Imaging condition calculation device, measurement system, imaging condition calculation method, and program

Abstract

The imaging condition calculation device comprises: an imaging target information acquisition unit that acquires imaging target information regarding the configuration of an imaging target that is measured by radiation penetrating the interior; an attenuation path length indicating the length of a path where the attenuation of radiation penetrating the imaging target is a first condition, a parameter regarding the energy dependence of the attenuation coefficient of the imaging target on the path, and the length of the imaging target through which the radiation penetrates, as imaging target characteristic information based on the acquired imaging target information; and an imaging condition calculation unit that calculates at least one of the state of the radiation source, the attitude of the imaging target, and the detection state by the radiation detector as imaging conditions based on the calculated imaging target characteristic information.

Description

Technology Field

[0001] The present invention relates to an imaging condition calculation device, a measurement system, an imaging condition calculation method, and a program. Background Technology

[0002] Conventionally, a technology for automatically setting imaging conditions of an X-ray fluoroscopy device has been disclosed (see, for example, Patent Document 1). Prior art literature

[0003] Patent Document 1: Japanese Patent Publication No. 2002-14059

[0004] One embodiment of the present invention is an imaging condition calculation device comprising: an imaging condition calculation unit that acquires imaging target information regarding the configuration of an imaging target to be measured by radiation penetrating the interior; an attenuation path length indicating the length of a path where the attenuation of radiation penetrating the imaging target is a first condition based on the acquired imaging target information; a parameter regarding the energy dependence of the attenuation coefficient of the imaging target on the path; and the length of the imaging target through which the radiation penetrates as imaging target characteristic information; and an imaging condition calculation unit that calculates at least one of the state of the radiation source, the attitude of the imaging target, and the detection state by the radiation detector as imaging conditions based on the calculated imaging target characteristic information.

[0005] One embodiment of the present invention is a measurement system comprising the above-described imaging condition calculation device and a measurement device that radiates radiation to a measurement target based on the output of the imaging condition calculation device.

[0006] One embodiment of the present invention is a method for calculating imaging conditions, comprising: acquiring measurement target information regarding the configuration of a measurement target to be measured by radiation penetrating the interior; based on the acquired measurement target information, calculating a reduction path length indicating the length of a path where the reduction of radiation penetrating the measurement target is a first condition, a parameter regarding the energy dependence of the reduction coefficient of the measurement target on the path, and the length of the measurement target through which the radiation penetrates as measurement target characteristic information; and based on the calculated measurement target characteristic information, calculating at least one of the state of the radiation source, the attitude of the measurement target, and the detection state by the radiation detector as imaging conditions.

[0007] One embodiment of the present invention is a program for enabling a computer to acquire measurement target information regarding the configuration of a measurement target that is measured by radiation penetrating the interior, and based on the acquired measurement target information, to calculate a attenuation path length representing the length of a path where the attenuation of radiation penetrating the measurement target is a first condition, a parameter regarding the energy dependence of the attenuation coefficient of the measurement target on the path, and the length of the measurement target through which the radiation penetrates as measurement target characteristic information, and based on the calculated measurement target characteristic information, to calculate at least one of the state of the radiation source, the attitude of the measurement target, and the detection state by the radiation detector as an imaging condition. Brief explanation of the drawing

[0008] FIG. 1 is a drawing showing an example of the external configuration of a measurement system of the present embodiment. FIG. 2 is a drawing showing an example of the configuration of a measuring chamber of the present embodiment. FIG. 3 is a drawing showing an example of a projected image of the present embodiment. FIG. 4 is a diagram showing an example of the functional configuration of the imaging condition calculation device of the present embodiment. FIG. 5 is a diagram showing an example of the maximum attenuation path length of the present embodiment. FIG. 6 is a diagram showing an example of the maximum path of the present embodiment. FIG. 7 is a drawing showing an example of the calculation of the maximum width of the present embodiment. FIG. 8 is a drawing showing an example of an imaging condition controllable by the imaging control device of the present embodiment. FIG. 9 is a diagram showing an example of the processing flow of the imaging condition calculation device of the present embodiment. FIG. 10 is a drawing showing an example of the result of a pre-scan of the present embodiment. FIG. 11 is a drawing showing an example of the result of a pre-scan of the first condition in the projection image of the maximum attenuation of the present embodiment. FIG. 12 is a drawing showing an example of the result of a pre-scan of the second condition in the projection image of the maximum attenuation of the present embodiment. FIG. 13 is a drawing showing an example of an assist image of the present embodiment. Specific details for implementing the invention

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0010] FIG. 1 is a drawing showing an example of the external configuration of the measurement system (1) of the present embodiment. The measurement system (1) is a system that measures the configuration of the measurement target SP (e.g., the internal structure of the measurement target SP) by irradiating the measurement target SP with radiation.

[0011] The measurement system (1) comprises a measurement device (10), an imaging condition calculation device (100), an operation unit (200), a display unit (300), and an imaging control device (400).

[0012] The control unit (200) is equipped with, for example, a keyboard, a mouse, a touch panel, etc., and receives operations by an operator of the measuring device (10). In the following description, the operator of the measuring device (10) is also referred to as a user. That is, the control unit (200) receives operations by the user. The user's operations include instructions to set measurement conditions by the measuring device (10) or instructions to start measurement.

[0013] The display unit (300) is equipped with, for example, a liquid crystal display and presents to the user the setting status of measurement conditions, the progress of measurement, measurement results, etc. Additionally, the display unit (300) may be a touch panel equipped with the function of the control unit (200). In other words, the control unit (200) and the display unit (300) may be the same.

[0014] The measuring device (10) is, for example, an industrial X-ray CT device and is equipped with a door (11) and a measuring room (12). The door (11) is opened and closed when installing a measurement target SP in the measuring room (12), etc. An example of the internal configuration of the measuring room (12) will be explained with reference to FIG. 2.

[0015] FIG. 2 is a drawing showing an example of the configuration of the measurement chamber (12) of the present embodiment. The measurement chamber (12) is equipped with a source (121), a filter (122), a stage (123), and a detection unit (124).

[0016] Also, as necessary for the following description, the direction or arrangement is indicated by the X, Y, and Z axes of the three-dimensional orthogonal coordinate system. Additionally, the X-axis direction is referred to as the width direction, the Y-axis direction as the depth direction, and the Z-axis direction as the height direction.

[0017] The source (121) is a device that emits radiation (e.g., X-rays, γ-rays, neutron rays). In the following description, the direction in which the source (121) emits radiation is also referred to as the optical axis AX. The position in which the source (121) emits radiation is also referred to as the emission position (1211). That is, the source (121) emits radiation from the emission position (1211) in the direction of the optical axis AX. Also, in one example of this embodiment, the optical axis AX coincides with the Y-axis direction of FIG. 2.

[0018] The filter (122) changes the spectrum of radiation emitted from the source (121). For example, the filter (122) blocks the soft X-ray component among the X-ray components emitted from the source (121). In this case, by blocking the soft X-ray component, the filter (122) improves the condition of so-called artifacts or beam hardening (BH) and improves the quality of the image resulting from the measurement.

