Radiation imaging system, method for operating the radiation imaging system, and program for operating the radiation imaging system

Abstract

To provide a radiographic system, an operation method of the radiographic system and an operation program of the radiographic system which can grasp the shape of a spinal column of a subject based on an optical image along with radiography without inhibiting layout of a radiation source.SOLUTION: A radiographic system includes a radiation source which irradiates a subject with the radiation; a camera; and a console. The camera is provided in the radiation source. The camera outputs an optical image by imaging the subject irradiated with illumination light being light with uniform luminance. A CPU of the console has a first acquisition unit and a derivation unit. The first acquisition unit acquires the optical image from the camera. The derivation unit derives spinal column shape information expressing the shape of the spinal column of the subject on the basis of the optical image.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The technology of the present disclosure relates to a radiation imaging system, an operation method for a radiation imaging system, and an operation program for a radiation imaging system. [Background technology]

[0002] As part of the treatment for scoliosis, a condition in which the spine (vertebrae, backbone) curves to the left or right, the shape of the spine is determined from optical images taken with a camera. This determination of the shape of the spine based on optical images is called a primary examination. The primary examination is conducted before the secondary examination, in which the shape of the spine is determined in detail using radiological images of the entire spine to confirm the diagnosis of scoliosis. The primary examination is conducted as part of school health checkups in accordance with the School Health and Safety Act, with the aim of early detection of scoliosis.

[0003] Patent Document 1 describes a technique for deriving spinal column shape information representing the shape of a subject's spine using a moiré fringe measurement device. The moiré fringe measurement device includes a light projector that irradiates a light pattern that generates moiré fringes on the subject's back, and a camera that photographs the subject's back. The optical image captured by the camera contains moiré fringes that represent the three-dimensional shape of the subject's back. In Patent Document 1, the moiré fringes in the optical image are analyzed to derive spinal column shape information of the subject. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6280676 Summary of the Invention [Problem to be solved by the invention]

[0005] If spinal column shape could be determined based on optical images in addition to frontal chest radiography, which is almost always performed in group health checkups such as school health checkups, the examination could be completed in a shorter time and the burden on the subject could be reduced. The quickest way to achieve spinal column shape determination based on optical images in addition to frontal chest radiography would be to incorporate the moiré fringe measurement device described in Patent Document 1 into the radiation source that irradiates the subject with radiation. However, the moiré fringe measurement device described in Patent Document 1 includes a large-scale mechanism, such as a light projector that irradiates a light pattern that generates moiré fringes on the subject's back. Therefore, incorporating the moiré fringe measurement device described in Patent Document 1 into the radiation source would result in another problem: the radiation source would be difficult to handle.

[0006] One embodiment of the technology disclosed herein provides a radiography system, an operating method for a radiography system, and an operating program for a radiography system that are capable of grasping the shape of a subject's spine based on optical images in addition to radiography without interfering with the handling of a radiation source. [Means for solving the problem]

[0007] The radiography system disclosed herein is a radiography system including a radiation source that irradiates a subject with radiation, a camera attached to the radiation source that photographs the subject irradiated with light of uniform brightness and outputs an optical image, and a processor, which acquires the optical image and derives spinal column shape information representing the shape of the subject's spine based on the optical image.

[0008] Preferably, the processor extracts feature points of the subject from the optical image, extracts derived reference information for deriving spine shape information from the feature points, and derives a polynomial representing the shape of the spine as the spine shape information based on the derived reference information.

[0009] The processor preferably calculates a Cobb angle, which indicates the degree of curvature of the spine, from the polynomial. In this case, the processor preferably controls the display of the Cobb angle.

[0010] The processor preferably determines whether or not the subject requires a secondary scoliosis screening by radiography based on the Cobb angle, and controls the display to display the determination result.

[0011] It is preferable that the processor extracts the subject's left and right shoulder joint points, left and right hip joint points, points indicating the maximum width of the left and right sides of the upper body, and points indicating the minimum width of the left and right sides of the upper body as feature points, and extracts the position coordinates of the midpoint of the line connecting the left and right shoulder joint points, the position coordinates of the midpoint of the line connecting the left and right hip joint points, the position coordinates of the midpoint of the line connecting the points indicating the maximum width, and the position coordinates of the midpoint of the line connecting the points indicating the minimum width as derivation reference information.

[0012] It is preferable that the processor extracts the left and right shoulder joint points and the left and right hip joint points of the subject as feature points, and extracts the position coordinates of the midpoint of the line connecting the left and right shoulder joint points, the position coordinates of the midpoint of the line connecting the left and right hip joint points, the slope of the line connecting the left and right shoulder joint points, and the slope of the line connecting the left and right hip joint points as derived reference information.

[0013] Prior to deriving spinal column shape information based on the optical image, the processor preferably acquires information on the subject's height, extracts the subject's left and right shoulder joint points and left and right hip joint points as feature points, and determines whether or not it is necessary to derive spinal column shape information based on the optical image based on the subject's height and the length of the line connecting the midpoint of the line connecting the left and right shoulder joint points and the midpoint of the line connecting the left and right hip joint points, and controls the display of the determination result.

[0014] When deriving spinal column shape information for a subject for whom spinal column shape information has previously been derived based on optical images, it is preferable that the processor controls the display to superimpose the previously acquired optical image on the current optical image when preparing for imaging before deriving the spinal column shape information.

[0015] Preferably, the radiation source is ceiling-mounted.

[0016] The method of operating a radiography system disclosed herein is a method of operating a radiography system equipped with a radiation source that irradiates a subject with radiation, and includes acquiring an optical image output from a camera provided in the radiation source that images a subject irradiated with light of uniform brightness, and deriving spinal column shape information representing the shape of the subject's spinal column based on the optical image.

[0017] The operating program for the radiography system disclosed herein is an operating program for a radiography system equipped with a radiation source that irradiates a subject with radiation, and causes a computer to execute processing including acquiring an optical image output from a camera attached to the radiation source that images a subject irradiated with light of uniform brightness, and deriving spinal column shape information representing the shape of the subject's spine based on the optical image. [Effects of the Invention]

[0018] According to the technology of the present disclosure, it is possible to provide a radiography system, an operating method for a radiography system, and an operating program for a radiography system that are capable of grasping the shape of a subject's spine based on optical images in addition to radiography without interfering with the handling of a radiation source. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a diagram illustrating a radiography system. [Figure 2] FIG. 1 shows a radiography room, a control room, and a waiting room. [Figure 3] FIG. 1 is a diagram showing how an optical image is captured by a camera. [Figure 4] FIG. 2 is a block diagram showing the configuration of a console. [Figure 5] FIG. 2 is a block diagram showing a processing unit of a CPU of the console. [Figure 6] FIG. 10 is a diagram illustrating the processing of an extraction unit. [Figure 7] FIG. 10 is a diagram illustrating the processing of an extraction unit. [Figure 8]FIG. 10 is a diagram illustrating the processing of a derivation unit. [Figure 9] FIG. 10 is a diagram illustrating the processing of a calculation unit. [Figure 10] FIG. 10 is a diagram showing an information display screen. [Figure 11] 10 is a flowchart showing a processing procedure of the console. [Figure 12] FIG. 10 is a diagram illustrating a process performed by an extraction unit according to a modified example. [Figure 13] FIG. 10 is a diagram illustrating a process performed by an extraction unit according to a modified example. [Figure 14] FIG. 10 illustrates a second embodiment for determining whether a subject requires a second radiographic scoliosis screening. [Figure 15] 15A and 15B show the processing of the first determination unit, where FIG. 15A shows the case where the first Cobb angle and the second Cobb angle are both less than the first threshold value, and FIG. 15B shows the case where either the first Cobb angle or the second Cobb angle is equal to or greater than the first threshold value. [Figure 16] FIG. 10 is a diagram showing an information display screen when the first Cobb angle and the second Cobb angle are both less than the first threshold value. [Figure 17] FIG. 10 is a diagram showing an information display screen when either the first Cobb angle or the second Cobb angle is equal to or greater than a first threshold value. [Figure 18] FIG. 10 is a diagram showing a third embodiment for determining whether or not it is necessary to derive spinal column shape information based on an optical image. [Figure 19] FIG. 10 is a diagram illustrating the processing of a second determination unit. [Figure 20] 20A shows the processing of the second judgment unit, where FIG. 20A shows the case where the ratio of the length of the line connecting the midpoint of the line connecting the left and right shoulder joint points to the midpoint of the line connecting the left and right hip joint points to the height is equal to or greater than the second threshold, and FIG. 20B shows the case where the ratio of the length of the line connecting the midpoint of the line connecting the left and right shoulder joint points to the midpoint of the line connecting the left and right hip joint points to the height is less than the second threshold. [Figure 21] This figure shows an information display screen when the ratio of the length of the line connecting the midpoint of the line connecting the left and right shoulder joint points and the midpoint of the line connecting the left and right hip joint points to height is equal to or greater than a second threshold value. [Figure 22]This figure shows an information display screen when the ratio of the length of the line connecting the midpoint of the line connecting the left and right shoulder joint points and the midpoint of the line connecting the left and right hip joint points to height is less than a second threshold value. [Figure 23] 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 24] FIG. 10 is a diagram showing an information display screen on which a past optical image is displayed superimposed on a current optical image. DETAILED DESCRIPTION OF THE INVENTION

