X-ray phase imaging apparatus and X-ray phase imaging image analysis method

Abstract

This X-ray phase imaging device (100) comprises: an X-ray light source (10), an X-ray detector (11), a plurality of lattices; a rotary mechanism (15) which rotates a subject (90) including fibers (91a) and the plurality of lattices relative to each other; an image processing unit (2a) which generates a plurality of X-ray phase contrast images (40) for each of the orientations of the subject with respect to the plurality of lattices; and a control unit (2b) which acquires orientation information (30) pertaining to the orientations of fibers included in the subject on the basis of the plurality of X-ray phase contrast images, and acquires a feature amount (31) pertaining to the mechanical strength of the subject.

Description

[Technical Field]

[0001] The present invention relates to an X-ray phase imaging apparatus and an X-ray phase imaging image analysis method, and particularly to an X-ray phase imaging apparatus and an X-ray phase imaging image analysis method for imaging a subject while relatively rotating the subject and a plurality of gratings. [Background Art]

[0002] Conventionally, X-ray phase imaging apparatuses that image a subject while relatively rotating the subject and a plurality of gratings are known. Such an X-ray phase imaging apparatus is disclosed in, for example, Japanese Patent No. 6943090.

[0003] Japanese Patent No. 6943090 discloses an X-ray imaging apparatus including an X-ray source, a plurality of gratings including a first grating and a second grating, a detector, an image processing unit, a control unit, and a direction changing mechanism. According to the configuration disclosed in Japanese Patent No. 6943090, by relatively rotating the subject and the plurality of gratings via the direction changing mechanism, imaging is performed while changing the orientation of the subject relative to the plurality of gratings, and a plurality of dark-field images corresponding to the orientation of the subject are generated. Further, in Japanese Patent No. 6943090, the X-ray imaging apparatus is configured to image carbon fiber reinforced plastic (CFRP) as a subject. Furthermore, Japanese Patent No. 6943090 discloses a configuration for extracting fibers extending in different directions included in the subject based on the generated dark-field images. [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent No. 6943090 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] It is known that CFRP containing carbon fibers has high mechanical strength against forces acting in the direction in which the fibers extend, and low mechanical strength against forces acting in a direction intersecting the direction in which the fibers extend. However, with X-ray phase imaging devices such as the one disclosed in Japanese Patent Publication No. 6943090, while it is possible to acquire the direction in which the fibers extend (orientation information), it is difficult for the user to identify areas where the mechanical strength is reduced due to the orientation of the fibers. Therefore, there is a need for an X-ray phase imaging device that can easily identify areas in a subject where the mechanical strength is reduced due to the orientation of the fibers.

[0006] This invention was made to solve the above-mentioned problems, and one of its objectives is to provide an X-ray phase imaging apparatus and an X-ray phase imaging image analysis method that can easily identify areas in a subject where the mechanical strength is reduced due to the orientation of fibers. [Means for solving the problem]

[0007] To achieve the above objective, the X-ray phase imaging apparatus in the first aspect of this invention is an X-ray phase imaging apparatus that predicts the location where the mechanical strength of a subject including fibers is reduced, comprising: an X-ray source that irradiates X-rays; an X-ray detector that detects X-rays irradiated from the X-ray source; a plurality of gratings disposed between the X-ray source and the X-ray detector; a rotation mechanism that rotates the subject and the plurality of gratings relative to each other in a rotational direction about the X-ray irradiation axis; an image processing unit that rotates the subject and the plurality of gratings relative to each other by the rotation mechanism and changes the orientation of the subject with respect to the plurality of gratings and then images the subject, and generates a plurality of X-ray phase contrast images for each orientation of the subject with respect to the plurality of gratings based on the intensity distribution of X-rays detected by the X-ray detector; and a plurality of X-ray phase contrast images Dark-field image in Based on this, the fibers contained in the subject This includes the orientation angle, which is the angle in the direction in which the fibers extend, and the degree of orientation, which is an indicator of how well the fibers are aligned in the same direction. Obtain orientation information Control, the direction of the force acting on the subject, and the direction intersecting the direction of the force. Orientation information and Based on the mechanical strength of the subject, Direction of force Extracting features Control and perform A control unit and The image processing unit is configured to generate an orientation information image, which is an image based on the degree of orientation at an orientation angle intersecting the direction of force application, and to generate a binarized image by binarizing the pixel values ​​of the generated orientation information image, and the control unit is configured to obtain feature quantities from the binarized region in the binarized image. .

