Imaging control device, method, and program

Abstract

To provide a fluoroscopic imaging apparatus, a method, and a program that, when performing fluoroscopic imaging using a plurality of fluoroscopic imaging apparatuses, reduce impact from radiation ray emitted from other fluoroscopic imaging apparatuses.SOLUTION: A processor registers other fluoroscopic imaging apparatuses than a fluoroscopic imaging apparatus controlling fluoroscopic imaging by itself mutually and, when the fluoroscopic imaging apparatus controlling fluoroscopic imaging by itself is instructed with starting of radiation ray emission and emits radiation ray, issue a notification of radiation ray emission to the other fluoroscopic imaging apparatuses.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to an imaging control device, method, and program. [Background technology]

[0002] In surgical operations and catheter treatments, it is necessary to grasp the positional relationship between surgical instruments and human body structures such as bones and blood vessels. For this reason, a subject is photographed during surgery using a fluoroscopic imaging device, and the positional relationship between the surgical instruments and the human body structures is grasped using the fluoroscopic images of radiation that are displayed on a display. However, while the surgical instruments and the human body structures are in a three-dimensional positional relationship, the fluoroscopic images are two-dimensional images. It is difficult to grasp the three-dimensional positional relationship between the surgical instruments and the human body structures by looking at such two-dimensional fluoroscopic images.

[0003] For this reason, a fluoroscopic imaging device has been proposed that includes two sets of detectors and radiation sources, and captures images of a subject from two directions to grasp the three-dimensional positional relationship between a surgical instrument and a human body structure (see Patent Document 1). In the device described in Patent Document 1, the timing of imaging is controlled so that the period during which radiation is irradiated to the first detector of the two detectors does not overlap with the period during which radiation is irradiated to the second detector.

[0004] On the other hand, two fluoroscopic imaging devices are used to capture images of a subject from two directions. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2019-087892 A Summary of the Invention [Problem to be solved by the invention]

[0006] When two fluoroscopic imaging devices are used, radiation irradiated from one device to a subject may be scattered by the subject, causing unintended radiation to be detected by the other device. In this case, the quality of the fluoroscopic images acquired by both devices may be degraded. In addition, if radiation is irradiated from one device to a subject while calibration is being performed by the other device, the one device may detect unnecessary radiation during calibration, which may cause the calibration to fail.

[0007] The present disclosure has been made in consideration of the above circumstances, and has an object to reduce the influence of radiation emitted by other fluoroscopic imaging apparatuses when fluoroscopic imaging is performed using a plurality of fluoroscopic imaging apparatuses. [Means for solving the problem]

[0008] The imaging control device according to the present disclosure is an imaging control device that controls fluoroscopic imaging in each of a plurality of fluoroscopic imaging devices that are used simultaneously when performing fluoroscopic imaging of a subject from a plurality of directions, at least one processor; The processor mutually registers other fluoroscopic imaging apparatuses other than the fluoroscopic imaging apparatus that the processor controls for the fluoroscopic imaging; When an instruction to start emitting radiation is given and the radiation is emitted in the fluoroscopic imaging apparatus which controls the fluoroscopic imaging, the other fluoroscopic imaging apparatus is notified that the radiation has been emitted.

[0009] In the imaging control device according to the present disclosure, the processor sets the fluoroscopic imaging apparatus that the processor controls to a registration waiting state, Searching for the other fluoroscopic imaging apparatuses waiting for registration; The searched other fluoroscopic imaging apparatus may be mutually registered.

[0010] In the imaging control device according to the present disclosure, the processor may notify the other fluoroscopic imaging apparatus that emission of the radiation has started, when an instruction to start emission of the radiation is given.

[0011] In the imaging control device according to the present disclosure, the instruction to start emitting radiation is given by turning on a radiation irradiation switch of the fluoroscopic imaging device, The processor may notify the other fluoroscopic imaging apparatus that emission of the radiation has started by transmitting a radiation irradiation start flag to the other fluoroscopic imaging apparatus.

[0012] In addition, in the imaging control device according to the present disclosure, the processor may be configured to, when an instruction to stop the emission of the radiation is given, notify the other fluoroscopic imaging apparatus that the emission of the radiation has been stopped.

[0013] In the imaging control device according to the present disclosure, the instruction to stop emission of radiation is given by turning off a radiation irradiation switch of the fluoroscopic imaging device, The processor may notify the other fluoroscopic imaging apparatus that emission of the radiation has been stopped by transmitting a radiation irradiation stop flag to the other fluoroscopic imaging apparatus.

[0014] In the imaging control device according to the present disclosure, the fluoroscopic imaging device emits the radiation in a pulsed manner, The processor may notify the other fluoroscopic imaging apparatus that the radiation has been emitted each time the radiation is emitted in a pulsed form.

[0015] In addition, in the imaging control device according to the present disclosure, when the processor is notified of the emission of radiation from the other fluoroscopic imaging device during fluoroscopic imaging of the subject, the processor may perform processing to reduce the influence of the radiation emitted from the other fluoroscopic imaging device on the fluoroscopic image acquired by the fluoroscopic imaging.

[0016] In the imaging control device according to the present disclosure, the process for reducing the influence of radiation may be a scattered ray removal process for removing scattered ray components from the fluoroscopic image.

[0017] In addition, in the imaging control device according to the present disclosure, when the processor calibrates the fluoroscopic imaging device for which it controls the fluoroscopic imaging, the processor may perform the calibration at a timing when no notification of the emission of radiation from the other fluoroscopic imaging device has been received.

[0018] In addition, in the imaging control device according to the present disclosure, the processor may cancel the calibration of the fluoroscopic imaging device for which the processor controls the fluoroscopic imaging when notified of the emission of radiation from the other fluoroscopic imaging device during the calibration of the fluoroscopic imaging device for which the processor controls the fluoroscopic imaging.