[0019] The filter (122) is composed of a thin sheet of metal, for example, aluminum, copper, brass, tin, lead, etc. The filter (122) can change its filter characteristics by changing the type or thickness of the metal used.

[0020] A filter (122) is placed between the source (121) and the measurement target SP. For example, it is placed at the radiation emission position (1211) of the source (121) so that radiation emitted immediately from the source (121) passes through. The radiation that passes through the filter (122) is irradiated onto the measurement target SP.

[0021] Additionally, depending on the measurement conditions, the filter (122) may be unnecessary. In this case, the radiation emitted from the source (121) is irradiated directly onto the measurement target SP without passing through the filter (122).

[0022] The stage (123) is a platform for mounting (or holding; the same applies in the following description) the SP to be measured. The stage (123) has the function of changing the orientation of the SP to be measured with respect to the optical axis AX. In an example shown in the drawing, the stage (123) is equipped with a rotation axis (1231) and can rotate around the Z-axis. For example, the stage (123) can change the orientation of the SP to be measured mounted on the stage (123) with respect to the optical axis AX by rotating around the rotation axis (1231) in the rotation direction DR shown in the drawing during measurement.

[0023] The detection unit (124) is a radiation detector composed of, for example, a plurality of pixels (not shown) arranged on an XZ plane, and detects the intensity of radiation incident on each pixel.

[0024] Radiation that has passed through the SP to be measured is irradiated onto the detection surface (1241) of the detection unit (124). The radiation that has passed through the SP to be measured has an intensity distribution according to the transmittance inside the SP to be measured. The radiation irradiated onto the detection surface (1241) (in other words, radiation having information about the internal structure of the SP to be measured) is also referred to as a projected image IMG.

[0025] The detector (124) outputs a signal (or information; the same applies in the following description) indicating the intensity of radiation incident on each pixel. The projected image IMG has information about the internal structure of the measurement target SP projected onto the XZ plane. Based on the signal output by the detector (124), a two-dimensional image can be generated in which the internal structure of the measurement target SP is projected onto the XZ plane.

[0026] In addition, in the following description, the information regarding the internal structure of the measurement target SP generated based on the projected image IMG is also simply referred to as the measurement result.

[0027] Here, the distance from the emission position (1211) of the source (121) to the measurement target SP (e.g., to the center of rotation of the stage (123)) is also referred to as the distance between the source and the measurement target SOD.

[0028] The distance from the emission position (1211) of the source (121) to the detection surface (1241) of the detection unit (124) is also called the distance SDD between the source and the detection unit.

[0029] As shown in the drawing, radiation emitted from the emission position (1211) in the direction of the optical axis AX spreads out in the direction of the XZ plane and reaches the detection surface (1241). A projected image IMG of the measurement target SP is formed on the detection surface (1241).

[0030] FIG. 3 is a drawing showing an example of a projected image IMG of the present embodiment. When the length in the X-axis direction of the measurement target SP (in other words, the width of the measurement target SP viewed from the emission position (1211)) is width W, the width of the projected image IMG on the detection surface (1241) is width L. The width L of this projected image IMG is greater than the width W of the measurement target SP. That is, the projected image IMG is an image of the measurement target SP magnified by a predetermined magnification ratio Mag.

[0031] The width of the portion of the detection surface (1241) where detection pixels are arranged and radiation can be detected is also called the effective detection width FOV. When increasing the resolution of the measurement result output by the detection unit (124), it is preferable that the projected image IMG be enlarged and projected so that it fills the entire effective detection width FOV.

[0032] When changing the width L of the projected image IMG, the magnification factor Mag should be changed. The relationship between the width L of the projected image IMG, the width W of the measurement target SP, and the magnification factor Mag is shown in Equation (1).

[0033] [Mathematical Formula 1]

[0034]

[0035] Returning to FIG. 2, the magnification ratio Mag is determined by the ratio of the distance SOD between the source and the measurement target to the distance SDD between the source and the detection unit. The magnification ratio Mag can be changed by changing the distance SOD between the source and the measurement target (e.g., the installation position in the Y-axis direction of the stage (123)).

[0036] That is, the resolution of the measurement result can be adjusted by changing the installation position of the stage (123) in the Y-axis direction in the measuring device (10). For example, the stage (123) may be a mechanism that can move in the Y-axis direction based on instructions from the imaging control device (400). In this case, the stage (123) may be said to have the function of changing the position of the measurement target SP with respect to the optical axis AX.

[0037] Returning to FIG. 1, the imaging control device (400) is a computer device that integrally controls the measuring device (10). The imaging control device (400) controls each part, such as the source (121), filter (122), stage (123), and detection unit (124), based on user operation, and outputs the measurement result of the measurement target SP. The imaging control device (400) is a computer device and is equipped with a computation unit and a memory unit, which are not illustrated. The memory unit of the imaging control device (400) is equipped with a device capable of storing information, such as a semiconductor memory or a hard disk device. Programs or data used for computation in the computation unit of the imaging control device (400) are stored in the memory unit of the imaging control device (400).

[0038] The operation unit of the imaging control device (400) is equipped with, for example, a CPU (central processing unit) and provides various functions based on a program stored in the memory unit of the imaging control device (400).

[0039] Here, the user desires to acquire measurement results with high resolution and minimal impact from noise, artifacts, beam hardening, etc., in the shortest possible time.

[0040] Conventionally, in order to satisfy these requirements, the user had to set imaging conditions such as the acceleration voltage of the source (121), the tube current value, the magnification ratio Mag, the filter (122), and the number of images to obtain a single measurement result. However, the setting of these imaging conditions varies depending on the type (model) of the measuring device (10) or the type and condition of the SP to be measured. Therefore, there was a problem in that if the user had to perform all of these settings, the work would become cumbersome and a lot of effort would be required for the settings.

[0041] The measurement system (1) of the present embodiment provides an imaging condition calculation device (100) that reduces the effort required for such setting. Below, an example of the functional configuration of the imaging condition calculation device (100) will be described.

[0042] [Functional Configuration of Imaging Condition Calculation Device]

[0043] FIG. 4 is a diagram showing an example of the functional configuration of the imaging condition calculation device (100) of the present embodiment. The imaging condition calculation device (100) is a computer device and is equipped with a calculation unit (110) and a memory unit (150).

[0044] The memory unit (150) is equipped with a device capable of storing information, such as a semiconductor memory or a hard disk device. The memory unit (150) stores a program or data used for calculations by the calculation unit (110).

[0045] The operation unit (110) is equipped with, for example, a CPU (central processing unit) and provides various functions based on a program stored in the memory unit (150). The operation unit (110) is equipped with a measurement target information acquisition unit (111), a measurement target characteristic calculation unit (112), an instruction acquisition unit (113), an imaging condition calculation unit (114), and an imaging condition output unit (115) as its software function unit (or hardware function unit (so-called circuit)).

