Imaging condition setting device for x-ray CT device, x-ray CT device, and imaging condition setting method for x-ray CT device

Abstract

An imaging condition setting device (100) for an X-ray CT device (200) comprises an X-ray source (20), an X-ray detector (21), a radiation source holding mechanism (22), a detector holding mechanism (23), and a drive unit (24) for driving the radiation source holding mechanism and / or the detector holding mechanism, the imaging condition setting device (100) further comprising a control unit (1), the control unit having a memory (10) and a processor (11), and the processor executing a program (30) stored in a memory to execute a step for acquiring three-dimensional structure data (31) of a subject (90) on the basis of operation input by a user, and a step for setting, by using the acquired three-dimensional structure data (31), imaging conditions to perform X-ray CT imaging.

Description

Imaging Condition Setting Device for X-ray CT Apparatus, X-ray CT Apparatus, and Imaging Condition Setting Method for X-ray CT Apparatus

[0001] The present invention relates to an imaging condition setting device for an X-ray CT apparatus, an X-ray CT apparatus, and an imaging condition setting method for an X-ray CT apparatus.

[0002] Conventionally, X-ray CT imaging apparatuses are known. Such X-ray CT imaging apparatuses are disclosed, for example, in Japanese Patent Laid-Open No. 2023-168125.

[0003] Japanese Patent Laid-Open No. 2023-168125 discloses an X-ray CT apparatus including an X-ray irradiation unit, an X-ray detection unit, and a rotary stage. In the X-ray CT apparatus disclosed in Japanese Patent Laid-Open No. 2023-168125, the rotary stage is disposed between the X-ray irradiation unit and the X-ray detection unit and is configured to rotate the subject by rotating around a predetermined rotation axis. Then, the X-ray CT apparatus disclosed in Japanese Patent Laid-Open No. 2023-168125 reconstructs a tomographic image of the subject based on the projection data acquired by imaging while rotating the subject by the rotary stage. In the configuration disclosed in Japanese Patent Laid-Open No. 2023-168125, the rotation axis of the rotary stage is fixed, and there is no need for an operator to set the rotation axis when acquiring projection data.

[0004] Japanese Patent Laid-Open No. 2023-168125

[0005] In a configuration where X-ray CT imaging is performed by rotating the subject using a rotating stage, as disclosed in the above-mentioned Japanese Patent Publication No. 2023-168125, it becomes difficult to rotate the subject using the rotating stage when the subject is large. In such cases, it is conceivable to perform X-ray CT imaging by moving at least one of the X-ray source and X-ray detector around the subject in an arbitrary trajectory. However, when at least one of the X-ray source and X-ray detector is moved in an arbitrary trajectory, it is possible to set imaging conditions for various trajectories, and the degree of freedom in setting is too high, making it difficult to set appropriate imaging conditions. Therefore, there is a need for a technology that can easily set appropriate imaging conditions when performing X-ray CT imaging by moving at least one of the X-ray source and X-ray detector around the subject.

[0006] This invention was made to solve the above-mentioned problems, and one object of this invention is to provide an X-ray CT scanner imaging condition setting device, an X-ray CT scanner, and a method for setting imaging conditions for an X-ray CT scanner that can easily set appropriate imaging conditions when performing X-ray CT imaging by moving at least one of the X-ray source and the X-ray detector around the subject.

[0007] The X-ray CT scanner imaging condition setting device in the first aspect of this invention comprises an X-ray source, an X-ray detector, a source holding mechanism for holding the X-ray source, a detector holding mechanism for holding the X-ray detector, and a drive unit for driving at least one of the source holding mechanism and the detector holding mechanism to move at least one of the X-ray source and the X-ray detector around a subject to perform X-ray CT imaging, wherein the device further comprises a control unit, the control unit having a memory and a processor, the processor executing a program stored in the memory to perform the steps of acquiring three-dimensional structural data of a subject based on user input and setting imaging conditions for performing X-ray CT imaging using the acquired three-dimensional structural data.

[0008] The X-ray CT apparatus in the second aspect of this invention comprises an X-ray source, an X-ray detector, a source holding mechanism for holding the X-ray source, a detector holding mechanism for holding the X-ray detector, a drive unit for driving at least one of the source holding mechanism and the detector holding mechanism to move at least one of the X-ray source and the X-ray detector around a subject to perform X-ray CT imaging, and a control unit, the control unit having a memory and a processor, the processor executing a program stored in the memory to perform the steps of acquiring three-dimensional structural data of a subject based on user input and setting imaging conditions for performing X-ray CT imaging using the acquired three-dimensional structural data.

[0009] A third aspect of this invention relates to a method for setting imaging conditions for an X-ray CT apparatus, comprising: an X-ray source; an X-ray detector; a source holding mechanism for holding the X-ray source; a detector holding mechanism for holding the X-ray detector; and a drive unit for driving at least one of the source holding mechanism and the detector holding mechanism to move at least one of the X-ray source and the X-ray detector around a subject to perform X-ray CT imaging, the method comprising the steps of: acquiring three-dimensional structural data of a subject; and using the acquired three-dimensional structural data to set imaging conditions for X-ray CT imaging.

[0010] In the X-ray CT scanner imaging condition setting device in the first aspect, the X-ray CT scanner in the second aspect, and the X-ray CT scanner imaging condition setting method in the third aspect, when performing X-ray CT imaging on a large subject, imaging conditions can be set based on the subject by using the three-dimensional structural data of the subject. Therefore, even when at least one of the X-ray source and X-ray detector is moved along an arbitrary trajectory, imaging conditions can be easily set based on the subject. As a result, appropriate imaging conditions can be easily set when performing X-ray CT imaging by moving at least one of the X-ray source and X-ray detector around the subject.

[0011] This is a block diagram showing the overall configuration of the X-ray CT apparatus and the X-ray CT apparatus imaging condition setting device according to the first embodiment. This is a schematic diagram showing the configuration of the radiation source holding mechanism, detector holding mechanism, and subject support mechanism according to the first embodiment. This is a schematic diagram showing the outline of the radiation source holding mechanism according to the first embodiment. This is a schematic diagram for explaining the imaging location of the subject set by the control unit according to the first embodiment. This is a schematic diagram for explaining the configuration in which X-rays irradiated from the X-ray source to the X-ray detector pass through the imaging location according to the first embodiment. This is a schematic diagram for explaining the configuration in which the control unit according to the first embodiment simulates the amount of X-ray transmission at multiple imaging angles. This is a graph showing the relationship between multiple imaging angles and brightness values ​​obtained by simulation by the control unit according to the first embodiment. This is a schematic diagram for explaining the configuration in which the control unit according to the first embodiment displays candidate imaging trajectories on the display unit. This is a schematic diagram for explaining the positional relationship between the X-ray source, the imaging location, and the X-ray detector. This is a schematic diagram for explaining the configuration in which the control unit according to the first embodiment sets the distance between the X-ray source and the X-ray detector. This is a flowchart illustrating the process by which the imaging condition setting device according to the first embodiment sets the imaging conditions and the X-ray CT apparatus performs X-ray CT imaging. This is a flowchart illustrating the process by which the control unit according to the first embodiment sets the imaging conditions. This is a flowchart illustrating the configuration by which the control unit according to the first embodiment sets the imaging trajectory axis and imaging trajectory. This is a block diagram showing the overall configuration of the X-ray CT apparatus and the imaging condition setting device for the X-ray CT apparatus according to the second embodiment. This is a flowchart illustrating the detailed process by which the control unit according to the second embodiment sets the imaging conditions. This is a block diagram showing the overall configuration of an X-ray CT apparatus according to a modified example.