[0019] The imaging control method according to the present disclosure is an imaging control method in which a computer controls fluoroscopic imaging in each of a plurality of fluoroscopic imaging apparatuses that are used simultaneously when performing fluoroscopic imaging of a subject from a plurality of directions, the method comprising: mutually registering fluoroscopic imaging apparatuses other than the fluoroscopic imaging apparatus that the fluoroscopic imaging apparatus controls, When an instruction to start emitting radiation is given and the radiation is emitted in the fluoroscopic imaging apparatus which controls the fluoroscopic imaging, the other fluoroscopic imaging apparatus is notified that the radiation has been emitted.

[0020] An imaging control program according to the present disclosure is an imaging control program that causes a computer to execute a process of controlling fluoroscopic imaging in each of a plurality of fluoroscopic imaging apparatuses that are used simultaneously when performing fluoroscopic imaging of a subject from a plurality of directions, the process comprising: a step of mutually registering a fluoroscopic imaging apparatus other than the fluoroscopic imaging apparatus that the fluoroscopic imaging apparatus controls; When an instruction to start emitting radiation is given in the fluoroscopic imaging device which controls the fluoroscopic imaging, the computer executes a procedure of notifying the other fluoroscopic imaging device that the radiation has been emitted. Effect of the Invention

[0021] According to the present disclosure, when performing fluoroscopic imaging using a plurality of fluoroscopic imaging apparatuses, it is possible to reduce the influence of radiation emitted by the other fluoroscopic imaging apparatuses. [Brief description of the drawings]

[0022] [Figure 1] FIG. 1 is a diagram showing an overview of a fluoroscopic imaging system including a plurality of fluoroscopic imaging devices each equipped with an imaging control device according to an embodiment of the present disclosure. [Diagram 2] FIG. 1 is a diagram showing the positional relationship between a first and a second fluoroscopic imaging apparatus; [Diagram 3] FIG. 1 is a diagram showing a schematic configuration of an imaging control device according to an embodiment of the present invention; [Figure 4] FIG. 1 is a diagram showing a functional configuration of an imaging control device according to an embodiment of the present invention; [Diagram 5] Diagram to explain notification timing [Figure 6] FIG. 1 shows a display screen for a fluoroscopic image. [Figure 7] A flowchart showing a radiation emission notification process performed in this embodiment. [Figure 8] A flowchart showing a registration process performed in this embodiment. [Figure 9] A flowchart showing image processing performed in this embodiment. [Figure 10] A flowchart showing a process related to the calibration performed in this embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. Fig. 1 is a schematic block diagram showing a configuration of a fluoroscopic photography system including a plurality of fluoroscopic photography apparatuses each equipped with an imaging control device according to an embodiment of the present disclosure. As shown in Fig. 1, a fluoroscopic photography system 100 according to this embodiment includes first and second fluoroscopic photography apparatuses 1A and 1B that are used simultaneously.

[0024] As shown in Fig. 1, a first fluoroscopic imaging apparatus 1A according to this embodiment includes a C-arm 2. A detection unit 3 is attached to one end of the C-arm 2, and a radiation irradiation unit 4 is attached to the other end thereof so as to face the detection unit 3. The second fluoroscopic imaging apparatus 1B has a similar configuration to the first fluoroscopic imaging apparatus 1A, but Fig. 1 shows only the C-arm 2, the detection unit 3, and the radiation irradiation unit 4, and the other components are not shown.

[0025] Fig. 2 is a diagram showing the positional relationship between the first and second fluoroscopic imaging apparatuses 1A and 1B. In this embodiment, the x-axis is set in the left-right direction of Fig. 1, the y-axis is set in the depth direction of Fig. 1, and the z-axis is set in the direction perpendicular to the surface on which the first and second fluoroscopic imaging apparatuses 1A and 1B shown in Fig. 1 are placed. Fig. 2(A) shows the state in which the fluoroscopic imaging system 100 is seen from the z direction, and Fig. 2(B) shows the state in which the fluoroscopic imaging system 100 is seen from the x direction. In the states shown in Figs. 1 and 2, the first fluoroscopic imaging apparatus 1A is disposed so as to image the subject H in the z direction, and the second fluoroscopic imaging apparatus 1B is disposed so as to image the subject H in the x direction.

[0026] The configuration of the first fluoroscopic imaging apparatus 1A will be described in detail below. Note that the configuration of the second fluoroscopic imaging apparatus 1B is the same as that of the first fluoroscopic imaging apparatus 1A, so a detailed description of the second fluoroscopic imaging apparatus 1B will be omitted.

[0027] The detection unit 3 is provided with a radiation detector 5 such as a flat panel detector. The detection unit 3 also has a circuit board and the like provided with a charge amplifier that converts a charge signal read out from the radiation detector 5 into a voltage signal, a correlated double sampling circuit that samples the voltage signal output from the charge amplifier, and an AD (Analog Digital) conversion unit that converts the voltage signal into a digital signal. In this embodiment, the radiation detector 5 is used, but the device is not limited to the radiation detector 5 as long as it can detect radiation and convert it into an image. For example, a detection device such as an image intensifier can also be used.

[0028] The radiation detector 5 is capable of repeatedly recording and reading out radiation images, and may be a so-called direct type radiation detector which directly converts radiation such as X-rays into electric charges, or a so-called indirect type radiation detector which first converts radiation into visible light and then converts the visible light into an electric charge signal. As a method for reading out the radiation image signal, it is preferable to use a so-called TFT readout method in which the radiation image signal is read out by turning a TFT (Thin Film Transistor) switch on and off, or a so-called optical readout method in which the radiation image signal is read out by irradiating the detector with readout light, but this is not limiting and other methods may also be used.

[0029] The radiation irradiation unit 4 contains a radiation source 6, and radiation is emitted from the radiation source 6 towards the detection unit 3. The radiation source 6 emits X-rays as radiation, and the timing of emission of radiation from the radiation source 6 and the timing of detection of radiation by the radiation detector 5 are controlled by an imaging control unit, which will be described later. In addition, the radiation generation conditions of the radiation source 6, i.e., the selection of the target and filter materials, the tube voltage, the irradiation time, etc., are also controlled by the imaging control unit.

