Image capture condition calculation device, measurement system, image capture condition calculation method, and program

Abstract

The present invention provides an image capture condition calculation device comprising: an object-of-measurement information acquisition unit that acquires object-of-measurement information pertaining to the composition of an object of measurement to be measured by interior-penetrating radiation; an object-of-measurement properties calculation unit that calculates, on the basis of the acquired object-of-measurement information, an attenuation path length that indicates the length of a path on which the attenuation of radiation penetrating the object of measurement becomes a first condition, a parameter related to the energy dependence of the attenuation coefficient of the object of measurement on the path, and the length of the object of measurement that is penetrated by the radiation as object-of-measurement properties information; and an image capture condition calculation unit that calculates, on the basis of the calculated object-of-measurement properties information, at least one from among the state of the radiation source, the orientation of the object of measurement, and the state of detection by a radiation detection unit as an image capture condition.

Description

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

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

[0002] 2. Description of the Related Art Conventionally, a technique for automatically setting imaging conditions of an X-ray fluoroscope has been disclosed (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2002-14059

[0004] An embodiment of the present invention is an imaging condition calculation device comprising: a measurement object information acquisition unit that acquires measurement object information related to the configuration of a measurement object to be measured by radiation that transmits through its interior; a measurement object characteristic calculation unit that calculates, based on the acquired measurement object information, the following as measurement object characteristic information: an attenuation path length that indicates the length of a path along which attenuation of the radiation that transmits through the measurement object satisfies a first condition; a parameter related to the energy dependence of an attenuation coefficient of the measurement object on the path; and the length of the measurement object through which the radiation transmits; and an imaging condition calculation unit that calculates, based on the calculated measurement object characteristic information, at least one of a state of a radiation source, an attitude of the measurement object, and a detection state by a radiation detection unit as an imaging condition.

[0005] One embodiment of the present invention is a measurement system including the imaging condition calculation device described above, and a measurement device that irradiates radiation to the measurement object based on an output of the imaging condition calculation device.

[0006] One embodiment of the present invention is an imaging condition calculation method including: acquiring measurement object information related to the configuration of a measurement object to be measured by radiation that passes through its interior; calculating, based on the acquired measurement object information, the following as measurement object characteristic information: an attenuation path length indicating the length of a path along which attenuation of the radiation passing through the measurement object satisfies a first condition; a parameter related to the energy dependence of an attenuation coefficient of the measurement object on the path; and the length of the measurement object through which the radiation passes; and calculating, based on the calculated measurement object characteristic information, at least one of the state of a radiation source, the attitude of the measurement object, and the detection state by a radiation detection unit as an imaging condition.

[0007] One embodiment of the present invention is a program for causing a computer to execute the following operations: acquire measurement object information regarding the configuration of a measurement object to be measured by radiation that passes through its interior; calculate, based on the acquired measurement object information, the following measurement object characteristic information: an attenuation path length indicating the length of the path along which attenuation of the radiation passing through the measurement object meets a first condition; a parameter related to the energy dependence of the attenuation coefficient of the measurement object on the path; and the length of the measurement object through which the radiation passes; and calculate, based on the calculated measurement object characteristic information, at least one of the state of the radiation source, the attitude of the measurement object, and the detection state by a radiation detection unit as imaging conditions.

[0008] 1 is a diagram showing an example of the external configuration of a measurement system according to this embodiment; FIG. 2 is a diagram showing an example of the configuration of a measurement room according to this embodiment; FIG. 3 is a diagram showing an example of a projection image according to this embodiment; FIG. 4 is a diagram showing an example of the functional configuration of an imaging condition calculation device according to this embodiment; FIG. 5 is a diagram showing an example of a maximum attenuation path length according to this embodiment; FIG. 6 is a diagram showing an example of a maximum path according to this embodiment; FIG. 7 is a diagram showing an example of calculation of a maximum width according to this embodiment; FIG. 8 is a diagram showing an example of an imaging condition that can be controlled by an imaging control device according to this embodiment; FIG. 9 is a diagram showing an example of the processing flow of an imaging condition calculation device according to this embodiment; FIG. 10 is a diagram showing an example of a pre-scan result according to this embodiment; FIG. 11 is a diagram showing an example of a pre-scan result according to a first condition in a projection image of maximum attenuation according to this embodiment; FIG. 12 is a diagram showing an example of a pre-scan result according to a second condition in a projection image of maximum attenuation according to this embodiment; FIG. 13 is a diagram showing an example of an assist image according to this embodiment;

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a diagram showing an example of the external configuration of a measurement system 1 according to this embodiment. The measurement system 1 is a system that irradiates a measurement target SP with radiation and measures the configuration of the measurement target SP (e.g., the internal structure of the measurement target SP). The measurement system 1 includes a measurement device 10, an imaging condition calculation device 100, an operation unit 200, a display unit 300, and an imaging control device 400.

[0010] The operation unit 200 includes, for example, a keyboard, a mouse, a touch panel, etc., and accepts operations by the operator of the measurement device 10. In the following description, the operator of the measurement device 10 is also referred to as the user. That is, the operation unit 200 accepts operations by the user. The user's operations include instructions to set measurement conditions by the measurement device 10, instructions to start measurement, etc.

[0011] The display unit 300 includes, for example, a liquid crystal display, and presents to the user the measurement condition settings, the measurement progress, the measurement results, etc. The display unit 300 may also be a touch panel that has the functions of the operation unit 200. In other words, the operation unit 200 and the display unit 300 may be the same unit.

[0012] The measurement device 10 is, for example, an industrial X-ray CT device, and includes a door 11 and a measurement room 12. The door 11 is opened and closed when, for example, installing a measurement target SP in the measurement room 12. An example of the internal configuration of the measurement room 12 will be described with reference to FIG.

[0013] 2 is a diagram showing an example of the configuration of the measurement chamber 12 of this embodiment. The measurement chamber 12 is equipped with a radiation source 121, a filter 122, a stage 123, and a detection unit 124. In the following description, where necessary, directions and arrangements are indicated by the X, Y, and Z axes of a three-dimensional orthogonal coordinate system. The X-axis direction is also referred to as the width direction, the Y-axis direction as the depth direction, and the Z-axis direction as the height direction.

[0014] The radiation source 121 is a device that emits radiation (e.g., X-rays, gamma rays, or neutron rays). In the following description, the direction in which the radiation source 121 emits radiation is also referred to as the optical axis AX. The position from which the radiation source 121 emits radiation is also referred to as the emission position 1211. That is, the radiation source 121 emits radiation in the direction of the optical axis AX from the emission position 1211. Note that, in one example of this embodiment, the optical axis AX coincides with the Y-axis direction in FIG. 2 .

