X-ray imaging system

Abstract

In this X-ray imaging system (100), display units (4, 5) are configured to, when setting at least one of a target angle (42Ac) of a first arm (23A) and a target angle (42Bc) of a second arm (23B) by operation units (5, 6), display on a dose distribution screen (42) a range (42d) in which the first arm (23A) and the second arm (23B) do not interfere with each other.

Description

X-ray imaging system

[0001] The present invention relates to an X-ray imaging system that displays the distribution of X-ray dose.

[0002] An X-ray imaging system that displays the distribution of X-ray doses is known, for example, as disclosed in U.S. Patent Application Publication No. 2011 / 0317815.

[0003] U.S. Patent Application Publication No. 2011 / 0317815 discloses an X-ray imaging device that displays the distribution of X-ray doses irradiated onto the surface of a patient. The X-ray imaging device disclosed in U.S. Patent Application Publication No. 2011 / 0317815 includes an arm that supports, in opposing positions, an X-ray irradiation unit having an X-ray source that irradiates X-rays and an X-ray detection unit that detects the X-rays irradiated from the X-ray irradiation unit.

[0004] US Patent Application Publication No. 2011 / 0317815

[0005] Conventionally, X-ray imaging devices such as those described in U.S. Patent Application Publication No. 2011 / 0317815 are used in interventional radiology (IVR). When performing treatment while irradiating X-rays in IVR, it is necessary to perform treatment while changing the angle of the arm in accordance with the increase in the X-ray dose in order to prevent the X-ray dose from becoming locally high on the body surface of the subject (patient).

[0006] Furthermore, conventional X-ray imaging devices such as those disclosed in US Patent Application Publication No. 2011 / 0317815 may include two arms that support an X-ray irradiation unit and an X-ray detection unit facing each other.

[0007] For this reason, in a configuration with two arms, it is conceivable that an operator sets a target angle for the arm while viewing the distribution of X-ray dose, and then moves the arm using a movement mechanism based on the set target angle. However, when an operator sets a target angle for the arm while viewing the distribution of X-ray dose, the operator is unable to recognize the extent to which the two arms will interfere with each other. For this reason, in a configuration with two arms, there is a problem in that an operator may set the target angle for the arm while viewing the distribution of X-ray dose such that the two arms will interfere with each other.

[0008] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide an X-ray imaging system having two arms that allows an operator to prevent setting the target angles of the arms in a way that causes interference between the two arms while viewing the distribution of X-ray dose.

[0009] An X-ray imaging system according to one aspect of the present invention includes a first arm that supports, in opposing relation, a first X-ray irradiator having an X-ray source that irradiates X-rays and a first X-ray detection unit that detects the X-rays irradiated from the first X-ray irradiator; a second arm that supports, in opposing relation, a second X-ray irradiator having an X-ray source and a second X-ray detection unit that detects the X-rays irradiated from the second X-ray irradiator; and a first radiation dose distribution that is an X-ray dose irradiated by the first X-ray irradiator, the first radiation dose distribution being associated with the angles of the first arm and the second arm, the second radiation dose distribution being associated with the angles of the first arm and the second arm, and a first radiation dose distribution being an X-ray irradiation range by the first X-ray irradiator. the first arm and the second arm based on the target angle set by the operation unit, and a moving mechanism that moves the first arm and the second arm based on the target angle set by the operation unit, and the display unit is configured to display, on the dose distribution screen, a range within which the first arm and the second arm do not interfere with each other when at least one of the target angle of the first arm and the target angle of the second arm is set by the operation unit.

[0010] In one aspect of the present invention, in the X-ray imaging system, as described above, the display unit is configured to display, on the dose distribution screen, a range within which the first arm and the second arm do not interfere with each other when setting at least one of the target angles of the first arm and the second arm using the operation unit. This allows the operator to visually recognize the range within which the first arm and the second arm do not interfere with each other when setting at least one of the target angles of the first arm and the second arm using the operation unit on the dose distribution screen. This prevents the operator, in a configuration including two arms, from setting the target angles of the arms in a way that causes the two arms to interfere with each other while viewing the X-ray dose distribution.

[0011] 1 is a schematic diagram for explaining the configuration of an X-ray imaging system according to this embodiment. FIG. 2 is a block diagram showing the overall configuration of the X-ray imaging system according to this embodiment. FIG. 3 is a diagram for explaining a monitor display according to this embodiment. FIG. 4 is a block diagram for explaining the functional configuration of a dose calculation processing unit according to this embodiment. FIG. 5 is a diagram for explaining acquisition of the positional relationship between the top plate and the first and second imaging units. FIG. 6 is a diagram for explaining calculation of the X-ray dose distribution in a virtual model. FIG. 7 is a diagram for explaining correspondence between the surface of the virtual model and the imaging unit angle. FIG. 8 is a diagram for explaining an angular dose image and a color scale image. FIG. 9 is a diagram for explaining updating of the angular dose image when the top plate is moved in the up-down direction of the subject. FIG. 10 is a diagram for explaining updating of the angular dose image when the top plate is moved in the left-right direction of the subject. FIG. 11 is a diagram for explaining updating of the angular dose image when the top plate is moved in the vertical direction. FIG. 12 is a diagram for explaining updating of the angular dose image when the angle interval is changed. FIG. 13 is a diagram for explaining setting of a target angle for the first arm. FIG. 14 is a diagram for explaining setting of a target angle for the second arm. FIG. 15 is a diagram for explaining a warning display indicating that the set target angle is within a range in which the first arm and the second arm interfere with each other. FIG. 1 is a diagram for explaining the display of a warning indicating that the set target angle is in a range in which the first dose and the second dose exceed predetermined thresholds. FIG. 2 is a diagram showing an example of a display of a recommended angle region. FIG. 3 is a diagram showing an example of a timeline display. FIG. 4 is a diagram showing an example of a display for selecting the imaging unit angle on a touch panel. FIG. 5 is a diagram showing a display of an angle dose image on a touch panel. FIG. 6 is a diagram showing an example of a display of a three-dimensional image.

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0013] The configuration of an X-ray imaging system 100 according to an embodiment of the present invention will be described with reference to FIGS.

[0014] As shown in FIG. 1 , the X-ray imaging system 100 is an apparatus that captures an X-ray image 41 (see FIG. 3 ) of the inside of a subject P, such as a human body, by irradiating the subject P with X-rays from outside the subject. An operator using the X-ray imaging system 100 can perform various treatments, such as interventional radiology (IVR), by inserting a treatment instrument such as a catheter into the blood vessels of the subject P (for example, the blood vessels of the subject P's heart) while visually viewing the X-ray image 41 of the subject P. Note that the term "operator using the X-ray imaging system 100" is not limited to an operator (doctor) who treats the subject P, but also includes an operator who simply operates the X-ray imaging system 100 without being directly involved in the treatment of the subject P.

[0015] 1 and 2, the X-ray imaging system 100 includes a tabletop 1, a first imaging unit 2A, a second imaging unit 2B, a moving mechanism 3, a monitor 4, a touch panel 5, and an operation unit 6. The monitor 4 is an example of a "display unit" in the claims. The touch panel 5 is an example of a "display unit" and an "operation unit" in the claims.

[0016] 1 and 2, the tabletop 1 is configured as an examination table on which a subject P lies (is placed) when an X-ray is taken. The tabletop 1 is supported by a tabletop support part 11.

[0017] 1 and 2, the first imaging unit 2A captures an X-ray image 41 (see FIG. 3) of the subject P. The first imaging unit 2A also includes a first X-ray irradiator 21A and a first X-ray detector 22A. The first X-ray irradiator 21A and the first X-ray detector 22A are supported by a first arm 23A so as to face each other across the tabletop 1 on which the subject P lies. That is, the X-ray imaging system 100 includes the first arm 23A that supports the first X-ray irradiator 21A and the first X-ray detector 22A so as to face each other.

[0018] The first X-ray irradiator 21A includes an X-ray source 21Aa and a collimator 21Ab. The X-ray source 21Aa irradiates X-rays onto a subject P lying on the tabletop 1. The X-ray source 21Aa is connected to a high-voltage generator (not shown) and is an X-ray tube that generates X-rays when a high voltage is applied thereto and irradiates the subject P with the generated X-rays. The X-ray source 21Aa is disposed with its X-ray emission direction facing the detection surface of the first X-ray detector 22A. The collimator 21Ab is configured to adjust the irradiation field of the X-rays irradiated by the X-ray source 21Aa. The first X-ray irradiator 21A generates X-rays according to preset imaging conditions, such as tube voltage, tube current, and time interval between X-ray irradiation, under the control of a control device 101 (described later).

[0019] The first X-ray detection unit 22A detects X-rays irradiated from the first X-ray irradiator 21A. The first X-ray detection unit 22A then outputs a detection signal corresponding to the detected X-ray intensity. The first X-ray detection unit 22A is configured by, for example, an FPD (Flat Panel Detector). The first X-ray detection unit 22A is connected to a control device 101, which will be described later.

[0020] The second imaging unit 2B captures an X-ray image 41 (see FIG. 3 ) of the subject P. The second imaging unit 2B also includes a second X-ray irradiator 21B and a second X-ray detector 22B. The second X-ray irradiator 21B and the second X-ray detector 22B are supported by a second arm 23B so as to face each other across the tabletop 1 on which the subject P lies. That is, the X-ray imaging system 100 includes the second arm 23B that supports the second X-ray irradiator 21B and the second X-ray detector 22B so as to face each other.

[0021] The second X-ray irradiator 21B includes an X-ray source 21Ba and a collimator 21Bb. The X-ray source 21Ba irradiates X-rays onto the subject P lying on the tabletop 1. The X-ray source 21Ba is connected to a high-voltage generator (not shown) and is an X-ray tube that generates X-rays when a high voltage is applied thereto and irradiates the subject P with the generated X-rays. The X-ray source 21Ba is disposed with its X-ray emission direction facing the detection surface of the second X-ray detector 22B. The collimator 21Bb is configured to adjust the irradiation field of the X-rays irradiated by the X-ray source 21Ba. The second X-ray irradiator 21B generates X-rays according to preset imaging conditions, such as tube voltage, tube current, and time interval between X-ray irradiation, under the control of a control device 101 (described later).