[0008] Furthermore, the X-ray phase imaging image analysis method in the second aspect of this invention is an X-ray phase imaging image analysis method for predicting the location where the mechanical strength of a subject including fibers is reduced, comprising the steps of: imaging the subject and a plurality of gratings arranged between the X-ray source and the X-ray detector at a plurality of imaging angles while relatively rotating them in a rotational direction about the direction of the X-ray irradiation axis; generating a plurality of X-ray phase contrast images for each orientation of the subject relative to the plurality of gratings based on the intensity distribution of X-rays detected by the X-ray detector; and the plurality of X-ray phase contrast images Dark-field image in Based on this, the fibers contained in the subject This includes the orientation angle, which is the angle in the direction in which the fibers extend, and the degree of orientation, which is an indicator of how well the fibers are aligned in the same direction. Steps to obtain orientation information, The direction of the force acting on the subject and the direction intersecting the direction of the force. Orientation information and Based on the mechanical strength of the subject, Direction of force The process includes a step of obtaining features, In the step of acquiring features, an orientation information image is generated, which is an image based on the degree of orientation at an orientation angle intersecting the direction of force application. A binarized image is then generated by binarizing the pixel values ​​of the generated orientation information image, and features are acquired from the binarized region in the binarized image. . [Effects of the Invention]

[0009] In the X-ray phase imaging apparatus in the first phase described above, and the X-ray phase imaging image analysis method in the second phase described above, as described above, feature quantities relating to the mechanical strength of the subject are acquired based on orientation information regarding the orientation of fibers contained in the subject. This allows the user to confirm the feature quantities relating to the mechanical strength of the subject acquired based on the orientation information. As a result, it is possible to easily identify parts of the subject where the mechanical strength is reduced due to the orientation of the fibers. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram showing the overall configuration of an X-ray phase imaging apparatus according to one embodiment. [Figure 2] This is a schematic diagram illustrating the configuration of an X-ray imaging unit according to one embodiment. [Figure 3]It is a schematic diagram for explaining the configuration of a rotation mechanism of an X-ray phase imaging apparatus according to an embodiment. [Figure 4] It is a schematic diagram for explaining the configuration of a grid position adjustment mechanism of an X-ray phase imaging apparatus according to an embodiment. [Figure 5] It is a schematic diagram for explaining a configuration for generating an X-ray phase contrast image. [Figure 6] It is a schematic diagram for explaining an absorption image, a phase differential image, and a dark-field image generated by the X-ray phase imaging apparatus according to an embodiment. [Figure 7] It is a schematic diagram for explaining the structure of a subject. [Figure 8] It is a schematic diagram for explaining imaging performed by dividing a subject into a plurality of test pieces. [Figure 9] It is a schematic diagram for explaining a configuration for acquiring orientation information from a dark-field image. [Figure 10] It is a graph for explaining a configuration for acquiring orientation information from a dark-field image. [Figure 11] It is a schematic diagram for explaining an orientation analysis image. [Figure 12] It is a schematic diagram for explaining a tensor image generated from an orientation analysis image. [Figure 13] It is a schematic diagram for explaining a binarized image generated by an image processing unit according to an embodiment. [Figure 14] It is a diagram for explaining a feature amount acquired by a control unit according to an embodiment and a fracture position when a tensile test is performed. [Figure 15] It is a graph showing the relationship between the position of the maximum binarized region and the fracture position when a tensile test is performed. [Figure 16] It is a graph showing the relationship between maximum stress and total area ratio. [Figure 17] These are schematic diagram (A) and schematic diagram (B) for explaining the tendency of deviation in fiber orientation. [Figure 18] It is a schematic diagram for explaining a configuration in which the X-ray phase imaging apparatus according to an embodiment displays a dark-field image, a binarized image, and a feature amount. [Figure 19] This is a flowchart illustrating the process of displaying feature quantities in an X-ray phase imaging apparatus according to one embodiment. [Figure 20] This is a schematic diagram showing the overall configuration of an X-ray phase imaging apparatus based on a modified example. [Figure 21] This is a schematic diagram illustrating the configuration of the X-ray imaging unit using a modified example. [Figure 22] This is a schematic diagram illustrating the thickness distribution of a specific fiber region using images captured by a modified X-ray phase imaging device. [Modes for carrying out the invention]

[0011] The following describes embodiments of the present invention based on the drawings.