[0015] The filter 122 changes the spectrum of the radiation emitted from the radiation source 121. For example, the filter 122 cuts out soft X-ray components from among the X-ray components emitted from the radiation source 121. In this case, by cutting out the soft X-ray components, the filter 122 improves the so-called artifact and beam hardening (BH) conditions and improves the quality of the image, which is the measurement result. The filter 122 is made of a thin metal plate, such as aluminum, copper, brass, tin, or lead. The filter characteristics of the filter 122 can be changed by changing the type and thickness of the metal used. The filter 122 is disposed between the radiation source 121 and the measurement target SP. For example, the filter 122 is disposed at the radiation emission position 1211 of the radiation source 121, and the radiation immediately after being emitted from the radiation source 121 passes through the filter 122. The radiation that has passed through the filter 122 is irradiated onto the measurement target SP.

[0016] Depending on the measurement conditions, there may be cases where the filter 122 is not necessary. In this case, the radiation emitted from the radiation source 121 is irradiated directly onto the measurement target SP without passing through the filter 122.

[0017] The stage 123 is a platform on which the measurement target SP is placed (or held; the same applies in the following description). The stage 123 has the function of changing the attitude of the measurement target SP with respect to the optical axis AX. In the example shown in the same figure, the stage 123 has a rotation axis 1231 and is rotatable around the Z axis. For example, during measurement, the stage 123 can change the attitude of the measurement target SP placed 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 figure.

[0018] The detection unit 124 is a radiation detector composed of, for example, multiple pixels (not shown) arranged on the XZ plane, and detects the intensity of radiation incident on each pixel. Radiation that has passed through the measurement target SP is irradiated onto the detection surface 1241 of the detection unit 124. The radiation that has passed through the measurement target SP has an intensity distribution that corresponds to the transmittance inside the measurement target SP. The radiation irradiated onto the detection surface 1241 (i.e., radiation that contains information about the internal structure of the measurement target SP) is also referred to as a projection image IMG. The detection unit 124 outputs a signal (or information; the same applies in the following description) indicating the intensity of the radiation incident on each pixel. The projection image IMG contains information about the internal structure of the measurement target SP projected onto the XZ plane. Based on the signal output by the detection unit 124, a two-dimensional image of the internal structure of the measurement target SP projected onto the XZ plane can be generated. Note that in the following description, the information about the internal structure of the measurement target SP generated based on the projection image IMG is also simply referred to as a measurement result.

[0019] Here, the distance from the emission position 1211 of the radiation source 121 to the measurement target SP (for example, to the rotation center of the stage 123) is also referred to as the radiation source-to-measurement target distance SOD. The distance from the emission position 1211 of the radiation source 121 to the detection surface 1241 of the detection unit 124 is also referred to as the radiation source-to-detection unit distance SDD. As shown in the figure, radiation emitted from the emission position 1211 in the direction of the optical axis AX spreads in the XZ plane direction before reaching the detection surface 1241. A projection image IMG of the measurement target SP is formed on the detection surface 1241.

[0020] 3 is a diagram showing an example of the projection image IMG of this embodiment. When the length of the measurement target SP in the X-axis direction (i.e., the width of the measurement target SP as seen from the emission position 1211) is width W, the width of the projection image IMG on the detection surface 1241 is width L. The width L of this projection image IMG is larger than the width W of the measurement target SP. In other words, the projection image IMG is an image of the measurement target SP enlarged by a certain magnification factor Mag.

[0021] The width of the portion of the detection surface 1241 where detection pixels are arranged and radiation can be detected is also referred to as the effective detection width FOV. To increase the resolution of the measurement results output by the detection unit 124, it is preferable that the projection image IMG is enlarged and projected to the full effective detection width FOV. To change the width L of the projection image IMG, the enlargement magnification Mag can be changed. The relationship between the width L of the projection image IMG, the width W of the measurement target SP, and the enlargement magnification Mag is shown in Equation (1).

[0022]

[0023] Returning to FIG. 2 , the magnification factor Mag is determined by the ratio of the radiation source-to-measurement object distance SOD to the radiation source-to-detector distance SDD. The magnification factor Mag can be changed by changing the radiation source-to-measurement object distance SOD (e.g., the installation position of the stage 123 in the Y-axis direction). That is, in the measurement device 10, the resolution of the measurement results can be adjusted by changing the installation position of the stage 123 in the Y-axis direction. 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, it can be said that the stage 123 has the function of changing the position and orientation of the measurement object SP relative to the optical axis AX.

[0024] Returning to FIG. 1 , the imaging control device 400 is a computer device that comprehensively controls the measurement device 10. The imaging control device 400 controls each component, such as the radiation source 121, the filter 122, the stage 123, and the detector 124, based on user operation, and outputs measurement results for the measurement target SP. The imaging control device 400 is a computer device and includes a calculation unit and a storage unit (not shown). The storage unit of the imaging control device 400 includes a device capable of storing information, such as a semiconductor memory or a hard disk drive. The storage unit of the imaging control device 400 stores programs and data used for calculations by the calculation unit of the imaging control device 400. The calculation unit of the imaging control device 400 includes, for example, a CPU (central processing unit) and provides various functions based on programs stored in the storage unit of the imaging control device 400.

[0025] Here, users desire high-resolution measurement results that are less affected by noise, artifacts, beam hardening, and the like, and that can be obtained in as short a time as possible. Conventionally, to satisfy these demands, users have had to set imaging conditions, such as the acceleration voltage of the radiation source 121, the tube current value, the magnification factor Mag, the filter 122, and the number of images to be captured per measurement result. However, the settings of these imaging conditions vary depending on the type (model) of the measurement device 10 and the type and state of the measurement target SP. Therefore, if the user were to perform all of these settings, the work would be cumbersome and time-consuming. The measurement system 1 of this embodiment provides an imaging condition calculation device 100 that reduces the time and effort required for these settings. An example of the functional configuration of the imaging condition calculation device 100 is described below.

[0026] [Functional Configuration of the Shooting Condition Calculation Apparatus] Fig. 4 is a diagram showing an example of the functional configuration of the shooting condition calculation apparatus 100 of this embodiment. The shooting condition calculation apparatus 100 is a computer apparatus, and includes a calculation unit 110 and a storage unit 150. The storage unit 150 includes a device capable of storing information, such as a semiconductor memory or a hard disk drive. The storage unit 150 stores programs and data used for calculations by the calculation unit 110.