[0046] The measurement target information acquisition unit (111) acquires measurement target information (501). Measurement target information (501) is information indicating the internal composition of the measurement target SP. The measurement target SP is a measurement target whose internal structure is measured by radiation penetrating the interior.

[0047] That is, the measurement target information acquisition unit (111) acquires measurement target information (501) representing the composition of the measurement target SP that is measured by radiation penetrating the interior.

[0048] Additionally, the measurement target information (501) may be stored in the measurement target information storage unit (500). In this case, the measurement target information acquisition unit (111) acquires the measurement target information (501) from the measurement target information storage unit (500). The measurement target information storage unit (500) is equipped with a device capable of storing information, such as a semiconductor memory or a hard disk device. The measurement target information storage unit (500) supplies the measurement target information (501) to the measurement target information acquisition unit (111) via wired or wireless communication. The measurement target information storage unit (500) may or may not be included in the imaging condition calculation device (100).

[0049] The measurement target information (501) may be design data of the measurement target SP or the measurement result of pre-scanning (or rough scanning) the measurement target SP.

[0050] In addition, a pre-scan is a simpler measurement than the main scan performed prior to the measurement of the SP (so-called main scan). For example, if the interval of the rotation angle of the stage (123) of the main scan (CT angle interval) is approximately 2000 to 4000 per 360 degrees, the CT angle interval of the pre-scan is approximately 100 to 360 degrees. That is, the pre-scan is a rough measurement with a rough CT angle interval compared to the main scan.

[0051] [When the measurement target information (501) is CAD data]

[0052] The measurement target information memory unit (500) stores design data (e.g., 3D CAD data) of the measurement target SP.

[0053] In this case, the measurement target information (501) acquires design data of the measurement target SP (e.g., 3D CAD data) as the measurement target information (501). The design data of the measurement target SP includes information such as the shape of the parts (e.g., sub-parts) constituting the measurement target SP and the material of the parts.

[0054] [When the measurement target information (501) is pre-scan data]

[0055] The measurement target information acquisition unit (111) acquires the measurement result of the measurement target SP obtained by the pre-scan of the measurement device (10) as measurement target information (501).

[0056] In addition, the measurement result of the measurement target SP by free scan may be supplied in real time from the imaging control device (400) of the measurement device (10) or may be stored in the measurement target information memory unit (500).

[0057] When the free scan measurement result is supplied in real time from the imaging control device (400), the measurement target information acquisition unit (111) acquires the free scan measurement result supplied by the imaging control device (400) as measurement target information (501).

[0058] When the free scan measurement result is stored in the measurement target information storage unit (500), the measurement target information acquisition unit (111) acquires the free scan measurement result stored in the measurement target information storage unit (500) as measurement target information (501).

[0059] That is, the measurement target information acquisition unit (111) acquires the measurement result obtained by irradiating the measurement target SP with radiation as measurement target information (501).

[0060] The measurement target characteristic calculation unit (112) calculates information (measurement target characteristic information (1121)) representing the characteristics of the measurement target SP based on the acquired measurement target information (501). Here, the characteristics of the measurement target SP refer to characteristics among the various characteristics of the measurement target SP that affect the resolution or quality of the measurement result, the time required for measurement, etc.

[0061] For example, the characteristics of the SP being measured include the maximum attenuation path length d of the SP being measured, the attenuation coefficient distribution (or parameter regarding the energy dependence of the attenuation coefficient) μ(E), and the maximum width WM.

[0062] [Calculation of maximum attenuation path length d]

[0063] FIG. 5 is a diagram illustrating an example of the maximum attenuation path length d of the present embodiment. Here, the case in which the measurement target characteristic calculation unit (112) calculates the maximum attenuation path length d based on design data of the measurement target SP (e.g., 3D CAD data) is described. Furthermore, the case in which the measurement target characteristic calculation unit (112) calculates the maximum attenuation path length d based on pre-scan data will be described later. There may be various path PS (e.g., paths PS1 to PS3) for the radiation emitted from the source (121) and passing through the measurement target SP. As the radiation travels through the measurement target SP, it is attenuated (its intensity weakens) by absorption and scattering due to the shape or material of the measurement target SP. Additionally, the degree of attenuation (attenuation coefficient μ) varies depending on the shape or material of the measurement target SP. Thus, the degree of radiation attenuation varies depending on the path PS. Among various radiation path PSs, the path PS in which the degree of radiation attenuation is maximum (including any value within the range of ±20% from the maximum; it may also be described as the first condition) is called the maximum path PSM. Here, path length refers to the length of the path PS through which radiation penetrates the measurement target SP. And the maximum attenuation path length d refers to the length of the path PS through which radiation that becomes the maximum path PSM penetrates the measurement target SP. In this embodiment, the value described as "maximum" does not necessarily have to be the literal maximum, and any value within the range of ±20% of the maximum is also treated as the maximum. This is the same whether or not a pre-scan is performed.

[0064] There are regions within the measurement target SP with different attenuation coefficients μ. The measurement target characteristic calculation unit (112) divides the interior of the measurement target SP into multiple regions with different attenuation coefficients μ based on the measurement target information (501). In the example shown in the drawing, the degree of attenuation is greater in the regions with attenuation coefficients μ2 and μ4 than in the regions with attenuation coefficients μ1, μ3, and μ5 (in other words, the attenuation coefficient μ is greater).

[0065] The measurement target characteristic calculation unit (112) calculates the product of the length dn in the Y direction of region n and the attenuation coefficient μn of region n. Here, the product of the length dn in the Y direction of region n and the attenuation coefficient μn of region n is also called the attenuation path length of region n. The measurement target characteristic calculation unit (112) calculates the total sum of the attenuation path lengths for each path PS. For example, the measurement target characteristic calculation unit (112) calculates the attenuation path length d of each path PS based on Equation (2).

[0066] [Mathematical Formula 2]

[0067]

[0068] In this example, the maximum path PSM where the attenuation path length is maximized is path PS2. The measurement target characteristic calculation unit (112) calculates the attenuation path length of the radiation path PS2 as the maximum attenuation path length d.

[0069] Also, the maximum path PSM refers to the path PS in which the attenuation path is maximized among the path PS calculated by the measurement target characteristic calculation unit (112). That is, there is a possibility that a true maximum attenuation path exists in the path PS of radiation that was not calculated by the measurement target characteristic calculation unit (112).

[0070] The measurement target characteristic calculation unit (112) may obtain the maximum attenuation path of the measurement target SP by making the path PS that determines the attenuation path length sufficiently large (in other words, by obtaining the maximum path PSM sufficiently finely) depending on the distribution situation of the area of ​​the measurement target SP.

[0071] [Calculation of the attenuation coefficient distribution (parameter regarding the energy dependence of the attenuation coefficient) μ(E)]

[0072] FIG. 6 is a diagram showing an example of a maximum path PSM of the present embodiment. Here, we describe the case where the measurement target characteristic calculation unit (112) calculates the attenuation coefficient distribution (parameter regarding the energy dependence of the attenuation coefficient) μ(E) based on the design data (e.g., 3D CAD data) of the measurement target SP. Furthermore, the case where the measurement target characteristic calculation unit (112) calculates the attenuation coefficient distribution (parameter regarding the energy dependence of the attenuation coefficient) μ(E) based on pre-scan data will be described later.