[0022] The second X-ray detection unit 22B detects the X-rays irradiated from the second X-ray irradiator 21B. The second X-ray detection unit 22B then outputs a detection signal corresponding to the detected X-ray intensity. The second X-ray detection unit 22B is configured by, for example, an FPD (Flat Panel Detector). The second X-ray detection unit 22B is connected to a control device 101, which will be described later.

[0023] The movement mechanism 3 moves at least one of the tabletop 1, the first imaging unit 2A, and the second imaging unit 2B. Specifically, the movement mechanism 3 changes the relative positional relationship between the tabletop 1 and the first imaging unit 2A, thereby changing the position of the body surface of the subject P irradiated with X-rays by the first X-ray irradiator 21A. The movement mechanism 3 also changes the relative positional relationship between the tabletop 1 and the second imaging unit 2B, thereby changing the position of the body surface of the subject P irradiated with X-rays by the second X-ray irradiator 21B.

[0024] In detail, the movement mechanism 3 includes a tabletop movement mechanism 31 that moves the tabletop 1, a first imager-moving mechanism 32A that changes the angle of the first imager 2A (the angle of the first arm 23A), and a second imager-moving mechanism 32B that changes the angle of the second imager 2B (the angle of the second arm 23B). The tabletop movement mechanism 31 is configured to move the tabletop 1 in the horizontal direction (a direction parallel to the horizontal plane) and the vertical direction. The tabletop movement mechanism 31 is also configured to change the angle of the tabletop 1. The first imager-moving mechanism 32A is configured to change the position and angle of the first imager 2A (first arm 23A). The first imager-moving mechanism 32A is also configured to change the distance between the first X-ray irradiator 21A and the first X-ray detector 22A. The second imager-moving mechanism 32B is configured to change the position and angle of the second imager 2B (second arm 23B). The second imaging unit moving mechanism 32B is configured to be able to change the distance between the second X-ray irradiator 21B and the second X-ray detector 22B. The moving mechanism 3 includes, for example, a servo motor controlled by a control device 101 described later.

[0025] For example, when cardiac catheterization is performed using interventional radiology (IVR), cardiac fluoroscopic images (X-ray images 41 (see FIG. 3 )) are continuously acquired as moving images, and the treatment is performed while changing the X-ray irradiation angle by the first X-ray irradiator 21A (the angle of the first imaging unit 2A) and the X-ray irradiation angle by the second X-ray irradiator 21B (the angle of the second imaging unit 2B) to suppress an increase in the local X-ray dose on the body surface (skin) of the subject P. The movement mechanism 3 is configured to change the angles of the first imaging unit 2A and the second imaging unit 2B through control processing by the control device 101, which will be described later. The angle of the first imaging unit 2A is the angle in the direction in which the first X-ray irradiator 21A and the first X-ray detection unit 22A face each other. The angle of the second imaging unit 2B is the angle in the direction in which the second X-ray irradiator 21B and the second X-ray detection unit 22B face each other. The angle of the first imaging unit 2A is changed based on a state in which the first X-ray irradiator 21A and the first X-ray detector 22A are arranged along the vertical direction, so that the first X-ray detector 22A moves to LAO (left anterior oblique) and RAO (right anterior oblique), which are left and right directions of the subject P, and to CRA (cranial) and CAU (caudal), which are up and down directions (head side and leg side) of the subject P. Similarly, the angle of the second imaging unit 2B is changed based on a state in which the second X-ray irradiator 21B and the second X-ray detector 22B are arranged along the vertical direction, so that the second X-ray detector 22B moves to LAO and RAO and to CRA and CAU.

[0026] As shown in Fig. 3, the monitor 4 displays an X-ray image 41, an angular dose image 42, a color scale image 43, a maximum value display 44, a timeline display 45 (see Fig. 18), and a three-dimensional image 46 under the control of a control device 101 (described later). The monitor 4 includes, for example, a display monitor that displays video signals of still images or moving images output from a device such as a computer. The display on the monitor 4 will be described in detail later. The angular dose image 42 is an example of a "dose distribution screen" in the claims.

[0027] 1 and 2 , the touch panel 5 accepts input operations by an operator (surgeon or operator) to operate the X-ray imaging system 100. The touch panel 5 is configured to transmit input signals based on the accepted input operations to a control device 101 and a dose calculation device 102 (described later). Specifically, the touch panel 5 is a tablet PC having a calculation device such as a CPU (Central Processing Unit) and a storage device such as a flash memory, and is configured to be able to communicate with the control device 101 and the dose calculation device 102 (described later). The touch panel 5 is also configured to display an indication regarding selection of the angle of the first imaging unit 2A and the angle of the second imaging unit 2B. The display on the touch panel 5 will be described in detail later.

[0028] The operation unit 6, like the touch panel 5, accepts input operations by an operator (surgeon or operator). The operation unit 6 includes, for example, a pointing device such as a keyboard or a mouse. The operation unit 6 also includes an irradiation button that accepts an input operation to irradiate X-rays, and a movement operation button that accepts an input operation to move the tabletop 1, the first imaging unit 2A, and the second imaging unit 2B. The operation unit 6 is also configured to transmit an input signal based on the accepted input operation to the control device 101, which will be described later.

[0029] That is, the operation of each unit of the X-ray imaging system 100 is controlled based on input operations on the touch panel 5 and the operation unit 6. For example, the touch panel 5 and the operation unit 6 accept an input operation to select (change) an angle at which X-ray imaging is performed from among the multiple angles of the first imaging unit 2A. Also, they accept an input operation to select (change) an angle at which X-ray imaging is performed from among the multiple angles of the second imaging unit 2B. Also, the touch panel 5 and the operation unit 6 accept an input operation to change the display on the monitor 4. Also, the touch panel 5 and the operation unit 6 accept an input operation to irradiate X-rays.

[0030] As shown in FIG. 2 , the X-ray imaging system 100 includes a control device 101 , a dose calculation device 102 , and a three-dimensional image generation device 103 .

[0031] The control device 101 is a computer (arithmetic device) including a CPU, a GPU (Graphics Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The control device 101 also includes storage devices such as an HDD (Hard Disk Drive) and an SSD (Solid State Drive). The control device 101 controls the operation of the X-ray imaging system 100 based on operations by an operator. The control device 101 also controls the display of the monitor 4. That is, the control device 101 controls X-ray imaging by controlling the first imaging unit 2A and the second imaging unit 2B, thereby generating an X-ray image 41. Specifically, the control device 101 controls the operations of the first X-ray irradiator 21A and the second X-ray irradiator 21B to irradiate X-rays onto the subject P. The control device 101 also acquires detection signals output from the first X-ray detector 22A and the second X-ray detector 22B, and generates an X-ray image 41 based on the acquired detection signals.

[0032] 3, the X-ray image 41 is an image showing the inside of the subject P based on a detection signal of X-rays that have passed through the subject P. The X-ray images 41 are continuously acquired so that an operator can observe the state inside the body of the subject P in real time. The X-ray images 41 are configured to be displayed on the monitor 4 as moving images.

[0033] Furthermore, the control device 101 changes the relative position and angle between the tabletop 1, the first imaging unit 2A, and the second imaging unit 2B, and the relative position and angle between the tabletop 1 and the second imaging unit 2B, by controlling the operation of the movement mechanism 3 based on input operations on the touch panel 5 and the operation unit 6. In other words, the control device 101 is configured to control the operation of the movement mechanism 3 to set the angle at which X-ray imaging is to be performed by the first imaging unit 2A and the second imaging unit 2B.

[0034] The dose calculation device 102 has a dose calculation processing unit 70, which is a computer (arithmetic device) including a CPU, a GPU, a ROM, a RAM, etc. The dose calculation device 102 also has a storage device such as an HDD or SSD that stores a predetermined program for operating the dose calculation processing unit 70. The storage device also stores a virtual model Pa (described later) and various setting values ​​(parameters), etc. The storage device also stores a history of the dose of X-rays irradiated to the subject P. The dose calculation processing unit 70 is configured to calculate the dose of X-rays irradiated to the subject P.

[0035] The three-dimensional image generation device 103 is a computer (arithmetic device) including a CPU, a GPU, a ROM, a RAM, etc., similar to the control device 101 and the dose calculation device 102. The three-dimensional image generation device 103 generates a three-dimensional image 46. The generation of the three-dimensional image 46 will be described in detail later.

[0036] In the X-ray imaging system 100, the control device 101, the dose calculation device 102, and the three-dimensional image generation device 103 are configured to transmit and receive signals to and from each other. The control device 101, the dose calculation device 102, and the three-dimensional image generation device 103 are connected to each other via a computer network such as a LAN (Local Area Network).

[0037] 3 , the monitor 4 displays the X-ray dose calculated by the dose calculation device 102. Specifically, the monitor 4 is configured to display an angular dose image 42 generated by the dose calculation device 102. Specifically, the angular dose image 42 generated by the dose calculation device 102 is transmitted to the control device 101. The control device 101 then causes the monitor 4 to display the angular dose image 42.

[0038] 4 , the dose calculation processing unit 70 of the dose calculation device 102 includes, as functional components, a positional relationship acquisition unit 71, a model dose calculation unit 72, an angle association unit 73, an angular dose calculation unit 74, an image generation unit 75, an irradiation region calculation unit 76, a storage processing unit 77, and a dose prediction unit 78. That is, the dose calculation processing unit 70 functions as the positional relationship acquisition unit 71, the model dose calculation unit 72, the angle association unit 73, the angular dose calculation unit 74, the image generation unit 75, the irradiation region calculation unit 76, the storage processing unit 77, and the dose prediction unit 78 by executing a predetermined program stored in the storage device.