[0027] The calculation unit 110 includes, for example, a CPU (Central Processing Unit), and provides various functions based on programs stored in the storage unit 150. The calculation unit 110 includes, as its software function units (or hardware function units (so-called circuits)), a measurement object information acquisition unit 111, a measurement object characteristic calculation unit 112, an instruction acquisition unit 113, an imaging condition calculation unit 114, and an imaging condition output unit 115.

[0028] The measurement target information acquisition unit 111 acquires measurement target information 501. The measurement target information 501 is information indicating the internal configuration of the measurement target SP. The measurement target SP is an object whose internal structure is measured by radiation that passes through the interior.

[0029] That is, the measurement object information acquisition unit 111 acquires measurement object information 501 that indicates the configuration of the measurement object SP that is measured by radiation that transmits through the interior thereof. The measurement object information 501 may be stored in the measurement object information storage unit 500. In this case, the measurement object information acquisition unit 111 acquires the measurement object information 501 from the measurement object information storage unit 500. The measurement object information storage unit 500 includes a device that can store information, such as a semiconductor memory or a hard disk drive. The measurement object information storage unit 500 supplies the measurement object information 501 to the measurement object information acquisition unit 111 via wired or wireless communication. The measurement object information storage unit 500 may or may not be included in the imaging condition calculation device 100.

[0030] The measurement target information 501 may be design data of the measurement target SP or the measurement results of a pre-scan (which may also be referred to as a rough scan) of the measurement target SP. A pre-scan is a measurement that is performed prior to measurement of the measurement target SP (a so-called main scan) and is simpler than a main scan. For example, if the rotation angle increment (CT angle increment) of the stage 123 in the main scan is approximately 2000 to 4000 per 360 degrees, the CT angle increment in the pre-scan is approximately 100 to 360. In other words, a pre-scan is a rough measurement with a coarser CT angle increment than a main scan.

[0031] [When the Measurement Target Information 501 is CAD Data] The measurement target information storage unit 500 stores design data (for example, three-dimensional CAD data) of the measurement target SP.

[0032] In this case, design data (e.g., three-dimensional CAD data) of the measurement target SP is acquired as the measurement target information 501. The design data of the measurement target SP includes information such as the shapes of components (e.g., subcomponents) that make up the measurement target SP, and the materials of the components.

[0033] [When the Measurement Target Information 501 is Pre-scan Data] The measurement target information acquisition unit 111 acquires, as the measurement target information 501, the measurement results of the measurement target SP obtained by the pre-scan of the measurement device 10.

[0034] The measurement results of the measurement object SP obtained by the prescan may be supplied in real time from the imaging control device 400 of the measurement device 10, or may be stored in the measurement object information storage unit 500. When the prescan measurement results are supplied in real time from the imaging control device 400, the measurement object information acquisition unit 111 acquires the prescan measurement results supplied by the imaging control device 400 as the measurement object information 501. When the prescan measurement results are stored in the measurement object information storage unit 500, the measurement object information acquisition unit 111 acquires the prescan measurement results stored in the measurement object information storage unit 500 as the measurement object information 501.

[0035] That is, the measurement target information acquisition unit 111 acquires, as measurement target information 501, the measurement results obtained by irradiating the measurement target SP with radiation.

[0036] The measurement target characteristic calculation unit 112 calculates information indicating the characteristics of the measurement target SP (measurement target characteristic information 1121) based on the acquired measurement target information 501. Here, the characteristics of the measurement target SP refer to, among various characteristics of the measurement target SP, characteristics that affect the resolution and quality of the measurement results, the time required for measurement, etc. For example, the characteristics of the measurement target SP include the maximum attenuation path length d of the measurement target SP, the attenuation coefficient distribution (or a parameter related to the energy dependence of the attenuation coefficient) μ(E), and the maximum width WM.

[0037] [Calculation of Maximum Attenuation Path Length d] FIG. 5 is a diagram showing an example of the maximum attenuation path length d according to this embodiment. Here, a case will be described in which the measurement object characteristic calculation unit 112 calculates the maximum attenuation path length d based on design data (e.g., three-dimensional CAD data) of the measurement object SP. A case in which the measurement object characteristic calculation unit 112 calculates the maximum attenuation path length d based on pre-scan data will be described later. Radiation emitted from the radiation source 121 and passing through the measurement object SP can take various paths PS (e.g., paths PS1 to PS3). As the radiation travels through the measurement object SP, it is attenuated (its intensity weakens) due to absorption and scattering due to the shape and material of the measurement object SP. Furthermore, the degree of attenuation (attenuation coefficient μ) differs depending on the shape and material of the measurement object SP. Thus, the degree of attenuation of the radiation differs depending on the path PS. Of the various radiation paths PS, the path PS where the degree of radiation attenuation is greatest (including any value in the range of ±20% from the maximum; this 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 along which radiation passes through the measurement object SP. The maximum attenuation path length d refers to the length of the path PS along which radiation with the maximum path PSM passes through the measurement object SP. In this embodiment, the value described as "maximum" does not necessarily have to be the literal maximum; any value within the range of ±20% of the maximum is also treated as the maximum. This applies whether a pre-scan is performed or not.

[0038] The measurement object SP has regions with different attenuation coefficients μ. The measurement object characteristic calculation unit 112 divides the measurement object SP into multiple regions with different attenuation coefficients μ based on the measurement object information 501. In the example shown in the figure, the regions with attenuation coefficients μ2 and μ4 have a greater degree of attenuation (i.e., a larger attenuation coefficient μ) than the regions with attenuation coefficients μ1, μ3, and μ5.

[0039] The measurement object characteristic calculation unit 112 calculates the product of the length dn of region n in the Y direction and the attenuation coefficient μn of region n. Here, the product of the length dn of region n in the Y direction and the attenuation coefficient μn of region n is also referred to as the attenuation path length of region n. The measurement object characteristic calculation unit 112 calculates the sum of the attenuation path lengths for each path PS. For example, the measurement object characteristic calculation unit 112 calculates the attenuation path length d of each path PS based on equation (2).

[0040]

[0041] In this example, the maximum path PSM, which has the longest attenuation path length, is path PS2. The measurement object property calculation unit 112 calculates the attenuation path length of the radiation path PS2 as the maximum attenuation path length d.

[0042] The maximum path PSM refers to the path PS with the maximum attenuation path among the paths PS that are calculation targets by the measurement object property calculation unit 112. In other words, there is a possibility that the true maximum attenuation path exists among the radiation paths PS that are not calculation targets by the measurement object property calculation unit 112. The measurement object property calculation unit 112 can also find the maximum attenuation path of the measurement object SP by sufficiently increasing the number of paths PS for which the attenuation path length is to be found (i.e., finding the maximum path PSM in sufficient detail) depending on the distribution of the area of ​​the measurement object SP.