[0030] The C-arm 2 in this embodiment is held by a C-arm holder 7 so as to be movable in the direction of arrow A shown in Fig. 1, so that the angles of the detection unit 3 and the radiation irradiation unit 4 with respect to the z direction (vertical direction) shown in Fig. 1 can be changed together. The C-arm holder 7 also has a shaft 8, which rotatably connects the C-arm 2 to a bearing 9. This allows the C-arm 2 to rotate in the direction of arrow B shown in Fig. 1 with the shaft 8 as the rotation axis.

[0031] As shown in Fig. 1, the first fluoroscopic imaging apparatus 1A includes a main body 10. A plurality of wheels 11 are attached to the bottom of the main body 10, which allows the first fluoroscopic imaging apparatus 1A to be movable. A support shaft 12 that expands and contracts in the z-axis direction in Fig. 1 is provided on the upper part of the housing of the main body 10 in Fig. 1. A bearing 9 is held on the upper part of the support shaft 12 so as to be movable in the direction of arrow C.

[0032] In addition, a foot switch 13 is connected to the main body 10 for turning on and off the emission of radiation from the radiation source 6 of the radiation irradiation unit 4. The foot switch 13 is turned on when the surgeon steps on it during surgery, causing radiation to be emitted from the radiation source 6. The foot switch 13 is turned off when the surgeon takes his foot off the foot switch 13, causing the emission of radiation from the radiation source 6 to stop. The foot switch 13 is an example of a radiation irradiation switch.

[0033] The first fluoroscopic imaging apparatus 1A, having the above-mentioned configuration, irradiates radiation to the subject H lying on his back on the imaging table 15 from below, detects the radiation that has passed through the subject H with the radiation detector 5 of the detection unit 3, and obtains a fluoroscopic image from the front of the subject H. On the other hand, the second fluoroscopic imaging apparatus 1B irradiates radiation to the subject H lying on his back on the imaging table 15 from the side, detects the radiation that has passed through the subject H with the radiation detector 5 of the detection unit 3, and obtains a fluoroscopic image from the side of the subject H. By displaying the two fluoroscopic images thus obtained, which are taken from different directions, the internal state of the subject H can be grasped in three dimensions.

[0034] Here, the C-arm 2 is movable in the directions of arrows A, B and C, and the first and second fluoroscopic imaging apparatuses 1A, 1B are movable on wheels 11. Therefore, the first and second fluoroscopic imaging apparatuses 1A, 1B can image a desired part of subject H lying supine on imaging table 15 from a desired direction while adjusting their own positions and the position of the C-arm 2.

[0035] The main body 10 includes an imaging control device 20 according to the present embodiment for controlling imaging of the first and second fluoroscopic imaging devices 1A and 1B. FIG. 3 is a diagram showing a hardware configuration of the imaging control device. As shown in FIG. 3, the imaging control device 20 is a computer such as a workstation, a server computer, or a personal computer, and includes a CPU (Central Processing Unit) 21, a non-volatile storage 23, and a memory 26 as a temporary storage area. The imaging control device 20 also includes a display 24 such as a liquid crystal display, an input device 25 such as a keyboard and a mouse, and a wired or wireless interface (I / F) 27 that is connected to the detection unit 3, the radiation irradiation unit 4, and the foot switch 13 and is used to exchange information with an external device. The CPU 21, the storage 23, the display 24, the input device 25, the memory 26, and the I / F 27 are connected to a bus 28. The CPU 21 is an example of a processor in the present disclosure.

[0036] The storage 23 is realized by a hard disk drive (HDD), a solid state drive (SSD), a flash memory, etc. The storage 23 as a storage medium stores the shooting control program 22 installed in the shooting control device 20. The CPU 21 reads out the shooting control program 22 from the storage 23, expands it in the memory 26, and executes the expanded shooting control program 22.

[0037] The imaging control program 22 is stored in a storage device of a server computer connected to a network or in a network storage in an externally accessible state, and is downloaded and installed in the imaging control device 20 upon request. Alternatively, the imaging control program 22 is recorded on a recording medium such as a DVD (Digital Versatile Disc) or a CD-ROM (Compact Disc Read Only Memory) and distributed, and is installed in the imaging control device 20 from the recording medium.

[0038] Next, the functional configuration of the imaging control device according to this embodiment will be described. Fig. 4 is a diagram showing the functional configuration of the imaging control device according to this embodiment. As shown in Fig. 4, the imaging control device 20 includes an imaging control unit 31, a registration unit 32, a notification unit 33, an image processing unit 34, a calibration unit 35, and a display control unit 36. When the CPU 21 executes the imaging control program 22, the CPU 21 functions as the imaging control unit 31, the registration unit 32, the notification unit 33, the image processing unit 34, the calibration unit 35, and the display control unit 36.

[0039] When the foot switch 13 is turned on and an on signal is input from the foot switch 13, the imaging control unit 31 causes the radiation source 6 of the radiation irradiation unit 4 to emit radiation based on imaging conditions set by a console (not shown). Furthermore, the imaging control unit 31 detects the radiation that has passed through the subject H using the radiation detector 5 of the detection unit 3 in accordance with the timing at which radiation is emitted from the radiation source 6, and generates a fluoroscopic image of the subject H. The generated fluoroscopic image is displayed on the display 24.

[0040] In this embodiment, while the foot switch 13 is on, the imaging control unit 31 controls the radiation source 6 to emit radiation in pulses. This causes pulsed radiation to be emitted from the radiation source 6, and fluoroscopic images are generated by the radiation detector 5 at timings according to the emission of radiation. Therefore, the display 24 displays the fluoroscopic images continuously like a moving image at timings according to the emission of pulsed radiation.

[0041] The registration unit 32 mutually registers fluoroscopic imaging apparatuses other than the fluoroscopic imaging apparatus for which the imaging control device 20 itself controls fluoroscopic imaging. Specifically, pairing is performed with fluoroscopic imaging apparatuses other than the fluoroscopic imaging apparatus for which the imaging control device 20 itself controls fluoroscopic imaging. In this embodiment, the registration unit 32 of the first fluoroscopic imaging apparatus 1A pairs with the second fluoroscopic imaging apparatus 1B, and the registration unit 32 of the second fluoroscopic imaging apparatus 1B pairs with the first fluoroscopic imaging apparatus 1A.