[0012] First, with reference to Figure 1, the overall configuration of the X-ray phase imaging apparatus 100 according to one embodiment of the present invention will be described.

[0013] As shown in Figure 1, the X-ray phase imaging apparatus 100 is a device that uses the Talbot effect to image the inside of a subject 90 (see Figure 2). The subject 90 is, for example, a fiber composite material containing fibers 91a (see Figure 7). The subject 90 is, for example, CFRP (Carbon Fiber Reinforced Plastic). In this embodiment, the X-ray phase imaging apparatus 100 is configured to predict the location where the mechanical strength of the subject 90 containing the fibers 91a is reduced.

[0014] The X-ray phase imaging apparatus 100 includes an X-ray imaging unit 1 and a computer 2. The X-ray phase imaging apparatus 100 also includes a display unit 3 and an input receiving unit 4.

[0015] The X-ray imaging unit 1 includes an X-ray source 10, a plurality of gratings, an X-ray detector 11, a rotation mechanism 15, and a grating position adjustment mechanism 16. The plurality of gratings include a first grating 12, a second grating 13, and a third grating 14. Details of the X-ray imaging unit 1, such as the arrangement of the X-ray source 10, the plurality of gratings, and the X-ray detector 11, will be described later.

[0016] Computer 2 includes an image processing unit 2a, a control unit 2b, memory such as ROM (Read Only Memory) and RAM (Random Access Memory), and a storage unit 2c. The image processing unit 2a is composed of, for example, a GPU (Graphics Processing Unit) or an FPGA (Field-Programmable Gate Array) configured for image processing, and circuitry. The control unit 2b is composed of a CPU (Central Processing Unit), a GPU or an FPGA configured for image processing, and circuitry.

[0017] The image processing unit 2a is configured to generate multiple X-ray phase contrast images 40 for each orientation of the subject 90 relative to the multiple grids by rotating the subject 90 relative to the multiple grids using a rotation mechanism 15 and taking images based on the intensity distribution of X-rays detected by the X-ray detector 11. The image processing unit 2a is also configured to generate a tensor image 42 (see Figure 12), which will be described later. Details of the configuration by which the image processing unit 2a generates the X-ray phase contrast images 40 and the configuration for generating the tensor image 42 will be described later. Note that the tensor image 42 is an example of an "orientation information image" within the scope of the claims.

[0018] The control unit 2b is configured to control the X-ray source 10, the rotation mechanism 15, and the lattice position adjustment mechanism 16, etc. The control unit 2b also includes an orientation information acquisition unit 20, a feature quantity acquisition unit 21, and an intensity reduction unit prediction unit 22. The orientation information acquisition unit 20, the feature quantity acquisition unit 21, and the intensity reduction unit prediction unit 22 are configured in software as functional blocks realized by the control unit 2b executing various programs. The orientation information acquisition unit 20, the feature quantity acquisition unit 21, and the intensity reduction unit prediction unit 22 may also be configured in hardware with a dedicated processor (processing circuit).

[0019] The orientation information acquisition unit 20 acquires orientation information 30 regarding the orientation of the fibers 91a (see Figure 7) contained in the subject 90 based on a plurality of X-ray phase contrast images 40. Details of the configuration in which the orientation information acquisition unit 20 acquires the orientation information 30 will be described later.

[0020] The feature acquisition unit 21 is configured to acquire feature quantities 31 related to the mechanical strength of the subject 90 based on the orientation information 30 acquired by the orientation information acquisition unit 20. Details of the configuration by which the feature acquisition unit 21 acquires feature quantities 31 will be described later.

[0021] The intensity reduction prediction unit 22 is configured to predict the location of the intensity reduction area 53 (see Figure 13) of the subject 90 based on the feature quantity 31. Details of how the intensity reduction prediction unit 22 predicts the location of the intensity reduction area 53 of the subject 90 will be described later.

[0022] The storage unit 2c is configured to store the X-ray phase contrast image 40 generated by the image processing unit 2a, the orientation information 30 acquired by the orientation information acquisition unit 20, the feature quantities 31 acquired by the feature quantity acquisition unit 21, the threshold values ​​32 (described later), and various programs executed by the control unit 2b. The storage unit 2c includes a non-volatile storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive).