[0043] [Calculation of Attenuation Coefficient Distribution (Parameter Related to Energy Dependence of Attenuation Coefficient) μ(E)] FIG. 6 is a diagram showing an example of a maximum path PSM according to this embodiment. Here, a case will be described in which the measurement object characteristic calculation unit 112 calculates the attenuation coefficient distribution (parameter related to energy dependence of attenuation coefficient) μ(E) based on design data (e.g., three-dimensional CAD data) of the measurement object SP. A case in which the measurement object characteristic calculation unit 112 calculates the attenuation coefficient distribution (parameter related to energy dependence of attenuation coefficient) μ(E) based on pre-scan data will be described later. The measurement object characteristic calculation unit 112 calculates the distribution of the attenuation coefficient μ (attenuation coefficient distribution μ(E)) for the maximum path PSM calculated above. μ(E) can also be considered a parameter related to the energy dependence of the attenuation coefficient of the material constituting the measurement object SP on the maximum path PSM. For example, the measurement object characteristic calculation unit 112 calculates the attenuation coefficient distribution μ(E) based on Equation (3).

[0044]

[0045] [Calculation of Maximum Width WM of Measurement Target SP] The measurement target characteristic calculation unit 112 calculates the maximum width WM of the measurement target SP. The maximum width WM is the dimension of the outer dimensions of each part of the measurement target SP in the direction in which the width L of the projected image IMG is maximum (including any value in the range of ±20% from the maximum; this 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 in the orientation in which the width L of the projected image IMG is largest 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.

[0046] 7 is a diagram showing an example of calculation of maximum width WM in this embodiment. For example, the measurement object characteristic calculation unit 112 performs a ray tracing simulation for the measurement object SP1 from the emission position 1211 toward the detection unit 124. The measurement object characteristic calculation unit 112 changes the orientation of the measurement object SP1 in various ways (for example, by changing the rotation angle θ around the Z axis) to find the orientation of the measurement object SP1 that maximizes the width L of the projection image IMG1. The measurement object characteristic calculation unit 112 calculates the width W of the measurement object SP1 found by the simulation as the maximum width WM.

[0047] The maximum width WM refers to the width W at the orientation of the measurement target SP that the measurement target characteristic calculation unit 112 selects as the calculation target, at which the width L of the projected image IMG is at its maximum. In other words, the true maximum width may exist in an orientation not selected as the calculation target by the measurement target characteristic calculation unit 112. The measurement target characteristic calculation unit 112 can also calculate the maximum width of the measurement target SP by sufficiently increasing the orientation change for calculating the maximum width WM (i.e., calculating the maximum width WM with sufficient precision) depending on the shape of the measurement target SP. While the calculation of the maximum width WM of the measurement target SP has been described here, depending on the shape of the sample, it may be important whether the maximum height HM fits within the field of view of the detection unit 124 shown in FIG. 3 . Even in such cases, the same calculation method as for the maximum width WM can be applied to the maximum height HM. In this embodiment, the value referred to as "maximum" does not necessarily have to be the literal maximum; any value within a range of ±20% of the maximum is also treated as the maximum. This applies whether or not a pre-scan is performed.

[0048] Returning to Figure 4, the measurement object characteristic calculation unit 112 outputs the calculated maximum attenuation path length d, attenuation coefficient distribution (a parameter related to the energy dependence of the attenuation coefficient) μ(E), and maximum width WM to the imaging condition calculation unit 114 as measurement object characteristic information 1121.

[0049] That is, based on the acquired measurement object information 501, the measurement object characteristic calculation unit 112 calculates, as measurement object characteristic information 1121, the maximum attenuation path length d indicating the length of the maximum path PSM along which the attenuation of the radiation passing through the measurement object SP is greatest, the attenuation coefficient distribution μ(E) (a parameter related to the energy dependence of the attenuation coefficient) indicating the distribution of the attenuation coefficient μ of the measurement object SP on the maximum path PSM, and the maximum width WM of the measurement object SP based on the position of the radiation source 121 and the position of the detection unit 124 for the radiation that has passed through the measurement object SP.

[0050] The imaging condition calculation section 114 calculates imaging conditions based on the measurement object characteristic information 1121 calculated by the measurement object characteristic calculation section 112 .

[0051] Here, the imaging condition calculation unit 114 calculates, as imaging conditions, at least one of the state of the radiation source 121, the orientation of the measurement target SP, and the detection state by the detection unit 124, based on the calculated measurement target characteristic information 1121. Here, the state of the radiation source 121 refers to various parameters that can be changed in the radiation 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 absence and type of filter of the radiation source 121. Furthermore, 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 taken per unit time, the number of images taken per measurement, exposure time, measurement time, and the presence or absence of a pre-scan. The imaging conditions refer to a combination of the parameters of the state of the radiation source 121 described above and a combination of the parameters of the detection state by the detection unit 124. Note that in this embodiment, 13 specific imaging conditions will be described later.

[0052] [Example of Imaging Conditions] 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).

[0053]

[0054] Equation (4) is expressed as a linear sum of individual objective functions (f_{i}). An example of the individual objective functions (f_{i}) will be described.

[0055] (A) Individual objective functions related to optimizing CNR (contrast to noise ratio), acceleration voltage, metal filter, noise, and BH (beam hardening) artifacts: Individual objective function (1) CNR(x) (contrast to noise ratio): weight w1 Individual objective function (2) Noise(x): weight w2 Individual objective function (3) BH(x) (BH artifact): weight w3 By adjusting the weights w1 to w3, it is possible to set which of CNR, noise, and BH artifact amount is to be prioritized for optimization.

[0056] (B) Individual objective functions related to the optimization of the effective spatial resolution, the source-to-object distance SOD, the spot diameter SZ, and the electron beam power and current: Individual objective function (4) Geometric unsharpness(x): weight w4 By adjusting the weight w4, it is possible to set the degree to which the effective spatial resolution is to be prioritized for optimization relative to the CNR, noise, and BH artifact amount.

[0057] (C) Individual objective function related to the optimization of the number of projection images acquired (number of measurements ns) and CT angle increments: Individual objective function (5) Projection number(x): weight w5 By adjusting the weight w5, it is possible to set the degree to which the effective spatial resolution is prioritized for optimization relative to the CNR, noise, and BH artifact amount.