[0042] The pairing may be performed by using a method similar to short-distance wireless communication such as Bluetooth (registered trademark). That is, the first fluoroscopic imaging apparatus 1A and the second fluoroscopic imaging apparatus 1B are made to recognize each other, and an instruction to perform pairing is given from the input device 25, thereby performing pairing.

[0043] When registering, a user such as a doctor or a medical assistant performs an operation for putting the first fluoroscopic imaging apparatus 1A and the second fluoroscopic imaging apparatus 1B into a registration waiting state using the input device 25. As a result, the registration unit 32 sets the fluoroscopic imaging apparatus in which the registration unit 32 is provided into a registration waiting state. Then, the registration unit 32 searches for other fluoroscopic imaging apparatuses in a registration waiting state. For example, in this embodiment, since both the first and second fluoroscopic imaging apparatuses 1A and 1B are set into a registration waiting state, when the registration unit 32 of the imaging control device 20 of the first fluoroscopic imaging apparatus 1A searches for an apparatus in a registration waiting state, the second fluoroscopic imaging apparatus 1B is searched for. On the other hand, when the registration unit 32 of the imaging control device 20 of the second fluoroscopic imaging apparatus 1B searches for an apparatus in a registration waiting state, the first fluoroscopic imaging apparatus 1A is searched for.

[0044] The registration unit 32 of the imaging control device 20 of the first fluoroscopic imaging apparatus 1A pairs with the found second fluoroscopic imaging apparatus 1B, and mutually registers the found second fluoroscopic imaging apparatus 1B. The registration unit 32 of the imaging control device 20 of the second fluoroscopic imaging apparatus 1B pairs with the found first fluoroscopic imaging apparatus 1A, and mutually registers the found first fluoroscopic imaging apparatus 1A.

[0045] When radiation is emitted from the radiation source 6 by the imaging control unit 31, the notification unit 33 notifies other mutually registered fluoroscopic imaging apparatuses that radiation has been emitted. That is, when radiation is emitted from the radiation source 6 of the first fluoroscopic imaging apparatus 1A, the notification unit 33 of the imaging control device 20 of the first fluoroscopic imaging apparatus 1A notifies the second fluoroscopic imaging apparatus 1B that radiation has been emitted. When radiation is emitted from the radiation source 6 of the second fluoroscopic imaging apparatus 1B, the notification unit 33 of the imaging control device 20 of the second fluoroscopic imaging apparatus 1B notifies the first fluoroscopic imaging apparatus 1A that radiation has been emitted. The notification is performed via short-range wireless communication.

[0046] Fig. 5 is a diagram for explaining the timing of notification. The horizontal axis in Fig. 5 represents time, and from the top to bottom, it shows the on / off of the foot switch 13, the timing of radiation emitted from the radiation source 6, and the timing of receiving a notification. As shown in Fig. 5, in this embodiment, when the foot switch 13 is turned on from an off state, radiation is emitted in pulses from the radiation source 6. The notification unit 33 transmits a flag for starting radiation irradiation to other mutually registered fluoroscopic imaging apparatuses at the timing when the foot switch 13 is turned on.

[0047] Furthermore, the notification unit 33 transmits a flag for notifying other mutually registered fluoroscopic imaging apparatuses of the emission of radiation at the timing when the radiation is emitted in a pulsed form.

[0048] The flag that is first transmitted after the foot switch 13 is turned on indicates both the start of radiation emission and that radiation has been emitted, thereby notifying other mutually registered fluoroscopic imaging apparatuses of the start of radiation emission and the timing at which radiation has been emitted in pulses.

[0049] On the other hand, when the foot switch 13 is turned off, the emission of radiation is stopped, and the notification unit 33 transmits a flag indicating that the emission of radiation has been stopped to the other mutually registered fluoroscopic imaging apparatus. As a result, the other mutually registered fluoroscopic imaging apparatus is notified of the stop of radiation irradiation. Thereafter, the notification unit 33 stops the notification.

[0050] When the image processing unit 34 receives notification of the emission of radiation from another fluoroscopic imaging device other than itself and performs fluoroscopic imaging of the subject H in its own fluoroscopic imaging device, i.e., when fluoroscopic imaging is performed simultaneously in both the first and second fluoroscopic imaging devices 1A, 1B, the image processing unit 34 performs processing to reduce the influence of the radiation emitted from the other fluoroscopic imaging device on the fluoroscopic image acquired by the fluoroscopic imaging.

[0051] Specifically, when the emission of radiation is notified from the second fluoroscopic imaging apparatus 1B and fluoroscopic imaging of the subject H is performed in the first fluoroscopic imaging apparatus 1A, the image processing unit 34 of the imaging control device 20 of the first fluoroscopic imaging apparatus 1A performs processing to reduce the influence of the radiation emitted from the second fluoroscopic imaging apparatus 1B on the fluoroscopic image acquired by fluoroscopic imaging. In this case, the image processing unit 34 of the imaging control device 20 of the second fluoroscopic imaging apparatus 1B performs processing to reduce the influence of the radiation emitted from the first fluoroscopic imaging apparatus 1A on the acquired fluoroscopic image.

[0052] An example of the process for reducing the influence of radiation is a scattered radiation removal process for removing scattered radiation components from a fluoroscopic image. In this embodiment, the image processing unit 34 removes scattered radiation components from the fluoroscopic image 1 using a method described in, for example, Japanese Patent Application Laid-Open No. 2014-207958 and Japanese Patent Application Laid-Open No. 2015-043959. Note that the method for removing scattered radiation components is not limited to this, and any method can be used. Hereinafter, a scattered radiation removal process using the method described in Japanese Patent Application Laid-Open No. 2015-043959 will be described. When using the method described in Japanese Patent Application Laid-Open No. 2015-043959, the body thickness distribution of the subject H and the scattered radiation components for removing the scattered radiation components are simultaneously derived.

[0053] When removing the scattered radiation components, a low-frequency image representing the low-frequency components of the fluoroscopic image may be generated, and the body thickness distribution may be derived using the low-frequency image.