[0023] The display unit 3 is configured to display the X-ray phase contrast image 40 generated by the image processing unit 2a. In this embodiment, the display unit 3 is also configured to display the feature quantities 31 and the binarized image 43, which will be described later. The display unit 3 includes, for example, a liquid crystal monitor.

[0024] The input receiving unit 4 is configured to receive operation input from the operator. The input receiving unit 4 includes, for example, an input device such as a keyboard or mouse.

[0025] As shown in Figure 2, the X-ray source 10, the third grating 14, the first grating 12, the second grating 13, and the X-ray detector 11 are arranged in this order along the X-ray irradiation axis 70. That is, the third grating 14, the first grating 12, and the second grating 13 are positioned between the X-ray source 10 and the X-ray detector 11. In this specification, the vertical direction is defined as the Z direction, with the upward direction being the Z1 direction and the downward direction being the Z2 direction. The direction from the X-ray source 10 toward the X-ray detector 11 is defined as the X direction, with one side being the X1 direction and the other side being the X2 direction. The direction perpendicular to the Z and X directions is defined as the Y direction, with one side being the Y1 direction and the other side being the Y2 direction.

[0026] The X-ray source 10 is configured to irradiate the subject 90 with X-rays. Specifically, the X-ray source 10 is configured to generate X-rays when a high voltage is applied.

[0027] The X-ray detector 11 is configured to detect X-rays irradiated from the X-ray source 10. The X-ray detector 11 is also configured to convert the detected X-rays into an electrical signal. The X-ray detector 11 is, for example, a Flat Panel Detector (FPD). The X-ray detector 11 consists of a plurality of conversion elements (not shown) and pixel electrodes (not shown) arranged on the plurality of conversion elements. The plurality of conversion elements and pixel electrodes are arranged in the Y and Z directions at a predetermined period (pixel pitch). The detection signal (image signal) from the X-ray detector 11 is sent to the image processing unit 2a, which will be described later.

[0028] The first grating 12 is positioned between the X-ray source 10 and the X-ray detector 11, and is irradiated with X-rays from the X-ray source 10. The first grating 12 has slits 12a and X-ray phase change sections 12b arranged in the Z direction with a predetermined period (grating pitch) 12c. Each slit 12a and X-ray phase change section 12b is formed to extend linearly in the Y direction. The first grating 12 is a so-called phase grating. The first grating 12 is positioned between the X-ray source 10 and the second grating 13 and is provided to form a self-image (by the Talbot effect) using X-rays irradiated from the X-ray source 10. The Talbot effect means that when coherent X-rays pass through a grating with slits formed therein, an image of the grating (a self-image) is formed at a predetermined distance (Talbot distance) from the grating.

[0029] The second grating 13 is irradiated with X-rays from the first grating 12. The second grating 13 has a plurality of X-ray transmitting sections 13a and X-ray absorbing sections 13b arranged in the Z direction with a predetermined period (grating pitch) 13c. Each X-ray transmitting section 13a and X-ray absorbing section 13b is formed to extend linearly in the Y direction. The second grating 13 is a so-called absorption grating. The second grating 13 is positioned between the first grating 12 and the X-ray detector 11 and is configured to interfere with the self-image formed by the first grating 12. The second grating 13 is positioned at a distance of the Talbot distance from the first grating 12 in order to interfere with the self-image.

[0030] The third grating 14 is positioned between the X-ray source 10 and the first grating 12. The third grating 14 has a plurality of slits 14a and X-ray absorbing sections 14b arranged in the Z direction at a predetermined period (pitch) 14c. Each slit 14a and X-ray absorbing section 14b is formed to extend linearly in the Y direction. Also, each slit 14a and X-ray absorbing section 14b is formed to extend parallel to each other. The third grating 14 is positioned between the X-ray source 10 and the first grating 12, and X-rays are irradiated from the X-ray source 10. The third grating 14 is configured to use the X-rays that have passed through each slit 14a as a line light source corresponding to the position of each slit 14a.

[0031] In this embodiment, the first grid 12, the second grid 13, and the third grid 14 are arranged in a direction such that the grid pattern extends in the Y direction. The grid pattern includes the slit 12a, the X-ray phase change section 12b, the X-ray transmission section 13a, the X-ray absorption section 13b, the slit 14a, and the X-ray absorption section 14b.