[0058] (D) Individual objective functions related to optimization of FPD exposure time (exposure time T_FPD) and CT measurement time (measurement time T_CT): Individual objective function (6) FPD exposure time(x): weight w6 Individual objective function (7) CT time(x): weight w7 By adjusting the weights w6 and w7, it is possible to set the degree to which the measurement time T_CT is to be prioritized for optimization relative to the CNR, noise, BH artifact amount, and effective spatial resolution.

[0059] The imaging condition calculation unit 114 calculates the imaging conditions by setting seven types of weights w1 to w7 in accordance with the user's operation (i.e., the user's preference) or automatically without the user's operation.

[0060] Generally, in the measurement device 10, there are a wide variety of setting items for determining imaging conditions. Therefore, there are an infinite number of setting results for these setting items. When attempting to automate the settings of the measurement device 10, it is difficult to uniquely determine what objective function should be used. In other words, it is generally difficult to automate the settings of the measurement device 10.

[0061] The measurement system 1 of this embodiment classifies the individual objective functions into the seven types described above and then weights the seven types of individual objective functions. This makes it possible for the measurement system 1 of this embodiment to set imaging conditions according to the user's preferences (or appropriate without user operation) from among the countless combinations of settings for the measurement device 10.

[0062] The imaging condition calculation unit 114 adjusts the balance of the weights between the individual objective functions described above by normalizing the values ​​of the weights w1 to w7 so that the total value of the weights w1 to w7 becomes 100, for example.

[0063] The variable x in equation (4) is a vector. The components of the variable x indicate imaging conditions that can be changed by the imaging control device 400 controlling the measurement device 10 (i.e., control conditions for controlling the radiation source 121 and the detection unit 124 of the measurement device 10). An example of the imaging conditions indicated by the variable x is shown in FIG. 8 .

[0064] 8 is a diagram showing an example of imaging conditions that can be controlled by the imaging control device 400 of this embodiment. As an example, the variable x includes 13 types of imaging conditions (i.e., imaging conditions x1 to x13). The measuring device 10 of this embodiment can change the state of at least these 13 types of imaging conditions.

[0065] Imaging conditions x1 to x4 are imaging conditions for the radiation source 121. Imaging condition x1 indicates the acceleration voltage of the radiation source 121. Imaging condition x2 indicates the beam intensity of the radiation emitted from the radiation source 121. Imaging condition x3 indicates the spot diameter SZ of the radiation emitted from the radiation source 121. Component x4 indicates the material and thickness (filter thickness DF) of the filter 122.

[0066] Imaging conditions x5 to x9 are imaging conditions for the stage 123. Imaging condition x5 indicates the source-to-measurement object distance SOD. Imaging condition x6 indicates the number of measurements ns (also called the number of projections). Imaging condition x7 indicates the CT angle increment. Imaging condition x8 indicates the mounting orientation of the measurement object SP on the stage 123. Imaging condition x9 indicates the rotation angle θ of the measurement object SP.

[0067] Imaging conditions x10 to x11 are imaging conditions for image processing of the projection image IMG. The component x10 indicates the effective spatial resolution. The imaging condition x11 indicates the amount of BH artifact suppression.

[0068] Imaging conditions x12 to x13 are imaging conditions for the exposure time and the series of measurement times in the detection unit 124. Imaging condition x12 indicates the exposure time T_FPD. Imaging condition x13 indicates the required measurement time T_CT.

[0069] As described above, the imaging condition calculation unit 114 can calculate various types of imaging conditions, such as the filter 122 that transmits radiation, radiation beam hardening, the position of the measurement target SP, the radiation spot diameter SZ, the beam current of the radiation source 121, the number of measurements ns by the detection unit 124, the slice interval of the measurement target SP, the exposure time T_FPD of the detection unit 124, the time required for measurement of the measurement target SP T_CT, the axis of change in posture of the measurement target SP, and the posture of the measurement target SP.

[0070] The imaging condition calculation unit 114 may calculate these various imaging conditions based on instructions from the user. In this case, the instruction acquisition unit 113 acquires user instructions regarding the imaging conditions from the operation unit 200. The instruction acquisition unit 113 outputs user instruction information 201 indicating the acquired user instructions to the imaging condition calculation unit 114. The imaging condition calculation unit 114 calculates the imaging conditions based on the instructions acquired by the instruction acquisition unit 113.

[0071] [Example of User Instruction: MODE 1 (One-Push Operation Mode)] The user instruction may include an automatic setting instruction 2011, which is an instruction that specifies neither the resolution of the measurement result nor the required measurement time T_CT. In this case, the display unit 300 displays a button image (full automatic measurement button; not shown) that instructs the user to perform measurement fully automatically. The user operates the full automatic measurement button displayed on the display unit 300. When the full automatic measurement button is operated, the instruction acquisition unit 113 acquires the automatic setting instruction 2011 and outputs the acquired automatic setting instruction 2011 to the imaging condition calculation unit 114. Based on the automatic setting instruction 2011, the imaging condition calculation unit 114 calculates imaging conditions that include at least the number of measurements ns of the detection unit 124, the exposure time T_FPD, and the required measurement time T_CT.

[0072] In this case, the imaging condition calculation unit 114 adjusts the imaging conditions so that an image of a typical image quality (resolution) is acquired in a typical time. For example, the weights w1 to w7 in the above-mentioned equation (4) are set equally (for example, 14% each) to set the weight w of the individual objective function.

[0073] As described above, the imaging condition calculation device 100 calculates desired imaging conditions by adjusting the weights of the individual objective functions shown in Equation 4. Therefore, when a user desires fully automatic measurement, the imaging condition calculation device 100 can set imaging conditions by a simple method of adjusting the weights of the individual objective functions based on the characteristics of the measurement object SP calculated by the measurement object characteristic calculation unit 112.

[0074] [Example of User Instruction: MODE 2 (Time Priority Mode) / MODE 3 (Resolution Priority Mode)] The user instruction may include an instruction as to which of the resolution (or resolution; the same applies in the following description) of the measurement results and the required measurement time T_CT should be prioritized. In this case, the display unit 300 displays a selection screen (not shown) that prompts the user to select which of the resolution of the measurement results and the required measurement time T_CT should be prioritized. The user selects which of the resolution of the measurement results and the required measurement time T_CT should be prioritized. The instruction acquisition unit 113 acquires user instruction information 201 indicating which of the resolution of the measurement results and the required measurement time T_CT should be prioritized, and outputs the acquired user instruction information 201 to the imaging condition calculation unit 114. The imaging condition calculation unit 114 calculates, based on a user instruction, at least one of the number of measurements ns of the detection unit 124, the exposure time T_FPD, and the required measurement time T_CT as the imaging condition.