[0039] 5, the positional relationship acquisition unit 71 (dose calculation processing unit 70) is configured to acquire the virtual positional relationship between the virtual model Pa and the first and second imaging units 2A and 2B based on the positional relationship between the tabletop 1 and the first and second imaging units 2A and 2B. Note that the second imaging unit 2B is not shown in FIG. 5.

[0040] Specifically, the dose calculation device 102 is configured to acquire the position and angle of the tabletop 1, the position and angle of the first imaging unit 2A, and the position and angle of the second imaging unit 2B from the control device 101. The positional relationship acquisition unit 71 then acquires the positional relationship between the tabletop 1, the first imaging unit 2A, and the second imaging unit 2B in the three-dimensional virtual space based on the acquired position and angle of the tabletop 1, the position and angle of the first imaging unit 2A (the first X-ray irradiator 21A and the first X-ray detector 22A), and the position and angle of the second imaging unit 2B (the second X-ray irradiator 21B and the second X-ray detector 22B). The positional relationship acquisition unit 71 also acquires a virtual model Pa (see FIG. 6 ) representing the subject P lying on the tabletop 1 in the three-dimensional virtual space. The virtual model Pa is a three-dimensional model having a cylindrical shape. The virtual model Pa is pre-stored in a storage device of the dose calculation device 102. The size of the virtual model Pa may be changed depending on the body size (BMI: Body Mass Index, etc.) of the subject P. The positional relationship acquisition unit 71 acquires the virtual positional relationship between the first imaging unit 2A and the second imaging unit 2B and the virtual model Pa in the three-dimensional virtual space. The position of the virtual model Pa in the three-dimensional virtual space is set based on the position and angle of the tabletop 1.

[0041] 6, the model dose calculation unit 72 (dose calculation processing unit 70) is configured to calculate the distribution of X-ray doses on the surface of the three-dimensional virtual model Pa based on the dose of X-rays irradiated to the subject P by X-ray irradiation from the first imaging unit 2A (first X-ray irradiator 21A) and the dose of X-rays irradiated to the subject P by X-ray irradiation from the second imaging unit 2B (second X-ray irradiator 21B). Note that the second imaging unit 2B is not shown in FIG.

[0042] Specifically, the dose calculation device 102 acquires from the control device 101 imaging conditions such as the period of X-ray irradiation, the imaging unit angles (the angles of the first imaging unit 2A and the second imaging unit 2B), the tube voltage, the tube current, and the time interval between X-ray irradiation. The dose calculation device 102 also acquires from the control device 101 the X-ray dose irradiated to the subject P and the imaging unit angles in association with each other. The model dose calculation unit 72 then calculates an integrated value of the X-ray dose on the surface of the virtual model Pa based on the X-ray dose irradiated to the subject P, the imaging unit angles, and the virtual positional relationship between the first imaging unit 2A and the second imaging unit 2B and the virtual model Pa in the three-dimensional virtual space. The model dose calculation unit 72 then updates the integrated value of the X-ray dose on the surface of the virtual model Pa every time X-rays are irradiated by the first imaging unit 2A and the second imaging unit 2B. Specifically, the model dose calculation unit 72 calculates the integrated value of the X-ray dose for each infinitesimal element on the surface of the virtual model Pa divided into infinitesimal elements.

[0043] As shown in Figure 7, the angle matching unit 73 (dose calculation processing unit 70) is configured to match the imaging unit angle to the surface of the virtual model Pa based on the imaging unit angle (the angle of the first imaging unit 2A and the angle of the second imaging unit 2B) and the position on the surface of the virtual model Pa where X-rays are irradiated.

[0044] Specifically, the angle association unit 73 acquires positions on the surface of the virtual model Pa where X-rays are irradiated for each image capture unit angle (the angle of the first image capture unit 2A and the angle of the second image capture unit 2B) at predetermined angular intervals based on the virtual positional relationship between the first image capture unit 2A and the second image capture unit 2B and the virtual model Pa in the three-dimensional virtual space. For example, when the predetermined angular intervals are 10 degrees, the angle association unit 73 acquires the image capture unit angle when the image capture unit angle is vertical (reference direction) as (0,0), the image capture unit angle when tilted 10 degrees toward the LAO as (10,0), and the image capture unit angle when tilted 20 degrees toward the LAO as (20,0). Furthermore, the angle association unit 73 acquires the image capture unit angle when tilted 10 degrees toward the LAO and 10 degrees toward the CRA as (10,10). Based on the positional relationship between the first imaging unit 2A and the second imaging unit 2B and the virtual model Pa at predetermined angular intervals (for example, 10 degrees) in the three-dimensional virtual space, the angle association unit 73 maps the positions of the centers of the irradiation axes (centers of the field of view) of the X-rays irradiated onto the surface of the virtual model Pa from the first imaging unit 2A and the second imaging unit 2B at predetermined angular intervals so as to associate them on the surface of the virtual model Pa. Then, the angle association unit 73 acquires angular regions partitioned on the surface of the virtual model Pa by connecting the positions of the centers of the irradiation axes (centers of the field of view) at predetermined angular intervals mapped on the surface of the virtual model Pa.

[0045] 8 , the angular dose calculator 74 (dose calculation processor 70) is configured to calculate the X-ray dose in each of a plurality of angular regions partitioned at predetermined angular intervals of the imaging unit angles, based on the X-ray dose distribution on the surface of the virtual model Pa calculated by the model dose calculator 72 and the imaging unit angles (the angle of the first imaging unit 2A and the angle of the second imaging unit 2B) associated with the surface of the virtual model Pa by the angle association unit 73. The image generator 75 (dose calculation processor 70) then generates an angular dose image 42 in which the magnitude of the X-ray dose in each of the plurality of angular regions calculated by the angular dose calculator 74 can be distinguished. The angular dose image 42 is an image in which the plurality of angular regions are partitioned in a lattice pattern at predetermined angular intervals of the imaging unit angles, and the magnitude of the X-ray dose in each of the plurality of angular regions partitioned in the lattice pattern can be distinguished. That is, the angular dose image 42 is an image that includes the angles of the first arm 23A and the second arm 23B, as well as a first dose distribution, which is the dose of X-rays irradiated by the first X-ray irradiator 21A, and a second dose distribution, which is the dose of X-rays irradiated by the second X-ray irradiator 21B, that are associated with the angles of the first arm 23A and the second arm 23B. The angular dose image 42 generated by the image generator 75 is output from the dose calculation device 102 to the control device 101 and displayed on the monitor 4.

[0046] Specifically, the angular dose calculator 74 acquires the maximum X-ray dose value in each of angular regions (see FIG. 7 ) defined at predetermined angular intervals on the surface of the virtual model Pa using the angle association unit 73 based on the distribution of X-ray dose on the surface of the virtual model Pa. The image generator 75 then generates an angular dose image 42 in which each angular region is defined as a square at predetermined angular intervals (e.g., 10 degrees), with the directions of LAO and RAO as the horizontal axis and the directions of CRA and CAU as the vertical axis. That is, the angular dose image 42 is configured so that the size of the angular interval on the horizontal axis and the size of the angular interval on the vertical axis are approximately equal (scaled). The ranges of the vertical and horizontal axes are set based on the movable angular ranges of the first and second imaging units 2A and 2B.

[0047] In the angular dose image 42, the magnitude of the X-ray dose in each of the multiple angular regions is represented by a different color. For example, in the angular dose image 42, the magnitude of the X-ray dose is represented by five colors, purple, red, orange, yellow, and green, in descending order of dose. In Fig. 8, differences in the color coding are represented by different hatching.

[0048] 3 and 8, the monitor 4 is configured to display a color scale image 43, which indicates the color coding of a plurality of angular regions in the angular dose image 42 corresponding to the magnitude of the X-ray dose, separately from the angular dose image 42. The monitor 4 is also configured to display preset X-ray dose thresholds 43a and 43b in a distinguishable manner on the color scale image 43.

[0049] Specifically, the image generator 75 generates a color scale image 43 that indicates the color-coding criteria for the angular dose image 42. In the color scale image 43, regions are color-coded in purple, red, orange, yellow, and green, in descending order of X-ray dose, corresponding to the color coding of the angular dose image 42. Furthermore, numerical values ​​indicating specific X-ray dose values ​​that serve as the color-coding criteria are displayed at the boundaries between the five regions. For example, in the color scale image 43, regions where the maximum X-ray dose is greater than 4000 mGy are displayed as purple, regions where the maximum X-ray dose is greater than 3000 mGy but not greater than 4000 mGy are displayed as red, regions where the maximum X-ray dose is greater than 2000 mGy but not greater than 3000 mGy are displayed as orange, regions where the maximum X-ray dose is greater than 1000 mGy but not greater than 2000 mGy are displayed as yellow, and regions where the maximum X-ray dose is greater than 0 mGy but not greater than 1000 mGy are displayed as green.

[0050] Furthermore, displays indicating preset X-ray dose thresholds 43a and 43b are displayed so as to be superimposed on the color scale image 43. The thresholds 43a and 43b are set in advance by the operator. Furthermore, if the X-ray dose exceeds the thresholds 43a and 43b in the angular region currently being irradiated during X-ray irradiation, a warning message is displayed on the monitor 4. The warning message is displayed, for example, as text (text information) in a predetermined portion of the monitor 4. The display of the warning message on the monitor 4 is stopped after a predetermined time has elapsed or by an input operation on the operation unit 6, for example.

[0051] The monitor 4 may also display the total skin dose of the subject P during surgery. For example, the dose calculation processing unit 70 calculates the total X-ray dose over the entire body surface of the subject P based on the acquired X-ray dose. The calculated total X-ray dose is then output from the dose calculation device 102 to the control device 101, and is displayed on the monitor 4 by control processing by the control device 101.