[0032] The rotation mechanism 15 is configured to rotate the X-ray source 10 and the multiple gratings relative to each other in a rotational direction about the X-ray irradiation axis 70. Specifically, the rotation mechanism 15 is provided on each of the multiple gratings, and by rotating each of the multiple gratings in a rotational direction about the X-ray irradiation axis 70, the object 90 and the multiple gratings are rotated relative to each other in a rotational direction about the X-ray irradiation axis 70. The detailed configuration of the rotation mechanism 15 will be described later.

[0033] The grid position adjustment mechanism 16 is configured to allow the first grid 12 to move in the X direction, Y direction, Z direction, rotational direction Rz around the Z axis (see Figure 4), rotational direction Rx around the X axis (see Figure 4), and rotational direction Ry around the Y axis (see Figure 4).

[0034] (Rotation mechanism) Next, with reference to Figure 3, the configuration of the rotation mechanism 15 according to this embodiment will be described. Although the rotation mechanism 15 is provided for each of the multiple grids, each rotation mechanism 15 has the same configuration except for the grid it rotates. Therefore, in Figure 3, the rotation mechanism 15 that rotates the first grid 12 will be described as a representative example.

[0035] The rotation mechanism 15 comprises a lattice holding part 15a, a drive unit 15b that rotates the lattice holding part 15a in a rotational direction around the X-ray irradiation axis 70 (see Figure 1), and a housing part 15c that rotatably houses the lattice holding part 15a. The housing part 15c is provided with an opening 15d. X-rays from the X-ray source 10 (see Figure 1) are irradiated onto the first lattice 12 held by the lattice holding part 15a at a position facing the opening 15d (the position of the first lattice 12 shown by the solid line in Figure 3). The drive unit 15b rotates the first lattice 12 in a rotational direction around the X-ray irradiation axis 70 by rotating the lattice holding part 15a in a rotational direction around the X-ray irradiation axis 70 (see Figure 1). The drive unit 15b includes, for example, a stepping motor, a pulley, and a belt member.

[0036] (grid position adjustment mechanism) As shown in Figure 4, the grid position adjustment mechanism 16 includes an X-direction linear motion mechanism 16a, a Z-direction linear motion mechanism 16b, a Y-direction linear motion mechanism 16c, a linear motion mechanism connection part 16d, a stage support drive part 16e, a stage support part 16f, a stage drive part 16g, and a stage 16h.

[0037] The X-direction linear motion mechanism 16a, the Z-direction linear motion mechanism 16b, and the Y-direction linear motion mechanism 16c are configured to be movable in the X, Z, and Y directions, respectively. The X-direction linear motion mechanism 16a, the Z-direction linear motion mechanism 16b, and the Y-direction linear motion mechanism 16c include, for example, stepping motors. The grid position adjustment mechanism 16 is configured to move the first grid 12 (see Figure 1) in the X, Z, and Y directions, respectively, through the operation of the X-direction linear motion mechanism 16a, the Z-direction linear motion mechanism 16b, and the Y-direction linear motion mechanism 16c.

[0038] The stage support section 16f supports the stage 16h, on which the first grid 12 is placed, from below (Z2 direction) in Figure 4. The stage drive unit 16g is configured to reciprocate the stage 16h in the X direction. The bottom of the stage 16h is formed in a convex curved shape toward the stage support section 16f, and is configured to rotate around the axis in the Y direction (Ry direction) when reciprocated in the X direction. The stage support drive unit 16e is configured to reciprocate the stage support section 16f in the Y direction. The bottom of the stage support section 16f is formed in a convex curved shape toward the linear motion mechanism connection section 16d, and is configured to rotate around the axis in the X direction (Rx direction) when reciprocated in the Y direction. The linear motion mechanism connection section 16d is provided on the Y-direction linear motion mechanism 16c so as to be rotatable around the axis in the Z direction (Rz direction). With the above configuration, the grid position adjustment mechanism 16 can perform stripe scanning of the first grid 12 in the Z direction by the operation of the Z-direction linear motion mechanism 16b.