[0020] [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, and is composed of a radiography apparatus 10 and a radiation generation apparatus 11. The radiography apparatus 10 has a standing radiography table 12, an electronic cassette 13, and a console 14. The radiation generation apparatus 11 has a radiation source suspension device 15, a radiation source 16, a radiation source control device 17, a tube voltage generator 18, and an exposure switch 19. A camera 20 is attached to the radiation source 16.

[0021] As shown in FIG. 2 as an example, the upright radiography platform 12, electronic cassette 13, radiation source suspension device 15, radiation source 16, camera 20, and tube voltage generator 18 are installed in a radiography room 25. Meanwhile, the console 14, radiation source control device 17, and exposure switch 19 are installed in a control room 26 adjacent to the radiography room 25. A speaker 27 is installed in the radiography room 25, and a microphone 28 is installed in the control room 26. The speaker 27 outputs the speech of an operator OP, such as a diagnostic radiologist, in the control room 26, which is picked up by the microphone 28. These speaker 27 and microphone 28 enable communication between the subject H in the radiography room 25 and the operator OP in the control room 26. A speaker 30 is also installed in the waiting room 29 for the subject H. Through this speaker 30 and microphone 28, the operator OP makes an announcement to guide the subject H, whose turn it is for radiography, from the waiting room 29 to the radiography room 25.

[0022] The subjects H are people who are undergoing a group medical examination such as a school medical examination. In this case, as radiation imaging, each subject H is subjected to frontal chest imaging in an upright position, as shown in FIG.

[0023] Returning to FIG. 1 , the upright radiography table 12 is an radiography table for radiographing the subject H in a standing position. The upright radiography table 12 has a base 35 installed on the floor of the radiography room 25, a support column 36 extending vertically from the base 35, and a holder 37 that holds the electronic cassette 13 therein. The holder 37 is connected to the support column 36 via a connection section 38. The connection section 38, and therefore the holder 37, is raised and lowered relative to the support column 36 by a motor or the like in accordance with the region to be radiographed or the physique of the subject H. The raised and lowered position of the holder 37 relative to the support column 36 is detected by, for example, a linear encoder. The holder 37 can be raised and lowered from the control room 26 via the console 14.

[0024] The electronic cassette 13 is a portable radiation image detector that detects a radiation image 66 (see FIG. 4) corresponding to the radiation R that has passed through the subject H. The electronic cassette 13 is connected to the console 14 via wire or wirelessly so that it can communicate with the console 14. The electronic cassette 13 is used by being housed in a holder 37 of the upright radiography stand 12. Alternatively, the electronic cassette 13 can be removed from the holder 37 and used by being held by the subject H or by being inserted under the subject H who is lying supine on a bed in a hospital room.

[0025] The electronic cassette 13 has a detection panel in which a plurality of pixels that accumulate charges corresponding to radiation R are arranged in a two-dimensional matrix. The detection panel is also called an FPD (Flat Panel Detector). When irradiation of radiation R begins, the detection panel starts a storage operation to accumulate charges in the pixels. When irradiation of radiation R ends, the detection panel starts a readout operation to read out the charges accumulated in the pixels as electrical signals.

[0026] The console 14 is, for example, a desktop personal computer. The console 14 has a display 40 that displays various screens and an input device 41 that includes a keyboard, a mouse, etc. and receives operation instructions from an operator OP. The console 14 transmits various signals to the electronic cassette 13. The console 14 also receives a radiographic image 66 from the electronic cassette 13. The console 14 displays the radiographic image 66 on the display 40. The display 40 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.

[0027] The radiation source suspension device 15 has an arm 45 and a carriage 46. The radiation source 16 is attached to the tip of the arm 45, and the base end of the arm 45 is attached to the carriage 46. The arm 45 is extendable and retractable in the vertical direction by a motor or the like. By extending and retracting the arm 45 in the vertical direction, the height position of the radiation source 16 can be changed to match the imaging region or the physique of the subject H. The extension / retraction position of the arm 45, and therefore the height position of the radiation source 16, is detected by, for example, a linear encoder. Furthermore, the radiation source 16 is rotated by, for example, a motor or the like around an axis perpendicular to the plane of the drawing relative to the arm 45 in order to adjust the angle of incidence of radiation R on the subject H. The rotation angle of the radiation source 16 is detected by, for example, a rotary encoder or a potentiometer. Similar to the elevation and lowering of the holder 37, the elevation and rotation of the radiation source 16 can also be controlled from the control room 26 via the console 14.

[0028] The dolly 46 is connected to rails 48 laid on the ceiling 47 of the radiography room 25. In other words, the radiation source 16 is ceiling-suspended. The rails 48 are linear and parallel to the normal to the detection surface of the radiation R of the electronic cassette 13 housed in the holder 37. The dolly 46, and therefore the radiation source 16, can be translated along the rails 48 by a motor or the like. This translation of the radiation source 16 along the rails 48 changes the source-to-image receptor distance (SID), which is the distance from the generation point of the radiation R to the detection surface of the radiation R of the electronic cassette 13. The position of the dolly 46 relative to the rails 48 is detected by, for example, a linear encoder. Similar to the raising and lowering of the holder 37, the translation of the radiation source 16 can also be controlled from the control room 26 via the console 14.

[0029] The radiation source 16 has a radiation tube 49 and an irradiation field limiter 50. The radiation tube 49 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 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.

[0030] The irradiation field limiter 50 is also called a collimator, and limits the irradiation field of the radiation R emitted from the radiation tube 49. The irradiation field limiter 50 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 50 changes the size of the exit opening by changing the position of each shielding plate, thereby changing the irradiation field of the radiation R.

[0031] A tube voltage generator 18 and an exposure switch 19 are connected to the radiation source control device 17. The radiation source control device 17 controls the operation of the radiation source 16 in response to various instruction signals from the exposure switch 19. The exposure switch 19 is operated when an operator OP instructs the radiation source 16 to start irradiating radiation R.

[0032] The radiation source control device 17 is set with radiation R irradiation conditions 63 (see FIG. 4). The irradiation conditions 63 include the tube voltage and tube current to be applied to the radiation tube 49, and the irradiation time of radiation R (see FIG. 4). When an instruction to start irradiating radiation R is given by operating the irradiation switch 19, the radiation source control device 17 operates the tube voltage generator 18 in accordance with the set irradiation conditions 63, causing the radiation tube 49 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 17 stops the irradiation of radiation R from the radiation tube 49. The tube voltage generator 18 generates a tube voltage by boosting the input voltage using a transformer. The tube voltage generated by the tube voltage generator 18 is supplied to the radiation tube 49 via a voltage cable (not shown).

[0033] 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 49 when the cumulative dose, which is the integrated value of the detected dose, reaches a preset target dose. In this case, the detection panel of the electronic cassette 13 starts a readout operation when the cumulative dose of radiation R reaches the target dose.

[0034] The camera 20 is a digital camera that captures a digital optical image 54 (see FIG. 3 ). The camera 20 is attached to the center of the tip of the irradiation field limiter 50 of the radiation source 16. The camera 20 is communicably connected to the console 14 via a wired or wireless connection. The camera 20 captures an image of the subject H standing in front of the standing imaging platform 12 for radiography in response to an imaging instruction from the console 14. The instruction to the camera 20 to capture the optical image 54 via the console 14 is given by an operator OP, for example, after guiding the subject H from the waiting room 29 to the radiography room 25 and having the subject H stand in front of the standing imaging platform 12. The camera 20 transmits the captured optical image 54 to the console 14. The camera 20 may be built into the irradiation field limiter 50.