[0012] The following describes embodiments of the present invention based on the drawings.

[0013] [First Embodiment] Referring to Figures 1 to 13, the configuration of the X-ray CT apparatus 200 and the X-ray CT apparatus imaging condition setting device 100 according to the first embodiment of the present invention will be described. The imaging condition setting device 100 is a device for setting the imaging conditions of the X-ray CT apparatus 200. Details of the imaging conditions will be described later.

[0014] As shown in Figure 1, the shooting condition setting device 100 comprises a control unit 1, an input receiving unit 2, and a display unit 3.

[0015] The control unit 1 includes a memory 10 and a processor 11.

[0016] Memory 10 is configured to store various programs 30 executed by the processor 11. Memory 10 also stores three-dimensional structure data 31 (described later), information on shooting locations 32 (described later), information on rotation axes 33 (described later), and a graph of brightness values ​​34 (described later). Memory 10 includes, for example, ROM (Read Only Memory) and RAM (Random Access Memory).

[0017] The processor 11 sets the imaging conditions for X-ray CT imaging using the X-ray CT scanner 200 by executing the program 30 stored in the memory 10. The processor 11 includes, for example, a CPU (Central Processing Unit) or a circuit. Details of the configuration in which the processor 11 sets the imaging conditions will be described later.

[0018] The input receiving unit 2 is configured to receive operation input from the operator. The input receiving unit 2 includes, for example, an input device such as a keyboard or mouse.

[0019] The display unit 3 is configured to display screens for setting the imaging conditions of the X-ray CT scanner 200, etc. The display unit 3 includes, for example, a liquid crystal monitor, an organic EL (Electroluminescence) monitor, and other display devices.

[0020] The X-ray CT apparatus 200 comprises an X-ray source 20, an X-ray detector 21, a source holding mechanism 22, a detector holding mechanism 23, a drive unit 24, a subject support mechanism 25, and a CT apparatus control unit 26.

[0021] The X-ray source 20 emits X-rays. The X-ray source 20 includes an X-ray tube. The X-ray tube is configured to emit X-rays when a predetermined tube current and tube voltage are applied.

[0022] The X-ray detector 21 is configured to detect X-rays irradiated from the X-ray source 20. The X-ray detector 21 includes a flat panel detector (FPD). The X-ray detector 21 outputs a signal based on the detected X-rays to the CT apparatus control unit 26.

[0023] The source holding mechanism 22 is configured to hold the X-ray source 20. Details of the source holding mechanism 22 will be described later.

[0024] The detector holding mechanism 23 is configured to hold the X-ray detector 21. Details of the detector holding mechanism 23 will be described later.

[0025] The drive unit 24 is configured to drive at least one of the source holding mechanism 22 and the detector holding mechanism 23 so as to move at least one of the X-ray source 20 and the X-ray detector 21 around the subject 90 (see Figure 2) to perform X-ray CT imaging.

[0026] The subject support mechanism 25 is configured to support the subject 90. Details of the subject support mechanism 25 will be described later.

[0027] The CT device control unit 26 is configured to control various parts of the X-ray CT device 200. The CT device control unit 26 is also configured to generate an X-ray image using a signal based on X-rays output from the X-ray detector 21. The CT device control unit 26 includes a CPU or circuitry, and a GPU (Graphics Processing Unit) or an FPGA (Field-Programmable Gate Array) configured for image processing.

[0028] In the X-ray CT apparatus 200, the drive unit 24 moves at least one of the X-ray source 20 and the X-ray detector 21 around the subject 90, and X-ray CT imaging of the subject 90 is performed.

[0029] (Radiation source holding mechanism, detector holding mechanism, and subject support mechanism) As shown in Figure 2, the radiation source holding mechanism 22 is a first robot arm 22a that drives the X-ray source 20. The first robot arm 22a is a vertical articulated robot. The first robot arm 22a is capable of moving the X-ray source 20 to any position and orientation within its range of motion in three-dimensional space. In this specification, the vertical direction is defined as the Z direction. The upper direction of the Z direction is defined as the Z1 direction, and the lower direction is defined as the Z2 direction. In addition, two mutually orthogonal directions in the horizontal plane perpendicular to the Z direction are defined as the X direction and the Y direction. One side of the X direction is defined as the X1 direction, and the other side as the X2 direction. In addition, one side of the Y direction is defined as the Y1 direction, and the other side as the Y2 direction.

[0030] Furthermore, the detector holding mechanism 23 is a second robot arm 23a that drives the X-ray detector 21. The second robot arm 23a is a vertical articulated robot. The second robot arm 23a is capable of moving the X-ray detector 21 to any position and orientation within its range of motion in three-dimensional space.

[0031] The drive unit 24 (see Figure 1) is configured to drive the first robot arm 22a and the second robot arm 23a when performing X-ray CT imaging.

[0032] The subject support mechanism 25 has a mounting portion 25a and a support member 25b. The subject 90 is placed on the mounting portion 25a. The support member 25b supports the mounting portion 25a from the Z2 direction side.

[0033] As shown in Figure 2, the X-rays emitted from the X-ray source 20 are irradiated along the X-ray irradiation axis 60, pass through the subject 90, and are then detected by the X-ray detector 21. The CT apparatus control unit 26 (see Figure 1) then rotates the X-ray source 20 and the X-ray detector 21 along a predetermined imaging trajectory 41 while taking images. Subsequently, the CT apparatus control unit 26 generates a CT image (reconstructed image) of the subject 90 based on multiple projection data acquired at multiple imaging angles 42 (see Figure 6).

[0034] As shown in Figure 3, the first robot arm 22a includes six joints 221a, 221b, 221c, 221d, 221e, and 221f, and links 222a, 222b, 222c, 222d, and 222e connecting each joint. Each of the six joints 221a to 221f is provided with a motor consisting of a servo motor and a position detection unit for detecting the rotational position of each joint. As also shown in Figure 3, an X-ray source 20 is attached to one end of the first robot arm 22a. The first robot arm 22a also includes a base 220 attached to the other end, which can be mounted on a floor, wall, column, etc.

[0035] Each of the six joints 221a to 221f rotates under the drive of a motor.

[0036] The first axis joint 221a is connected to the base 220. The joint 221a rotates the link 222a around the rotation axis 61a relative to the base 220. The second axis joint 221b rotates the link 222b around the rotation axis 61b which is perpendicular to the rotation axis 61a.

[0037] The third joint 221c rotates link 222c relative to link 222b around a rotation axis 61c that is parallel to the rotation axis 61b. The fourth joint 221d rotates link 222d relative to link 222c around a rotation axis 61d that is perpendicular to the rotation axis 61c.