[0039] (Configuration for generating X-ray phase contrast images) Next, referring to Figure 5, the configuration in which the image processing unit 2a (see Figure 1) generates the X-ray phase contrast image 40 (see Figure 1) will be described. The image processing unit 2a generates the X-ray phase contrast image 40 using the intensity signal curve 60 and intensity signal curve 61 obtained based on the intensity distribution of X-rays detected by the X-ray detector 11 (see Figure 1). The X-ray phase contrast image 40 includes an absorption image 40a (see Figure 6), a phase differential image 40b (see Figure 6), and a dark-field image 40c (see Figure 6). The intensity signal curve 60 is a curve showing the distribution of X-ray intensity obtained by imaging with the subject 90 (see Figure 1) in place. The intensity signal curve 61 is a curve showing the distribution of X-ray intensity obtained by imaging without the subject 90 in place.

[0040] As shown in Figure 5, the absorption image 40a can be generated by the ratio of the average X-ray intensity Cs when imaging with the subject 90 (see Figure 1) in place to the average X-ray intensity Cr when imaging without the subject 90 in place. The phase differential image 40b can be generated by multiplying the phase difference Δφ between the intensity signal curve 60 acquired when imaging with the subject 90 in place and the intensity signal curve 61 acquired when imaging without the subject 90 in place by a number determined by a predetermined calculation. The dark-field image 40c can be generated by the ratio of the visibility (Vr) when imaging without the subject 90 in place to the visibility (Vs) when imaging with the subject 90 in place. Vr can be determined by the ratio of the amplitude Ar of the intensity signal curve 60 to the average intensity Cr. Vs can be determined by the ratio of the amplitude As of the intensity signal curve 61 to the average intensity Cs.

[0041] (Absorption images, phase differential images, and dark-field images) As shown in Figure 6, the image processing unit 2a generates an absorption image 40a, a phase differential image 40b, and a dark-field image 40c.

[0042] (The structure of the subject) Next, the structure of the subject 90 will be described with reference to Figure 7.

[0043] As shown in Figure 7, the object 90 has a plate-like shape. The object 90 is, for example, a carbon fiber reinforced plastic (CFRP), which is a composite material of carbon fibers (fibers 91a) and a base resin. The object 90 can be formed, for example, by applying pressure (pressing) to multiple CFRP tapes 91, each containing multiple randomly arranged resins and fibers 91a. When pressed, the resin within the CFRP tapes 91 flows, filling the gaps between the CFRP tapes 91 and forming a single plate-like shape. In this embodiment, the height direction of the object 90 is referred to as direction A, the width direction as direction B, and the thickness direction as direction C.

[0044] As shown in Figure 7, in a subject 90 in which randomly arranged CFRP tapes 91 are laminated, the orientation of the fibers 91a is also random. In this case, regions may occur where the proportion of fibers 91a oriented in a particular direction is large. Regions where the proportion of fibers 91a oriented in a particular direction is large will have reduced mechanical strength against forces acting in a direction intersecting the direction in which the fibers 91a extend. For example, in the plane of the subject 90 (in the AB plane), regions where the proportion of fibers 91a oriented in direction A is large will have reduced mechanical strength against forces acting in direction B.

[0045] Therefore, in this embodiment, the control unit 2b (see Figure 1) is configured to predict the portion of the object 90 in which the mechanical strength has decreased. In this embodiment, for example, assuming that a tensile force acts on the object 90 in direction B, an example will be described in which the control unit 2b predicts the portion of the object in which the mechanical strength has decreased in relation to the tensile force acting in direction B.

[0046] As shown in Figure 7, if the subject 90 has a single plate-like shape, the X-ray phase imaging apparatus 100 (see Figure 1) may find it difficult to image the entire subject 90 at once, depending on the size of the multiple gratings (the area of ​​the plane perpendicular to the X-ray irradiation axis (YZ plane)). Therefore, in this embodiment, as shown in Figure 8, an example of imaging the subject 90 by dividing it into multiple regions will be described. Specifically, an example will be described in which the subject 90 is divided into regions 1 90b to 7 90h at the positions shown by the dashed lines 71a to 71f in Figure 8, and imaging is performed for each region.

[0047] The first region 90b is the region between the upper end of the subject 90 and the dashed line 71a. The second region 90c is the region between the dashed line 71a and the dashed line 71b. The third region 90d is the region between the dashed line 71b and the dashed line 71c. The fourth region 90e is the region between the dashed line 71c and the dashed line 71d. The fifth region 90f is the region between the dashed line 71d and the dashed line 71e. The sixth region 90g is the region between the dashed line 71e and the dashed line 71f. The seventh region 90h is the region between the dashed line 71f and the lower end of the subject 90. The example shown below is an image of the first region 90b of the subject 90.