[0052] 9 to 11 , when the positional relationship between the tabletop 1 and the first and second image capturing units 2A and 2B is changed, the angle associating unit 73 is configured to update the association of image capturing unit angles (the angle of the first image capturing unit 2A and the angle of the second image capturing unit 2B) on the surface of the virtual model Pa based on the virtual positional relationship acquired by the positional relationship acquiring unit 71. The angular dose calculating unit 74 is configured to update the X-ray dose in each of the plurality of angular regions based on the updated association of image capturing unit angles on the surface of the virtual model Pa. The image generating unit 75 is configured to regenerate the angular dose image 42 based on the updated X-ray dose in each of the plurality of angular regions.

[0053] Specifically, when an operation to change the position and angle of the tabletop 1 is accepted, the positional relationship acquisition unit 71 updates the position and angle of the virtual model Pa in the three-dimensional virtual space based on information indicating the position and angle of the tabletop 1 newly acquired from the control device 101. Furthermore, when an operation to change the position and angle of the first imaging unit 2A is accepted, the positional relationship acquisition unit 71 updates the position and angle of the first imaging unit 2A in the three-dimensional virtual space based on information indicating the position and angle of the first imaging unit 2A newly acquired from the control device 101. Furthermore, when an operation to change the position and angle of the second imaging unit 2B is accepted, the positional relationship acquisition unit 71 updates the position and angle of the second imaging unit 2B in the three-dimensional virtual space based on information indicating the position and angle of the second imaging unit 2B newly acquired from the control device 101. That is, when the positional relationship acquisition unit 71 acquires a signal from the control device 101 indicating that the positional relationship between the tabletop 1 and the first and second imaging units 2A and 2B has been changed, the positional relationship acquisition unit 71 changes the virtual positional relationship between the virtual model Pa and the first and second imaging units 2A and 2B in the three-dimensional virtual space.

[0054] When the virtual positional relationship between the virtual model Pa and the first and second image capturing units 2A and 2B in the three-dimensional virtual space is changed, the angle associating unit 73 reacquires (calculates) new positions on the surface of the virtual model Pa where X-rays are irradiated for each image capturing unit angle (the angle of the first image capturing unit 2A and the angle of the second image capturing unit 2B) at predetermined angular intervals, based on the changed virtual positional relationship, thereby updating the association (mapping) of the image capturing unit angles on the surface of the virtual model Pa. Then, the angle associating unit 73 reacquires newly partitioned angular regions on the surface of the virtual model Pa based on the updated association (mapping).

[0055] The angular dose calculation unit 74 recalculates the X-ray dose in each of the plurality of angular regions defined at predetermined angular intervals based on the X-ray dose distribution on the surface of the virtual model Pa calculated by the model dose calculation unit 72 and the angular regions resulting from the correspondence between the image capture unit angles (the angle of the first image capture unit 2A and the angle of the second image capture unit 2B) updated by the angle correspondence unit 73. The image generation unit 75 then updates the angular dose image 42 so that the magnitude of the X-ray dose in each of the newly calculated angular regions can be distinguished. In other words, when the positional relationship between the tabletop 1 and the first and second image capture units 2A and 2B is changed, the degree of X-ray dose distribution in the angular dose image 42 changes based on the newly calculated X-ray dose in each of the plurality of angular regions. Note that when only the image capture unit angles are moved (changed) without moving the tabletop 1, the correspondence between the image capture unit angles on the surface of the virtual model Pa in the three-dimensional virtual space remains unchanged. That is, when only the imaging unit angle is changed, the angular dose image 42 is not updated, and the degree of distribution of the X-ray dose in the angular dose image 42 does not change.

[0056] For example, as shown in FIG. 9, when the top 1 is moved in the longitudinal direction of the top 1 (the vertical direction of the subject P) based on an input operation on the touch panel 5 or the operation unit 6, the degree of distribution of the X-ray dose in the angular dose image 42 shifts in the vertical direction (the CRA and CAU directions).

[0057] Furthermore, as shown in FIG. 10, when the top 1 is moved in the short direction of the top 1 (left-right direction of the subject P) based on an input operation on the touch panel 5 or the operation unit 6, the degree of distribution of the X-ray dose in the angular dose image 42 shifts left-right (in the RAO and LAO directions).

[0058] Also, as shown in Figure 11, when the tabletop 1 is moved vertically based on an input operation on the touch panel 5 or the operation unit 6, the degree of distribution of the X-ray dose in the angular dose image 42 changes so as to be enlarged or reduced.

[0059] Similarly, when the angle of the tabletop 1 is changed by rotating it, the degree of distribution of X-ray dose in the angular dose image 42 also changes. Furthermore, when the positions of the first imaging unit 2A and the second imaging unit 2B relative to the tabletop 1 are moved, the degree of distribution of X-ray dose in the angular dose image 42 also changes. Note that the change in the degree of distribution of X-ray dose in the angular dose image 42 when the positional relationship between the tabletop 1 and the first and second imaging units 2A and 2B is changed is different from simple translation (shift) movement and scaling because the correspondence between the imaging unit angles (the angle of the first imaging unit 2A and the angle of the second imaging unit 2B) on the surface of the cylindrical virtual model Pa is changed.

[0060] 12 , when an operation to change the size of the predetermined angular intervals dividing the plurality of angular regions is received via the touch panel 5 or the operation unit 6, the angular dose calculator 74 (dose calculation processing unit 70) is configured to calculate the X-ray dose in each of the plurality of angular regions divided by the changed predetermined angular intervals. The image generator 75 then generates an angular dose image 42 in which the magnitude of the X-ray dose in each of the plurality of angular regions divided by the changed predetermined angular intervals can be distinguished. The monitor 4 is then configured to display the angular dose image 42 with the changed size of the predetermined angular intervals.

[0061] Specifically, when an input operation to change the size of the predetermined angular interval is received based on an input operation on the touch panel 5 or the operation unit 6, the angle association unit 73 updates the association (mapping) of the image capture unit angles (the angles of the first image capture unit 2A and the second image capture unit 2B) on the surface of the virtual model Pa so that the surface is divided into predetermined angular intervals of the changed size, thereby reacquiring newly divided angular regions on the surface of the virtual model Pa. The angular dose calculation unit 74 recalculates the X-ray dose in each of the angular regions of the updated size. The image generation unit 75 then updates the angular dose image 42 so that the magnitude of the X-ray dose in each of the newly calculated angular regions can be distinguished. The image generation unit 75 also generates the angular dose image 42 in which the size of each divided angular region has been changed in accordance with the change in the angular interval. For example, if the predetermined angular interval is changed from 10 degrees to 5 degrees, the size of the angular dose image 42 itself remains unchanged, and the size of the regions in the angular dose image 42 is halved. In addition, in the angular dose image 42 divided into 5-degree sections, the X-ray dose is displayed in a color-coded manner so that it can be distinguished based on the distribution of X-ray dose in angular regions divided into 5-degree sections on the surface of the virtual model Pa.

[0062] 8 , the monitor 4 is configured to display a display (first irradiation area display 42Aa) indicating an angular area included in the irradiation area of ​​the first X-ray irradiator 21A and a display (second irradiation area display 42Ba) indicating an angular area included in the irradiation area of ​​the second X-ray irradiator 21B from among the multiple angular areas in the angular dose image 42. That is, the angular dose image 42 is an image including a first irradiation area display 42Aa, which is the area irradiated with X-rays by the first X-ray irradiator 21A, and a second irradiation area display 42Ba, which is the area irradiated with X-rays by the second X-ray irradiator 21B. The first irradiation area display 42Aa and the second irradiation area display 42Ba are examples of the "first irradiation area" and the "second irradiation area," respectively, in the claims.

[0063] Specifically, the irradiation area calculation unit 76 (dose calculation processing unit 70) is configured to calculate the irradiation area of ​​the first X-ray irradiator 21A and the irradiation area of ​​the second X-ray irradiator 21B, which are areas on the surface of the virtual model Pa to be irradiated with X-rays at the current imaging unit angles (the angle of the first imaging unit 2A and the angle of the second imaging unit 2B). In more detail, the irradiation area calculation unit 76 calculates the irradiation area (the irradiation area of ​​the first X-ray irradiator 21A and the irradiation area of ​​the second X-ray irradiator 21B) on the surface of the virtual model Pa to be irradiated with X-rays at the current imaging unit angle, based on the virtual positional relationship between the virtual model Pa and the first imaging unit 2A and the second imaging unit 2B in the three-dimensional virtual space acquired by the positional relationship acquisition unit 71 and the imaging conditions acquired from the control device 101. The irradiation area calculation unit 76 then acquires, as the angular area included in the irradiation area, an angular area that includes a part or the entire irradiation area to be irradiated with X-rays from among the plurality of angular areas partitioned at predetermined angular intervals by the angle association unit 73. The image generation unit 75 superimposes irradiation area displays (first irradiation area display 42Aa and second irradiation area display 42Ba) indicating the angular area included in the irradiation area acquired by the irradiation area calculation unit 76 on the angular dose image 42. The angular dose image 42 with the superimposed irradiation area display 42a is then output to the control device 101 and displayed on the monitor 4.

[0064] The first irradiation area display 42Aa indicates the irradiation area of ​​the first X-ray irradiator 21A so as to surround the entire angular area included in the irradiation area of ​​the first X-ray irradiator 21A. The first irradiation area display 42Aa may color the angular area included in the irradiation area of ​​the first X-ray irradiator 21A or may display it by superimposing diagonal lines or the like. The first irradiation area display 42Aa includes an indication that allows identification of an angular area including the center of the irradiation axis of the irradiated X-rays (center of the field of view) from the angular area included in the irradiation area of ​​the first X-ray irradiator 21A. For example, the first irradiation area display 42Aa includes an icon 42Ab that indicates the angular area including the center of the irradiation axis (center of the field of view) in the irradiation area of ​​the first X-ray irradiator 21A. That is, the angular dose image 42 is an image that includes the angle of the first imaging unit 2A (first arm 23A). The size and shape of the first irradiation region display 42Aa change depending on the irradiation region (field of view size) of X-rays irradiated from the first X-ray irradiator 21A, the opening amount of the collimator 21Ab, or the distance (SID: focus detector distance) between the first X-ray irradiator 21A and the first X-ray detector 22A. The first irradiation region display 42Aa may be a square region in the angular dose image 42, or may be a rectangle or a polygon.