[0038] The fifth joint 221e rotates link 222e relative to link 222d around a rotation axis 61e that is perpendicular to the rotation axis 61d. The sixth joint 221f rotates the X-ray source 20 relative to link 222e around a rotation axis 61f that is perpendicular to the rotation axis 61e.

[0039] The second robot arm 23a has the same configuration as the first robot arm 22a, except that it rotates the X-ray detector 21 instead of the X-ray source 20, so a detailed explanation of its configuration will be omitted.

[0040] (Subject and shooting location) As shown in Figure 4, the subject 90 is, for example, a large die-cast part (giga-cast part). Large means having a long side of about 1 to 2 meters.

[0041] In the X-ray CT scanner 200 (see Figure 1), X-ray CT imaging is performed so that a predetermined imaging location 91 of the subject 90 is captured. When performing X-ray CT imaging, the control unit 1 (see Figure 1) sets the imaging conditions by performing the steps of acquiring three-dimensional structural data 31 (see Figure 1) of the subject 90 based on user input and setting the imaging conditions for X-ray CT imaging using the acquired three-dimensional structural data 31. The imaging conditions include the imaging trajectory 41 (see Figure 6) in which the X-ray source 20 and X-ray detector 21 move, the positions of the X-ray source 20 and X-ray detector 21, and the irradiation conditions of the X-rays emitted from the X-ray source 20.

[0042] (Setting the shooting trajectory) First, referring to Figures 5 to 8, we will explain the configuration in which the processor 11 (see Figure 1) sets the shooting trajectory 41 (see Figure 6).

[0043] In the first embodiment, the X-ray source 20 and the X-ray detector 21 are moved by the first robot arm 22a and the second robot arm 23a, so there is a high degree of freedom in setting the imaging trajectory 41. For this reason, it is difficult for the operator to set the positions of the X-ray source 20 and the X-ray detector 21 and set the imaging trajectory 41 while controlling the first robot arm 22a and the second robot arm 23a.

[0044] Therefore, in the first embodiment, the processor 11 sets the imaging trajectory 41 by performing a simulation using the three-dimensional structure data 31. As shown in FIG. 5, the processor 11 calculates, by simulation, the X-ray transmission amount (luminance value) when the X-ray irradiated from the direction indicated by the arrow 80 reaches the X-ray detector 21 at the imaging location 91. Specifically, the processor 11 uses the acquired three-dimensional structure data 31 to set the positions of the first robotic arm 22a and the second robotic arm 23a during X-ray CT imaging. The three-dimensional structure data 31 is any one of three-dimensional design data of the subject 90, three-dimensional CAD data of the subject 90, X-ray CT data obtained by previously imaging the entire subject 90, and three-dimensional measurement data of the subject 90 acquired using a three-dimensional measuring instrument.

[0045] The processor 11 executes a step of acquiring the imaging location information 32 in the three-dimensional structure data 31 based on the user's operation input. The imaging location information 32 is, for example, information on the operator's selection operation for a predetermined location in the three-dimensional structure data 31, or coordinate information indicating a predetermined location in the three-dimensional structure data 31.

[0046] Next, the processor 11 executes a step of acquiring the rotation axis information 33 (see FIG. 1) of the X-ray source 20 and the X-ray detector 21 in X-ray CT imaging based on the user's operation input. The rotation axis information 33 is, for example, a vector indicating the imaging trajectory axis 40 (see FIG. 6) in the space (XYZ space) defined by the X-axis, Y-axis, and Z-axis, or either the angle in the XY plane of the imaging trajectory axis 40 and the angle in the XZ plane (or YZ plane).

[0047] After acquiring the rotation axis information 33, in the step of setting the above positions, the processor 11 uses the rotation axis information 33 to set the imaging trajectory 41 of the X-ray source 20 and the X-ray detector 21 in X-ray CT imaging.

[0048] Specifically, as shown in FIG. 6, based on the information 33 of the rotation axis, the processor 11 sets the imaging trajectory axis 40 of the X-ray source 20 and the X-ray detector 21 with respect to the imaging location 91 of the subject 90. Then, as shown by the arrows 80a to 80h, the processor 11 executes forward projection calculation while rotating the X-ray source 20 and the X-ray detector 21 along the imaging trajectory 41 at every predetermined imaging angle 42 around the imaging trajectory axis 40. Note that the forward projection calculation means obtaining, by calculation (simulation), the dose (luminance value) of the X-ray when the X-ray irradiated from the X-ray source 20 at a predetermined imaging angle 42 passes through the subject 90 and is detected by the X-ray detector 21. Also, the search range (range of the imaging angle 42) in the imaging trajectory 41 when performing the simulation is set to a range where the X-ray source 20 and the X-ray detector 21 basically go around half of the circumference of the subject 90. That is, the search range is basically set to a range up to 180 degrees with respect to the predetermined imaging angle 42. When each of the first robot arm 22a (see FIG. 2) and the second robot arm 23a (see FIG. 2) is arranged on the floor, the search range of the imaging trajectory 41 is 180 degrees. Also, the pitch when changing the predetermined imaging angle 42 is, for example, 10 degrees or 20 degrees. The search range of the imaging trajectory 41 and the pitch of the imaging angle 42 are set based on the operator's operation input.

[0049] The graph 34 shown in FIG. 7 shows the change in the luminance value of the X-ray in a predetermined imaging trajectory 41 obtained by forward projection calculation. In the graph 34, the vertical axis represents the luminance value and the horizontal axis represents the imaging angle 42.

[0050] Here, as shown in Graph 34, if an opaque area 35 is included, the contrast of the subject 90 (imaging location 91) in the projection data at the imaging angle 42 corresponding to the opaque area 35 decreases, and the image quality of the reconstructed image deteriorates. Therefore, in the first embodiment, a plurality of candidate imaging trajectories 41 are acquired. The opaque area 35 is the portion of the imaging angle 42 where the brightness value is lower than a preset threshold brightness value. The opaque area 35 occurs, for example, when X-rays pass through a portion containing heavy metals such as gold or lead, or in the case of an imaging trajectory 41 where X-rays pass in the direction of longer X-ray transmission distance (path length). The brightness threshold value is preset by the subject 90. If the subject 90 is an aluminum or aluminum alloy product, the brightness threshold value is, for example, the brightness value at which the amount of X-ray transmission is 10%.

[0051] In the first embodiment, in the step of acquiring rotation axis information 33, the processor 11 acquires information 33 for multiple rotation axes. Then, in the step of setting the position, the processor 11 performs forward projection calculations for multiple imaging trajectories 41 based on the information 33 for multiple rotation axes. Specifically, the processor 11 performs forward projection calculations for the multiple imaging trajectories 41 between the X-ray source 20 and the X-ray detector 21 in X-ray CT imaging, in which the acquired imaging location 91 is projected.