[0048] (Feature extraction) Next, with reference to Figures 9 to 17, the configuration in which the control unit 2b (see Figure 1) acquires feature quantities 31 (see Figure 1) according to this embodiment will be described. In this embodiment, the control unit 2b acquires orientation information 30 (see Figure 9) based on the dark-field image 40c (see Figure 6) generated by the image processing unit 2a (see Figure 1), and acquires feature quantities 31 based on the acquired orientation information 30.

[0049] (Orientation information) First, with reference to Figures 9 and 10, the configuration in which the orientation information acquisition unit 20 (see Figure 1) acquires orientation information 30 (see Figure 9) will be described. As shown in Figure 9, in this embodiment, the orientation information acquisition unit 20 acquires orientation information 30 based on a dark-field image 40c. The orientation information 30 includes an orientation angle 30a, which is the angle in the direction in which the fibers 91a (see Figure 7) contained in the subject 90 (see Figure 1) extend, and an orientation degree 30b, which is an indicator of how well the fibers 91a are aligned in the same direction. That is, the orientation angle 30a means the angle in the direction in which the fibers 91a extend, with the width direction (B direction) of the subject 90 being the reference (0 degrees) within the plane of the subject 90 (for example, within the AB plane). The orientation degree 30b is a value that indicates how well the fibers 91a are aligned in the same direction, and is a value between 0 and 1 depending on the proportion of the direction of the fibers 91a that are aligned.

[0050] The orientation information acquisition unit 20 acquires orientation information 30 based on the dark-field image 40c. Specifically, the orientation information acquisition unit 20 acquires orientation information 30 based on multiple dark-field images 40c captured by changing the orientation of the subject 90 with respect to multiple grids. For example, a configuration in which orientation information 30 of a pixel 80 in the subject 90 is acquired in each dark-field image 40c will be explained using the graph 33 shown in Figure 10, focusing on a predetermined pixel 80 in the subject 90.

[0051] In Graph 33, the vertical axis represents the pixel values ​​of the dark-field image 40c (see Figure 9), and the horizontal axis represents the angle of the subject 90 relative to multiple grids. Graph 33 is a graph plotting the pixel values ​​of the corresponding pixels 80 (see Figure 9) of multiple dark-field images 40c captured by changing the orientation of the subject 90 relative to multiple grids.

[0052] As shown in Graph 33, the pixel values ​​corresponding to pixels 80 in multiple dark-field images 40c are plotted, and the angle R at which the maximum signal intensity Vmax value is obtained in the sinusoidal fitted curve 33a is the orientation angle 30a (see Figure 9) of the fiber 91a (see Figure 7) at pixel 80. In addition, the value calculated by the ratio of amplitude Va to average signal intensity Vave is the degree of orientation 30b (see Figure 9).

[0053] The orientation information acquisition unit 20 performs the same processing on each pixel of the multiple dark-field images 40c to acquire orientation information 30. In this embodiment, the orientation information acquisition unit 20 acquires the orientation information 30 as tensor data indicating the orientation of the fibers 91a. The tensor data indicating orientation is obtained by converting the orientation degree 30b, which is a value between 0 and 1, to a value between 0.5 and 1, and rotating the coordinate system by the orientation angle 30a. That is, when the orientation angle 30a is set to 90 degrees to generate tensor data, the value in the principal direction of the tensor (value of the AA component) becomes the proportion of fibers 91a facing in direction A.

[0054] (Orientation analysis image) The orientation analysis image 41 shown in Figure 11 is an image generated based on the orientation information 30 (see Figure 9). Note that the orientation analysis image 41 is a convenient image for explaining the configuration in which the feature acquisition unit 21 acquires the feature quantities 31. The image processing unit 2a does not have to actually create the orientation analysis image 41. The orientation analysis image 41 is an image of the fibers 91a (see Figure 7) contained in the subject 90 (see Figure 1) visualized using color based on the orientation angle 30a (see Figure 9) and brightness based on the degree of orientation 30b (see Figure 9), as shown in the legend 81. The legend 81 indicates that the color of the fibers 91a changes in stages from red, purple, blue, and light blue in the range of 0 to 90 degrees. The legend 81 also indicates that the color changes in stages from light blue, green, yellow, and red in the range of 90 to 180 degrees. Furthermore, in the orientation analysis image 41, each pixel is displayed with the color and brightness corresponding to the orientation angle 30a with the largest orientation degree 30b value among the orientation angles 30a contained in each pixel. For example, if a pixel has the largest orientation degree 30b value in the 90-degree direction, that pixel will be displayed in light blue. Also, if the orientation angles 30a are the same, a larger orientation degree 30b value results in a brighter display, and a smaller orientation degree 30b value results in a darker display.