[0054] First, the image processing unit 34 acquires a virtual model K1 of the subject H having an initial body thickness distribution Ts(x,y). The virtual model K1 is data virtually representing the subject H, in which the body thickness according to the initial body thickness distribution Ts(x,y) is associated with the coordinate position of each pixel of the perspective image. Note that the virtual model K1 of the subject H having the initial body thickness distribution Ts(x,y) is pre-stored in the storage 23, but may be acquired from an external server in which the virtual model K1 is saved.

[0055] Next, the image processing unit 34 derives an estimated primary ray image Ip(x,y) that is an estimate of a primary ray image obtained by photographing the virtual model K1, and an estimated scattered ray image Is(x,y) that is an estimate of a scattered ray image obtained by photographing the virtual model K1, based on the virtual model K1, as shown in the following formula (1) and (2). Furthermore, the image processing unit 34 derives an image obtained by combining the estimated primary ray image Ip(x,y) and the estimated scattered ray image Is(x,y) as an estimated image Im(x,y) that is an estimate of a fluoroscopic image obtained by photographing the subject H, as shown in the following formula (3). Ip(x,y) = Io(x,y)×exp(-μls×T(x,y)) (1) Is(x,y) = Io(x,y)*Sσ(T(x,y)) (2) Im(x,y) = Is(x,y) + Ip(x,y) (3)

[0056] Here, (x, y) are the coordinates of the pixel position of the fluoroscopic image, Ip(x, y) is the primary ray component at the pixel position (x, y), Is(x, y) is the scattered ray component at the pixel position (x, y), Io(x, y) is the incident dose to the surface of the subject H at the pixel position (x, y), μls is the attenuation coefficient of the subject H, and Sσ(T(x, y)) is a convolution kernel that represents the scattering characteristics according to the body thickness distribution T(x, y) of the subject H at the pixel position (x, y). Note that when deriving the first estimated image Im(x, y), the initial body thickness distribution Ts(x, y) is used as the body thickness distribution T(x, y) in equations (1) and (2). Equation (1) is based on the known exponential attenuation law, and equation (2) is based on the method described in "JM Boon et al., An analytical model of the scattered radiation distribution in diagnostic radiolog, Med. Phys. 15(5), Sep / Oct 1988" (Reference 1). The incident dose Io(x,y) on the surface of the subject H is an exposure dose derived based on the imaging conditions. The attenuation coefficient μls of the subject H in equation (1) is the attenuation coefficient of soft tissue for the low-energy image of the subject H.

[0057] In addition, * in formula (2) is an operator representing a convolution operation. The nature of the kernel changes depending on the body thickness of the subject H, as well as the distribution of the irradiation field in the fluoroscopic imaging devices 1A and 1B, the distribution of the composition of the subject H, the irradiation dose during imaging, the tube voltage, the imaging distance, and the characteristics of the radiation detector 5 used in the detection unit 3. According to the method described in Reference 1, the scattered radiation can be approximated by convolution of the point spread function (Sσ(T(x,y)) in formula (2)) for the primary radiation. Note that Sσ(T(x,y)) can be experimentally obtained according to the irradiation field information, the subject information, the imaging conditions, and the like.

[0058] In this embodiment, Sσ(T(x,y)) may be calculated based on the irradiation field information, object information, and imaging conditions at the time of imaging, but a table that associates various irradiation field information, various object information, and various imaging conditions with Sσ(T(x,y)) may be stored in the storage 23, and Sσ(T(x,y)) may be obtained by referring to this table based on the irradiation field information, object information, and imaging conditions at the time of imaging. Sσ(T(x,y)) may be approximated by T(x,y).

[0059] Next, the image processing unit 34 corrects the initial body thickness distribution Ts(x,y) of the virtual model K1 so that the difference between the estimated image Im and the fluoroscopic image becomes small. The image processing unit 34 repeatedly generates the estimated image Im using the corrected body thickness distribution T(x,y) and corrects the body thickness distribution T(x,y) until the difference between the estimated image Im and the fluoroscopic image satisfies a predetermined termination condition. When the termination condition is satisfied, the image processing unit 34 subtracts the scattered radiation component Is(x,y) derived by equation (3) from the fluoroscopic image. This removes the scattered radiation component contained in the fluoroscopic image.

[0060] The calibration unit 35 calibrates the fluoroscopic imaging apparatus in which it is provided. Here, the dark current, sensitivity, and the like of the radiation detector 5 included in the first and second fluoroscopic imaging apparatuses 1A and 1B change due to changes in the surrounding environment (temperature, humidity, and the like) or aging. This causes a change in the signal value output from the radiation detector 5. The calibration unit 35 irradiates the radiation detector 5 with radiation from the radiation source 6 in a state in which the subject H is not provided, and acquires the data output from the radiation detector 5 as calibration data for compensating for changes in the signal value output from the radiation detector 5. The process of acquiring the calibration data in this way is called calibration. The calibration data acquired in this way is used to correct the fluoroscopic images acquired by the first and second fluoroscopic imaging apparatuses 1A and 1B.

[0061] The calibration unit 35 performs calibration at a timing when no notification of radiation emission has been received from another mutually registered fluoroscopic imaging apparatus. That is, the calibration unit 35 of the imaging control device 20 of the first fluoroscopic imaging apparatus 1A performs calibration at a timing when no notification of radiation emission has been received from the second fluoroscopic imaging apparatus 1B. Also, the calibration unit 35 of the imaging control device 20 of the second fluoroscopic imaging apparatus 1B performs calibration at a timing when no notification of radiation emission has been received from the first fluoroscopic imaging apparatus 1A.

[0062] Note that if radiation emission is notified from another fluoroscopic imaging apparatus during calibration, the calibration section 35 stops the calibration. That is, if radiation emission is notified from the second fluoroscopic imaging apparatus 1B during calibration, the calibration section 35 of the imaging control device 20 of the first fluoroscopic imaging apparatus 1A stops the calibration. If radiation emission is notified from the first fluoroscopic imaging apparatus 1A during calibration, the calibration section 35 of the imaging control device 20 of the second fluoroscopic imaging apparatus 1B stops the calibration.