[0052] Furthermore, the processor 11 calculates brightness values ​​for each of the multiple imaging angles 42 for each of the multiple imaging trajectories 41, and uses the calculated brightness values ​​for each of the multiple imaging angles 42 to set the imaging trajectory 41 between the X-ray source 20 and the X-ray detector 21 in X-ray CT imaging. Specifically, the processor 11 calculates brightness values ​​for each of the multiple imaging angles 42 for each of the multiple imaging trajectories 41 for each of the multiple imaging angles 41. Then, the processor 11 uses the calculated brightness values ​​for each of the multiple imaging angles 42 to set the imaging trajectory 41 between the X-ray source 20 and the X-ray detector 21 in X-ray CT imaging.

[0053] (Display of shooting trajectory candidates) In the first embodiment, the processor 11 is configured to display a plurality of shooting trajectory candidate screen 3a, as shown in Figure 8. For example, in the example shown in Figure 8, the processor 11 displays shooting trajectory candidates A to C.

[0054] Furthermore, when the processor 11 displays multiple candidate shooting trajectories 41 on the shooting trajectory candidate selection screen 3a, it displays a graph of brightness values ​​34, a shooting trajectory axis 40, and a shooting trajectory 41. For shooting trajectory candidate A, a graph of brightness values ​​34a, a shooting trajectory axis 40a, and a shooting trajectory 41a are displayed. For shooting trajectory candidate B, a graph of brightness values ​​34b, a shooting trajectory axis 40b, and a shooting trajectory 41b are displayed. For shooting trajectory candidate C, a graph of brightness values ​​34c, a shooting trajectory axis 40c, and a shooting trajectory 41c are displayed.

[0055] Then, the processor 11 sets the shooting trajectory 41 based on the user's operation input to select a shooting trajectory candidate via the input reception unit 2. In other words, the processor 11 sets the candidate selected by the user from among a plurality of shooting trajectory candidates as the shooting trajectory 41.

[0056] (Setting the positions of the X-ray source and X-ray detector) Next, with reference to Figures 9 and 10, a configuration in which the processor 11 sets the positions of the X-ray source 20 and the X-ray detector 21 will be described.

[0057] Here, as shown in Figure 9, after the imaging trajectory axis 40 and imaging trajectory 41 (see Figure 6) during X-ray CT imaging are determined, the processor 11 sets the positions of the X-ray source 20 and X-ray detector 21 in the imaging trajectory 41 so that the magnification of the subject 90 (imaging area 91) is the set magnification.

[0058] Specifically, as shown in Figure 10, in the step of setting the position, the processor 11 uses the imaging location information 32 to set the relationship between the source-subject distance 70 between the X-ray source 20 and the subject 90, and the subject-detector distance 71 between the X-ray detector 21 and the subject 90. In the first embodiment, in the step of setting the position, the processor 11 sets the ratio of the source-subject distance 70 to the subject-detector distance 71 so that the entire imaging location 91 is projected onto the X-ray detector 21. The magnification of the subject 90 is determined by the ratio of the source-subject distance 70 to the subject-detector distance 71.

[0059] Furthermore, the processor 11 sets the source-to-subject distance 70 and the subject-to-detector distance 71 so that the source-to-detector distance 72 between the X-ray source 20 and the X-ray detector 21 is minimized, while ensuring that the first robot arm 22a (see Figure 2), the second robot arm 23a (see Figure 2), the X-ray source 20, and the X-ray detector 21 do not come into contact with the subject 90, and while maintaining the ratio of the source-to-subject distance 70 to the subject-to-detector distance 71. The processor 11 sets the source-to-subject distance 70 and the subject-to-detector distance 71 by simulating the positions of the X-ray source 20 and the X-ray detector 21 in the imaging trajectory 41 with respect to the three-dimensional structure data 31 (see Figure 9). Specifically, the processor 11 reduces the source-to-detector distance 72 by a predetermined value while maintaining the ratio of the source-to-subject distance 70 to the subject-to-detector distance 71. The processor 11 then uses simulation to verify whether the first robot arm 22a, the second robot arm 23a, the X-ray source 20, and the X-ray detector 21 will come into contact with the subject 90 when the X-ray source 20 and X-ray detector 21 are moved along the imaging trajectory 41. If the first robot arm 22a, the second robot arm 23a, the X-ray source 20, and the X-ray detector 21 do not come into contact with the subject 90, the processor 11 further reduces the source-detector distance 72. The processor 11 repeats this process, and if the simulation result shows that the X-ray source 20 and the X-ray detector 21 come into contact with the subject 90, it sets the source-subject distance 70 and subject-detector distance 71 to the previous source-detector distance 72.

[0060] (Setting X-ray irradiation conditions) In the first embodiment, the processor 11 sets the X-ray irradiation conditions after the imaging trajectory 41 has been set. For example, the processor 11 sets the value of the tube current applied to the X-ray source 20, the value of the tube voltage, and the X-ray irradiation time as X-ray irradiation conditions. If the set imaging trajectory 41 includes an X-ray opaque area 35 (see Figure 7), the processor 11 sets the irradiation conditions such that the amount of X-ray transmission is high. That is, in the step of setting the imaging conditions, the processor 11 sets the X-ray irradiation conditions for X-ray CT imaging using the calculated brightness value. Generally, when the X-ray output is high, the X-ray focal size increases, and the spatial resolution in the reconstructed image decreases. Therefore, when the processor 11 sets the X-ray irradiation conditions using the brightness value, it sets the X-ray irradiation conditions such that the amount of X-ray transmission is high while maintaining spatial resolution.

[0061] (X-ray CT imaging process) Next, referring to Figure 11, the process in which the processor 11 (see Figure 1) sets the imaging conditions and the CT device control unit 26 (see Figure 1) performs X-ray CT imaging will be described.

[0062] In step 101, the processor 11 acquires three-dimensional structure data 31 (see Figure 1) of the subject 90 (see Figure 2).

[0063] Next, in step 102, the processor 11 acquires information 32 (see Figure 1) about the shooting location in the three-dimensional structure data 31 based on the user's input.

[0064] Next, in step 103, the processor 11 sets the imaging location 91 for the three-dimensional structure data 31 based on the imaging location information 32.

[0065] Next, in step 104, the processor 11 uses the acquired 3D structure data 31 to set the imaging conditions for X-ray CT imaging.

[0066] Next, in step 105, the CT device control unit 26 performs X-ray CT imaging based on the imaging conditions set by the processor 11. After that, the process ends.

[0067] (Shooting Condition Setting Process) Next, referring to Figure 12, the process by which the processor 11 (see Figure 1) sets the shooting conditions will be explained.

[0068] In step 110, the processor 11 sets the imaging trajectory axis 40 (see Figure 6) and the imaging trajectory 41 (see Figure 6). Details of the process by which the processor 11 sets the imaging trajectory axis 40 and the imaging trajectory 41 will be described later.

[0069] Next, in step 111, the processor 11 sets the ratio of the source-subject distance 70 (see Figure 10) to the subject-detector distance 71 (see Figure 10). Specifically, the processor 11 uses the imaging location information 32 to set the ratio of the source-subject distance 70 to the subject-detector distance 71 so that the entire imaging location 91 is projected onto the X-ray detector 21.

[0070] Next, in step 112, the processor 11 sets the range of the source detector distance 72 (see Figure 10) based on the operator's input. The upper limit of the source detector distance 72 is determined by the installation positions of the first robot arm 22a and the second robot arm 23a, and the range of motion of each robot arm.

