 is deviated from the target point TP, the radiation source 140 may be prohibited from emitting radiation R.

[0119] The position of the camera 19 when capturing the optical image 25 is not limited to the home position, which is the center position in the long and short side directions of the supine position imaging table 12 as illustrated in Figure 3. The optical image 25 may be captured at any position. However, when capturing the optical image 25 at any position, the function F that converts the pixel OI(X, Y) of the optical image 25 into the pixel RI(x, y) of the radiographic image 30 must be modified according to the positional relationship between the camera 19 and the radiographic image detector 13.

[0120] The imaging table is not limited to the illustrated supine position imaging table 12. It may be a standing position imaging table for radiographing a subject H in a standing position, or a sitting position imaging table for radiographing a subject H in a sitting position. Furthermore, the radiation sources 15 and 140 may be of a type that is suspended from the ceiling of the radiography room.

[0121] A display may be attached to the supine position imaging platform 12, and the information display screen 115 may be displayed on the display. In this way, the information display screen 115 can be checked even near the supine position imaging platform 12. Positioning guides and the like can also be displayed on the subject H.

[0122] The SS model 71 may identify the bone itself as the region MTA of the measurement target site.

[0123] Various screens, such as the measurement result display screen 95 and the information display screen 115, may be transmitted from the console 14 to a mobile terminal, such as a tablet terminal, owned by the operator in the form of screen data for web distribution created using a markup language such as XML (Extensible Markup Language). In this case, the mobile terminal reproduces various screens to be displayed on a web browser based on the screen data and displays them on the display. Note that other data description languages, such as JSON (Javascript (registered trademark) Object Notation), may be used instead of XML.

[0124] The hardware configuration of the computer constituting the photography support device according to the technology of the present disclosure can be modified in various ways. For example, the photography support device can be configured with multiple computers separated as hardware to improve processing power and reliability. For example, the functions of the first acquisition unit 75, second acquisition unit 76, third acquisition unit 77, and identification unit 78, and the functions of the extraction unit 79, calculation unit 80, and display control unit 81 can be distributed and performed by two computers. In this case, the photography support device is configured with two computers.

[0125] In this way, the hardware configuration of the computer of the photography support device can be changed as appropriate depending on the required performance, such as processing power, safety, reliability, etc. Furthermore, not only the hardware, but also application programs such as the operating program 70 can be duplicated or stored in multiple storage devices in order to ensure safety and reliability.

[0126] In each of the above embodiments, the following various processors may be used as the hardware structure of processing units that perform various processes, such as the first acquisition unit 75, the second acquisition unit 76, the third acquisition unit 77, the identification unit 78, the extraction unit 79, the calculation unit 80, the display control unit 81, the determination unit 110, the reception unit 130, and the light source control unit 145. As described above, the various processors include the CPU 57, which is a general-purpose processor that executes software (operation program 70) and functions as various processing units, as well as dedicated electrical circuits that are processors having a circuit configuration specifically designed to perform specific processes, such as a programmable logic device (PLD) that is a processor whose circuit configuration can be changed after manufacture, such as an FPGA (Field Programmable Gate Array), and an ASIC (Application Specific Integrated Circuit).

[0127] A single processing unit may be configured with one of these various processors, or may be configured with a combination of two or more processors of the same or different types (e.g., a combination of multiple ASICs and / or a combination of an ASIC and an FPGA). Also, multiple processing units may be configured with a single processor.

[0128] Examples of configuring multiple processing units with a single processor include, first, a form in which one processor is configured with a combination of one or more CPUs and software, and this processor functions as multiple processing units, as typified by client and server computers. Second, a form in which a processor is used to realize the functions of an entire system including multiple processing units with a single IC (Integrated Circuit) chip, as typified by System on Chip (SoC). In this way, various processing units are configured using one or more of the above-mentioned various processors as a hardware structure.

[0129] Furthermore, more specifically, the hardware structure of these various processors can be an electric circuit that combines circuit elements such as semiconductor elements.

[0130] The technology of the present disclosure can be appropriately combined with the various embodiments and / or various modified examples described above. Furthermore, it is not limited to the above-described embodiments, and various configurations can be adopted without departing from the spirit of the present disclosure. Furthermore, the technology of the present disclosure extends not only to programs but also to storage media that non-temporarily store programs.

[0131] The above-described description and illustrations are a detailed explanation of the parts related to the technology of the present disclosure and are merely an example of the technology of the present disclosure. For example, the above description of the configuration, functions, actions, and effects is an explanation of an example of the configuration, functions, actions, and effects of the parts related to the technology of the present disclosure. Therefore, it goes without saying that unnecessary parts may be deleted, new elements may be added, or replacements may be made to the above-described description and illustrations within the scope of the gist of the technology of the present disclosure. Furthermore, to avoid confusion and facilitate understanding of the parts related to the technology of the present disclosure, the above-described description and illustrations omit explanations of common technical knowledge that do not require particular explanation to enable the implementation of the technology of the present disclosure.

[0132] In this specification, "A and / or B" is synonymous with "at least one of A and B." In other words, "A and / or B" means that it may be only A, only B, or a combination of A and B. Furthermore, in this specification, the same concept as "A and / or B" is also applied when three or more things are expressed connected by "and / or."