[0065] The second irradiation area display 42Ba indicates the irradiation area of ​​the second X-ray irradiator 21B so as to surround the entire angular area included in the irradiation area of ​​the second X-ray irradiator 21B. The second irradiation area display 42Ba may color the angular area included in the irradiation area of ​​the second X-ray irradiator 21B or may display it by superimposing diagonal lines or the like. The second irradiation area display 42Ba includes an indication that allows identification of an angular area including the center of the irradiation axis of the irradiated X-rays (center of the field of view) from the angular area included in the irradiation area of ​​the second X-ray irradiator 21B. For example, the second irradiation area display 42Ba includes an icon 42Bb that indicates an angular area including the center of the irradiation axis (center of the field of view) in the irradiation area of ​​the second X-ray irradiator 21B. In other words, the angular dose image 42 is an image that includes the angle of the second imaging unit 2B (second arm 23B). The size and shape of the second irradiation region display 42Ba change depending on the irradiation region (field of view size) of X-rays irradiated from the second X-ray irradiator 21B, the opening amount of the collimator 21Bb, or the distance (SID: focus-detector distance) between the second X-ray irradiator 21B and the second X-ray detector 22B. The second irradiation region display 42Ba may be a square region in the angular dose image 42, or may be a rectangle or a polygon.

[0066] As shown in FIG. 3 , the monitor 4 is configured to identifiably display the maximum value of the X-ray dose in an angular region included in the irradiation region, separately from the angular dose image 42. Specifically, the irradiation region calculation unit 76 is configured to acquire the angular region with the maximum X-ray dose from among multiple angular regions included in the irradiation region. A signal indicating the X-ray dose in the angular region with the maximum X-ray dose is then output from the dose calculation device 102 to the control device 101. The control device 101 displays a maximum value display 44 on the monitor 4, indicating the maximum value of the X-ray dose in the angular region included in the irradiation region (irradiation region display 42 a). The maximum value display 44 displays the maximum value of each of the X-ray doses in the multiple angular regions included in the irradiation region (irradiation region display 42 a) in the same color as the color coding of the angular dose image 42. Furthermore, the maximum value display 44 may display a warning message when the X-ray dose exceeds a preset dose (e.g., a threshold value 43 a).

[0067] 13 to 16 , X-ray imaging system 100 is configured to change the imaging unit angles (the angle of first imaging unit 2A and the angle of second imaging unit 2B) based on an input operation on touch panel 5 or operation unit 6. Specifically, touch panel 5 accepts an operation to set a target angle 42Ac of first arm 23A and a target angle 42Bc of second arm 23B on an angular dose image 42 displayed on touch panel 5. Then, movement mechanism 3 moves first arm 23A and second arm 23B based on the target angle 42Ac of first arm 23A and the target angle 42Bc of second arm 23B set via touch panel 5. Furthermore, operation unit 6 accepts an operation to set a target angle 42Ac of first arm 23A and a target angle 42Bc of second arm 23B on an angular dose image 42 displayed on monitor 4. Then, movement mechanism 3 moves first arm 23A and second arm 23B based on target angle 42Ac of first arm 23A and target angle 42Bc of second arm 23B, respectively, set by operation unit 6. Note that Figures 13 to 16 show an example in which target angle 42Ac of first arm 23A and target angle 42Bc of second arm 23B are set by operation unit 6 on angle dose image 42 displayed on monitor 4.

[0068] 13 , the operator sets a target angle 42Ac of the first arm 23A by operating the operation unit 6 to move an icon 42Ab indicating the center of the irradiation axis of the irradiation area of ​​the first X-ray irradiator 21A on the angle dose image 42 displayed on the monitor 4. Also, as shown in FIG. 14 , the operator sets a target angle 42Bc of the second arm 23B by operating the operation unit 6 to move an icon 42Bb indicating the center of the irradiation axis of the irradiation area of ​​the second X-ray irradiator 21B on the angle dose image 42 displayed on the monitor 4. Then, when the operator wants to change the imaging unit angles (the angle of the first imaging unit 2A and the angle of the second imaging unit 2B) based on the set target angle 42Ac of the first arm 23A and the set target angle 42Bc of the second arm 23B, the operator operates the setting end button. Then, based on the operation of the setting end button, the control device 101 controls the movement mechanism 3 to move the first arm 23A and the second arm 23B based on the set target angle 42Ac of the first arm 23A and the set target angle 42Bc of the second arm 23B. That is, the movement mechanism 3 moves the first arm 23A and the second arm 23B based on the set target angle 42Ac of the first arm 23A and the set target angle 42Bc of the second arm 23B by the operation unit 6.

[0069] The irradiation area calculation unit 76 acquires a new first irradiation area display 42Aa and a new second irradiation area display 42Ba each time the angle of the first imaging unit 2A and the angle of the second imaging unit 2B are changed. The irradiation area calculation unit 76 is also configured to acquire a new first irradiation area display 42Aa and a new second irradiation area display 42Ba when the positional relationship between the angle of the first imaging unit 2A and the second imaging unit 2B and the tabletop 1 is changed, other than the imaging unit angle. In the X-ray imaging system 100, when only the angle of the first imaging unit 2A and the angle of the second imaging unit 2B are changed, the degree of X-ray dose distribution in the angle dose image 42 remains unchanged, and only the first irradiation area display 42Aa and the second irradiation area display 42Ba are moved (changed). Note that, when selecting the imaging unit angle in the angular dose image 42, the color-coded display (colored portion) indicating the magnitude of the X-ray dose in the angular dose image 42 may be displayed semitransparently to improve the visibility of the first irradiation region display 42Aa and the second irradiation region display 42Ba. Furthermore, while the imaging unit angle is being changed (while the angles of the first imaging unit 2A and the second imaging unit 2B are being moved), the first irradiation region display 42Aa and the second irradiation region display 42Ba that are being moved and the first irradiation region display 42Aa and the second irradiation region display 42Ba at the destination of the movement may be displayed in the angular dose image 42.

[0070] 17 , the monitor 4 is configured to identifiably display, among multiple angular regions in the angular dose image 42, angular regions for which X-ray irradiation is recommended. For example, the image generation unit 75 (dose calculation processing unit 70) colors the recommended angular regions in the angular dose image 42 to indicate the imaging unit angles (the angles of the first imaging unit 2A and the second imaging unit 2B) for which X-ray irradiation is recommended. Note that the display (coloring) indicating the recommended imaging unit angle (angular region) is displayed on the monitor 4 when the maximum value of the X-ray dose in the angular region included in the irradiation region (irradiation region display 42 a) at the current imaging unit angle becomes greater than a predetermined dose (e.g., threshold value 43 a).

[0071] The recommended imaging unit angle (angle region) is selected based on the region of the subject P to be treated or examined, from information previously input by the operator, a database stored in the system, or a database acquired via a network. For example, when imaging cardiac blood vessels, recommended imaging unit angles are set in advance for each type of blood vessel. If imaging of the right coronary artery (RCA) is preset based on an input operation on the touch panel 5 or the operation unit 6, the image generator 75 displays the recommended imaging unit angle (angle region) set to correspond to the right coronary artery in color in the angular dose image 42. If the recommended imaging unit angles (angle regions) have a rank (priority), a display (text information) that identifies the rank, such as "1st," "2nd," and "3rd" in the figure, is also displayed. The image generator 75 displays the imaging unit angles (angle regions) corresponding to each rank in color in the angular dose image 42 so that the rank can be identified. In this case, the recommended imaging unit angle (angle area) may be displayed while excluding areas where the dose is already high.

[0072] 13 , when at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B is set via the operation unit 6, the monitor 4 is configured to display, on the angular dose image 42, a range 42d in which the first arm 23A and the second arm 23B do not interfere with each other. Furthermore, when at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B is set via the touch panel 5, the touch panel 5 is configured to display, on the angular dose image 42, a range 42d in which the first arm 23A and the second arm 23B do not interfere with each other. The range 42d in which the first arm 23A and the second arm 23B do not interfere with each other is displayed, for example, by displaying a frame surrounding the non-interference range 42d or by changing the color of the non-interference range 42d to a different color from that of the other angle regions.

[0073] The monitor 4 is configured to display, on the angular dose image 42, a range 42d within which the first arm 23A and the second arm 23B do not interfere with each other when the monitor 4 is in an angle setting mode in which at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B is set, or when an operation is being performed to set at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B. The touch panel 5 is configured to display, on the angular dose image 42, a range 42d within which the first arm 23A and the second arm 23B do not interfere with each other when the monitor 4 is in an angle setting mode in which at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B is set, or when an operation is being performed to set at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B. The angle setting mode is started, for example, when a button (not shown) for transitioning to the angle setting mode is operated. The operation for setting at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B is, for example, an operation for moving the icon 42Ab and the icon 42Bb.

[0074] As shown in FIG. 15 , when at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operation unit 6 is within the range 42e in which the first arm 23A and the second arm 23B interfere with each other, the monitor 4 is configured to display a warning on the angle dose image 42 indicating that at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operation unit 6 is within the range 42e in which the first arm 23A and the second arm 23B interfere with each other. Specifically, when at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operation unit 6 is within the range 42e in which the first arm 23A and the second arm 23B interfere with each other, the monitor 4 displays a warning message 42f on the angle dose image 42 indicating that at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operation unit 6 is within the range 42e in which the first arm 23A and the second arm 23B interfere with each other. In addition, the touch panel 5 is configured to display a warning on the angle dose image 42 indicating that at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the touch panel 5 is in the range 42e in which the first arm 23A and the second arm 23B interfere with each other when at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the touch panel 5 is in the range 42e in which the first arm 23A and the second arm 23B interfere with each other. Specifically, when at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the touch panel 5 is within the range 42e in which the first arm 23A and the second arm 23B interfere with each other, the touch panel 5 displays a warning message 42f on the angle dose image 42 indicating that at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the touch panel 5 is within the range 42e in which the first arm 23A and the second arm 23B interfere with each other.