[0071] Next, in step 113, the processor 11 moves the X-ray source 20 and the X-ray detector 21 to the position of the maximum value in the range of the source-detector distance 72 in the virtual space, while maintaining the ratio of the source-subject distance 70 to the subject-detector distance 71.

[0072] Next, in step 114, the processor 11 simulates whether the X-ray source 20, X-ray detector 21, first robot arm 22a, and second robot arm 23a will come into contact with the subject 90. If they do not come into contact with the subject 90, the process proceeds to step 115. If they do come into contact with the subject 90, the process proceeds to step 116.

[0073] If the process proceeds from step 114 to step 115, in step 115, the processor 11 reduces the distance 72 between the radiation source and detector. After that, the process proceeds to step 114.

[0074] Furthermore, if the process proceeds from step 114 to step 116, in step 116, the processor 11 sets the distance at which it does not come into contact with the subject 90 to the source detector distance 72.

[0075] Next, in step 117, the processor 11 determines whether or not there has been an input to change the shooting trajectory 41. If there has been an input to change the shooting trajectory 41, the process proceeds to step 110. If there has been no input to change the shooting trajectory 41, the process proceeds to step 118.

[0076] Next, in step 118, the processor 11 sets the irradiation conditions for the X-rays emitted from the X-ray source 20. In the first embodiment, the processor 11 sets the X-ray irradiation conditions based on the brightness values ​​obtained in the processing of step 110. After that, the processing ends.

[0077] (Setting the shooting trajectory axis and shooting trajectory) Next, referring to Figure 13, the process by which the processor 11 (see Figure 1) sets the shooting trajectory axis 40 (see Figure 6) and the shooting trajectory 41 (see Figure 6) will be described.

[0078] In step 120, the processor 11 acquires rotation axis information 33 (see Figure 1) based on the user's operation input. In the first embodiment, the processor 11 acquires information 33 for multiple rotation axes based on the user's operation input.

[0079] Next, in step 121, the search range of the shooting trajectory 41 and the pitch of the shooting angle 42 (see Figure 6) are set based on the rotation axis information 33 and the user's operation input. In the first embodiment, the processor 11 sets the search range of the shooting trajectory 41 and the pitch of the shooting angle 42 for each of the multiple rotation axis information 33.

[0080] Next, in step 122, the processor 11 obtains the brightness value of a predetermined shooting angle 42 in a predetermined shooting trajectory 41 by simulating it using forward projection calculation.

[0081] Next, in step 123, the processor 11 determines whether or not brightness values ​​have been acquired at all shooting angles 42 within the search range set in step 121. If brightness values ​​have not been acquired at all shooting angles 42, the process proceeds to step 124. If brightness values ​​have been acquired at all shooting angles 42, the process proceeds to step 125.

[0082] If the process proceeds from step 123 to step 124, in step 124, the processor 11 changes the shooting angle 42. After that, the process proceeds to step 122.

[0083] Furthermore, if the process proceeds from step 123 to step 125, in step 125, the processor 11 creates a graph 34 of the brightness values ​​(see Figure 7).

[0084] Next, in step 126, the processor 11 determines whether or not a graph 34 of the brightness values ​​has been created for all of the shooting trajectories 41. If a graph 34 of the brightness values ​​has not been created for all of the shooting trajectories 41, the process proceeds to step 127. If a graph 34 of the brightness values ​​has been created for all of the shooting trajectories 41, the process proceeds to step 128.

[0085] If the process proceeds from step 126 to step 127, in step 127, the processor 11 changes the shooting trajectory 41. After that, the process proceeds to step 122.

[0086] If the process proceeds from step 126 to step 128, in step 128, the processor 11 determines whether or not there was an operation input to change the shooting trajectory 41. If there was an operation input to change the shooting trajectory 41, the process proceeds to step 120. If there was no operation input to change the shooting trajectory 41, the process proceeds to step 129.

[0087] If the process proceeds from step 128 to step 129, in step 129, the processor 11 displays candidates for the shooting trajectory 41. In the first embodiment, the processor 11 displays on the display unit 3 (see Figure 1) a plurality of candidates that satisfy the conditions that the graph 34 of the brightness values ​​does not include the opaque portion 35 (see Figure 7), or that the brightness value of the opaque portion 35 is greater than or equal to a predetermined value.

[0088] Next, in step 130, the processor 11 sets the shooting trajectory 41. Specifically, the processor 11 sets the shooting trajectory 41 based on the user's input to select a candidate for the shooting trajectory 41. After that, the process ends.

[0089] [Second Embodiment] Next, the shooting condition setting device 300 according to the second embodiment will be described with reference to Figures 14 and 15. Components similar to those in the first embodiment are denoted by the same reference numerals, and detailed explanations are omitted.

[0090] As shown in Figure 14, the shooting condition setting device 300 according to the second embodiment comprises a control unit 301, an input receiving unit 2, and a display unit 3.

[0091] The control unit 301 includes a memory 10 and a processor 301a.

[0092] In the second embodiment, the memory 10 stores the program 30, three-dimensional structure data 31, imaging location information 32, rotation axis information 33, and X-ray condition information 36. The X-ray condition information 36 includes material information 36a of the subject 90. Also in the second embodiment, the memory 10 does not store the brightness value graph 34 (see Figure 1).

[0093] The processor 301a according to the second embodiment performs the step of acquiring information 36 regarding the conditions of the X-rays irradiated from the X-ray source 20 based on user input.

[0094] Furthermore, in the second embodiment, in the step of setting the imaging conditions, the processor 301a uses the X-ray condition information 36 to set the X-ray irradiation conditions for X-ray CT imaging. The processor 301a uses the X-ray condition information 36 to set the value of the tube current applied to the X-ray source 20, the value of the tube voltage, the X-ray irradiation time, and so on.

[0095] Next, referring to Figure 15, the process by which the processor 301a (see Figure 14) according to the second embodiment sets the shooting conditions will be described.

[0096] In steps 110 to 116, the processor 301a sets the imaging trajectory axis 40 and imaging trajectory 41, and sets the distance between the radiation source detectors 72.

[0097] Next, in step 117, the processor 301a determines whether or not there has been an operation input to change the shooting trajectory 41. If there has been an operation input to change the shooting trajectory 41, the process proceeds to step 110. If there has been no operation input to change the shooting trajectory 41, the process proceeds to step 140.

[0098] If the process proceeds from step 117 to step 140, in step 140, the processor 301a acquires information 36 regarding the conditions of the X-rays irradiated from the X-ray source 20 based on the user's input. Specifically, in step 140, where the X-ray condition information 36 is acquired, the processor 301a acquires material information 36a of the subject 90 as the X-ray condition information 36.

[0099] Next, in step 141, the processor 301a sets the X-ray irradiation conditions for X-ray CT imaging using the acquired X-ray condition information 36. Specifically, in step 141, where the X-ray irradiation conditions are set, the processor 301a sets the X-ray irradiation conditions using the acquired material information 36a. After that, the process ends.

[0100] Furthermore, the other configurations of the second embodiment are the same as those of the first embodiment described above.