[0063] The display control unit 36 ​​displays the fluoroscopic images acquired by the first and second fluoroscopic imaging apparatuses 1A and 1B on the display 24. FIG. 6 is a diagram showing a display screen of the fluoroscopic images. As shown in FIG. 6, a fluoroscopic image 41 acquired by the first fluoroscopic imaging apparatus 1A and a fluoroscopic image 42 acquired by the second fluoroscopic imaging apparatus 1B are displayed side by side on a display screen 40. The fluoroscopic image 41 is a front image of the subject H, and the fluoroscopic image 42 is a side image of the subject H. Note that, although it is preferable that the two fluoroscopic images 41 and 42 are displayed side by side on the displays 24 of both the fluoroscopic imaging apparatuses 1A and 1B, they may be displayed side by side on the display 24 of either one of the fluoroscopic imaging apparatuses 1A and 1B.

[0064] Next, the processing performed in this embodiment will be described. Fig. 7 is a flow chart showing the processing for notifying radiation emission. Fig. 7 shows only the processing performed in one of the first fluoroscopic imaging apparatus 1A and the second fluoroscopic imaging apparatus 1B. First, the registration unit 32 performs pairing to mutually register the first fluoroscopic imaging apparatus 1A and the second fluoroscopic imaging apparatus 1B (step ST1).

[0065] 8 is a flowchart showing the mutual registration process. The registration unit 32 sets the fluoroscopic imaging apparatus in which it is provided to a registration waiting state (step ST11). Next, the registration unit 32 searches for other fluoroscopic imaging apparatuses that are in a registration waiting state (step ST12). Then, the registration unit 32 performs pairing with the other fluoroscopic imaging apparatus found (step ST13), thereby mutually registering the other fluoroscopic imaging apparatus found, and the mutual registration process ends.

[0066] 7, the imaging control unit 31 then starts monitoring whether or not an instruction to start emitting radiation has been issued by turning on the foot switch 13 (step ST2). If step ST2 is positive, the notification unit 33 notifies the start of radiation emission (step ST3), and further notifies the emission of radiation at the timing when radiation is emitted from the radiation source 6 (step ST4).

[0067] Next, the imaging control unit 31 starts monitoring whether or not an instruction to stop the emission of radiation has been issued by turning off the foot switch 13 (step ST5), and if step ST5 is negative, the process returns to step ST4. If step ST5 is positive, the notification unit 33 notifies the user of the stop of the emission of radiation (step ST6), and the process returns to step ST2.

[0068] 9 is a flow chart showing image processing performed in this embodiment. It is assumed that the mutual registration of the first and second fluoroscopic imaging apparatuses 1A and 1B has been completed. First, the imaging control unit 31 starts monitoring whether or not an instruction to start emitting radiation is given by turning on the foot switch 13 (step ST21). If step ST21 is positive, the imaging control unit 31 emits radiation from the radiation source 6 to start fluoroscopic imaging of the subject H (step ST22). Next, the imaging control unit 31 starts monitoring whether or not an instruction to stop emitting radiation is given by turning off the foot switch 13 (step ST23), and if step ST23 is positive, stops fluoroscopic imaging (step ST24).

[0069] Next, the imaging control unit 31 judges whether or not a notification of radiation emission has been received from another fluoroscopic imaging device during imaging (step ST25). If step ST25 is positive, the image processing unit 34 performs image processing (scattered radiation removal processing) on ​​the obtained fluoroscopic image (step ST26). Then, the display control unit 36 ​​displays the fluoroscopic image on the display 24 (step ST27), and ends the processing. If step ST25 is negative, the image processing unit 34 does not perform any processing, but displays the fluoroscopic image obtained in the processing of step ST27 on the display 24, and ends the processing.

[0070] 10 is a flow chart showing a process related to the calibration performed in this embodiment. First, the calibration unit 35 monitors whether a calibration instruction has been issued (step ST31). If the result of step ST31 is positive, the calibration unit 35 determines whether a notification of radiation emission has been received from another fluoroscopic imaging apparatus (step ST32). If the result of step ST32 is positive, the calibration unit 35 suspends the calibration process (step ST33) and returns to step ST32.

[0071] If step ST32 is negative, the calibration unit 35 starts calibration (step ST34). Furthermore, the calibration unit 35 judges whether or not a notification of radiation emission has been received from another fluoroscopic imaging apparatus (step ST35). If step ST35 is negative, the calibration unit 35 judges whether or not the calibration has been completed (step ST36), and if step ST36 is positive, the processing ends. If step ST36 is negative, the processing returns to step ST35. If step ST35 is positive, the calibration unit 35 stops the calibration (step ST37), proceeds to the processing of step ST33, where the calibration unit 35 suspends the calibration processing, and returns to the processing of step ST32.

[0072] In this embodiment, when multiple fluoroscopic imaging apparatuses are used simultaneously to perform fluoroscopic imaging of a subject from multiple directions, the multiple fluoroscopic imaging apparatuses are registered with each other, and when radiation is emitted, the other fluoroscopic imaging apparatuses are notified of the emission of radiation. Therefore, the other fluoroscopic imaging apparatuses that receive the notification can perform various processes taking into consideration the influence of the radiation emitted by the fluoroscopic imaging apparatus that issued the notification. Therefore, when performing fluoroscopic imaging using multiple fluoroscopic imaging apparatuses, the influence of the emission of radiation from the other fluoroscopic imaging apparatuses can be reduced.

[0073] In particular, in this embodiment, when emission of radiation is notified from another fluoroscopic imaging apparatus other than the own, and fluoroscopic imaging of the subject H is performed by the own fluoroscopic imaging apparatus, a process for reducing the influence of the radiation emitted from the other fluoroscopic imaging apparatus, for example, a scattered radiation removal process, is performed on the fluoroscopic image acquired by the fluoroscopic imaging. Therefore, since the influence of the scattered radiation generated by the radiation emitted from the other fluoroscopic imaging apparatus can be removed from the acquired fluoroscopic image, the image quality of the acquired fluoroscopic image can be improved.