[0075] As shown in FIG. 16 , when at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operation unit 6 is in a range in which at least one of the first dose, which is the dose of X-rays irradiated by the first X-ray irradiator 21A, and the second dose, which is the dose of X-rays irradiated by the second X-ray irradiator 21B, exceeds a predetermined threshold value 43 b, the monitor 4 is configured to display a warning on the angle dose image 42 indicating that at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operation unit 6 is in a range in which at least one of the first dose and the second dose exceeds the predetermined threshold value 43 b. Specifically, when at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operation unit 6 is in a range in which at least one of the first dose and the second dose exceeds the predetermined threshold value 43b, the monitor 4 displays a warning message 42g on the angle dose image 42 indicating that at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operation unit 6 is in a range in which at least one of the first dose and the second dose exceeds the predetermined threshold value 43b. Furthermore, when at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the touch panel 5 is in a range in which at least one of the first dose, which is the dose of X-rays irradiated by the first X-ray irradiator 21A, and the second dose, which is the dose of X-rays irradiated by the second X-ray irradiator 21B, exceeds a predetermined threshold value 43b, the touch panel 5 is configured to display a warning on the angle dose image 42 indicating that at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the touch panel 5 is in a range in which at least one of the first dose and the second dose exceeds the predetermined threshold value 43b.Specifically, when at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set via the touch panel 5 is in a range in which at least one of the first dose and the second dose exceeds the predetermined threshold 43b, the touch panel 5 displays a warning message 42g indicating that at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set via the touch panel 5 is in a range in which at least one of the first dose and the second dose exceeds the predetermined threshold 43b on the angle dose image 42. Note that Fig. 16 illustrates a case in which at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set via the operation unit 6 is in a range 42e in which the first arm 23A and the second arm 23B interfere with each other and in which at least one of the first dose and the second dose exceeds the predetermined threshold 43b.

[0076] As shown in Figures 13 and 14, the operation unit 6 is configured to set one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B on the angle dose image 42 within a range 42d in which the first arm 23A and the second arm 23B do not interfere with each other, and then set the other of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B within a range 42d in which the first arm 23A and the second arm 23B do not interfere with each other. Furthermore, the touch panel 5 is configured to set one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B within a range 42d in which the first arm 23A and the second arm 23B do not interfere with each other on the angular dose image 42, and then set the other of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B within a range 42d in which the first arm 23A and the second arm 23B do not interfere with each other. That is, as shown in FIG. 13 , the operator first sets the target angle 42Ac of the first arm 23A so that the first arm 23A and the second arm 23B do not interfere with each other. Then, as shown in FIG. 14 , the operator next sets the target angle 42Ac of the second arm 23B so that the first arm 23A and the second arm 23B do not interfere with each other.

[0077] Furthermore, even if at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operating unit 6 is within the range 42e in which the first arm 23A and the second arm 23B interfere with each other, the moving mechanism 3 is configured to move the first arm 23A and the second arm 23B based on the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operating unit 6 until the relative positions of the first arm 23A and the second arm 23B are at a position where the first arm 23A and the second arm 23B do not interfere with each other and are close to a position where the first arm 23A and the second arm 23B interfere with each other. Furthermore, even if at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the touch panel 5 is within the range 42e in which the first arm 23A and the second arm 23B interfere with each other, the moving mechanism 3 is configured to move the first arm 23A and the second arm 23B based on the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the touch panel 5 until the relative positions of the first arm 23A and the second arm 23B are at a position where the first arm 23A and the second arm 23B do not interfere with each other and are close to a position where the first arm 23A and the second arm 23B interfere with each other.

[0078] 18 , the monitor 4 displays a timeline display 45 for checking the progress of the dose of irradiated X-rays. The timeline display 45 is displayed on the monitor 4 based on an input operation on the touch panel 5 or the operation unit 6, for example. The X-ray imaging system 100 is configured to display an angular dose image 42 at a predetermined time in the past on the monitor 4 based on a selection operation on the timeline display 45.

[0079] Specifically, the storage processing unit 77 (dose calculation processing unit 70) is configured to store history information of the distribution of X-ray doses on the surface of the virtual model Pa based on the X-ray irradiation by the first imaging unit 2A and the X-ray irradiation by the second imaging unit 2B. The storage processing unit 77 stores the history of the irradiated X-ray doses in the storage device of the dose calculation device 102 every time the first imaging unit 2A and the second imaging unit 2B irradiate X-rays.

[0080] The dose calculation processing unit 70 then acquires from the storage device history information including the X-ray dose value at the selected predetermined past timing based on an operation to select any timing from the time series in the timeline display 45. Here, in the X-ray imaging system 100, in order to capture an X-ray image 41 as a moving image, X-rays are continuously irradiated over a predetermined period in capturing one X-ray image 41. In the timeline display 45, predetermined past timings are displayed in a selectable manner for each predetermined period for generating one X-ray image 41 as a moving image.

[0081] The monitor 4 is configured to display an angular dose image 42 at a predetermined past timing based on the history information stored by the storage processing unit 77. That is, based on the stored history information, the X-ray dose distribution on the surface of the virtual model Pa at a selected predetermined past timing and the virtual positional relationship between the first imaging unit 2A and the second imaging unit 2B and the virtual model Pa are acquired. Then, by executing a process similar to that used to generate the current angular dose image 42, the image generation unit 75 generates an angular dose image 42 based on the X-ray dose values ​​at the predetermined past timing. The generated angular dose image 42 at the predetermined past timing is output to the control device 101 and displayed on the monitor 4. The storage processing unit 77 may be configured to directly store the generated angular dose image 42 in a storage device for each timing at which an X-ray image 41 is generated.

[0082] Furthermore, the X-ray imaging system 100 is configured to display a predicted angular dose image 42 on the monitor 4 based on a selection operation on the timeline display 45 .

[0083] Specifically, the dose prediction unit 78 (dose calculation processing unit 70) is configured to calculate a predicted value of the X-ray dose irradiated by the first imaging unit 2A and a predicted value of the X-ray dose irradiated by the second imaging unit 2B based on the X-ray dose distribution on the surface of the virtual model Pa calculated by the model dose calculation unit 72. For example, the dose calculation processing unit 70 accepts a selection of a predicted portion of the timeline display 45 (a portion beyond the current timing (current position)) based on an input operation on the touch panel 5 or the operation unit 6. Based on the acceptance of the selection of the predicted portion of the timeline display 45, the dose prediction unit 78 predicts an increase in the X-ray dose if X-ray irradiation in the current irradiation area is continued. The dose prediction unit 78 predicts an increase in the X-ray dose if irradiation is continued, for example, based on history information. The dose prediction unit 78 may also predict an increase in the X-ray dose in the current irradiation area based on a preset database. The dose prediction unit 78 may also calculate a predicted value of the X-ray dose when the imaging conditions are changed.

[0084] The dose prediction unit 78 then calculates a predicted value of the X-ray dose, thereby calculating a predicted value of the X-ray dose distribution on the surface of the virtual model Pa. The monitor 4 is configured to display a predicted angular dose image 42 based on the predicted value predicted by the dose prediction unit 78. That is, the image generation unit 75 generates the predicted angular dose image 42 based on the predicted value of the dose distribution on the surface of the virtual model Pa. The generated predicted angular dose image 42 is then output to the control device 101 and displayed on the monitor 4.

[0085] (Details of Touch Panel) As shown in FIG. 19 , the touch panel 5 displays selectable imaging unit angles (the angle of the first imaging unit 2A and the angle of the second imaging unit 2B). The touch panel 5 also accepts an input operation to change the imaging unit angle. The touch panel 5 displays a list of multiple imaging unit angle displays 5a so that the imaging unit angle can be selected, based on a database stored in a storage unit such as a flash memory included in the touch panel 5, the storage device of the control device 101, or the storage device of the dose calculation device 102. The touch panel 5 also displays a current angle display 5b indicating the current imaging unit angle so that it can be distinguished from the multiple imaging unit angle displays 5a displayed as a list. Specifically, the touch panel 5 acquires information indicating the positions of the first imaging unit 2A and the second imaging unit 2B from the control device 101. Based on the information acquired from the control device 101, the touch panel 5 displays the background of the multiple imaging unit angle displays 5a displayed as a list in white and the background of the current angle display 5b in blue, thereby visually distinguishing the current imaging unit angle.

[0086] The touch panel 5 also displays a non-recommended angle indicator 5c indicating non-recommended imaging unit angles (the angle of the first imaging unit 2A and the angle of the second imaging unit 2B) in a manner that makes them visually identifiable from among the multiple imaging unit angle indicators 5a displayed as a list. Specifically, the touch panel 5 acquires the X-ray doses calculated for each of the multiple angle regions from the dose calculation device 102. The touch panel 5 then displays the non-recommended angle indicator 5c for imaging unit angles included in an angle region exceeding a predetermined dose (e.g., threshold value 43a) from among the imaging unit angles corresponding to the multiple imaging unit angle indicators 5a in a manner that makes them visually identifiable as non-recommended imaging unit angles. For example, the touch panel 5 displays the non-recommended angle indicator 5c against a red background to visually identify the non-recommended imaging unit angles.

[0087] The touch panel 5 also displays a recommended angle indicator 5d (e.g., a star mark) indicating the imaging unit angles (the angle of the first imaging unit 2A and the angle of the second imaging unit 2B) recommended for X-ray irradiation. The recommended imaging unit angle is selected based on the region of the subject P to be treated or examined, from information input in advance by the operator, a database stored in the system, or a database obtained via the network. The touch panel 5 also selectably displays a desired angle indicator 5e indicating a desired imaging unit angle registered in advance by the operator. The recommended imaging unit angle and the desired imaging unit angle may be stored in a storage unit such as a flash memory included in the touch panel 5, or may be stored in a storage unit of the control device 101 or a storage unit of the dose calculation device 102.