[0101] [Modifications] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims rather than the description of the embodiments above, and further includes all modifications (modifications) within the meaning and scope equivalent to the claims.

[0102] For example, the imaging condition setting device and the X-ray CT apparatus do not have to be separate devices. For example, as shown in Figure 16, the X-ray CT apparatus 400 includes a control unit 401, an input receiving unit 2, and a display unit 3, and the control unit 401 may have a memory 10 and a processor 401a. The processor 401a may execute a program 30 stored in the memory 10 to perform the steps of acquiring three-dimensional structural data 31 of the subject 90 based on user input and setting imaging conditions for X-ray CT imaging using the acquired three-dimensional structural data 31. The drive unit may be configured to drive either the first robot arm or the second robot arm, and the processor may be configured to set the position of either the first robot arm or the second robot arm. The three-dimensional structural data may be any data other than the three-dimensional design data, three-dimensional CAD data, previously acquired X-ray CT data, and three-dimensional measurement data of the subject, as long as it is three-dimensional shape data of the subject. For example, the three-dimensional structural data may be three-dimensional MRI (Magnetic Resonance Imaging) data. Also, when performing X-ray CT imaging of the entire subject, the processor may set the center position of the subject as the imaging location, without relying on user input. The processor may also be configured to set the relationship between the source-subject distance and the source-detector distance, or the relationship between the subject-detector distance and the source-detector distance. The processor may also be configured to set the ratio of the source-subject distance or subject-detector distance to the source-detector distance. Furthermore, the processor may set the source-subject distance and subject-detector distance that minimize the source-detector distance while maintaining the ratio of the source-subject distance to the subject-detector distance through a single calculation (simulation). Also, when performing X-ray CT imaging of the entire subject, the processor may be configured to set the axis passing through the center position of the subject as the imaging trajectory axis, without relying on user input. The processor does not necessarily have to be configured to acquire information on multiple rotation axes.In this case, the processor may be configured to set the imaging trajectory using information from one rotation axis. Furthermore, when performing X-ray CT imaging of the entire subject, the processor may be configured to perform forward projection calculations when the center of the subject is projected, rather than when the imaging area is projected. Also, the processor does not have to be configured to set the X-ray irradiation conditions. In this case, the CT device control unit may be configured to set the X-ray irradiation conditions. Furthermore, the number of imaging trajectory candidates displayed by the processor may be two or three or more. Also, the processor does not have to display imaging trajectory candidates. Also, when the processor displays imaging trajectory candidates, it may only display a graph of brightness values. Furthermore, the processor may be configured to set the X-ray irradiation conditions using information about the surface shape of the subject, rather than the material information of the subject. Also, the processor may be configured to be able to perform both the configurations of the first and second embodiments described above. Furthermore, the search range for the imaging trajectory may be set to less than half a rotation (less than 180 degrees). Furthermore, if one of the first and second robot arms is positioned on the floor and the other on the ceiling, the search range of the imaging trajectory can be set to 360 degrees. Also, if one of the first and second robot arms is fixed and the other is moved, the search range of the imaging trajectory can be set to 360 degrees. Additionally, when the processor moves the X-ray source and X-ray detector along the imaging trajectory, it may move the X-ray source and X-ray detector while changing the ratio of the distance between the source and subject to the distance between the subject and the detector. That is, the processor may be configured to move the first and second robot arms so as to change the magnification of the subject. Furthermore, the first and second robot arms may be so-called dual-arm robot arms mounted on a single base. Also, the subject is not limited to large die-cast parts (giga-cast parts). The subject may be an automobile body, for example.Furthermore, the processing performed by the processor and the CT device control unit may be flow-driven processing, which performs processing sequentially according to the processing flow; event-driven processing, which executes processing on an event-by-event basis; or a combination of event-driven and flow-driven processing.

[0103] [Embodiments] The exemplary embodiments described above will be understood by those skilled in the art to be specific examples of the following embodiments.