[0035] FIG. 3 shows an example of how a subject H standing in front of the standing radiography platform 12 is photographed by the camera 20 in response to an operator's instructions. The subject H is illuminated with illumination light 53 from a light source 52 installed on the ceiling 47 of the radiography room 25. The light source 52 is a white light source such as a fluorescent lamp or a white LED (Light-Emitting Diode), and the illumination light 53 is white light. White light is a substantially uniform mixture of light with wavelengths in the visible light range (light with wavelengths of 360 nm to 830 nm). The illumination light 53 is an example of "light of uniform brightness" according to the technology of the present disclosure. "Light of uniform brightness" refers to light in which the difference in brightness from location to location in a macroscopic space such as the radiography room 25 falls within a specified range. Note that "light of uniform brightness" may also be natural light (sunlight).

[0036] The camera 20 has a field of view (FOV) that is capable of capturing the back of the subject H from the top of the head to below the knees (the entire upper body and part of the lower body) standing in front of the standing photographing stand 12. In this way, the optical image 54 captured by the camera 20 captures part of the standing photographing stand 12 and the back of the subject H from the top of the head to below the knees standing in front of the standing photographing stand 12.

[0037] 4, the console 14 includes, in addition to the display 40 and input device 41, a storage 55, a memory 56, a CPU (Central Processing Unit) 57, and a communication I / F (Interface) 58. The display 40, the input device 41, the storage 55, the memory 56, the CPU 57, and the communication I / F 58 are interconnected via a bus line (not shown). The storage 55, the memory 56, the CPU 57, and the bus line are an example of a "computer" according to the technology of the present disclosure.

[0038] 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.

[0039] 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 according to 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 electronic cassette 13.

[0040] 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) 161 (see FIG. 23) for identifying the subject H, instructions on imaging procedures from a doctor or the like of the medical department who issued the imaging order 61, and the like. The CPU 57 displays the imaging order 61 on the display 40 in response to an operation by an operator OP via the input device 41. The operator OP checks the contents of the imaging order 61 through the display 40.

[0041] The CPU 57 displays a plurality of types of imaging menus 62 on the display 40 in a selectable format. The imaging menu 62 specifies an imaging procedure, which is a set of imaging region of the subject H, imaging posture of the subject H, and imaging direction of the subject H, such as "chest, upright, front." In addition to the chest, imaging regions include the head, neck, abdomen, waist, shoulders, elbows, hands, knees, ankles, etc. In addition to the upright position, imaging postures include the supine position and the sitting position, etc. In addition to the front, imaging directions include the back and side. The operator OP operates the input device 41 to select one of the multiple types of imaging menus 62 that matches the imaging procedure specified in the imaging order 61. This causes the CPU 57 to accept the imaging menu 62. The CPU 57 reads out irradiation conditions 63 corresponding to the accepted imaging menu 62 from the irradiation condition table 64 stored in the storage 55. The CPU 57 displays the read irradiation conditions 63 on the display 40. The irradiation condition table 64 registers irradiation conditions 63 corresponding to the various imaging menus 62. As described above, the irradiation conditions 63 are the tube voltage and tube current applied to the radiation tube 49, 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.

[0042] The CPU 57 transmits the set irradiation conditions 63 to the radiation source control device 17 via the communication I / F 58. Although not shown in the figure, when an instruction to start irradiation of radiation R is given to the radiation source control device 17 via the irradiation switch 19, the CPU 57 receives an irradiation start signal from the radiation source control device 17 indicating that irradiation of radiation R will start. Upon receiving the irradiation start signal, the CPU 57 transmits a synchronization signal 65 indicating that irradiation of radiation R will start to the electronic cassette 13. Furthermore, the CPU 57 receives an irradiation end signal from the radiation source control device 17 indicating that irradiation of radiation R has ended. Upon receiving the irradiation end signal, the CPU 57 transmits a synchronization signal 65 indicating that irradiation of radiation R has ended to the electronic cassette 13.

[0043] When the electronic cassette 13 receives a synchronization signal 65 from the console 14 indicating that irradiation of radiation R has started, the electronic cassette 13 causes the detection panel to start a storage operation. Furthermore, when the electronic cassette 13 receives a synchronization signal 65 from the console 14 indicating that irradiation of radiation R has ended, the electronic cassette 13 causes the detection panel to start a readout operation. Note that the electronic cassette 13 may have a function for detecting the start and end of irradiation of radiation R, and may cause the detection panel to start a storage operation when the start of irradiation of radiation R is detected by this function, and to start a readout operation when the end of irradiation of radiation R is detected.

[0044] The CPU 57 receives the radiographic image 66 from the electronic cassette 13 via the communication I / F 58. The CPU 57 performs various image processing on the radiographic image 66, and then displays the radiographic image 66 on the display 40 for viewing by the operator.

[0045] Although not shown, the CPU 57 also transmits a shooting instruction to the camera 20 via the communication I / F 58. The CPU 57 receives the optical image 54 captured by the camera 20 in response to the shooting instruction.

[0046] 5, an operating program 70 is stored in the storage 55. The operating program 70 is an example of an "operating program for a radiation imaging system" according to the technique of the present disclosure.

[0047] When the operating program 70 is started, the CPU 57 functions as a first acquisition unit 75, an extraction unit 76, a derivation unit 77, a calculation unit 78, and a display control unit 79 in cooperation with the memory 56 and the like.

[0048] The first acquisition unit 75 sequentially acquires the optical images 54 output at a predetermined frame rate from the camera 20. The first acquisition unit 75 outputs the optical images 54 to the extraction unit 76 and the display control unit 79.

[0049] The extraction unit 76 performs image processing on the optical image 54 to extract derived reference information 85 for deriving spinal column shape information 86 that represents the shape of the spinal column of the subject H. The extraction unit 76 outputs the derived reference information 85 to the derivation unit 77.

[0050] The derivation unit 77 derives spine shape information 86 based on the derivation reference information 85. The derivation unit 77 outputs the spine shape information 86 to the calculation unit 78 and the display control unit 79.

[0051] The calculation unit 78 calculates the Cobb angle, which indicates the degree of curvature of the spine of the subject H, from the spinal column shape information 86. The calculation unit 78 outputs the Cobb angle calculation result 87 to the display control unit 79.

[0052] The display control unit 79 controls the display of various screens on the display 40. The various screens include a display screen for an imaging order 61, a selection screen for an imaging menu 62, and an information display screen 100 (see FIG. 10). Although not shown, in addition to these processing units 75 to 79, the CPU 57 also includes a reception unit 160 (see FIG. 23) that receives the imaging order 61 from the RIS 60, an image processing unit that performs various image processing on the radiographic image 66, and a setting unit that sets the irradiation conditions 63 in the radiation source control device 17.

[0053] As an example, as shown in FIG. 6 , the extraction unit 76 performs a first extraction process 90 on the optical image 54. The first extraction process 90 is a process for extracting feature points of the subject H captured in the optical image 54 using a known image recognition technique or a machine learning model. The feature points are left and right shoulder joint points CP1 and CP2, left and right hip joint points CP3 and CP4, points CP5 and CP6 indicating the maximum width of the left and right armpits of the upper body, and points CP7 and CP8 indicating the minimum width of the left and right armpits of the upper body. The shoulder joint points are the connection points between the shoulder blades and the humerus. The hip joint points are the connection points between the hip bones and the femur. The point indicating the maximum width is a point under the armpit, which is the point where a tape measure passes when measuring, for example, chest circumference. The point indicating the minimum width is a point at the waist, which is the point where a tape measure passes when measuring, for example, abdominal circumference.

[0054] 7 , the extraction unit 76 performs a second extraction process 92 on the optical image 54 following the first extraction process 90. The second extraction process 92 extracts, as derived reference information 85, the position coordinate OI_MP1(X,Y) of the midpoint MP1 of the line L1 connecting the left and right shoulder joint points CP1 and CP2, the position coordinate OI_MP2(X,Y) of the midpoint MP2 of the line L2 connecting the left and right hip joint points CP3 and CP4, the position coordinate OI_MP3(X,Y) of the midpoint MP3 of the line L3 connecting the points CP5 and CP6 that indicate the maximum width, and the position coordinate OI_MP4(X,Y) of the midpoint MP4 of the line L4 connecting the points CP7 and CP8 that indicate the minimum width. Note that the origin of the position coordinates OI(X,Y) of the optical image 54 is, for example, the left edge of the optical image 54, the X axis is oriented along the short side of the optical image 54, and the Y axis is oriented along the long side of the optical image 54.