[0133] All publications, patent applications, and technical standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference. [Explanation of symbols]

[0134] 2 Radiography system 10 Radiography equipment 11 Radiation Generator 12 Recumbent photography stand 13 Electronic cassette 14 Console 15, 140 radiation source 16 Radiation source control device 17 Tube voltage generator 18 Irradiation switch 19 Camera 20 Display 21 Input Devices 22 Radiation tube 23, 141 Irradiation field limiter 25 Optical Images 25P past images 30, 30A Radiography 35 cabinet 36 First Radiation Detector 37 Radiation Restriction Plate 38 Second Radiation Detector 39 1st circuit section 40 Second circuit section 41 First detection panel 42 First Scintillator 43 Second Detection Panel 44 Second scintillator 55 Storage 56 memory 57 CPU 58 Communication I / F 60 Radiology Information System (RIS) 61 Photoshoot Order 62 Specification information 63 Irradiation conditions 64 sync signals 70 Operating Program 71 Semantic Segmentation Model (SS Model) 72 Correspondence information 75 First acquisition part 76 Second acquisition part 77 Third acquisition part 78 Specific part 79 Extraction part 80 Calculation Unit 81 Display control unit 85 Information on the area of ​​the specified measurement target part (specific area information) 86 Information on the extracted bone density measurement area (extracted area information) 87 Bone density information 90 Semantic Segmentation Images (SS Images) 95 Measurement result display screen 96 cutout images 97 More Information 98 graphs 99 Points showing the subject's bone density 100 Save button 101 Print button 102 Close button 110 Judgment section 111 Judgment result 115 Information display screen 116, 117, 118, 119 display area 120 Exclamation Mark 121, 156 Messages 125 Feature Point Extraction Processing 126 minutiae 127 Area-specific processing 128 Specific reference information 130 Reception 131 Subject ID 132 Past Image Database (Past Image DB) 142 Light source 143 Mirror 145 Light source control unit 146 Femur 147 Greater Trochanter 148 Femoral head 149 Acetabulum 150 Ilium 151 Sciatica 152 Femoral neck 155 marks EA Bone density measurement area FOV Camera field of view H Subject L1, L2, L3, L4, L5, L6, L7 line MTA Measurement target area PL position display light R Radiation RA rectangular area SA Measurement target area ST100, ST110, ST120, ST130, ST140, ST150, ST200, ST210, ST220 Step TH threshold TP target point TPP line tip point

Claims

1. An imaging support device that supports radiography for obtaining a radiographic image for measuring bone density of a subject, a processor; The processor: acquiring designation information including the name of the bone density measurement target site input by an operator; an optical image obtained by photographing the subject undergoing the radiation imaging with a camera; Identifying an area in the optical image that corresponds to the measurement target portion of the specified information; an imaging support device that extracts, based on a correspondence relationship between pixels of the radiographic image and pixels of the optical image, a region in the radiographic image that corresponds to a region of the measurement target site as the bone density measurement region;

2. The processor: The photography support device according to claim 1 , wherein the region of the measurement target portion is identified by performing semantic segmentation processing for identifying an object on the optical image.

3. The processor: If the area of ​​the region of the measurement target part identified by the semantic segmentation processing is less than a predetermined threshold, it is determined that the positioning of the subject is inappropriate; The photographing support device according to claim 2, wherein information according to the determination result is output.

4. The processor: performing a feature point extraction process on the optical image to extract feature points; The photographing support device according to claim 1 , wherein the feature points are used to identify an area in the optical image that corresponds to the measurement target portion of the designation information.

5. The processor:

5. The imaging support device according to claim 1, wherein when radiography is performed again on a subject who has previously undergone radiography, control is performed such that, during preparation for the radiography before the radiography, a past optical image obtained during the previous radiography is superimposed on a current optical image and displayed on a display.

6. a position adjustment support function for supporting adjustment of the position of a radiation source that irradiates radiation when preparing for radiography before the radiography; Furthermore, the radiation source is provided with a light source that irradiates position indication light that indicates a position of the radiation source, The processor: When preparing to photograph, the position indication light is emitted from the light source; The optical image is obtained by photographing the subject illuminated with the position indication light with the camera; 6. The imaging support device according to claim 1, wherein the position adjustment support function is realized by controlling a display to superimpose a mark on the optical image, the mark being affixed to a region of the measurement target portion identified based on the optical image and indicating a target point for the position of the radiation source.

7. A method for operating an imaging support device that supports radiography to obtain a radiographic image for measuring bone density of a subject, comprising: acquiring designation information including the name of the bone density measurement target site input by an operator; acquiring an optical image obtained by photographing the subject undergoing the radiation imaging with a camera; Identifying an area in the optical image that corresponds to the measurement target portion of the designation information; and extracting a region in the radiographic image corresponding to the region of the measurement target site as the bone density measurement region based on a correspondence relationship between pixels of the radiographic image and pixels of the optical image; A method for operating a photography support device including:

8. An operation program for an imaging support device that supports radiography to obtain a radiographic image for measuring bone density of a subject, acquiring designation information including the name of the bone density measurement target site input by an operator; acquiring an optical image obtained by photographing the subject undergoing the radiation imaging with a camera; Identifying an area in the optical image that corresponds to the measurement target portion of the designation information; and extracting a region in the radiographic image corresponding to the region of the measurement target site as the bone density measurement region based on a correspondence relationship between pixels of the radiographic image and pixels of the optical image; An operating program for a photography support device that causes a computer to execute processing including the steps of:

Images