[0104] (Item 1) An X-ray CT scanner imaging condition setting device comprising: an X-ray source; an X-ray detector; a source holding mechanism for holding the X-ray source; a detector holding mechanism for holding the X-ray detector; and a drive unit for driving at least one of the source holding mechanism and the detector holding mechanism to move at least one of the X-ray source and the X-ray detector around a subject to perform X-ray CT imaging, wherein the device comprises a control unit, the control unit having a memory and a processor, and the processor executing a program stored in the memory to perform the steps of: acquiring three-dimensional structural data of the subject based on user input; and setting imaging conditions for performing X-ray CT imaging using the acquired three-dimensional structural data. When performing X-ray CT imaging of a large subject, imaging conditions can be set based on the subject by using the three-dimensional structural data of the subject. Therefore, even when at least one of the X-ray source and the X-ray detector is moved along an arbitrary trajectory, imaging conditions can be easily set based on the subject. As a result, when performing X-ray CT imaging by moving at least one of the X-ray source and the X-ray detector around the subject, appropriate imaging conditions can be easily set. (Item 2) The source holding mechanism is a first robot arm that drives the X-ray source, the detector holding mechanism is a second robot arm that drives the X-ray detector, the drive unit is configured to drive the first robot arm and the second robot arm when performing X-ray CT imaging, and in the step of setting the imaging conditions, the processor uses the acquired three-dimensional structure data to set the positions of the first robot arm and the second robot arm during X-ray CT imaging, as described in Item 1. By using three-dimensional structure data, the positions of the first robot arm and the second robot arm can be set with respect to the subject. As a result, when performing X-ray CT imaging while moving the X-ray source and the X-ray detector with the first robot arm and the second robot arm, which have a high degree of freedom of position control, appropriate imaging conditions can be easily set.(Item 3) The X-ray CT scanner imaging condition setting device according to Item 2, wherein the three-dimensional structural data is one of the following: three-dimensional design data of the subject, three-dimensional CAD data of the subject, X-ray CT data of the entire subject taken in advance, and three-dimensional measurement data of the subject acquired using a three-dimensional measuring instrument. By using one of the following as three-dimensional structural data: three-dimensional design data of the subject, three-dimensional CAD data of the subject, X-ray CT data of the entire subject taken in advance, and three-dimensional measurement data of the subject acquired using a three-dimensional measuring instrument, the positional relationship between the subject, the X-ray source and the X-ray detector in three dimensions can be easily set with the subject as the reference. As a result, imaging conditions can be easily set using the three-dimensional structural data. (Item 4) The X-ray CT scanner imaging condition setting device according to Item 2 or 3, wherein the processor further performs the step of acquiring information on the imaging location in the three-dimensional structure data based on user input, and in the step of setting the position, the processor uses the information on the imaging location to set the relationship between the source-subject distance between the X-ray source and the subject-detector distance between the X-ray detector and the subject. By setting the relationship between the source-subject distance and the subject-detector distance using the information on the imaging location, imaging conditions can be easily set that allow the magnification of the subject during X-ray CT imaging to be set to the magnification desired by the user. (Item 5) The X-ray CT scanner imaging condition setting device according to Item 4, wherein in the step of setting the position, the processor sets the ratio of the source-subject distance and the subject-detector distance so that the entire imaging location is projected onto the X-ray detector. Since the ratio of the source-subject distance to the subject-detector distance is set so that the entire area being scanned is projected onto the X-ray detector, it is possible to easily set imaging conditions that allow the user to obtain a reconstructed image (reconstructed image) that shows the entire area being scanned at the magnification desired by the user.(Item 6) In the step of setting the position, the processor sets the source-to-subject distance and the subject-to-detector distance so that the source-to-detector distance between the X-ray source and the X-ray detector is minimized, while the first robot arm, the second robot arm, the X-ray source, and the X-ray detector do not come into contact with the subject, and while maintaining the ratio of the source-to-subject distance to the subject-to-detector distance. This is an imaging condition setting device for an X-ray CT apparatus according to Item 5. Since the source-to-detector distance is minimized while maintaining the ratio of the source-to-subject distance to the subject-to-detector distance, the amount of attenuation of X-rays detected by the X-ray detector can be reduced while maintaining the magnification of the subject. As a result, the SNR (Signal Noise Ratio) of the image reconstructed by X-ray CT imaging (reconstructed image) can be improved while maintaining the magnification of the subject. (Item 7) The X-ray CT scanner imaging condition setting device according to Item 2 or 3, wherein the processor further performs the step of acquiring information on the rotation axis between the X-ray source and the X-ray detector in X-ray CT imaging based on user input, and in the step of setting the position, the processor uses the rotation axis information to set the imaging trajectory of the X-ray source and the X-ray detector in X-ray CT imaging. Since the imaging trajectory is set by the operator inputting the rotation axis information, the operator can set an imaging trajectory with a high degree of freedom without having to set the imaging trajectory themselves. As a result, user convenience (usability) can be improved. (Item 8) In the step of acquiring information on the rotation axis, the processor acquires information on a plurality of rotation axes; in the step of setting the position, the processor performs forward projection calculations on a plurality of imaging trajectories based on the information on the plurality of rotation axes, calculates brightness values ​​for a plurality of imaging angles for each of the plurality of imaging trajectories, and sets the imaging trajectory of the X-ray source and the X-ray detector in X-ray CT imaging using the calculated brightness values ​​for a plurality of imaging angles, the imaging condition setting device for the X-ray CT apparatus according to Item 7.Here, if heavy metals such as gold or lead are present near the imaging area, or if the imaging trajectory is such that the X-rays pass through in the direction of the longer path length, the amount of X-rays transmitted through that area will be reduced. In this case, the contrast of the subject (imaging area) in the projection data for a specific imaging angle in X-ray CT imaging will decrease, resulting in a decrease in the image quality of the image reconstructed by X-ray CT imaging (reconstructed image). Therefore, as described above, by setting the imaging trajectory using multiple brightness values ​​for each of the multiple imaging angles in each of the multiple imaging trajectories, it is possible to suppress the setting of imaging trajectories that include imaging angles in which the amount of X-ray transmission is reduced. As a result, it is possible to suppress a decrease in the image quality of the reconstructed image. (Item 9) The X-ray CT scanner setting device according to Item 8, wherein the processor further performs the step of acquiring information on the imaging location in the three-dimensional structure data based on user input, and in the step of setting the position, the processor performs a forward projection calculation when the acquired imaging location is projected in the plurality of imaging trajectories of the X-ray source and the X-ray detector in X-ray CT imaging, calculates the brightness value of the imaging location for each of the plurality of imaging angles for each of the plurality of imaging trajectories, and sets the imaging trajectory of the X-ray source and the X-ray detector in X-ray CT imaging using the calculated brightness value of the imaging location for each of the plurality of imaging angles. (Item 10) The X-ray CT scanner imaging condition setting device according to any one of items 1 to 10, wherein the processor further performs the step of acquiring information on the conditions of the X-rays irradiated from the X-ray source based on user operation input, and in the step of setting the imaging conditions, the processor sets the X-ray irradiation conditions for X-ray CT imaging using the information on the X-ray conditions.Item 11) The X-ray CT scanner setting device according to Item 10, wherein in the step of acquiring the X-ray condition information, the processor acquires the material information of the subject as the X-ray condition information, and in the step of setting the X-ray irradiation conditions, the processor sets the X-ray irradiation conditions using the acquired material information. Since the X-ray irradiation conditions are set according to the material information of the subject, X-rays can be irradiated under conditions suitable for the material of the subject. As a result, the degradation of the image quality of the image reconstructed by X-ray CT scanner (reconstructed image) can be further suppressed. (Item 12) The X-ray scanner setting device according to Item 9, wherein in the step of setting the X-ray condition information, the processor sets the X-ray irradiation conditions for X-ray CT scanner using the calculated brightness value. Since the X-ray irradiation conditions are set based on the brightness value calculated by simulation using forward projection calculation, X-rays can be irradiated with irradiation conditions suitable for the position of the X-ray source and X-ray detector, and the imaging trajectory. As a result, the deterioration of the image quality of the reconstructed X-ray CT image can be further suppressed. (Item 13) An X-ray CT apparatus comprising: an X-ray source; an X-ray detector; a source holding mechanism for holding the X-ray source; a detector holding mechanism for holding the X-ray detector; a drive unit for driving at least one of the source holding mechanism and the detector holding mechanism to move at least one of the X-ray source and the X-ray detector around a subject to perform X-ray CT imaging; and a control unit, wherein the control unit has a memory and a processor, and the processor executes a program stored in the memory to perform the steps of acquiring three-dimensional structural data of the subject based on user input and setting imaging conditions for performing X-ray CT imaging using the acquired three-dimensional structural data.Similar to an imaging condition setting device, an X-ray CT apparatus can be provided that allows for easy setting of appropriate imaging conditions when performing X-ray CT imaging by moving at least one of the X-ray source and the X-ray detector around a subject. (Item 14) A method for setting imaging conditions for an X-ray CT apparatus comprising: an X-ray source; an X-ray detector; a source holding mechanism for holding the X-ray source; a detector holding mechanism for holding the X-ray detector; and a drive unit for driving at least one of the source holding mechanism and the detector holding mechanism to perform X-ray CT imaging by moving at least one of the X-ray source and the X-ray detector around a subject, the method comprising: acquiring three-dimensional structural data of the subject; and using the acquired three-dimensional structural data to set imaging conditions for X-ray CT imaging. Similar to an imaging condition setting device, an X-ray CT apparatus can be provided that allows for easy setting of appropriate imaging conditions when performing X-ray CT imaging by moving at least one of the X-ray source and the X-ray detector around a subject. (Item 15) The method for setting imaging conditions for an X-ray CT apparatus as described in Item 14, wherein the source holding mechanism is a first robot arm that drives the X-ray source, the detector holding mechanism is a second robot arm that drives the X-ray detector, the drive unit is configured to drive the first robot arm and the second robot arm when performing X-ray CT imaging, and in the step of setting the imaging conditions, the acquired three-dimensional structure data is used to set the positions of the first robot arm and the second robot arm during X-ray CT imaging. Similar to the imaging condition setting device, the method for setting imaging conditions for an X-ray CT apparatus can be provided that makes it easy to set appropriate imaging conditions even when performing X-ray CT imaging while moving the X-ray source and the X-ray detector with the first robot arm and the second robot arm.