[0075] The user's instruction may include an instruction to specify the required measurement time T_CT. In this case, the imaging condition calculation unit 114 calculates the imaging conditions so that the measurement is completed within the required measurement time T_CT specified by the user.

[0076] The user's instructions may also include an instruction to balance the resolution of the measurement result and the required measurement time T_CT. In this case, the imaging condition calculation unit 114 calculates, based on the user's instructions, imaging conditions that achieve a balance between the number of measurements ns by the detection unit 124, the exposure time T_FPD, and the required measurement time T_CT.

[0077] As described above, the individual objective functions shown in equation (4) are classified into a group of individual objective functions that affect the resolution (weights w4 and w5) and a group of individual objective functions that affect the time required for measurement (weights w5, w6, and w7). Therefore, by adjusting these weights w, the imaging condition calculation unit 114 can set whether to prioritize resolution, the time required for measurement, or a balance between these, using a simple method of adjusting the weights.

[0078] [Other Examples of User Instructions] The user's instructions may include instructions to specify both the resolution of the measurement results and the required measurement time T_CT. In this case, the display unit 300 displays a screen (not shown) for the user to specify the resolution of the measurement results and a screen (not shown) for specifying the required measurement time T_CT. The user inputs the resolution of the measurement results and the required measurement time T_CT. The instruction acquisition unit 113 acquires user instruction information 201 that specifies the resolution of the measurement results and the required measurement time T_CT, and outputs the acquired user instruction information 201 to the imaging condition calculation unit 114. Based on the user's instructions, the imaging condition calculation unit 114 calculates imaging conditions that include at least the number of measurements ns of the detection unit 124, the exposure time T_FPD, and the required measurement time T_CT.

[0079] The user's instruction may also include an instruction specifying the degree of noise or artifacts contained in the measurement results. In this case, the imaging condition calculation unit 114 calculates, as the imaging condition, at least one of the number of measurements ns by the detection unit 124, the exposure time T_FPD, and the measurement required time T_CT, based on the user's instruction.

[0080] The imaging condition calculation unit 114 outputs the imaging conditions calculated as described above to the imaging condition output unit 115. 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 unit of the measurement device 10 based on the imaging conditions calculated by the imaging condition calculation device 100. According to the measurement system 1 configured in this manner, the imaging condition calculation device 100 assists the user's operation, thereby reducing the effort required for the user to set the imaging conditions. The flow of a series of processes performed by the imaging condition calculation device 100 described above will be described with reference to FIG. 9 .

[0081] [Processing Flow of the Shooting Condition Calculation Apparatus 100] FIG. 9 is a diagram showing an example of the processing flow of the shooting condition calculation apparatus 100 of this embodiment.

[0082] (Step S10) The instruction acquisition unit 113 acquires user instruction information 201 indicating a user 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.

[0083] (Step S20) The measurement target information acquisition unit 111 determines whether or not three-dimensional CAD data (design data) of the measurement target SP is available. If the measurement target information acquisition unit 111 determines that three-dimensional CAD data of the measurement target SP is available, the process proceeds to step S30. If the measurement target information acquisition unit 111 determines that three-dimensional CAD data of the measurement target SP is not available, the process proceeds to step S40.

[0084] (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 three-dimensional CAD data of the measurement target SP. This three-dimensional CAD data includes information on the material and internal structure of the measurement target SP.

[0085] (Step S40) The measurement target information acquisition unit 111 acquires measurement target information 501. In this case, the measurement target information 501 is prescan data of the measurement target SP. This prescan data includes information on the material and internal structure of the measurement target SP. An example of prescanning will now be described. In prescanning, the imaging control device 400 fixes imaging conditions such as the acceleration voltage of the radiation source 121, beam intensity, spot diameter SZ, material and thickness of the filter 122, and source-to-measurement target distance SOD, and rotates the stage 123 around the Z axis in predetermined angular increments. As a result, projection images IMG are captured for each rotation angle θ, as shown in FIG. 10 .

[0086] 10 is a diagram showing an example of the results of a pre-scan according to this embodiment. The imaging condition calculation unit 114 identifies the rotation angle θmax with the greatest attenuation and the pixel with the greatest attenuation from among n projection images IMG with rotation angles θ1 to θn. In the example shown in the figure, the imaging condition calculation unit 114 determines that the projection image IMG with the i-th rotation angle θi is the projection image IMG with the greatest attenuation.

[0087] The imaging control device 400 captures projection images IMG (projection image IMG_I1 and projection image IMG_I2) under two different imaging conditions at the rotation angle θi.

[0088] 11 is a diagram showing an example of the results of a pre-scan under the first condition on a projection image IMG of maximum attenuation in this embodiment. This diagram shows an example of a projection image IMG_I1. FIG. 12 is a diagram showing an example of the results of a pre-scan under the second condition on a projection image IMG of maximum attenuation in this embodiment. This diagram shows an example of a projection image IMG_I2.

[0089] (Step S50) The measurement object characteristic calculation unit 112 calculates measurement object characteristic information 1121 based on either the design data (e.g., three-dimensional CAD data) of the measurement object SP acquired in step S30 or the pre-scan results acquired in step S40.

[0090] When based on design data (e.g., three-dimensional CAD data) of the measurement object SP, the measurement object characteristic calculation unit 112 calculates the measurement object characteristic information 1121 by the procedure described with reference to Figures 5 and 6 above (by irradiating the measurement object SP with virtual radiation through simulation).

[0091] On the other hand, when the measurement is based on pre-scan data, the measurement object property calculation unit 112 calculates the measurement object property information 1121 as follows: The measurement object property calculation unit 112 acquires the projection images IMG_I1 and IMG_I2. The measurement object property calculation unit 112 performs optimization by a known local optimization method with constraints using the acquired projection images IMG_I1 and IMG_I2, the fitting function shown in equation (5), and the objective function shown in equation (6).

[0092]

[0093]

[0094] Here, the fitting function of Equation (5) is expressed by separating it into the first term, a photoelectric absorption term, and the second term (constant term), a Compton scattering term. The coefficients (a, b, c) of Equation (5) depend on the atomic number. The objective function of Equation (6) is expressed by the projection images IMG_I1 and IMG_I2, the fitting function of Equation (5), and the intensity (spectral) difference formula δS(E). As a result of the above optimization, the measurement object characteristic calculation unit 112 obtains the maximum attenuation path length d (e.g., maximum attenuation path length), atomic number Z, and attenuation distribution μ(E). The measurement object characteristic calculation unit 112 outputs the calculated maximum attenuation path length d, atomic number Z, and attenuation distribution μ(E) to the imaging condition calculation unit 114 as measurement object characteristic information 1121. It should be noted that μ(E) based on pre-scan data can also be said to be a parameter relating to the energy dependency of the equivalent attenuation coefficient when the measurement target SP on the maximum path PSM is regarded as a homogeneous object.