[0073] The measurement target characteristic calculation unit (112) calculates the distribution of the attenuation coefficient μ (attenuation coefficient distribution μ(E)) for the maximum path PSM calculated earlier. μ(E) can also be described as a parameter regarding the energy dependence of the attenuation coefficient of the material constituting the measurement target SP on the maximum path PSM. For example, the measurement target characteristic calculation unit (112) calculates the attenuation coefficient distribution μ(E) based on Equation (3).

[0074] [Mathematical Formula 3]

[0075]

[0076] [Calculation of the maximum width WM of the SP under measurement]

[0077] The measurement target characteristic calculation unit (112) calculates the maximum width WM of the measurement target SP. The maximum width WM is the dimension in the direction where the width L of the projected image IMG among the external dimensions of each part of the measurement target SP becomes maximum (including any value within the range of ±20% from the maximum; it may also be described as the first condition). As described with reference to FIGS. 2 and 3, the projected image IMG of the measurement target SP is enlarged and projected onto the detection surface (1241) of the detection unit (124). When the orientation of the measurement target SP with respect to the optical axis AX changes, the width L of the projected image IMG enlarged and projected onto the detection surface (1241) changes. The measurement target characteristic calculation unit (112) calculates the width W of the measurement target SP at the orientation where the width L of the projected image IMG is largest among the orientations of the measurement target SP as the maximum width WM of the measurement target SP. The maximum width WM may be defined as the maximum length of the measurement target through which radiation passes.

[0078] FIG. 7 is a diagram illustrating an example of the calculation of the maximum width WM of the present embodiment. The measurement target characteristic calculation unit (112) performs a ray tracing simulation from the emission position (1211) toward the detection unit (124) for, for example, the measurement target SP1. The measurement target characteristic calculation unit (112) changes the orientation of the measurement target SP1 in various ways (for example, by changing the rotation angle θ around the Z-axis) to obtain the orientation of the measurement target SP1 in which the width L of the projected image IMG1 is maximized. The measurement target characteristic calculation unit (112) calculates the width W of the measurement target SP1 obtained by the simulation as the maximum width WM.

[0079] Also, the maximum width WM refers to the width W in the posture where the width L of the projected image IMG is maximized among the postures of the measurement target SP that the measurement target characteristic calculation unit (112) has calculated. That is, there is a possibility that a true maximum width exists in a posture that the measurement target characteristic calculation unit (112) has not calculated.

[0080] The measurement target characteristic calculation unit (112) may obtain the maximum width of the measurement target SP by making the change in attitude for obtaining the maximum width WM sufficiently large according to the shape of the measurement target SP (in other words, by obtaining the maximum width WM sufficiently finely).

[0081] Here, the calculation of the maximum width WM of the measurement target SP has been explained, but depending on the shape of the sample, it becomes important whether the maximum height HM falls within the field of view of the detector (124) shown in FIG. 3. In such cases, the same calculation method as that for the maximum width WM can be applied to the maximum height HM. In this embodiment, the value described as "maximum" does not necessarily have to be the literal maximum, and any value within the range of ±20% of the maximum is also treated as the maximum. This is the same whether a pre-scan is performed or not.

[0082] Returning to FIG. 4, the measurement target characteristic calculation unit (112) outputs the calculated maximum attenuation path length d, the attenuation coefficient distribution (a parameter regarding the energy dependence of the attenuation coefficient) μ(E), and the maximum width WM to the imaging condition calculation unit (114) as measurement target characteristic information (1121).

[0083] That is, the measurement target characteristic calculation unit (112) calculates, based on the acquired measurement target information (501), the maximum attenuation path length d, which represents the length of the maximum path PSM where the attenuation of radiation passing through the measurement target SP is maximized, the attenuation coefficient distribution (parameter regarding the energy dependence of the attenuation coefficient) μ(E), which represents the distribution of the attenuation coefficient μ of the measurement target SP on the maximum path PSM, and the maximum width WM of the measurement target SP based on the position of the radiation source (121) and the position of the radiation detector (124) that has passed through the measurement target SP as measurement target characteristic information (1121).

[0084] The imaging condition calculation unit (114) calculates imaging conditions based on the measurement target characteristic information (1121) calculated by the measurement target characteristic calculation unit (112).

[0085] Here, the imaging condition calculation unit (114) calculates at least one of the state of the source (121), the posture of the measurement target SP, and the detection state by the detection unit (124) as an imaging condition based on the calculated measurement target characteristic information (1121).

[0086] Here, the state of the source (121) refers to various parameters that can be changed in the source (121), such as the emission position, emission direction, emission angle range, emission intensity, acceleration voltage, tube current value, spot diameter, and the presence or type of filter. In addition, the detection state by the detection unit (124) refers to various parameters that can be changed in the detection unit (124), such as the imaging time, the number of images per unit time, the number of images per measurement, the exposure time, the measurement time, and the presence or absence of a pre-scan. The imaging condition refers to a combination of each parameter of the state of the source (121) described above and a combination of each parameter of the detection state by the detection unit (124). Furthermore, in this embodiment, 13 types of specific imaging conditions will be described later.

[0087] [Example of imaging conditions]

[0088] The imaging condition calculation unit (114) calculates imaging conditions using an objective function. An example of the objective function used by the imaging condition calculation unit (114) is shown in Equation (4).

[0089] [Mathematical Formula 4]

[0090]

[0091] Equation (4) is expressed as a linear sum of individual objective functions (f_{i}). An example of an individual objective function (f_{i}) is described.

[0092] (A) Individual objective functions related to the optimization of CNR (contrast-noise ratio), acceleration voltage, metal filter, noise, and BH (beam hardening) artifacts:

[0093] Individual objective function (1) CNR(x)(contrast noise ratio): weight w1

[0094] Individual objective function (2) Noise(x): weight w2

[0095] Individual objective function (3) BH(x)(BH artifact): weight w3

[0096] By adjusting weights w1 to w3, you can set which of CNR, noise, and BH artifact amount to prioritize for optimization.

[0097] (B) Individual objective functions related to the optimization of effective spatial resolution, distance between source and target, spot diameter SZ, electron beam power, and current:

[0098] Individual objective function (4) Geometric unsharpness(x): weight w4

[0099] By adjusting the weight w4, it is possible to set the priority for optimizing the effective spatial resolution with respect to CNR, noise, and BH artifact amounts.

[0100] (C) Individual objective functions related to the optimization of the number of projected image acquisitions (number of measurements ns) and CT angle intervals:

[0101] Individual objective function (5) Projection number(x): weight w5

[0102] By adjusting the weight w5, it is possible to set the priority for optimizing the effective spatial resolution with respect to CNR, noise, and BH artifacts.