[0055] 8, the derivation unit 77 performs a derivation process 94 on the optical image 54. The derivation process 94 is a process for calculating coefficients A to D of the primitive polynomial by solving an equation obtained by substituting the position coordinates OI_MP1(X, Y) to OI_MP4(X, Y) of each of the midpoints MP1 to MP4 of the derivation reference information 85 into the primitive polynomial Y=AX1+BX2+CX3+D, which is a cubic polynomial assuming that the curvature of the spine is an S-curve. The first term AX1 of the primitive polynomial is the line L5 connecting the midpoint MP1 of the line L1 connecting the left and right shoulder joint points CP1 and CP2 with the midpoint MP3 of the line L3 connecting the points CP5 and CP6 indicating the maximum width, and A is the slope of the line L5. The second term BX2 is the line L6 connecting the midpoint MP3 of the line L3 connecting the points CP5 and CP6 that indicate the maximum width to the midpoint MP4 of the line L4 connecting the points CP7 and CP8 that indicate the minimum width, and B is the slope of line L6. Similarly, the third term CX3 is the line L7 connecting the midpoint MP4 of the line L4 connecting the points CP7 and CP8 that indicate the minimum width to the midpoint MP2 of the line L2 that connects the left and right hip joint points CP3 and CP4, and C is the slope of line L7. D is the intercept obtained by combining the intercepts of lines L5 to L7.

[0056] Through this derivation process 94, the derivation unit 77 derives a polynomial that represents the shape of the spine of the subject H as spine shape information 86. Figure 8 illustrates an example where A = -20, B = 16, C = -18, and D = 10, and the polynomial is Y = -20X1 + 16X2 - 18X3 + 10.

[0057] As an example, as shown in FIG. 9 , the calculation unit 78 calculates the Cobb angle from a polynomial. More specifically, the calculation unit 78 calculates the angle between a perpendicular line PL1 to line L5 and a perpendicular line PL2 to line L6 as a first Cobb angle θ1. The calculation unit 78 also calculates the angle between a perpendicular line PL2 to line L6 and a perpendicular line PL3 to line L7 as a second Cobb angle θ2. The perpendicular line PL1 is a line parallel to the upper edge of vertebra V1, which is the vertebral body with the greatest inclination on the cephalad side. The perpendicular line PL2 is a line parallel to the upper and lower edges of vertebra V2, which is the vertebral body with the greatest inclination on the lumbar side and inclined in the opposite direction to vertebra V1. The perpendicular line PL3 is a line parallel to the lower edge of vertebra V3, which is the vertebral body with the greatest inclination on the lumbar side and inclined in the opposite direction to vertebra V2. FIG. 9 illustrates an example in which the first Cobb angle θ1 is calculated to be 41° and the second Cobb angle θ2 is calculated to be 37°.

[0058] 10, an information display screen 100 has a display area 101 for the imaging menu 62 and a display area 102 for the irradiation conditions 63. The display area 101 displays a combination of the imaging menu 62 registered up to that point, the subject ID 161 (P0001, P0002, etc.), and the name of the subject H. The imaging menu 62 currently being used for radiography is displayed in a different color from the other imaging menus 62, as indicated by hatching. The display area 102 displays the irradiation conditions 63, including the tube voltage, tube current, and irradiation time, in an adjustable state.

[0059] The information display screen 100 also has a display area 103 for the optical image 54 and a display area 104 for the calculation results 87. A shooting instruction button 105 is provided above the display area 103. The shooting instruction button 105 is an on / off button. When the shooting instruction button 105 is in the off state, an instruction to shoot the optical image 54 is not sent to the camera 20. Therefore, the optical image 54 is not displayed in the display area 103. On the other hand, when the shooting instruction button 105 is on, an instruction to shoot the optical image 54 is sent to the camera 20, and the optical image 54 is displayed in the display area 103. The display control unit 79 displays the optical image 54 output from the camera 20 at a predetermined frame rate in the display area 104 while successively updating it. In other words, the optical image 54 displayed in the display area 104 is a live view image (moving image).

[0060] A spine shape derivation button 106 is provided in the display area 104. When the spine shape derivation button 106 is selected, the optical image 54 acquired by the first acquisition unit 75 at that time is subjected to the processes shown in FIGS. 6 to 9, i.e., the first extraction process 90, the second extraction process 92, the derivation process 94, and the Cobb angle calculation process, by the extraction unit 76, the derivation unit 77, and the calculation unit 78. The display control unit 79 displays the calculation results 87 obtained thereby in the display area 104.

[0061] Furthermore, the display control unit 79 displays a still image of the optical image 54 in the display area 103 when the spine shape derivation button 106 is selected, and also superimposes a broken line 107 representing the polynomial lines L5 to L7 of the spine shape information 86 on the optical image 54. Furthermore, the display control unit 79 superimposes on the optical image 54 a numerical value 109 of the first Cobb angle θ1 together with an auxiliary line 108 indicating the perpendicular lines PL1 and PL2, and a numerical value 111 of the second Cobb angle θ2 together with an auxiliary line 110 indicating the perpendicular lines PL2 and PL3.

[0062] The display area 104 is provided with a save button 112 and a print button 113. When the save button 112 is selected, the polynomial of the spine shape information 86 and the calculation result 87 are stored in the storage 55. The polynomial of the spine shape information 86 and the calculation result 87 stored in the storage 55 are registered in, for example, an electronic medical record of an electronic medical record system connected to the console 14 via a network. When the print button 113 is selected, the contents displayed in the display area 103 (optical image 54, broken line 107, auxiliary lines 108 and 110, and numerical values ​​109 and 111) are printed on a paper medium. The paper medium is distributed to the subject H.

[0063] Next, the operation of the above configuration will be described with reference to the flowchart shown in FIG. 11 as an example. Prior to radiography, the operator OP performs radiography preparation work. The radiography preparation work includes selecting an radiography menu 62, setting radiation R irradiation conditions 63, positioning the electronic cassette 13 and radiation source 16 (adjusting the height position and SID), and positioning the subject H (adjusting the position and posture relative to the electronic cassette 13 and radiation source 16). The operator OP operates the console 14 in the control room 26 to select the radiography menu 62 appropriate for the radiography to be performed, and then sets the radiation R irradiation conditions 63. Next, the operator OP makes an announcement via the microphone 28 to the speaker 30 in the waiting room 29, and guides the subject H from the waiting room 29 to the radiography room 25.

[0064] The operator OP makes an announcement via the microphone 28 to the speaker 27 in the radiography room 25 and has the subject H stand in front of the standing radiography platform 12. The operator OP operates the console 14 to raise and lower the holder 37, and therefore the electronic cassette 13, to match the height of the subject H, thereby adjusting the height of the electronic cassette 13. The operator OP also operates the console 14 to raise and lower the radiation source 16, moving the radiation source 16 to a height position that matches the height of the electronic cassette 13. The operator OP also operates the console 14 to translate the radiation source 16 along the rails 48, moving the radiation source 16 to the SID position corresponding to the selected radiography menu 62, in this case "chest, upright position, front".

[0065] The operator OP guides the subject H from the waiting room 29 to the radiography room 25 and has the subject H stand in front of the standing radiography platform 12. Then, the operator OP turns on the radiography instruction button 105 on the information display screen 100 (YES in step ST100) in order to grasp the shape of the spine of the subject H from the optical image 54. This causes the console 14 to send an instruction to capture the optical image 54 to the camera 20 (step ST110), and the camera 20 starts capturing the optical image 54.

[0066] In the console 14, the operating program 70 is started, causing the CPU 57 to function as a first acquisition unit 75, an extraction unit 76, a derivation unit 77, a calculation unit 78, and a display control unit 79. The optical image 54 from the camera 20 is acquired by the first acquisition unit 75 (step ST120). The optical image 54 is output from the first acquisition unit 75 to the extraction unit 76 and the display control unit 79.