[0088] 20 , the touch panel 5 is configured to display an angular dose image 42. Specifically, the touch panel 5 acquires the angular dose image 42 generated by the image generator 75 from the dose calculation device 102. The touch panel 5 is configured to display the acquired angular dose image 42 by switching the display based on, for example, an input operation by the operator.

[0089] 3 and 21 , the monitor 4 displays a three-dimensional image 46 of the inside of the body of the subject P that has been acquired in advance. Specifically, the three-dimensional image 46 is generated by a three-dimensional image generating device 103. The three-dimensional image generating device 103 generates the three-dimensional image 46 representing the inside of the body of the subject P based on three-dimensional image data of the inside of the body of the subject P that has been acquired in advance by a CT (Computed Tomography) device or the like. The three-dimensional image 46 generated by the three-dimensional image generating device 103 is then output from the three-dimensional image generating device 103 to the control device 101, and is thereby displayed on the monitor 4.

[0090] 21 , the monitor 4 is configured to identifiably display the X-ray doses in angular regions at the imaging unit angles (the angle of the first imaging unit 2A and the angle of the second imaging unit 2B) corresponding to the display angle of the displayed 3D image 46. Specifically, the 3D image generation device 103 generates an angle indicator 46a along with the 3D image 46. The angle indicator 46a indicates the display angle of the displayed 3D image 46 by indicating the positional relationship between the display showing the subject P as the subject and the displays showing the first imaging unit 2A and the second imaging unit 2B so as to correspond to the spatial viewpoint (camera position) of the displayed 3D image 46. The 3D image generation device 103 then acquires the X-ray doses in each of the multiple angular regions from the dose calculation device 102, and causes the angle indicator 46a to identifiably display the magnitudes of the acquired X-ray doses. For example, the three-dimensional image generating device 103 displays the indications of the first imaging unit 2A and the second imaging unit 2B in the angle indicator 46a in the same color coding as the angular dose image 42. That is, the three-dimensional image generating device 103 distinguishably displays the magnitude of the X-ray dose in the angle region that includes the imaging unit angle corresponding to the current display angle by color coding in the angle indicator 46a. Note that the X-ray dose in the angle region that includes the imaging unit angle corresponding to the current display angle may be displayed by an icon display that is color coded similarly to the angular dose image 42, separate from the angle indicator 46a.

[0091] (Effects of this embodiment) In this embodiment, the following effects can be obtained.

[0092] As described above, in this embodiment, the monitor 4 (display unit) and the touch panel 5 (display unit) are configured to display the range 42d in which the first arm 23A and the second arm 23B do not interfere with each other on the angle dose image 42 (dose distribution screen) when setting at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B using the operation unit 6 and the touch panel 5 (operation unit). This allows the operator to visually recognize the range 42d in which the first arm 23A and the second arm 23B do not interfere with each other on the angle dose image 42 when setting at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B using the operation unit 6 and the touch panel 5. This prevents the operator from setting the target angles of the arms in a way that causes the two arms to interfere with each other while viewing the X-ray dose distribution in a configuration including two arms.

[0093] Furthermore, in this embodiment, the following additional effects can be obtained by the following configuration.

[0094] That is, in the present embodiment, as described above, the monitor 4 (display unit) and the touch panel 5 (display unit) are configured to display the range 42d in which the first arm 23A and the second arm 23B do not interfere with each other on the angular dose image 42 (dose distribution screen) when the angle setting mode is in which at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B is set, and when an operation to set at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B is being performed. This makes it possible to effectively display the range 42d in which the first arm 23A and the second arm 23B do not interfere with each other on the angular dose image 42 in any of the above cases in which the operator needs to be aware of the range 42d in which the first arm 23A and the second arm 23B do not interfere with each other.

[0095] Furthermore, in the present embodiment, as described above, the monitor 4 (display unit) and the touch panel 5 (display unit) are configured to display a warning on the angle dose image 42 (dose distribution screen) indicating that at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operation unit 6 and the touch panel 5 (operation unit) is within the range 42e in which the first arm 23A and the second arm 23B interfere with each other when the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operation unit 6 and the touch panel 5 is within the range 42e in which the first arm 23A and the second arm 23B interfere with each other. This allows the operator to easily visually recognize that at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B is set within the range 42e in which the first arm 23A and the second arm 23B interfere with each other. This allows the operator to immediately reset the target angles of the arms so that they do not interfere with each other, even if the operator sets the target angles of the arms while looking at the distribution of X-ray doses so that the two arms interfere with each other.

[0096] Furthermore, in the present embodiment, as described above, when at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operation unit 6 and the touch panel 5 (operation unit) is within the range 42e in which the first arm 23A and the second arm 23B interfere with each other, the monitor 4 (display unit) and the touch panel 5 (display unit) display a warning on the angle dose image 42 (dose distribution screen) indicating that at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operation unit 6 and the touch panel 5 is within the range 42e in which the first arm 23A and the second arm 23B interfere with each other. When at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the touch panel 5 is in a range in which at least one of the first dose, which is the dose of X-rays irradiated by the first X-ray irradiator 21A, and the second dose, which is the dose of X-rays irradiated by the second X-ray irradiator 21B, exceeds a predetermined threshold value 43b, a warning is displayed on the angle dose image 42, indicating that at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operation unit 6 and the touch panel 5 is in a range in which at least one of the first dose and the second dose exceeds the predetermined threshold value 43b. This allows the operator to easily visually recognize that at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B is set in the range 42e in which the first arm 23A and the second arm 23B interfere with each other, and also allows the operator to easily visually recognize that at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B is set in the range in which at least one of the first dose and the second dose exceeds the predetermined threshold value 43b.As a result, even if the operator, while looking at the distribution of X-ray dose, accidentally sets the target angle of the arms in a way that causes the two arms to interfere with each other, the operator can immediately reset the target angle of the arms so that it is within a range in which the two arms do not interfere with each other, and even if the operator, while looking at the distribution of X-ray dose, accidentally sets the target angle of the arms in a range in which the X-ray dose exceeds the predetermined threshold value 43b, the operator can immediately reset the target angle of the arms so that it is within a range in which the X-ray dose does not exceed the predetermined threshold value 43b.

[0097] Furthermore, in this embodiment, as described above, the operation unit 6 and the touch panel 5 (operation unit) are configured to set one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B on the angle dose image 42 (dose distribution screen) within the range 42d in which the first arm 23A and the second arm 23B do not interfere with each other, and then set the other of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B within the range 42d in which the first arm 23A and the second arm 23B do not interfere with each other. This simplifies the operator's operations on the operation unit 6 and the touch panel 5 when setting the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B, since the operator only needs to set the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B one by one so that the first arm 23A and the second arm 23B do not interfere with each other. This reduces the operator's workload when setting the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B.

[0098] Furthermore, in this embodiment, as described above, even if at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operation unit 6 and the touch panel 5 (operation unit) is within the range 42e in which the first arm 23A and the second arm 23B interfere with each other, the moving mechanism 3 is configured to move the first arm 23A and the second arm 23B based on the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operation unit 6 and the touch panel 5 until the relative positions of the first arm 23A and the second arm 23B are at a position where the first arm 23A and the second arm 23B do not interfere with each other and are close to a position where the first arm 23A and the second arm 23B interfere with each other. That is, if the operator sets at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B to a range in which the first arm 23A and the second arm 23B interfere with each other, the movement mechanism 3 moves the first arm 23A and the second arm 23B to a position halfway along the movement path based on the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set via the operation unit 6 and the touch panel 5. In this case, the operator needs to reset the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set via the operation unit 6 and the touch panel 5 and move the first arm 23A and the second arm 23B again. This increases the examination time for the subject. Therefore, a configuration that can prevent the operator from setting the target angles of the arms so that the two arms interfere with each other while viewing the X-ray dose distribution can be effectively applied.

[0099] [Modifications] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the description of the above-mentioned embodiments, and further includes all modifications (modifications) within the meaning and scope of the claims.

[0100] For example, in the above embodiment, an example was shown in which the moving mechanism 3 is configured to move the first arm 23A and the second arm 23B based on the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operation unit 6 and the touch panel 5 (operation unit) until the relative positions of the first arm 23A and the second arm 23B are at a position where the first arm 23A and the second arm 23B do not interfere with each other and are close to a position where the first arm 23A and the second arm 23B interfere with each other, even if at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operation unit 6 and the touch panel 5 (operation unit) is within the range 42e where the first arm 23A and the second arm 23B interfere with each other; however, the present invention is not limited to this. In the present invention, the movement mechanism may be configured not to move the first arm and the second arm based on the target angle of the first arm and the target angle of the second arm set by the operation unit when at least one of the target angle of the first arm and the target angle of the second arm set by the operation unit is within a range in which the first arm and the second arm interfere with each other.

[0101] In the above embodiment, the operation unit 6 and the touch panel 5 (operation unit) are configured to set one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B within the range 42d where the first arm 23A and the second arm 23B do not interfere with each other on the angle dose image 42 (dose distribution screen), and then set the other of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B within the range 42d where the first arm 23A and the second arm 23B do not interfere with each other. However, the present invention is not limited to this. In the present invention, the operation unit may be configured to simultaneously set both the target angle of the first arm and the target angle of the second arm within the range where the first arm and the second arm do not interfere with each other on the dose distribution screen.

[0102] Furthermore, in the above embodiment, an example has been shown in which the monitor 4 (display unit) and the touch panel 5 (display unit) are configured to display a warning on the angle dose image 42, indicating that at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B, which are set by the operation unit 6 and the touch panel 5 (operation unit), is in a range in which at least one of the first dose, which is the dose of X-rays irradiated by the first X-ray irradiator 21A, and the second dose, which is the dose of X-rays irradiated by the second X-ray irradiator 21B, exceeds the predetermined threshold value 43b. However, the present invention is not limited to this. In the present invention, the display unit may be configured not to display the warning on the angle dose image when at least one of the target angle of the first arm and the target angle of the second arm set by the operation unit is within a range in which at least one of the first dose, which is the dose of X-rays irradiated by the first X-ray irradiator, and the second dose, which is the dose of X-rays irradiated by the second X-ray irradiator, exceeds a predetermined threshold value.