[0103] (D) Individual objective functions related to the optimization of FPD exposure time (exposure time T_FPD) and CT measurement time (measurement time T_CT):

[0104] Individual objective function (6) FPD exposure time(x): weight w6

[0105] Individual objective function (7) CT time(x): weight w7

[0106] By adjusting weights w6 and w7, it is possible to set the degree to which the measurement time T_CT is optimized with respect to CNR, noise, BH artifact amount, and effective spatial resolution.

[0107] The imaging condition calculation unit (114) calculates imaging conditions by setting seven types of weights w1 to w7 automatically, either according to user operation (in other words, user preference) or without relying on user operation.

[0108] Generally, there are various setting items for determining imaging conditions in a measuring device (10). For this reason, there are countless setting results for these setting items. When attempting to automate the settings of the measuring device (10), it is difficult to unequivocally determine which objective function should be used. In other words, it is generally difficult to automate the settings of the measuring device (10).

[0109] The measurement system (1) of the present embodiment classifies individual objective functions into the seven types described above and assigns weights to the seven types of individual objective functions. Accordingly, the measurement system (1) of the present embodiment is able to set imaging conditions according to the user's preference (or appropriately without relying on user operation) among the combinations of settings of countless measurement devices (10).

[0110] Also, the imaging condition calculation unit (114) adjusts the balance of weights between the individual objective functions described above by normalizing the values ​​of weights w1 to w7 so that, for example, the sum of weights w1 to w7 becomes 100.

[0111] The variable x in equation (4) is a vector. The component of the variable x represents an imaging condition that can be changed by the imaging control device (400) controlling the measuring device (10) (in other words, a control condition for controlling the source (121) or the detector (124) of the measuring device (10). An example of the imaging condition represented by the variable x is shown in FIG. 8.

[0112] FIG. 8 is a drawing showing an example of an imaging condition controllable by the imaging control device (400) of the present embodiment.

[0113] For example, variable x includes 13 types of imaging conditions (i.e., imaging conditions x1 to x13). The measuring device (10) of the present embodiment can change the state for at least these 13 types of imaging conditions.

[0114] Imaging conditions x1 to x4 are imaging conditions regarding the source (121). Imaging condition x1 represents the acceleration voltage of the source (121). Imaging condition x2 represents the beam intensity of the radiation emitted from the source (121). Imaging condition x3 represents the spot diameter SZ of the radiation emitted from the source (121). Component x4 represents the material or thickness (filter thickness DF) of the filter (122).

[0115] Imaging conditions x5 to x9 are imaging conditions regarding the stage (123). Imaging condition x5 represents the distance SOD between the source and the measurement target. Imaging condition x6 represents the number of measurements ns (also called the number of projections). Imaging condition x7 represents the CT angle interval. Imaging condition x8 represents the mounting position of the measurement target SP on the stage (123). Imaging condition x9 represents the rotation angle θ of the measurement target SP.

[0116] Imaging conditions x10~x11 are imaging conditions regarding image processing of the projected image IMG. Component x10 represents the effective spatial resolution. Imaging condition x11 represents the amount of BH artifact suppression.

[0117] Imaging conditions x12 to x13 are imaging conditions regarding the exposure time and a series of measurement times at the detector (124). Imaging condition x12 represents the exposure time T_FPD. Imaging condition x13 represents the measurement time T_CT.

[0118] As described above, the imaging condition calculation unit (114) can calculate various types of imaging conditions.

[0119] For example, the imaging condition calculation unit (114) may use a filter (122) that transmits radiation, beam hardening of radiation, position of the measurement target SP, spot diameter SZ of radiation, beam current of the source (121), number of measurements ns by the detector (124), slice interval of the measurement target SP, exposure time T_FPD of the detector (124), measurement time T_CT of the measurement target SP, orientation change axis of the measurement target SP, orientation of the measurement target SP, etc. as imaging conditions.

[0120] Also, the imaging condition calculation unit (114) may calculate these various imaging conditions based on the user's instructions.

[0121] In this case, the instruction acquisition unit (113) acquires the user's instruction regarding the imaging condition from the operation unit (200). The instruction acquisition unit (113) outputs user instruction information (201) indicating the acquired user instruction to the imaging condition calculation unit (114).

[0122] The imaging condition calculation unit (114) calculates imaging conditions based on instructions acquired by the instruction acquisition unit (113).

[0123] [Example of user instruction: MODE 1 (One-push operation mode)]

[0124] The user's instructions may include an automatic setting instruction (2011) that does not specify either the resolution of the measurement result or the measurement time T_CT.

[0125] In this case, a button image (fully automatic measurement button, not shown) specifying that measurement should be performed fully automatically is displayed to the user through the display unit (300). The user operates the fully automatic measurement button displayed on the display unit (300).

[0126] The instruction acquisition unit (113) acquires the automatic setting instruction (2011) when the fully automatic measurement button is operated, and outputs the acquired automatic setting instruction (2011) to the imaging condition calculation unit (114).

[0127] The imaging condition calculation unit (114) calculates an imaging condition based on an automatic setting instruction (2011) that includes at least the number of measurements ns of the detection unit (124), the exposure time T_FPD, and the measurement time T_CT.

[0128] In this case, the imaging condition calculation unit (114) adjusts to acquire an image of typical quality (resolution) at a typical time.

[0129] For example, the weights w1 to w7 of the above-described equation (4) are set equally (e.g., 14%) to set the weight w of each objective function.

[0130] As described above, the imaging condition calculation device (100) calculates the desired imaging condition by adjusting the weights of the individual objective functions shown in Equation (4). Accordingly, when a user desires fully automatic measurement, the imaging condition calculation device (100) can set the imaging condition by a simple method of adjusting the weights of the individual objective functions based on the characteristics of the measurement target SP calculated by the measurement target characteristic calculation unit (112).

[0131] [Example of user instructions: MODE 2 (Time Priority Mode) / MODE 3 (Resolution Priority Mode)]

[0132] The user's instructions may include instructions on which to prioritize between the resolution (or resolution of the measurement results; the same applies in the following description) and the measurement time T_CT.

[0133] In this case, a selection screen (not shown) is displayed to the user through the display unit (300) to select which to prioritize between the resolution of the measurement result and the measurement time T_CT. The user selects which to prioritize between the resolution of the measurement result and the measurement time T_CT.

[0134] The instruction acquisition unit (113) acquires user instruction information (201) indicating which of the resolution of the measurement result and the measurement time T_CT should be prioritized, and outputs the acquired user instruction information (201) to the imaging condition calculation unit (114).

[0135] The imaging condition calculation unit (114) calculates at least one of the number of measurements ns of the detection unit (124), the exposure time T_FPD, and the measurement time T_CT as an imaging condition based on the user's instructions.

[0136] In addition, the user's instructions may include instructions for specifying the measurement time T_CT. In this case, the imaging condition calculation unit (114) calculates imaging conditions such that the measurement is completed within the measurement time T_CT specified by the user.

[0137] Additionally, the user's instructions may include instructions to balance the resolution of the measurement result and the measurement time T_CT. In this case, the imaging condition calculation unit (114) calculates, based on the user's instructions, a balanced condition for the number of measurements ns of the detection unit (124), the exposure time T_FPD, and the measurement time T_CT as an imaging condition.