[0067] The operator OP positions the subject H with his / her back straight in front of the standing position imaging platform 12, and after adjusting the posture of the subject H to a state suitable for calculating the Cobb angle, selects the spine shape derivation button 106 (YES in step ST130). As a result, the extraction unit 76 first performs a first extraction process 90 on the optical image 54, as shown in Fig. 6. Then, the following points of the subject H's left and right shoulder joint points CP1 and CP2, left and right hip joint points CP3 and CP4, points CP5 and CP6 indicating the maximum width between the left and right sides of the upper body, and points CP7 and CP8 indicating the minimum width between the left and right sides of the upper body are extracted as feature points (step ST140).

[0068] Next, the extraction unit 76 performs a second extraction process 92 on the optical image 54. Then, the position coordinate OI_MP1(X,Y) of the midpoint MP1 of the line L1 connecting the left and right shoulder joint points CP1 and CP2, the position coordinate OI_MP2(X,Y) of the midpoint MP2 of the line L2 connecting the left and right hip joint points CP3 and CP4, the position coordinate OI_MP3(X,Y) of the midpoint MP3 of the line L3 connecting the points CP5 and CP6 indicating the maximum width, and the position coordinate OI_MP4(X,Y) of the midpoint MP4 of the line L4 connecting the points CP7 and CP8 indicating the minimum width are extracted as derived reference information 85 (step ST150). The derived reference information 85 is output from the extraction unit 76 to the derivation unit 77.

[0069] 8, the derivation unit 77 performs a derivation process 94 using the derivation reference information 85. As a result, a polynomial representing the shape of the spine of the subject H is derived as spine shape information 86 (step ST160). The spine shape information 86 is output from the derivation unit 77 to the calculation unit 78 and the display control unit 79.

[0070] 9, the calculation unit 78 calculates the first Cobb angle θ1 and the second Cobb angle θ2, which indicate the degree of curvature of the spine, from the polynomial of the spinal column shape information 86 (step ST170). The calculation results 87 of the first Cobb angle θ1 and the second Cobb angle θ2 are output from the calculation unit 78 to the display control unit 79.

[0071] As shown in FIG. 10, under the control of the display control unit 79, a broken line 107 representing the lines L5 to L7 of the polynomial of the spine shape information 86, a numerical value 109 of the first Cobb angle θ1, and a numerical value 111 of the second Cobb angle θ2 are superimposed on the optical image 54 in the display area 103 of the information display screen 100. In addition, the calculation result 87 is displayed in the display area 104 (step ST180). The operator OP selects the save button 112 to store the polynomial of the spine shape information 86 and the calculation result 87 in the storage 55. In addition, the operator OP selects the print button 113 to print the content displayed in the display area 103 on a paper medium and distribute it to the subject H.

[0072] After calculating the Cobb angle, the operator OP makes an announcement via the microphone 28 to the speaker 27 in the radiography room 25. That is, the operator OP urges the subject H to place his chin on the holder 37, place his hands on his hips, thrust his elbows forward, spread his shoulder blades so that they overlap the holder 37, and press his chest against the holder 37. Next, the operator OP instructs the subject H to take a breath and hold it. Thereafter, the operator OP operates the irradiation switch 19 to instruct the radiation source 16 to start irradiating the radiation R. As a result, the radiation source 16 irradiates the radiation R toward the subject H.

[0073] The radiation R that has passed through the subject H reaches the electronic cassette 13. It is then detected as a radiographic image 66 by the electronic cassette 13. The radiographic image 66 is output from the electronic cassette 13 to the console 14. The console 14 then performs various image processing on the radiographic image 66 from the electronic cassette 13. Thereafter, the radiographic image 66 is displayed in the display area 103 of the information display screen 100 in place of the optical image 54.

[0074] As described above, the radiation imaging system 2 includes the radiation source 16 that irradiates the subject H with radiation R, the camera 20, and the console 14. The camera 20 is provided in the radiation source 16. The camera 20 captures an image of the subject H illuminated with illumination light 53, which is light of uniform brightness, and outputs an optical image 54. The CPU 57 of the console 14 includes a first acquisition unit 75 and a derivation unit 77. The first acquisition unit 75 acquires the optical image 54 from the camera 20. The derivation unit 77 derives spinal column shape information 86 that represents the shape of the spinal column of the subject H, based on the optical image 54.

[0075] In the technology of the present disclosure, only the camera 20 is provided on the radiation source 16, and no large-scale mechanism such as a light projector that projects a light pattern that generates moiré fringes onto the back of the subject H, as in the moiré fringe measurement device described in Patent Document 1, is provided. Therefore, it is possible to grasp the shape of the spinal column of the subject H based on the optical image 54 in addition to radiography, without interfering with the handling of the radiation source 16.

[0076] The extraction unit 76 extracts feature points of the subject H from the optical image 54. The extraction unit 76 extracts derived reference information 85 for deriving spine shape information 86 from the feature points. The derivation unit 77 derives a polynomial representing the shape of the spine as the spine shape information 86 based on the derived reference information 85. In this way, by first extracting the feature points and then extracting the derived reference information 85, the extraction accuracy of the derived reference information 85 can be improved compared to when the derived reference information 85 is extracted directly from the optical image 54. As a result, the reliability of the polynomial of the spine shape information 86 can be improved. Furthermore, the polynomial allows the operator OP to easily grasp the shape of the spine of the subject H.

[0077] The calculation unit 78 calculates a first Cobb angle θ1 and a second Cobb angle θ2, which indicate the degree of curvature of the spine, from the polynomial. The display control unit 79 performs control to display the first Cobb angle θ1 and the second Cobb angle θ2 on the display 40 by superimposing a numerical value 109 of the first Cobb angle θ1 and a numerical value 111 of the second Cobb angle θ2 on the optical image 54 in the display area 103, and by displaying calculation results 87 of the first Cobb angle θ1 and the second Cobb angle θ2 in the display area 104. This allows the operator OP to easily grasp the shape of the spine of the subject H. This facilitates the operator OP in determining whether or not a secondary scoliosis examination using radiography is necessary for the subject H.

[0078] The extraction unit 76 extracts as feature points the left and right shoulder joint points CP1 and CP2, the left and right hip joint points CP3 and CP4, the points CP5 and CP6 indicating the maximum width of the left and right armpits of the upper body, and the points CP7 and CP8 indicating the minimum width of the left and right armpits of the upper body of the subject H. Then, the extraction unit 76 extracts as derivation reference information 85 the position coordinate OI_MP1(X,Y) of the midpoint MP1 of the line L1 connecting the left and right shoulder joint points CP1 and CP2, the position coordinate OI_MP2(X,Y) of the midpoint MP2 of the line L2 connecting the left and right hip joint points CP3 and CP4, the position coordinate OI_MP3(X,Y) of the midpoint MP3 of the line L3 connecting the points CP5 and CP6 indicating the maximum width, and the position coordinate OI_MP4(X,Y) of the midpoint MP4 of the line L4 connecting the points CP7 and CP8 indicating the minimum width. Therefore, the polynomial of the spine shape information 86 can be obtained by a simple calculation of substituting the position coordinates OI_MP1(X, Y) to OI_MP4(X, Y) of the respective midpoints MP1 to MP4 into the basic polynomial and solving the equation.

[0079] Radiation source 16 is suspended from the ceiling. Therefore, if the weight of radiation source 16 increases due to the addition of a device for determining the shape of the spinal column of subject H, arm 45 must be made thicker to ensure stability, which would hinder the handling of radiation source 16. If the moiré fringe measurement device described in Patent Document 1 were added to radiation source 16, the weight would be very heavy, which would significantly hinder the handling of radiation source 16. However, in the technology disclosed herein, the only device for determining the shape of the spinal column of subject H is camera 20, which weighs approximately several tens of grams. Therefore, it is considered that there is little risk that the handling of radiation source 16 will be hindered.

[0080] (Variation) As an example, as shown in FIG. 12, in this modification, the extraction unit 76 extracts left and right shoulder joint points CP1 and CP2 and left and right hip joint points CP3 and CP4 as feature points in a first extraction process 120.