[0103] In the above embodiment, the monitor 4 (display unit) and the touch panel 5 (display unit) are configured to display a warning on the angle dose image 42 (dose distribution screen) indicating that at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operation unit 6 and the touch panel 5 (operation unit) is within the range 42e in which the first arm 23A and the second arm 23B interfere with each other. However, the present invention is not limited to this. In the present invention, the display unit may be configured not to display the warning on the dose distribution screen when at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B set by the operation unit is within the range 42e in which the first arm 23A and the second arm 23B interfere with each other.

[0104] Furthermore, in the above embodiment, an example was shown in which the monitor 4 (display unit) and the touch panel 5 (display unit) are configured to display the range 42d in which the first arm 23A and the second arm 23B do not interfere with each other on the angle dose image 42 (dose distribution screen) when the monitor 4 (display unit) is in an angle setting mode in which at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B is set, and when an operation is being performed to set at least one of the target angle 42Ac of the first arm 23A and the target angle 42Bc of the second arm 23B. However, the present invention is not limited to this. In the present invention, the display unit may be configured not to display on the dose distribution screen the range in which the first arm and the second arm do not interfere with each other when in an angle setting mode in which at least one of the target angle of the first arm and the target angle of the second arm is set, or may be configured not to display on the dose distribution screen the range in which the first arm and the second arm do not interfere with each other when an operation is being performed to set at least one of the target angle of the first arm and the target angle of the second arm.

[0105] Aspects It will be appreciated by those skilled in the art that the exemplary embodiments described above are examples of the following aspects.

[0106] (Item 1) A first arm supporting a first X-ray irradiator having an X-ray source that irradiates X-rays and a first X-ray detection unit that detects the X-rays irradiated from the first X-ray irradiator, in opposing relation to each other; a second arm supporting a second X-ray irradiator having the X-ray source and a second X-ray detection unit that detects the X-rays irradiated from the second X-ray irradiator, in opposing relation to each other; a display unit that displays a dose distribution screen including an angle of the first arm, an angle of the second arm, a first dose distribution that is an X-ray dose irradiated by the first X-ray irradiator, a second dose distribution that is an X-ray dose irradiated by the second X-ray irradiator, a first irradiation range that is an irradiation range of X-rays by the first X-ray irradiator, and a second irradiation range that is an irradiation range of X-rays by the second X-ray irradiator, all of which are associated with the angle of the first arm and the angle of the second arm; and an operation unit that accepts an operation to set a target angle of the first arm and a target angle of the second arm on the dose distribution screen displayed on the display unit. a movement mechanism that moves the first arm and the second arm based on a target angle of the first arm and a target angle of the second arm that are set by the operation unit, respectively; and the display unit is configured to display on the dose distribution screen a range within which the first arm and the second arm do not interfere with each other when at least one of the target angle of the first arm and the target angle of the second arm is set by the operation unit.

[0107] (Item 2) The display unit is configured to display on the dose distribution screen the range within which the first arm and the second arm do not interfere with each other when the display unit is in an angle setting mode in which at least one of the target angle of the first arm and the target angle of the second arm is set, and when an operation is being performed to set at least one of the target angle of the first arm and the target angle of the second arm.

[0108] (Item 3) The X-ray imaging system according to item 1 or 2, wherein the display unit is configured to, when at least one of the target angle of the first arm and the target angle of the second arm set by the operation unit is within a range in which the first arm and the second arm interfere with each other, display a warning on the dose distribution screen indicating that at least one of the target angle of the first arm and the target angle of the second arm set by the operation unit is within a range in which the first arm and the second arm interfere with each other.

[0109] (Item 4) The X-ray imaging system according to Item 3, wherein the display unit is configured to: when at least one of the target angle of the first arm and the target angle of the second arm set by the operation unit is in a range where the first arm and the second arm interfere with each other, display a warning on the dose distribution screen indicating that at least one of the target angle of the first arm and the target angle of the second arm set by the operation unit is in a range where the first arm and the second arm interfere with each other; and when at least one of the target angle of the first arm and the target angle of the second arm set by the operation unit is in a range where at least one of a first dose that is a dose of X-rays irradiated by the first X-ray irradiator and a second dose that is a dose of X-rays irradiated by the second X-ray irradiator exceeds a predetermined threshold, display a warning on the dose distribution screen indicating that at least one of the target angle of the first arm and the target angle of the second arm set by the operation unit is in a range where at least one of the first dose and the second dose exceeds the predetermined threshold.

[0110] (Item 5) The X-ray imaging system described in any one of Items 1 to 4, wherein the operation unit is configured to set one of the target angle of the first arm and the target angle of the second arm on the dose distribution screen within a range in which the first arm and the second arm do not interfere with each other, and then set the other of the target angle of the first arm and the target angle of the second arm within a range in which the first arm and the second arm do not interfere with each other.

[0111] (Item 6) The X-ray imaging system according to any one of Items 1 to 5, wherein the movement mechanism is configured to move the first arm and the second arm based on the target angle of the first arm and the target angle of the second arm set by the operation unit, even if at least one of the target angle of the first arm and the target angle of the second arm set by the operation unit is within a range in which the first arm and the second arm interfere with each other, until the relative positions of the first arm and the second arm are at a position where the first arm and the second arm do not interfere with each other and are close to a position where the first arm and the second arm interfere with each other.

[0112] DESCRIPTION OF SYMBOLS 3 Moving mechanism 4 Display unit 5 Touch panel (display unit, operation unit) 6 Operation unit 21A First X-ray irradiator 22A First X-ray detector 21B Second X-ray irradiator 22B Second X-ray detector 23A First arm 23B Second arm 42 Angular dose image (dose distribution screen) 42Aa First irradiation area display (first irradiation range) 42Ac Target angle of first arm 42Ba Second irradiation area display (second irradiation range) 42Bc Target angle of second arm 42d Range in which the first arm and the second arm do not interfere with each other 42e Range in which the first arm and the second arm interfere with each other 43b Predetermined threshold value 100 X-ray imaging system

Claims

1. a first arm supporting a first X-ray irradiator having an X-ray source for irradiating X-rays and a first X-ray detection unit for detecting X-rays irradiated from the first X-ray irradiator in opposing relation to each other; a second arm supporting a second X-ray irradiator having the X-ray source and a second X-ray detection unit for detecting X-rays irradiated from the second X-ray irradiator in opposing relation to each other; a display unit for displaying a dose distribution screen including an angle of the first arm and an angle of the second arm, a first dose distribution which is the dose of X-rays irradiated by the first X-ray irradiator, a second dose distribution which is the dose of X-rays irradiated by the second X-ray irradiator, a first irradiation range which is the irradiation range of X-rays by the first X-ray irradiator, and a second irradiation range which is the irradiation range of X-rays by the second X-ray irradiator, which are associated with the angle of the first arm and the angle of the second arm; and an operation unit for receiving an operation to set a target angle of the first arm and a target angle of the second arm on the dose distribution screen displayed on the display unit. a moving mechanism that moves the first arm and the second arm based on a target angle of the first arm and a target angle of the second arm set by the operation unit, respectively, and the display unit is configured to display on the dose distribution screen a range within which the first arm and the second arm do not interfere with each other when at least one of the target angle of the first arm and the target angle of the second arm is set by the operation unit.

2. The X-ray imaging system of claim 1, wherein the display unit is configured to display on the dose distribution screen the range within which the first arm and the second arm do not interfere with each other when the display unit is in an angle setting mode in which at least one of a target angle of the first arm and a target angle of the second arm is set, and when an operation is being performed to set at least one of a target angle of the first arm and a target angle of the second arm.

3. The X-ray imaging system of claim 1, wherein the display unit is configured to, when at least one of the target angle of the first arm and the target angle of the second arm set by the operation unit is within a range in which the first arm and the second arm interfere with each other, display a warning on the dose distribution screen indicating that at least one of the target angle of the first arm and the target angle of the second arm set by the operation unit is within a range in which the first arm and the second arm interfere with each other.

4. The X-ray imaging system according to claim 3, wherein the display unit is configured to, when at least one of the target angle of the first arm and the target angle of the second arm set by the operation unit is in a range where the first arm and the second arm interfere with each other, display a warning on the dose distribution screen indicating that at least one of the target angle of the first arm and the target angle of the second arm set by the operation unit is in a range where the first arm and the second arm interfere with each other, and, when at least one of the target angle of the first arm and the target angle of the second arm set by the operation unit is in a range where at least one of a first dose, which is a dose of X-rays irradiated by the first X-ray irradiator, and a second dose, which is a dose of X-rays irradiated by the second X-ray irradiator, exceeds a predetermined threshold value, display a warning on the dose distribution screen indicating that at least one of the target angle of the first arm and the target angle of the second arm set by the operation unit is in a range where at least one of the first dose and the second dose exceeds the predetermined threshold value.

5. The X-ray imaging system of claim 1, wherein the operation unit is configured to set one of the target angle of the first arm and the target angle of the second arm on the dose distribution screen within a range in which the first arm and the second arm do not interfere with each other, and then set the other of the target angle of the first arm and the target angle of the second arm within a range in which the first arm and the second arm do not interfere with each other.

6. The X-ray imaging system of claim 1, wherein the moving mechanism is configured to move the first arm and the second arm based on the target angle of the first arm and the target angle of the second arm set by the operation unit, even if at least one of the target angle of the first arm and the target angle of the second arm set by the operation unit is within a range in which the first arm and the second arm interfere with each other, until the relative positions of the first arm and the second arm are at a position where they do not interfere with each other and are close to a position where they interfere with each other.