[0095] (Step S60) The imaging condition calculation unit 114 acquires apparatus configuration information 601 from the apparatus configuration information storage unit 600. The apparatus configuration information 601 is information prepared in advance for each type of measurement apparatus 10. The apparatus configuration information 601 is information indicating the specifications of each unit of the measurement apparatus 10 (e.g., the radiation source 121, the filter 122, the stage 123, and the detection unit 124). The apparatus configuration information storage unit 600 includes a device capable of storing information, such as a semiconductor memory or a hard disk drive. The apparatus configuration information storage unit 600 supplies the apparatus configuration information 601 to the imaging condition calculation unit 114 via wired or wireless communication. The apparatus configuration information storage unit 600 may or may not be included in the imaging condition calculation device 100.

[0096] (Step S70) The imaging condition calculation unit 114 calculates imaging conditions based on the measurement object characteristic information 1121 calculated by the measurement object characteristic calculation unit 112 in step S50 and the device configuration information 601 acquired in step S60. Note that the details of the calculation of the imaging conditions are as described above, and therefore will not be described here.

[0097] (Step S80) The imaging condition calculation unit 114 determines whether the imaging conditions calculated in step S70 are consistent with the specifications of the measuring device 10 indicated by the device configuration information 601 acquired in step S60. For example, depending on the type (model) of the measuring device 10, the imaging conditions calculated in step S70 may not be realized by the radiation source 121, filter 122, stage 123, and detection unit 124 of the measuring device 10 being determined. In this case, the imaging condition calculation unit 114 determines that the imaging conditions do not match the specifications of the measuring device 10, and proceeds to step S100. On the other hand, if the imaging condition calculation unit 114 determines that the imaging conditions are consistent with the specifications of the measuring device 10, it outputs imaging condition information 1141 indicating the calculated imaging conditions to the imaging condition output unit 115, and proceeds to step S90.

[0098] (Step S90) The imaging condition output unit 115 outputs the imaging condition information 1141 to the display unit 300 and the imaging control device 400.

[0099] (Step S100) If it is determined that the imaging conditions do not match the specifications of the measurement device 10, the imaging condition output unit 115 suggests to the user to use another model that matches the imaging conditions.

[0100] That is, the imaging condition output unit 115 outputs recommended device information indicating the type of measuring device 10 that is recommended for measurement under the calculated imaging conditions, from among multiple types of measuring devices 10 that measure the inside of an object by irradiating with radiation. The measurement system 1 configured in this manner can suggest a more appropriate model of measuring device 10 to the user, enabling measurement that meets the user's needs.

[0101] [Modification 1] The imaging condition output unit 115 may output an assist image P1 (installation information) indicating how to install the measurement target SP, based on the calculated orientation of the measurement target SP.

[0102] 13 is a diagram showing an example of an assist image P1 according to this 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 orientation of the measurement target SP. This image P11 showing the orientation of the measurement target SP shows the orientation of the measurement target SP based on the maximum attenuation path length d, maximum width WM, attenuation coefficient distribution μ(E), and the like used by the imaging condition calculation unit 114 when calculating the imaging conditions. In other words, by placing the measurement target SP on the stage 123 in accordance with the orientation of the measurement target SP shown in the image P11 showing the orientation of the measurement target SP, the imaging conditions calculated by the imaging condition calculation unit 114 can be satisfied.

[0103] The measurement system 1 configured in this manner can visually indicate to the user in what orientation the target object SP should be placed in to satisfy the calculated imaging conditions when the target object SP is placed on the stage 123. In other words, the measurement system 1 of this embodiment can reduce the user's effort during measurement.

[0104] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and appropriate modifications can be made without departing from the spirit of the present invention. The configurations described in the above-described embodiments may be combined.

[0105] Each unit included in each device in the above-described embodiments may be realized by dedicated hardware, or may be realized by a memory and a microprocessor.

[0106] In addition, each part of each device may be composed of a memory and a CPU (central processing unit), and the functions of each part of each device may be realized by loading a program into memory and executing it.

[0107] In addition, a program for realizing the functions of each unit of each device may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into a computer system and executed to perform processing by each unit of the control unit. Note that the term "computer system" here includes hardware such as the OS and peripheral devices.

[0108] Furthermore, if a WWW system is used, the term "computer system" also includes the homepage provision environment (or display environment). Furthermore, the term "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, as well as storage devices such as hard disks built into computer systems. Furthermore, the term "computer-readable recording medium" also refers to devices that dynamically store programs for a short period of time, such as communication lines used when transmitting programs via networks such as the Internet or communication lines such as telephone lines, and devices that store programs for a fixed period of time, such as volatile memory within computer systems that serve as servers or clients in such cases. The program may be for implementing part of the aforementioned functions, or may be capable of implementing the aforementioned functions in combination with a program already stored in the computer system. Furthermore, 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.

[0109] 1... measurement system, 10... measurement device, 11... door, 12... measurement room, 121... radiation source, 1211... emission position, 1212... spot position, 122... filter, 123... stage, 1231... rotation axis, 124... detection unit, 1241... detection surface, 100... imaging condition calculation device, 110... calculation unit, 111... measurement object information acquisition unit, 112... measurement object characteristic calculation unit, 1121... measurement object characteristic information, 113... instruction acquisition unit, 11 4...imaging condition calculation unit, 1141...imaging condition information, 115...imaging condition output unit, 150...storage 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 object information storage unit, 501...measurement object information, 600...device configuration information storage unit, 601...device configuration information, SP...measurement object

Claims

1. An imaging condition calculation device comprising: a measurement object information acquisition unit that acquires measurement object information related to the configuration of a measurement object measured by radiation that passes through its interior; a measurement object characteristic calculation unit that calculates, based on the acquired measurement object information, the following measurement object characteristic information: an attenuation path length that indicates the length of the path along which attenuation of the radiation passing through the measurement object meets a first condition, a parameter related to the energy dependence of the attenuation coefficient of the measurement object on the path, and the length of the measurement object through which the radiation passes; and an imaging condition calculation unit that calculates, based on the calculated measurement object characteristic information, at least one of the state of the radiation source, the attitude of the measurement object, and the detection state by a radiation detection unit as an imaging condition.

2. The imaging condition calculation device according to claim 1, wherein the measurement object information acquisition unit acquires design data of the measurement object as the measurement object information.