[0138] As described above, the individual objective functions shown in Equation (4) are classified into a group of individual objective functions that affect resolution (weight w4, weight w5) and a group of individual objective functions that affect measurement time (weight w5, weight w6, weight w7). Therefore, the imaging condition calculation unit (114) can set whether to prioritize resolution, prioritize measurement time, or balance the two by adjusting these weights w using a simple method called weight adjustment.

[0139] [Examples of user instructions (other)]

[0140] The user's instructions may include instructions that specify both the resolution of the measurement results and the measurement time T_CT.

[0141] In this case, a screen (not shown) for specifying the resolution of the measurement result and a screen (not shown) for specifying the measurement time T_CT are displayed to the user through the display unit (300). The user inputs the resolution of the measurement result and the measurement time T_CT.

[0142] The instruction acquisition unit (113) acquires user instruction information (201) that specifies the resolution of the measurement result and the measurement time T_CT, and outputs the acquired user instruction information (201) to the imaging condition calculation unit (114).

[0143] The imaging condition calculation unit (114) calculates an imaging condition based on the user's instructions, including at least the number of measurements ns of the detection unit (124), the exposure time T_FPD, and the measurement time T_CT.

[0144] In addition, the user's instructions may include instructions specifying the degree of noise or artifacts included in the measurement results.

[0145] In this case, the imaging condition calculation unit (114) calculates at least one of the number of measurements ns of the detection unit (124), the exposure time T_FPD, and the measurement time T_CT as an imaging condition based on the user's instructions.

[0146] The imaging condition calculation unit (114) outputs the imaging condition calculated as described above to the imaging condition output unit (115).

[0147] The imaging condition output unit (115) outputs the calculated imaging conditions. For example, the imaging condition output unit (115) outputs the imaging conditions to the imaging control device (400). The imaging control device (400) controls each part of the measuring device (10) based on the imaging conditions calculated by the imaging condition calculation device (100).

[0148] According to the measurement system (1) configured in this way, since the imaging condition calculation device (100) assists the user's operation, the user can reduce the effort required to set imaging conditions.

[0149] The flow of a series of processing steps by the above-described imaging condition calculation device (100) will be explained with reference to FIG. 9.

[0150] [Flow of processing of the imaging condition calculation device (100)]

[0151] FIG. 9 is a diagram showing an example of the processing flow of the imaging condition calculation device (100) of the present embodiment.

[0152] (Step S10) The instruction acquisition unit (113) acquires user instruction information (201) indicating a user's instruction from the operation unit (200). The instruction acquisition unit (113) outputs the acquired user instruction information (201) to the imaging condition calculation unit (114).

[0153] (Step S20) The measurement target information acquisition unit (111) determines whether there is 3D CAD data (design data) of the measurement target SP. If the measurement target information acquisition unit (111) determines that there is 3D CAD data of the measurement target SP, the processing proceeds to Step S30. If the measurement target information acquisition unit (111) determines that there is no 3D CAD data of the measurement target SP, the processing proceeds to Step S40.

[0154] (Step S30) The measurement target information acquisition unit (111) acquires measurement target information (501) from the measurement target information storage unit (500). In this case, the measurement target information (501) is 3D CAD data of the measurement target SP. This 3D CAD data includes information on the material or internal structure of the measurement target SP.

[0155] (Step S40) The measurement target information acquisition unit (111) acquires measurement target information (501). In this case, the measurement target information (501) is pre-scan data of the measurement target SP. This pre-scan data includes information on the material or internal structure of the measurement target SP.

[0156] Here, an example of a free scan is described. In a free scan, the imaging control device (400) fixes imaging conditions such as the acceleration voltage of the source (121), beam intensity, spot diameter SZ, the material or thickness of the filter (122), and the distance between the source and the measurement target SOD, and rotates the stage (123) around the Z-axis at predetermined angle intervals. As a result, as shown in FIG. 10, a projected image IMG is captured for each rotation angle θ.

[0157] FIG. 10 is a drawing showing an example of the result of a pre-scan of the present embodiment. The imaging condition calculation unit (114) identifies the rotation angle θmax with the greatest attenuation and the pixel with the greatest attenuation among n projection images IMGs from rotation angle θ1 to θn. In the example shown in the drawing, the imaging condition calculation unit (114) determines that the projection image IMG of the i-th rotation angle θi is the projection image IMG with the greatest attenuation.

[0158] The imaging control device (400) captures two different imaging conditions of projection images IMG (projection image IMG_I1 and projection image IMG_I2) at a rotation angle θi.

[0159] FIG. 11 is a drawing showing an example of the result of a pre-scan under the first condition in the projection image IMG of the maximum attenuation of the present embodiment. The drawing shows an example of the projection image IMG_I1.

[0160] FIG. 12 is a drawing showing an example of the result of a pre-scan under the second condition in the projection image IMG of the maximum attenuation of the present embodiment. The drawing shows an example of the projection image IMG_I2.

[0161] (Step S50) The measurement target characteristic calculation unit (112) calculates measurement target characteristic information (1121) based on either the design data of the measurement target SP acquired in Step S30 (e.g., 3D CAD data) or the result of the pre-scan acquired in Step S40.

[0162] When based on design data of the SP to be measured (e.g., 3D CAD data), the measurement target characteristic calculation unit (112) calculates measurement target characteristic information (1121) by the procedure described with reference to the above-described FIG. 5 and FIG. 6 (virtually irradiating the SP to be measured with radiation by simulation).

[0163] Meanwhile, when based on pre-scan data, the measurement target characteristic calculation unit (112) calculates the measurement target characteristic information (1121) as follows.

[0164] The measurement target characteristic calculation unit (112) acquires projected image IMG_I1 and projected image IMG_I2. The measurement target characteristic calculation unit (112) performs optimization using a local optimization method including known constraints, using the acquired projected image IMG_I1 and projected image IMG_I2, the fitting function shown in Equation (5), and the objective function shown in Equation (6).

[0165] [Mathematical Formula 5]

[0166]

[0167] [Mathematical Formula 6]

[0168]

[0169] Here, the fitting function of Equation (5) is expressed by separating the photoelectric absorption term of the first term and the Compton scattering term of the second term (constant term). Also, the coefficients (a, b, c) of Equation (5) depend on the atomic number.

[0170] The objective function of Equation (6) is expressed by the projected images IMG_I1 and IMG_I2 and the fitting function and intensity (spectrum) difference equation δS(E) of Equation (5).

[0171] The measurement target characteristic calculation unit (112) obtains the maximum attenuation path length d (e.g., maximum attenuation path length), the atomic number Z, and the attenuation distribution μ(E) as a result of the optimization described above. The measurement target characteristic calculation unit (112) outputs the calculated maximum attenuation path length d, the atomic number Z, and the attenuation distribution μ(E) to the imaging condition calculation unit (114) as measurement target characteristic information (1121).