[0081] As shown in FIG. 13 as an example, in this modification, the extraction unit 76 extracts, in the second extraction process 122, the position coordinate OI_MP1(X,Y) of the midpoint MP1 of the line L1 connecting the left and right shoulder joint points CP1 and CP2, the position coordinate OI_MP2(X,Y) of the midpoint MP2 of the line L2 connecting the left and right hip joint points CP3 and CP4, the slope φ1 of the line L1 connecting the left and right shoulder joint points CP1 and CP2, and the slope φ2 of the line L2 connecting the left and right hip joint points CP3 and CP4 as the derived reference information 125. This derived reference information 125 can also be used to determine the polynomial of the spine shape information 86. Fewer feature points need to be extracted than in the first embodiment, thereby reducing the load on the first extraction process 120. The slope φ1 can be rephrased as the angle between the X-axis and the line L1 connecting the left and right shoulder joint points CP1 and CP2. Similarly, the inclination φ2 can be rephrased as the angle between the X axis and the line L2 connecting the left and right hip joint points CP3 and CP4.

[0082] In this way, the feature points extracted from the optical image 54 and the derived reference information extracted from the feature points are not limited to the points CP1 to CP8 and the derived reference information 85 exemplified in the first embodiment.

[0083] The basic polynomial is not limited to the illustrated third-order polynomial. It may be a quadratic polynomial. It may also be a fourth-order or higher polynomial. The degree of the polynomial may be changed depending on the subject H. In the case of a fourth-order or higher polynomial, it is necessary to further extract the midpoint MP whose position coordinates are registered in the derived reference information 85, and furthermore, the feature points for extracting the midpoint MP.

[0084] The operator OP may attach markers to feature points such as the left and right shoulder joint points, and extract the feature points by performing image recognition of the markers that appear in the optical image 54. Similarly, the operator OP may attach markers to some of the vertebral bodies, and extract the vertebral bodies by performing image recognition of the markers that appear in the optical image 54, and the position coordinates of the extracted vertebral bodies may be included in the derivation reference information 85.

[0085] [Second embodiment] As an example, as shown in FIG. 14, the CPU 57 of the console 14 of the second embodiment functions as a first judgment unit 130 in addition to each processing unit 75 to 79 of the first embodiment (all but the calculation unit 78 and the display control unit 79 are not shown).

[0086] The first determination unit 130 receives the calculation result 87 from the calculation unit 78. The first determination unit 130 compares the first Cobb angle θ1 and the second Cobb angle θ2 of the calculation result 87 with a preset first threshold value TH1 to determine whether or not the subject H needs a secondary scoliosis examination by radiography. The first determination unit 130 outputs a first determination result 131 indicating whether or not the secondary examination is necessary to the display control unit 79.

[0087] 14, the first threshold TH1 is set to 10°. This value of "10°" is the Cobb angle value at which the presence of scoliosis of the spine is generally diagnosed.

[0088] 15, the first determination unit 130 determines whether a secondary examination is necessary based on whether the first Cobb angle θ1 and the second Cobb angle θ2 in the calculation result 87 are less than the first threshold value TH1. As shown in FIG. 15A, if the first Cobb angle θ1 and the second Cobb angle θ2 in the calculation result 87 are both less than the first threshold value TH1 of 10°, the first determination unit 130 determines that a secondary examination is unnecessary and outputs a first determination result 131 indicating that a secondary examination is unnecessary. On the other hand, as shown in FIG. 15B, if either the first Cobb angle θ1 or the second Cobb angle θ2 in the calculation result 87 is equal to or greater than the first threshold value TH1 of 10°, the first determination unit 130 determines that a secondary examination is necessary and outputs a first determination result 131 indicating that a secondary examination is necessary.

[0089] 16 shows the information display screen 100 in the case where, in the determination shown in FIG. 15, the first Cobb angle θ1 and the second Cobb angle θ2 in the calculation result 87 are both less than the first threshold value TH1, resulting in a first determination result 131 indicating that a secondary examination is unnecessary (as in FIG. 15A). In this case, the display control unit 79 displays a message 135 indicating that a secondary examination is unnecessary in the display area 104. The operator OP makes an announcement via the microphone 28 to the speaker 27 in the radiography room 25 to inform the subject H that a secondary examination is unnecessary.

[0090] 17 shows the information display screen 100 in the case where, in the determination shown in FIG. 15, either the first Cobb angle θ1 or the second Cobb angle θ2 in the calculation result 87 is equal to or greater than the first threshold value TH1, resulting in a first determination result 131 indicating that a secondary examination is necessary (as in FIG. 15B). In this case, the display control unit 79 displays a message 136 indicating that a secondary examination is necessary in the display area 104. The operator OP makes an announcement via the microphone 28 to the speaker 27 in the radiography room 25 to inform the subject H that a secondary examination is necessary.

[0091] As described above, in the second embodiment, the first determination unit 130 determines whether or not the subject H needs a secondary scoliosis examination by radiography, based on the first Cobb angle θ1 and the second Cobb angle θ2. The display control unit 79 controls the display of the first determination result 131 of the first determination unit 130 on the display 40 by displaying a message 135 or 136 in the display area 104. This allows the operator OP to easily know whether or not the subject H needs a secondary examination, and can inform the subject H on the spot whether or not the secondary examination is necessary.

[0092] In addition, it is possible to omit superimposing the numerical value 109 of the first Cobb angle θ1 and the numerical value 111 of the second Cobb angle θ2 on the optical image 54, and to omit displaying the calculation results 87 of the first Cobb angle θ1 and the second Cobb angle θ2 in the display area 104, and to simply display the message 135 or 136 in the display area 104.

[0093] Instead of or in addition to displaying the first determination result 131 on the information display screen 100, the first determination result 131 may be notified by voice. Also, the first determination result 131 may be notified by an indicator such as a warning lamp.

[0094] [Third embodiment] As an example, as shown in FIG. 18, the CPU 57 of the console 14 of the third embodiment functions as a second acquisition unit 140 and a second judgment unit 141 in addition to each processing unit 75 to 79 of the first embodiment (all units except the extraction unit 76 and the display control unit 79 are omitted from the illustration).

[0095] The second acquisition unit 140 acquires height information 142, which is information about the height of the subject H. The second acquisition unit 140 outputs the height information 142 to the second determination unit 141. The height information 142 may be input by the operator OP via the input device 41, or may be estimated from the height of the subject H shown in the optical image 54. Alternatively, the height information 142 may be estimated from the height position of the holder 37 of the upright imaging platform 12 after it has been adjusted to match the height of the subject H, or the height position of the radiation source 16. Alternatively, a ruler indicating the height may be placed within the field of view FOV of the optical image 54, such as on the support pillar 36 of the upright imaging platform 12 or on a wall of the radiography room 25 near the upright imaging platform 12, and the scale of the ruler shown in the optical image 54 may be image-recognized.

[0096] The second determination unit 141 receives, as input, height information 142 from the second acquisition unit 140, as well as feature point information 143 from the extraction unit 76. The feature point information 143 is the position coordinates of left and right shoulder joint points CP1 and CP2 and the position coordinates of left and right hip joint points CP3 and CP4, which are feature points extracted by the extraction unit 76 in the first extraction process 90 or 120. The second determination unit 141 determines whether or not it is necessary to derive spine shape information 86 based on the optical image 54, based on the height information 142, the feature point information 143, and a preset second threshold value TH2. The second determination unit 141 makes this determination before the imaging instruction button 105 is turned on and the spine shape derivation button 106 is selected. The second determination unit 141 outputs a second determination result 144, indicating whether or not it is necessary to derive spine shape information 86 based on the optical image 54, to the display control unit 79.

[0097] 18, the second threshold value TH2 is set to 0.3. This value of "0.3" is statistically determined from past data of an unspecified number of subjects H. The value of the second threshold value TH2 may be changed depending on the attributes of the subject H, such as gender, age, and body type.

[0098] 19, the second determination unit 141 calculates the length of a line L8 connecting a midpoint MP1 of a line L1 connecting the left and right shoulder joint points CP1 and CP2 and a midpoint MP2 of a line L2 connecting the left and right hip joint points CP3 and CP4, based on the feature point information 143. Then, the calculated length of the line L8 is converted into a length in real space according to the SID and the FOV of the camera 20. The second determination unit 141 sets the thus calculated length of the line L8 in real space together with the height from the height information 142 as determination reference information 145.

[0099] 20, the second determination unit 141 determines whether or not it is necessary to derive spinal column shape information 86 based on the optical image 54, depending on whether or not the ratio of the length of line L8 to height is equal to or greater than a second threshold value TH2. This determination method is based on the finding that when the spine has scoliosis, the length of line L8 relative to height is shorter than that of a healthy person.