3. The imaging condition calculation device according to claim 1, wherein the measurement object information acquisition unit acquires, as the measurement object information, measurement results obtained by irradiating the measurement object with radiation.

4. The 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 passing through the object to be measured is maximum, obtained by simulating based on the design data.

5. The imaging condition calculation device according to claim 3, wherein the first condition is any value within ±20% of the value at which the attenuation of radiation passing through the measurement object obtained by irradiating the measurement object with radiation is maximum.

6. The imaging condition calculation device according to claim 2, wherein the parameter relates to the energy dependency of the attenuation coefficient of the material constituting the measurement object on the path.

7. The imaging condition calculation device according to claim 3, wherein the parameter relates to the energy dependency of the equivalent attenuation coefficient when the measurement object on the path is considered to be a homogeneous object.

8. The imaging condition calculation device according to claim 2, wherein the length of the measurement object is any value within ±20% of the maximum value.

9. The imaging condition calculation device according to claim 3, wherein the length of the object to be measured is any value within ±20% of the maximum value.

10. The imaging condition calculation device according to claim 1, further comprising an imaging condition output unit that outputs the calculated imaging conditions.

11. The imaging condition calculation device according to claim 1, wherein the imaging conditions include at least one of a filter that transmits the radiation, beam hardening of the radiation, the position of the measurement object, the spot diameter of the radiation, the beam current of the radiation source, the number of measurements by the radiation detection unit, the slice interval of the measurement object, the exposure time of the radiation detection unit, the time required for measurement of the measurement object, the axis of change in posture of the measurement object, and the posture of the measurement object.

12. The imaging condition calculation device according to claim 1, wherein the imaging condition calculation unit calculates, as the imaging condition, the posture of the object to be measured along which the radiation passes through the longest path that maximizes the attenuation of the radiation.

13. The imaging condition calculation device according to claim 1, further comprising an instruction acquisition unit that acquires user instructions for imaging conditions, wherein the imaging condition calculation unit calculates the imaging conditions based on the instructions acquired by the instruction acquisition unit.

14. The imaging condition calculation device according to claim 13, wherein the instructions include an instruction as to which of the resolution of the measurement results and the time required for measurement should be given priority, and the imaging condition calculation unit calculates, based on the instructions, at least one of the number of measurements by the radiation detection unit, the exposure time, and the time required for measurement as the imaging condition.

15. The imaging condition calculation device according to claim 13, wherein the instructions include instructions specifying both the resolution of the measurement results and the time required for measurement, and the imaging condition calculation unit calculates, based on the instructions, conditions including at least the number of measurements by the radiation detection unit, the exposure time, and the time required for measurement, as the imaging conditions.

16. The imaging condition calculation device according to claim 13, wherein the instructions include an automatic setting instruction that specifies neither the resolution of the measurement result nor the time required for measurement, and the imaging condition calculation unit calculates, based on the automatic setting instruction, conditions including at least the number of measurements by the radiation detection unit, exposure time, and the time required for measurement, as the imaging conditions.

17. The imaging condition calculation device according to claim 13, wherein the instructions include an instruction to specify the degree of noise or artifacts contained in the measurement results, and the imaging condition calculation unit calculates, based on the instructions, at least one of the number of measurements by the radiation detection unit, exposure time, and measurement time required as the imaging condition.

18. The imaging condition calculation device according to claim 10, wherein the imaging condition output unit further outputs recommended device information indicating the type of measuring device recommended for measurement under the calculated imaging conditions, from among multiple types of measuring devices that measure the inside of an object by irradiating it with radiation.

19. The imaging condition calculation device according to claim 10, wherein the imaging condition output unit outputs installation information indicating a method of installing the measurement object based on the calculated attitude of the measurement object.

20. An imaging condition calculation device comprising: a measurement object information acquisition unit that acquires measurement object information related to the configuration of a measurement object measured by radiation that passes through its interior; a measurement object characteristic calculation unit that calculates, based on the acquired measurement object information, the attenuation path length that indicates the length of the path along which attenuation of the radiation passing through the measurement object is greatest, a parameter related to the energy dependence of the equivalent attenuation coefficient when the measurement object on said path is considered to be a homogeneous object, and the maximum value of the measurement object based on the position of the radiation source and the position of a detection unit for the radiation that has passed through the measurement object; an imaging condition calculation unit that calculates, based on the calculated measurement object characteristic information, at least one of the state of the radiation source, the attitude of the measurement object, and the detection state by the detection unit as an imaging condition; and an imaging condition output unit that outputs the calculated imaging conditions.

21. An imaging condition calculation device comprising: a measurement object information acquisition unit that acquires measurement object information related to the configuration of a measurement object measured by radiation that passes through its interior; a measurement object characteristic calculation unit that calculates, based on the acquired measurement object information, the attenuation path length that indicates the length of the path along which the attenuation of the radiation passing through the measurement object is greatest, a parameter related to the energy dependence of the attenuation coefficient of the material that makes up the measurement object on said path, and the length of the measurement object through which the radiation passes, as measurement object characteristic information; an imaging condition calculation unit that calculates, based on the calculated measurement object characteristic information, at least one of the state of the radiation source, the attitude of the measurement object, and the detection state by a radiation detection unit, as imaging conditions; and an imaging condition output unit that outputs the calculated imaging conditions.

22. A measurement system comprising: an imaging condition calculation device according to any one of claims 1 to 21; and a measurement device that irradiates radiation to the measurement object based on the output of said imaging condition calculation device.

23. A method for calculating imaging conditions, comprising: acquiring measurement object information relating to the configuration of a measurement object measured by radiation passing through its interior; calculating, based on the acquired measurement object information, the attenuation path length indicating the length of the path along which attenuation of the radiation passing through the measurement object meets a first condition, a parameter relating to the energy dependence of the attenuation coefficient of the measurement object on the path, and the length of the measurement object through which the radiation passes, as measurement object characteristic information; and calculating, based on the calculated measurement object characteristic information, at least one of the state of the radiation source, the attitude of the measurement object, and the detection state by a radiation detection unit, as imaging conditions.

24. A program causing a computer to execute the following steps: acquire measurement object information relating to the configuration of a measurement object measured by radiation passing through its interior; calculate, based on the acquired measurement object information, the attenuation path length indicating the length of the path along which attenuation of radiation passing through the measurement object meets a first condition, a parameter relating to the energy dependence of the attenuation coefficient of the measurement object on the path, and the length of the measurement object through which the radiation passes, as measurement object characteristic information; and calculate, based on the calculated measurement object characteristic information, at least one of the state of the radiation source, the attitude of the measurement object, and the detection state by a radiation detection unit as an imaging condition.

Images