[0172] Also, μ(E) in the case based on pre-scan data can be described as a parameter regarding the energy dependence of the equivalent attenuation coefficient when the measurement target SP on the maximum path PSM is considered as a homogeneous object.

[0173] (Step S60) The imaging condition calculation unit (114) obtains device configuration information (601) from the device configuration information storage unit (600). The device configuration information (601) is information that is prepared in advance for each type of measuring device (10). The device configuration information (601) is information indicating the specifications of each part of the measuring device (10) (e.g., source (121), filter (122), stage (123), and detection unit (124)). The device configuration information storage unit (600) is equipped with a device capable of storing information, such as a semiconductor memory or a hard disk device. The device configuration information storage unit (600) supplies the device configuration information (601) to the imaging condition calculation unit (114) via wired or wireless communication. The device configuration information storage unit (600) may or may not be included in the imaging condition calculation device (100).

[0174] (Step S70) The imaging condition calculation unit (114) calculates imaging conditions based on the measurement target characteristic information (1121) calculated by the measurement target characteristic calculation unit (112) in Step S50 and the device configuration information (601) acquired in Step S60.

[0175] Also, as the details of the calculation of imaging conditions are as described above, an explanation is omitted here.

[0176] (Step S80) The imaging condition calculation unit (114) determines whether the imaging condition calculated in Step S70 is suitable for the specifications of the measuring device (10) indicated by the device configuration information (601) acquired in Step S60.

[0177] For example, depending on the type (model) of the measuring device (10), the imaging condition calculated in step S70 may not be realized by the source (121), filter (122), stage (123), and detector (124) of the measuring device (10) to be judged.

[0178] In this case, the imaging condition calculation unit (114) determines that the measurement device (10) is not suitable for the specifications and proceeds to step S100.

[0179] Meanwhile, when the imaging condition calculation unit (114) determines that the imaging condition is suitable for the specifications of the measuring device (10), it outputs imaging condition information (1141) indicating the calculated imaging condition to the imaging condition output unit (115) and proceeds with processing to step S90.

[0180] (Step S90) The imaging condition output unit (115) outputs imaging condition information (1141) to the display unit (300) or the imaging control device (400).

[0181] (Step S100) If the imaging condition output unit (115) determines that the imaging condition is not suitable for the specifications of the measuring device (10), it suggests to the user to use another model suitable for the imaging condition.

[0182] That is, the imaging condition output unit (115) outputs recommended device information indicating the type of measuring device (10) recommended for measurement based on the calculated imaging condition among a plurality of types of measuring devices (10) that measure the inside of an object by radiation irradiation.

[0183] According to the measurement system (1) configured in this way, a more suitable type of measuring device (10) can be suggested to the user, and measurement that meets the user's requirements can be made possible.

[0184] [Variation Example 1]

[0185] The imaging condition output unit (115) may output an assist image P1 (installation information) indicating the installation method of the measurement target SP based on the calculated posture of the measurement target SP.

[0186] FIG. 13 is a diagram showing an example of an assist image P1 of the present embodiment. The imaging condition output unit (115) displays the assist image P1 on the display unit (300). The assist image P1 includes an image P11 showing the posture of a measurement target. This image P11 showing the posture of a measurement target represents the posture of a measurement target SP based on the maximum attenuation path length d, maximum width WM, and attenuation coefficient distribution μ(E), etc., used by the imaging condition calculation unit (114) when calculating the imaging condition. That is, by mounting the measurement target SP on the stage (123) according to the posture of the measurement target SP shown in the image P11 showing the posture of the measurement target, the imaging condition calculated by the imaging condition calculation unit (114) can be satisfied.

[0187] According to the measurement system (1) configured in this manner, when a user mounts the measurement target SP on the stage (123), it can visually present in what posture the mounting satisfies the calculated imaging conditions. That is, according to the measurement system (1) of the present embodiment, the user's effort during measurement can be reduced.

[0188] Although embodiments of the present invention have been described in detail with reference to the drawings, the specific configurations are not limited to these embodiments, and appropriate modifications may be made within the scope of the spirit of the invention. It is also acceptable to combine the configurations described in each of the above-described embodiments.

[0189] In addition, each part of each device in the above embodiment may be realized by dedicated hardware, or may be realized by memory and a microprocessor.

[0190] In addition, each part of each device is configured by memory and a CPU (central processing unit), and the function may be realized by loading a program for realizing the function of each part of each device into memory and executing it.

[0191] In addition, a program for realizing the function of each part equipped with each device may be recorded on a computer-readable recording medium, and processing by each part equipped with the control unit may be performed by reading and executing the program recorded on the recording medium into a computer system. Furthermore, the term "computer system" as used herein shall include hardware such as an OS and peripheral devices.

[0192] In addition, the term 'computer system' shall include the homepage provision environment (or display environment) in cases where a WWW system is used.

[0193] In addition, "computer-readable recording medium" refers to portable media such as flexible disks, magneto-optical disks, ROMs, and CD-ROMs, and storage devices such as hard disks embedded in computer systems. Furthermore, "computer-readable recording medium" includes devices that dynamically maintain a program for a short period of time, such as communication lines when transmitting a program through a network such as the Internet or a telephone line, and devices that maintain a program for a certain period of time, such as volatile memory within a computer system that serves as a server or client in such cases. In addition, the above-mentioned program may be intended to realize a part of the aforementioned function, and furthermore, it may be capable of realizing the above-mentioned function in combination with a program already recorded in a computer system.

[0194] Additionally, the imaging control device (400) may be the imaging condition calculation device (100). Specifically, the calculation unit of the imaging control device (400) may be the calculation unit (110) of the imaging condition calculation device (100), and the memory unit of the imaging control device (400) may be the memory unit (150) of the imaging condition calculation device (100). Explanation of the symbols

[0195] 1: Measurement system, 10: Measurement device, 11: Door, 12: Measurement chamber, 121: Source, 1211: Ejection position, 1212: Spot position, 122: Filter, 123: Stage, 1231: Rotation axis, 124: Detector, 1241: Detector surface, 100: Imaging condition calculation device, 110: Calculation unit, 111: Measurement target information acquisition unit, 112: Measurement target characteristic calculation unit, 1121: Measurement target characteristic information, 113: Instruction acquisition unit, 114: Imaging condition calculation unit, 1141: Imaging condition information, 115: Imaging condition output unit, 150: Memory unit, 200: Operation unit, 201: User instruction information, 2011: Automatic setting instruction, 2012: Resolution priority instruction, 2013: Measurement time priority Instruction, 300: Display unit, 400: Imaging control device, 500: Measurement target information storage unit, 501: Measurement target information, 600: Device configuration information storage unit, 601: Device configuration information, SP: Measurement target