[0100] 20A, when the ratio of the length of L8 to the height (50 cm / 145 cm ≒ 0.34) of the determination reference information 145 is equal to or greater than the second threshold value TH2 of 0.3, the second determination unit 141 determines that it is not necessary to derive the spine shape information 86 based on the optical image 54, and outputs a second determination result 144 indicating that it is not necessary to derive the spine shape information 86. On the other hand, when the ratio of the length of L8 to the height (40 cm / 145 cm ≒ 0.28) of the determination reference information 145 is less than the second threshold value TH2 of 0.3, as shown in FIG. 20B, the second determination unit 141 determines that it is necessary to derive the spine shape information 86 based on the optical image 54, and outputs a second determination result 144 indicating that it is necessary to derive the spine shape information 86.

[0101] 21 shows the information display screen 100 when, in the determination shown in Fig. 20, the ratio of the length of L8 to the height in the determination reference information 145 is equal to or greater than the second threshold value TH2, and the second determination result 144 indicates that it is not necessary to derive the spine shape information 86 based on the optical image 54 (as in Fig. 20A). In this case, the display control unit 79 displays a message 150 in the display area 104 indicating that there is no risk of scoliosis in the subject H and that it is not necessary to derive the spine shape information 86. The operator OP does not select the spine shape derivation button 106, and immediately proceeds to radiography.

[0102] 22 shows the information display screen 100 in the case where, in the determination shown in FIG. 20, the ratio of the length of L8 to the height in the determination reference information 145 is less than the second threshold value TH2, and the second determination result 144 indicates that it is necessary to derive the spine shape information 86 based on the optical image 54 (as in FIG. 20B). In this case, the display control unit 79 displays a message 151 in the display area 104 indicating that the subject H may have scoliosis and that it is necessary to derive the spine shape information 86. The operator OP selects the spine shape derivation button 106 and causes the CPU 57 to derive the spine shape information 86.

[0103] As described above, in the third embodiment, the second acquisition unit 140 acquires height information 142 of the subject H prior to deriving spine shape information 86 based on the optical image 54. The extraction unit 76 extracts the left and right shoulder joint points CP1 and CP2 and the left and right hip joint points CP3 and CP4 of the subject H as feature points. The second determination unit 141 determines whether or not it is necessary to derive spine shape information 86 based on the optical image 54 based on the subject's height and the length of a line L8 connecting a midpoint MP1 of a line L1 connecting the left and right shoulder joint points CP1 and CP2 and a midpoint MP2 of a line L2 connecting the left and right hip joint points CP3 and CP4. The display control unit 79 controls the display of a second determination result 144 of the second determination unit 141 on the display 40 by displaying a message 150 or 151 in the display area 104. Therefore, it is possible to selectively derive spinal column shape information 86 of a subject H who is at risk of having scoliosis, and it is possible to avoid the waste of deriving spinal column shape information 86 of a subject H who is not at risk of having scoliosis.

[0104] If the second judgment result 144 indicates that it is not necessary to derive the spine shape information 86 based on the optical image 54, the spine shape derivation button 106 itself may not be displayed in the display area 104, or the spine shape derivation button 106 may be grayed out to make it unselectable, thereby making it impossible to derive the spine shape information 86.

[0105] Furthermore, when the operator OP selects the spine shape derivation button 106, the second determination unit 141 may make a determination. In this case, if the second determination result 144 indicates that it is not necessary to derive the spine shape information 86 based on the optical image 54, a message 150 is displayed in the display area 104. On the other hand, if the second determination result 144 indicates that it is necessary to derive the spine shape information 86 based on the optical image 54, the message 151 is not displayed in the display area 104, and the CPU 57 is caused to derive the spine shape information 86.

[0106] Instead of or in addition to displaying the second determination result 144 on the information display screen 100, the second determination result 144 may be notified by voice. The second determination result 144 may also be notified by an indicator such as a warning lamp.

[0107] [Fourth embodiment] As an example, as shown in FIG. 23, the CPU 57 of the console 14 of the fourth embodiment functions as a reception unit 160 in addition to each processing unit 75 to 79 of the first embodiment (all but the first acquisition unit 75 and the display control unit 79 are not shown).

[0108] The reception unit 160 receives an imaging order 61 from the RIS 60. The reception unit 160 outputs a subject ID 161 included in the imaging order 61 to a past image database (hereinafter referred to as DB (Data Base)) 162. The past image DB 162 stores a pair of the subject ID 161 of a subject H for whom spine shape information 86 was previously derived by the radiation imaging system 2 based on an optical image 54, and a past image 54P, which is a past optical image 54 obtained by photographing the subject H with the subject ID 161 with the camera 20 when the past spine shape information 86 was derivation. The past image 54P is a single still image photographed with the camera 20 when the most recent spine shape information 86 was derivation.

[0109] Upon receiving subject ID 161 from reception unit 160, past image DB 162 reads out past image 54P corresponding to subject ID 161 and transmits read out past image 54P to reception unit 160. Reception unit 160 outputs past image 54P to display control unit 79. If subject ID 161 from reception unit 160 has not been registered, past image DB 162 transmits to reception unit 160 a message that subject ID 161 has not been registered.

[0110] 24, during preparation for imaging before derivation of spine shape information 86, the display control unit 79 displays a moving current optical image 54 and a still past image 54P in a superimposed manner in the display area 103. The preparation for imaging before derivation of spine shape information 86 specifically refers to the time before the imaging instruction button 105 is turned on and the spine shape derivation button 106 is selected. As indicated by the dashed line, the past image 54P is displayed with, for example, 50% transparency. If the reception unit 160 receives information that the subject ID 161 is not registered, a dialog box containing a message indicating that there is no past image 54P is displayed as a pop-up on the information display screen 100.

[0111] 24 illustrates an example in which the position of subject H in the current optical image 54 is different from the position of subject H in the previous image 54P by a threshold value or more. In this case, an exclamation mark 165 and a message 166 indicating that the positioning of subject H is inappropriate are displayed in the display area 104.

[0112] Whether the distance between the position of subject H in the current optical image 54 and the position of subject H in the previous image 54P is equal to or greater than a threshold value is determined, for example, as follows: That is, a first extraction process 90 or 120 is performed on each of the current optical image 54 and the previous image 54P. Then, the distance between the feature point in the current optical image 54 and the feature point in the previous image 54P (for example, the distance between the left shoulder joint points CP1) is calculated, and the calculated distance is compared with a preset threshold value.

[0113] As described above, in the fourth embodiment, when spine shape information 86 is to be derived again for subject H for whom spine shape information 86 was previously derived based on the optical image 54, the display control unit 79 controls the display 40 to superimpose the previous image 54P, which is a previous optical image acquired in the past, on the current optical image 54 during preparation for imaging before the spine shape information 86 is derived. This allows the operator OP to easily confirm the degree to which the current position of subject H deviates from the previous position of subject H. The operator OP can instruct the subject H to correct his / her positioning to eliminate the deviation from the previous position, and can easily align the current position of subject H with the previous position of subject H. This ensures the reproducibility of the spine shape information 86. If subject H has been treated for scoliosis, the effectiveness of the treatment can be accurately assessed.

[0114] Instead of or in addition to displaying the fact that the positioning of the subject H is inappropriate on the information display screen 100, the fact that the positioning of the subject H is inappropriate may be notified by audio. Also, the fact that the positioning of the subject H is inappropriate may be notified by an indicator such as a warning lamp.

[0115] A mat with a pressure sensor may be placed on the floor of the radiography room 25 below the upright radiography platform 12, and based on the measurement results of the pressure sensor, it may be determined whether or not the subject H is standing directly in front of the upright radiography platform 12. Alternatively, it may be determined from the optical image 54 whether or not the subject H is standing directly in front of the upright radiography platform 12. If it is determined that the subject H is not standing directly in front of the upright radiography platform 12, a warning may be displayed or irradiation of radiation R may be prohibited. Furthermore, body movement of the subject H may be detected from the optical image 54, and if the amount of body movement is equal to or greater than a preset threshold, a warning may be displayed or irradiation of radiation R may be prohibited.

[0116] The first Cobb angle θ1 and the second Cobb angle θ2 may also be calculated from the radiographic image 66. In this case, the first Cobb angle θ1 and the second Cobb angle θ2 calculated from the radiographic image 66 may be displayed so as to be comparable to the first Cobb angle θ1 and the second Cobb angle θ2 calculated from the optical image 54. Alternatively, during a secondary scoliosis screening using radiography, the first Cobb angle θ1 and the second Cobb angle θ2 calculated from the radiographic image obtained in the secondary screening may be displayed so as to be comparable to the first Cobb angle θ1 and the second Cobb angle θ2 calculated from the optical image 54. In this way, the validity of the first Cobb angle θ1 and the second Cobb angle θ2 calculated from the optical image 54 can be confirmed.