[0105] 1, 301, 401 Control unit 10 Memory 11, 301a, 401a Processor 20 X-ray source 21 X-ray detector 22 Source holding mechanism 22a First robot arm 23 Detector holding mechanism 23a Second robot arm 24 Drive unit 30 Program 31 Three-dimensional structure data 32 Information on imaging location 33 Information on rotation axis 36 Information on X-ray conditions 36a Material information 41, 41a, 41b, 41c Imaging trajectory 42 Imaging angle 70 Distance between source and subject 71 Distance between subject and detector 72 Distance between source and detector 90 Subject 91 Imaging location 100, 300, 400 Imaging condition setting device 200 X-ray CT apparatus

Claims

1. An X-ray CT scanner imaging condition setting device comprising: an X-ray source; an X-ray detector; a source holding mechanism for holding the X-ray source; a detector holding mechanism for holding the X-ray detector; and a drive unit for driving at least one of the source holding mechanism and the detector holding mechanism to move at least one of the X-ray source and the X-ray detector around a subject to perform X-ray CT imaging, wherein the device further comprises a control unit, the control unit having a memory and a processor, and the processor executing a program stored in the memory to perform the steps of: acquiring three-dimensional structural data of the subject based on user input; and setting imaging conditions for performing X-ray CT imaging using the acquired three-dimensional structural data.

2. The imaging condition setting device for an X-ray CT apparatus according to claim 1, wherein the radiation source holding mechanism is a first robot arm that drives the X-ray source, the detector holding mechanism is a second robot arm that drives the X-ray detector, the drive unit is configured to drive the first robot arm and the second robot arm when performing X-ray CT imaging, and in the step of setting the imaging conditions, the processor uses the acquired three-dimensional structure data to set the positions of the first robot arm and the second robot arm during X-ray CT imaging.

3. The X-ray CT scanner imaging condition setting device according to claim 2, wherein the three-dimensional structure data is any one of the following: three-dimensional design data of the subject, three-dimensional CAD data of the subject, X-ray CT data of the entire subject taken in advance, and three-dimensional measurement data of the subject acquired using a three-dimensional measuring instrument.

4. The X-ray CT scanner imaging condition setting device according to claim 2, wherein the processor further performs the step of acquiring information on the imaging location in the three-dimensional structure data based on user input, and in the step of setting the position, the processor uses the information on the imaging location to set the relationship between the source-subject distance between the X-ray source and the subject and the subject-detector distance between the X-ray detector and the subject.

5. In the step of setting the position, the processor sets the ratio of the distance between the radiation source and the subject detector so that the entire imaging area is projected onto the X-ray detector, the imaging condition setting device for an X-ray CT apparatus according to claim 4.

6. In the step of setting the position, the processor sets the distance between the X-ray source and the X-ray detector and the distance between the subject and the detector so that the distance between the X-ray source and the X-ray detector is minimized, while the first robot arm, the second robot arm, the X-ray source, and the X-ray detector do not come into contact with the subject and the ratio of the distance between the X-ray source and the distance between the subject and the detector is maintained. This is an imaging condition setting device for an X-ray CT apparatus according to claim 5.

7. The imaging condition setting device for an X-ray CT apparatus according to claim 2, wherein the processor further performs the step of acquiring information on the rotation axis between the X-ray source and the X-ray detector in X-ray CT imaging based on user input, and in the step of setting the position, the processor uses the rotation axis information to set the imaging trajectory between the X-ray source and the X-ray detector in X-ray CT imaging.

8. In the step of acquiring information on the rotation axis, the processor acquires information on a plurality of rotation axes; in the step of setting the position, the processor performs forward projection calculations on a plurality of imaging trajectories based on the information on the plurality of rotation axes, calculates a plurality of brightness values ​​for each of the plurality of imaging angles for each of the plurality of imaging trajectories, and sets the imaging trajectory of the X-ray source and the X-ray detector in X-ray CT imaging using the calculated brightness values ​​for each of the plurality of imaging angles, the imaging condition setting device for an X-ray CT apparatus according to claim 7.

9. The X-ray CT scanner setting device according to claim 8, wherein the processor further performs the step of acquiring information on the imaging location in the three-dimensional structure data based on user input, and in the step of setting the position, the processor performs a forward projection calculation when the acquired imaging location is projected onto the plurality of imaging trajectories of the X-ray source and the X-ray detector in X-ray CT imaging, calculates the brightness value of the imaging location for each of the plurality of imaging angles for each of the plurality of imaging trajectories, and sets the imaging trajectory of the X-ray source and the X-ray detector in X-ray CT imaging using the calculated brightness value of the imaging location for each of the plurality of imaging angles.

10. The X-ray CT scanner setting device according to claim 1, wherein the processor further performs the step of acquiring information on the conditions of the X-rays irradiated from the X-ray source based on user input, and in the step of setting the imaging conditions, the processor uses the information on the X-ray conditions to set the X-ray irradiation conditions for X-ray CT imaging.

11. In the step of acquiring information on the X-ray conditions, the processor acquires material information of the subject as the information on the X-ray conditions, and in the step of setting the X-ray irradiation conditions, the processor sets the X-ray irradiation conditions using the acquired material information, the imaging condition setting device for an X-ray CT apparatus according to claim 10.

12. In the step of setting the imaging conditions, the processor sets the X-ray irradiation conditions for X-ray CT imaging using the calculated brightness value, the imaging condition setting device for an X-ray CT apparatus according to claim 9.

13. An X-ray CT apparatus comprising: an X-ray source; an X-ray detector; a source holding mechanism for holding the X-ray source; a detector holding mechanism for holding the X-ray detector; a drive unit for driving at least one of the source holding mechanism and the detector holding mechanism to move at least one of the X-ray source and the X-ray detector around a subject to perform X-ray CT imaging; and a control unit, wherein the control unit comprises a memory and a processor, and the processor executes a program stored in the memory to perform the steps of: acquiring three-dimensional structural data of the subject based on user input; and setting imaging conditions for performing X-ray CT imaging using the acquired three-dimensional structural data.

14. A method for setting imaging conditions for an X-ray CT apparatus, comprising: an X-ray source; an X-ray detector; a source holding mechanism for holding the X-ray source; a detector holding mechanism for holding the X-ray detector; and a drive unit for driving at least one of the source holding mechanism and the detector holding mechanism to move at least one of the X-ray source and the X-ray detector around a subject to perform X-ray CT imaging, the method comprising: acquiring three-dimensional structural data of the subject; and using the acquired three-dimensional structural data to set imaging conditions for X-ray CT imaging.

15. The method for setting imaging conditions for an X-ray CT apparatus according to claim 14, wherein the radiation source holding mechanism is a first robot arm that drives the X-ray source, the detector holding mechanism is a second robot arm that drives the X-ray detector, the drive unit is configured to drive the first robot arm and the second robot arm when performing X-ray CT imaging, and in the step of setting the imaging conditions, the acquired three-dimensional structure data is used to set the positions of the first robot arm and the second robot arm during X-ray CT imaging.

Images