Claims

Claim 1 An imaging condition calculation device comprising: an imaging condition calculation unit that acquires imaging target information regarding the configuration of an imaging target to be measured by radiation penetrating the interior; an attenuation path length indicating the length of a path where the attenuation of radiation penetrating the imaging target becomes a first condition, a parameter regarding the energy dependence of the attenuation coefficient of the imaging target on the path, and the length of the imaging target through which the radiation penetrates, as imaging target characteristic information based on the acquired imaging target information; and an imaging condition calculation unit that calculates at least one of the state of the radiation source, the attitude of the imaging target, and the detection state by the radiation detector as an imaging condition based on the calculated imaging target characteristic information. Claim 2 In claim 1, the measurement target information acquisition unit is an imaging condition calculation device that acquires design data of a measurement target as the measurement target information. Claim 3 In claim 1, the measurement target information acquisition unit is an imaging condition calculation device that acquires a measurement result obtained by irradiating a measurement target with radiation as the measurement target information. Claim 4 An imaging condition calculation device according to claim 2, wherein the first condition is any value within ±20% of the value at which the attenuation of radiation penetrating a measurement target is maximized by simulating based on the design data. Claim 5 In claim 3, the imaging condition calculation device wherein the first condition is any value within ±20% of the value at which the attenuation of radiation penetrating the measurement target obtained by irradiating the measurement target with radiation becomes maximum. Claim 6 An imaging condition calculation device according to claim 2, wherein the parameter relates to the energy dependence of the attenuation coefficient of a material constituting a measurement target on the path. Claim 7 An imaging condition calculation device according to claim 3, wherein the parameter relates to the energy dependence of an equivalent attenuation coefficient when the measurement target on the path is considered as a homogeneous object. Claim 8 An imaging condition calculation device according to claim 2, wherein the length of the measurement target is any value within ±20% of the maximum value. Claim 9 In claim 3, an imaging condition calculation device in which the length of the measurement target is any value within ±20% of the maximum value. Claim 10 An imaging condition calculation device according to claim 1, further comprising an imaging condition output unit that outputs the calculated imaging conditions. Claim 11 An imaging condition calculation device according to claim 1, wherein the imaging condition includes at least one of a filter that transmits the radiation, beam hardening of the radiation, position of a measurement target, spot diameter of the radiation, beam current of the source, number of measurements by a radiation detector, slice interval of a measurement target, exposure time of a radiation detector, measurement time required for a measurement target, attitude change axis of a measurement target, and attitude of a measurement target. Claim 12 In claim 1, the imaging condition calculation unit calculates the attitude of a measurement target through which the radiation passes the maximum path attenuated by the radiation as the imaging condition. Claim 13 An imaging condition calculation device according to claim 1, further comprising an instruction acquiring unit for acquiring instructions from a user of imaging conditions, wherein the imaging condition calculation unit calculates the imaging conditions based on the instructions acquired by the instruction acquiring unit. Claim 14 In claim 13, the above instruction includes an instruction on which to prioritize between the resolution of the measurement result and the measurement time required, and the imaging condition calculation unit calculates at least one of the number of measurements of the radiation detector, the exposure time, and the measurement time required as the imaging condition based on the above instruction. Claim 15 In claim 13, the above instructions include instructions specifying both the resolution of the measurement result and the measurement time required, and the imaging condition calculation unit calculates, based on the above instructions, conditions including at least the number of measurements of the radiation detector, the exposure time, and the measurement time required as the imaging condition, an imaging condition calculation device. Claim 16 In claim 13, the above instructions include an automatic setting instruction which does not specify either the resolution of the measurement result or the measurement time required, and the imaging condition calculation unit calculates, based on the above automatic setting instruction, a condition including at least the number of measurements of the radiation detector, the exposure time, and the measurement time required as the imaging condition. Claim 17 In claim 13, the above instructions include instructions specifying the degree of noise or artifacts included in the measurement result, and the imaging condition calculation unit calculates at least one of the number of measurements of the radiation detector, the exposure time, and the measurement time required as the imaging condition based on the above instructions. Claim 18 In claim 10, the imaging condition output unit further outputs recommended device information indicating a type of measuring device recommended for measurement based on the calculated imaging condition among a plurality of types of measuring devices that measure the interior of an object by radiation irradiation. Claim 19 In claim 10, the imaging condition output unit is an imaging condition calculation device that outputs installation information indicating an installation method of a measurement target based on the calculated posture of the measurement target. Claim 20 An imaging condition calculation device comprising: an imaging condition information acquisition unit for acquiring imaging target information regarding the configuration of an imaging target measured by radiation penetrating the interior; an attenuation path length indicating the length of a path where the attenuation of radiation penetrating the imaging target is maximized based on the acquired imaging target information; a parameter regarding the energy dependence of an equivalent attenuation coefficient when the imaging target on the path is considered a homogeneous object; an imaging target characteristic calculation unit for calculating the maximum value of the imaging target based on the position of the radiation source and the position of the radiation detector penetrating the imaging target as imaging target characteristic information; an imaging condition calculation unit for calculating at least one of the state of the source, the attitude of the imaging target, and the detection state by the detector as an imaging condition based on the calculated imaging target characteristic information; and an imaging condition output unit for outputting the calculated imaging condition. Claim 21 An imaging condition calculation device comprising: an imaging condition information acquisition unit for acquiring imaging target information regarding the configuration of an imaging target to be measured by radiation penetrating the interior; an attenuation path length indicating the length of a path where the attenuation of radiation penetrating the imaging target is maximized, a parameter regarding the energy dependence of the attenuation coefficient of a material constituting the imaging target along said path, and the length of the imaging target through which the radiation penetrates as imaging target characteristic information based on the acquired imaging target information; an imaging condition calculation unit for calculating at least one of the state of the radiation source, the attitude of the imaging target, and the detection state by a radiation detector as an imaging condition based on the calculated imaging target characteristic information; and an imaging condition output unit for outputting the calculated imaging condition. Claim 22 A measuring system comprising an imaging condition calculation device described in any one of claims 1 to 21, and a measuring device that radiates radiation to a measurement target based on the output of the imaging condition calculation device. Claim 23 A method for calculating imaging conditions, comprising: acquiring measurement target information regarding the configuration of a measurement target to be measured by radiation penetrating the interior; calculating, based on the acquired measurement target information, a reduction path length indicating the length of a path where the reduction of radiation penetrating the measurement target is a first condition, a parameter regarding the energy dependence of the reduction coefficient of the measurement target on the path, and the length of the measurement target through which the radiation penetrates as measurement target characteristic information; and calculating at least one of the state of the radiation source, the attitude of the measurement target, and the detection state by the radiation detector as imaging conditions based on the calculated measurement target characteristic information. Claim 24 A program for enabling a computer to perform the following: acquiring measurement target information regarding the configuration of a measurement target to be measured by radiation penetrating the interior; calculating, based on the acquired measurement target information, a attenuation path length indicating the length of a path where the attenuation of radiation penetrating the measurement target is a first condition, a parameter regarding the energy dependence of the attenuation coefficient of the measurement target on said path, and the length of the measurement target through which the radiation penetrates as measurement target characteristic information; and calculating at least one of the state of the radiation source, the attitude of the measurement target, and the detection state by the radiation detector as an imaging condition based on the calculated measurement target characteristic information.

Images