[0117] Although the electronic cassette 13 has been exemplified as a radiation image detector, the present invention is not limited to this. A radiation image detector mounted on the upright radiography stand 12 may also be used. Furthermore, the radiation source 16 does not have to be a ceiling-suspended type, but may be a type attached to a support that is installed on the floor of the radiography room 25 so as to be movable in parallel.

[0118] A display may be attached to the upright radiography platform 12, and various screens such as the information display screen 100 may be displayed on the display. In this way, the information display screen 100 and the like can be checked even in the radiography room 25. Positioning guides and the like can also be displayed to the subject H.

[0119] Various screens such as the information display screen 100 may be transmitted from the console 14 to a mobile terminal such as a tablet terminal owned by the operator OP 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 a display. Note that instead of XML, other data description languages ​​such as JSON (Javascript (registered trademark) Object Notation) may be used.

[0120] The hardware configuration of the computer that constitutes the console 14 can be modified in various ways. For example, the console 14 can be configured with multiple computers separated as hardware in order to improve processing power and reliability. For example, the functions of the first acquisition unit 75 and the extraction unit 76 and the functions of the derivation unit 77, the calculation unit 78, and the display control unit 79 can be distributed and performed by two computers. In this case, the console 14 is configured with two computers.

[0121] In this way, the hardware configuration of the computer of the console 14 can be changed as needed depending on the required performance, such as processing power, safety, and reliability. 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.

[0122] 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, extraction unit 76, derivation unit 77, calculation unit 78, display control unit 79, first determination unit 130, second acquisition unit 140, second determination unit 141, and reception unit 160. 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).

[0123] 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.

[0124] 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.

[0125] Furthermore, more specifically, the hardware structure of these various processors can be an electric circuit that combines circuit elements such as semiconductor elements.

[0126] 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.

[0127] 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.

[0128] 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."

[0129] 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]

[0130] 2 Radiography system 10 Radiography equipment 11 Radiation Generator 12 Standing photography stand 13 Electronic cassette 14 Console 15 Source suspension system 16 Radiation source 17 Radiation source control device 18 Tube voltage generator 19 Irradiation switch 20 Camera 25 Radiography Room 26 Control Room 27, 30 speakers 28 microphones 29 Waiting Room 35 Pedestal 36 Posts 37 Holder 38 Connection 40 Display 41 Input Devices 45 Arm 46 Cart 47 Ceiling 48 Rail 49 Radiation Tube 50 Irradiation field limiter 52 Light source 53 Illumination 54 Optical Images 54P Past Images 55 Storage 56 memory 57 CPU 58 Communication I / F 60 Radiology Information System (RIS) 61 Photoshoot Order 62 Shooting Menu 63 Irradiation conditions 64 Irradiation Condition Table 65 Sync Signal 66 Radiography 70 Operating Program 75 First acquisition part 76 Extraction part 77 Derivation part 78 Calculation Unit 79 Display control unit 85, 125 Derivation reference information 86 Spinal column shape information 87 Calculation results 90, 120 First extraction process 92, 122 Second extraction process 94 Derivation Processing 100 Information display screen 101, 102, 103, 104 display area 105 Shooting instruction button 106 Spine shape derivation button 107 Polynomial Lines 108, 110 Auxiliary lines showing perpendicular lines 109, 111 Cobb angle values 112 Save button 113 Print button 130 1st Judgment Section 131 First judgment result 135, 136, 150, 151, 166 messages 140 Second acquisition part 141 Second Judgment Section 142 Height Information 143 Minutiae Information 144 Second judgment result 145 Judgment reference information 160 Reception 161 Subject ID 162 Past Image Database (Past Image DB) 165 Exclamation Mark CP1, CP2 left and right shoulder joint points CP3, CP4 left and right hip joint points CP5, CP6: The points that indicate the maximum width of the upper body on both sides CP7, CP8: The points that indicate the minimum width of the upper body on both sides FOV Camera field of view H Subject L1, L2, L3, L4, L5, L6, L7, L8 line MP1, MP2, MP3, MP4 midpoint OP Operator PL1, PL2, PL3 Perpendiculars R Radiation ST100, ST110, ST120, ST130, ST140, ST150, ST160, ST170, ST180 Step TH1 First threshold TH2 Second threshold V1, V2, V3 vertebral bodies θ1 First Cobb angle θ2 Second Cobb angle φ1: Inclination of the line connecting the left and right shoulder joint points φ2: Inclination of the line connecting the left and right hip joints

Claims

1. A radiography system including a radiation source that irradiates a subject with radiation, a camera provided on the radiation source, the camera capturing an image of the subject illuminated with light of uniform brightness and outputting an optical image; a processor; Equipped with The processor: acquiring the optical image; deriving spinal column shape information representing a shape of the spinal column of the subject based on the optical image; Radiography system.

2. The processor: extracting feature points of the object from the optical image; extracting derivation reference information for deriving the spine shape information from the feature points; 2. The radiography system according to claim 1, wherein a polynomial representing the shape of the spine is derived as the spine shape information based on the derived reference information.

3. The processor:

3. The radiographic imaging system according to claim 2, wherein a Cobb angle indicating the degree of curvature of the spine is calculated from the polynomial.

4. The processor: The radiation imaging system according to claim 3 , wherein the Cobb angle is displayed on a display.

5. The processor: determining whether the subject requires a second radiographic scoliosis screening based on the Cobb angle; 5. The radiographic imaging system according to claim 3, wherein the system controls displaying the determination result on a display.

6. The processor: extracting, as the feature points, left and right shoulder joint points, left and right hip joint points, points indicating the maximum width of the left and right sides of the upper body, and points indicating the minimum width of the left and right sides of the upper body of the subject; 6. The radiography system according to claim 2, wherein the position coordinates of the midpoint of the line connecting the left and right shoulder joint points, the position coordinates of the midpoint of the line connecting the left and right hip joint points, the position coordinates of the midpoint of the line connecting the points indicating the maximum width, and the position coordinates of the midpoint of the line connecting the points indicating the minimum width are extracted as the derived reference information.

7. The processor: extracting left and right shoulder joint points and left and right hip joint points of the subject as the feature points; 6. The radiography system according to claim 2, wherein the position coordinates of the midpoint of the line connecting the left and right shoulder joint points, the position coordinates of the midpoint of the line connecting the left and right hip joint points, the inclination of the line connecting the left and right shoulder joint points, and the inclination of the line connecting the left and right hip joint points are extracted as the derived reference information.

8. The processor: Prior to deriving the spinal column shape information based on the optical image, acquiring height information of the subject; extracting left and right shoulder joint points and left and right hip joint points of the subject as the feature points; determining whether or not it is necessary to derive the spinal column shape information based on the optical image based on the height of the subject and the length of a line connecting the midpoint of a line connecting the left and right shoulder joint points and the midpoint of a line connecting the left and right hip joint points; 8. The radiation imaging system according to claim 2, wherein control is performed to display the determination result on a display device.

9. The processor:

9. The radiographic imaging system according to claim 1, wherein when spinal column shape information is to be derived again for a subject for whom spinal column shape information was previously derived based on the optical image, control is performed to superimpose a previously acquired optical image on a current optical image and display it on a display device during preparation for imaging before deriving the spinal column shape information.

10. 10. The radiography system according to claim 1, wherein the radiation source is a ceiling-suspended type.

11. 1. A method of operating a radiography system including a radiation source that irradiates a subject with radiation, the method comprising: acquiring an optical image output from a single camera attached to the radiation source, the camera capturing an image of the object illuminated with light of uniform brightness; and deriving spinal column shape information representing a shape of the spinal column of the subject based on the optical image; A method of operating a radiography system comprising:

12. An operating program for a radiography system including a radiation source that irradiates a subject with radiation, acquiring an optical image output from a single camera attached to the radiation source, the camera capturing an image of the object illuminated with light of uniform brightness; and deriving spinal column shape information representing a shape of the spinal column of the subject based on the optical image; An operating program for a radiation imaging system that causes a computer to execute processing including the steps of:

Images