[0074] In addition, the calibration is performed at a timing when no notification of radiation emission from other fluoroscopic imaging devices is received. Also, if notification of radiation emission from other imaging devices is received during calibration, the calibration is stopped. This makes it possible to prevent the calibration from being unable to be performed accurately due to the influence of radiation from other fluoroscopic imaging devices.

[0075] In the above embodiment, an example is shown in which two fluoroscopic imaging apparatuses 1A and 1B are used, but it goes without saying that the technique of the present disclosure can also be applied to a case in which three or more fluoroscopic imaging apparatuses are used.

[0076] In the above embodiment, radiation is emitted from the radiation source 6 in a pulsed manner, but the present invention is not limited to this. Radiation may be emitted continuously while the foot switch 13 is turned on. In this case, the notification unit 33 may be configured to continuously notify other fluoroscopic imaging apparatuses that radiation is being emitted.

[0077] Moreover, the radiation in each of the above embodiments is not particularly limited, and in addition to X-rays, α-rays, γ-rays, etc. can be used.

[0078] In the above embodiment, the following various processors can be used as the hardware structure of the processing units that execute various processes, such as the imaging control unit 31, the registration unit 32, the notification unit 33, the image processing unit 34, the calibration unit 35, and the display control unit 36. As described above, the above various processors include a CPU, which is a general-purpose processor that executes software (programs) and functions as various processing units, as well as a programmable logic device (PLD), which is a processor whose circuit configuration can be changed after manufacture, such as an FPGA (Field Programmable Gate Array), and a dedicated electric circuit, which is a processor having a circuit configuration designed specifically for executing specific processes, such as an ASIC (Application Specific Integrated Circuit).

[0079] 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 FPGAs or a combination of a CPU and an FPGA). Also, multiple processing units may be configured with a single processor.

[0080] As an example of configuring multiple processing units with one processor, first, there is a form in which one processor is configured with a combination of one or more CPUs and software, as typified by computers such as client and server, and this processor functions as multiple processing units. Second, there is a form in which a processor is used that realizes the functions of the entire system including multiple processing units with one IC (Integrated Circuit) chip, as typified by System On Chip (SoC), etc. In this way, the various processing units are configured using one or more of the above various processors as a hardware structure.

[0081] Furthermore, more specifically, the hardware structure of these various processors can be an electric circuit that combines circuit elements such as semiconductor elements.

[0082] The following are appended claims to this disclosure. (Additional note 1) 1. An imaging control device that controls fluoroscopic imaging in a plurality of fluoroscopic imaging devices that are used simultaneously when performing fluoroscopic imaging of a subject from a plurality of directions, comprising: at least one processor; The processor mutually registers other fluoroscopic imaging apparatuses other than the fluoroscopic imaging apparatus that the processor controls for the fluoroscopic imaging; an imaging control device that, when an instruction to start emitting radiation is given in a fluoroscopic imaging device that controls the fluoroscopic imaging and the radiation is emitted, notifies the other fluoroscopic imaging device that the radiation has been emitted. (Additional note 2) The processor sets the fluoroscopic imaging apparatus that the processor controls to a registration waiting state; Searching for the other fluoroscopic imaging apparatuses waiting for registration; The imaging control device according to supplementary item 1, wherein the other fluoroscopic imaging devices found by the search are mutually registered. (Additional note 3) 3. The imaging control device according to claim 1 or 2, wherein the processor, when instructed to start emission of the radiation, notifies the other fluoroscopic imaging apparatus that emission of the radiation has started. (Additional note 4) the instruction to start emission of radiation is given by turning on a radiation irradiation switch of the fluoroscopic imaging apparatus; 4. The imaging control device according to claim 3, wherein the processor notifies the other fluoroscopic imaging apparatus that emission of the radiation has started by transmitting a radiation irradiation start flag to the other fluoroscopic imaging apparatus. (Additional note 5) 5. The imaging control device according to claim 1, wherein, when an instruction to stop the emission of the radiation is given, the processor notifies the other fluoroscopic imaging apparatus that the emission of the radiation has been stopped. (Additional note 6) the instruction to stop the emission of radiation is given by turning off a radiation irradiation switch of the fluoroscopic imaging apparatus, 6. The imaging control device according to claim 5, wherein the processor notifies the other fluoroscopic imaging apparatus that emission of the radiation has been stopped by transmitting a radiation irradiation stop flag to the other fluoroscopic imaging apparatus. (Additional note 7) The fluoroscopic imaging device emits the radiation in a pulsed form, 7. The imaging control device according to any one of appended items 1 to 6, wherein the processor notifies the other fluoroscopic imaging apparatus that the radiation has been emitted each time the radiation is emitted in a pulsed manner. (Additional note 8) 8. The imaging control device according to claim 1, wherein, when notified of the emission of the radiation from the other fluoroscopic imaging device during fluoroscopic imaging of the subject, the processor performs a process to reduce an influence of the radiation emitted from the other fluoroscopic imaging device on a fluoroscopic image acquired by the fluoroscopic imaging. (Additional note 9) 9. The imaging control device according to claim 8, wherein the process for reducing the effect of radiation is a scattered radiation removal process for removing scattered radiation components from the fluoroscopic image. (Additional note 10) 10. The imaging control device according to any one of appendixes 1 to 9, wherein when the processor calibrates a fluoroscopic imaging device that the processor controls the fluoroscopic imaging, the processor performs the calibration at a timing when no notification of emission of the radiation from the other fluoroscopic imaging devices has been received. (Additional note 11) 11. The imaging control device according to any one of appendixes 1 to 10, wherein the processor, when notified of emission of the radiation from the other fluoroscopic imaging device during calibration of the fluoroscopic imaging device that the processor controls the fluoroscopic imaging, cancels the calibration. (Additional note 12) 1. An imaging control method in which a computer controls fluoroscopic imaging in a plurality of fluoroscopic imaging apparatuses that are simultaneously used when performing fluoroscopic imaging of a subject from a plurality of directions, comprising: mutually registering fluoroscopic imaging apparatuses other than the fluoroscopic imaging apparatus that the fluoroscopic imaging apparatus controls, An imaging control method for notifying the other fluoroscopic imaging apparatus that, when an instruction to start emitting radiation is given in a fluoroscopic imaging apparatus that controls the fluoroscopic imaging, the other fluoroscopic imaging apparatus is notified that the radiation has been emitted. (Additional note 13) 1. An imaging control program for causing a computer to execute a process for controlling fluoroscopic imaging in each of a plurality of fluoroscopic imaging apparatuses used simultaneously when performing fluoroscopic imaging of a subject from a plurality of directions, the process comprising: a step of mutually registering a fluoroscopic imaging apparatus other than the fluoroscopic imaging apparatus that the fluoroscopic imaging apparatus controls; and when an instruction to start emitting radiation is given in the fluoroscopic imaging apparatus that controls the fluoroscopic imaging, the fluoroscopic imaging apparatus notifies the other fluoroscopic imaging apparatus that the radiation has been emitted. [Explanation of symbols]

[0083] 1A, 1B Fluoroscopy equipment 2 C-arm 3. Photography Department 4. Radiation irradiation section 5. Radiation detectors 6 Radiation source 7 C-arm holder 8 Shaft 9 Bearings 10 Main body 11 wheels 12 Spindle 13 Foot Switch 15. Shooting stand 20 Shooting control device 21 CPU 22 Radiological image processing program 23. Storage 24 Display 25 Input Devices 26 Memory 27 Network Interface 28 Bus 31 Shooting control section 32 Registration Department 33 Notification Department 34 Image processing section 35 Calibration section 40 display screen 41,42 Fluoroscopic images

Claims

1. 1. An imaging control device that controls fluoroscopic imaging in a plurality of fluoroscopic imaging devices that are used simultaneously when performing fluoroscopic imaging of a subject from a plurality of directions, comprising: At least one processor; The processor mutually registers other fluoroscopic imaging apparatuses other than the fluoroscopic imaging apparatus that the processor controls for the fluoroscopic imaging; an imaging control device that, when an instruction to start emitting radiation is given in a fluoroscopic imaging device that controls the fluoroscopic imaging and the radiation is emitted, notifies the other fluoroscopic imaging device that the radiation has been emitted.

2. The processor sets the fluoroscopic imaging apparatus that the processor controls to a registration waiting state; Searching for the other fluoroscopic imaging apparatuses waiting for registration; The imaging control device according to claim 1 , wherein the other fluoroscopic imaging devices found by the search are mutually registered.

3. 3 . The imaging control device according to claim 1 , wherein, when an instruction to start the emission of the radiation is given, the processor notifies the other fluoroscopic imaging apparatus that the emission of the radiation has started.

4. the instruction to start emission of radiation is given by turning on a radiation irradiation switch of the fluoroscopic imaging apparatus; The imaging control device according to claim 3 , wherein the processor notifies the other fluoroscopic imaging apparatus that emission of the radiation has started by transmitting a radiation irradiation start flag to the other fluoroscopic imaging apparatus.

5. The imaging control device according to claim 1 , wherein the processor, when receiving an instruction to stop the emission of the radiation, notifies the other fluoroscopic imaging apparatus that the emission of the radiation has been stopped.

6. the instruction to stop the emission of radiation is given by turning off a radiation irradiation switch of the fluoroscopic imaging apparatus, The imaging control device according to claim 5 , wherein the processor notifies the other fluoroscopic imaging apparatus that emission of the radiation has been stopped by transmitting a radiation irradiation stop flag to the other fluoroscopic imaging apparatus.

7. The fluoroscopic imaging device emits the radiation in a pulsed form, The imaging control device according to claim 1 , wherein the processor notifies the other fluoroscopic imaging apparatus that the radiation has been emitted each time the radiation is emitted in a pulsed form.

8. 8. The imaging control device according to claim 1, wherein, when notified of the emission of the radiation from the other fluoroscopic imaging device during fluoroscopic imaging of the subject, the processor performs processing to reduce an influence of the radiation emitted from the other fluoroscopic imaging device on a fluoroscopic image acquired by the fluoroscopic imaging.

9. The imaging control device according to claim 8 , wherein the process for reducing the effect of radiation is a scattered radiation removal process for removing scattered radiation components from the fluoroscopic image.

10. 10. The imaging control device according to claim 1, wherein when the processor performs calibration of the fluoroscopic imaging device for which the processor itself controls the fluoroscopic imaging, the processor performs the calibration at a timing when no notification of emission of the radiation from the other fluoroscopic imaging device has been received.

11. The imaging control device according to claim 1 , wherein the processor cancels the calibration when notified of emission of the radiation from the other fluoroscopic imaging device during calibration of the fluoroscopic imaging device that the processor controls.

12. 1. An imaging control method in which a computer controls fluoroscopic imaging in a plurality of fluoroscopic imaging apparatuses that are simultaneously used when performing fluoroscopic imaging of a subject from a plurality of directions, comprising: mutually registering fluoroscopic imaging apparatuses other than the fluoroscopic imaging apparatus that the fluoroscopic imaging apparatus controls, An imaging control method for notifying the other fluoroscopic imaging apparatus that, when an instruction to start emitting radiation is given in a fluoroscopic imaging apparatus that controls the fluoroscopic imaging, the other fluoroscopic imaging apparatus is notified that the radiation has been emitted.

13. 1. An imaging control program for causing a computer to execute a process for controlling fluoroscopic imaging in each of a plurality of fluoroscopic imaging apparatuses used simultaneously when performing fluoroscopic imaging of a subject from a plurality of directions, the process comprising: a step of mutually registering a fluoroscopic imaging apparatus other than the fluoroscopic imaging apparatus that the fluoroscopic imaging apparatus controls; and when an instruction to start emitting radiation is given in the fluoroscopic imaging apparatus which controls the fluoroscopic imaging, the fluoroscopic imaging apparatus notifies the other fluoroscopic imaging apparatus that the radiation has been emitted.

Images