[0055] Here, if the direction of the force acting on the subject 90 is in direction B, by understanding the distribution of fibers 91a extending along direction A, which is the direction intersecting direction B, it is possible to identify the portion of the subject 90 where the mechanical strength in direction B is reduced. Therefore, in this embodiment, the orientation information acquisition unit 20 (see Figure 1) is configured to acquire a feature quantity 31 (see Figure 1) of the direction of force action based on the direction of force action acting on the subject 90 and orientation information 30 in the direction intersecting the direction of force action.

[0056] In the example shown in Figure 11, the fibers 91a (see Figure 7) in the regions 50a, 50b, and 50c are light blue and blue, respectively, and their orientation angle 30a (see Figure 9) is close to 90 degrees. That is, regions 50a, 50b, and 50c are specific-direction fiber regions 50, which are regions of fibers 91a oriented in a direction along a specific orientation angle 30a. In the example shown in Figure 11, the region of fibers 91a oriented in a direction along 90 degrees is the specific-direction fiber region 50. Note that, as shown in Figure 11, the orientation analysis image 41 shows fibers 91a with various orientation angles 30a.

[0057] (Tensor image) Therefore, in this embodiment, the image processing unit 2a generates a tensor image 42 shown in Figure 12 in order to make it easier to grasp the specific direction fiber region 50. Specifically, as shown in Figure 12, the image processing unit 2a (see Figure 1) generates a tensor image 42 which is an image based on the orientation degree 30b (see Figure 9) of a specific orientation angle 30a (see Figure 9). The tensor image 42 shown in Figure 12 is an image in which the pixel value is the value of the tensor principal direction obtained by converting the orientation degree 30b value, which is in the range of 0 to 1, to the range of 0.5 to 1 for each pixel, and rotating the coordinate system according to the orientation angle 30a. In this embodiment, the tensor image 42 is an image in which the pixel value is the value of the tensor principal direction of the tensor data when the orientation angle 30a is 90 degrees. In the example shown in Figure 12, the tensor image 42 is an image in the range of 0 (zero) to 1, as shown in Legend 82. In regions where there is a large proportion of fibers 91a oriented at 90 degrees (see Figure 7), the value of the degree of orientation 30b is large when the orientation angle 30a is 90 degrees. On the other hand, in regions where there is a large proportion of fibers 91a oriented at 0 degrees, the degree of orientation 30b is large when the orientation angle 30a is 0 degrees, but the value of the degree of orientation 30b is small when the orientation angle 30a is 90 degrees. In other words, in the tensor image 42, the closer to white it is, the greater the proportion of fibers 91a oriented at 90 degrees, and the closer to black it is, the greater the proportion of fibers 91a oriented at 0 degrees.

[0058] In the tensor image 42, the white regions (regions 50d, 50e, and 50f) are areas where the proportion of fibers 91a (see Figure 7) facing 90 degrees is large. However, in the tensor image 42, the boundary between the white regions and the black regions is unclear.

[0059] (Binarized image) Therefore, in this embodiment, the feature acquisition unit 21 (see Figure 1) is configured to acquire feature quantities 31 (see Figure 1) based on the tensor image 42 in order to accurately acquire the size of the specific direction fiber region 50 (see Figure 11). Specifically, as shown in Figure 13, the image processing unit 2a (see Figure 1) is configured to generate a binarized image 43 by performing a binarization process on the pixel values ​​(tensor values) of the tensor image 42. In this embodiment, the image processing unit 2a is configured to generate a binarized image 43 by binarizing the pixel values ​​of the tensor image 42 using a preset threshold 32 (see Figure 1).

[0060] (Features) In this embodiment, the feature acquisition unit 21 is configured to acquire the size of a specific direction fiber region 50 (see Figure 11), which is the region of fibers 91a oriented along a specific orientation angle 30a as depicted in the tensor image 42 (see Figure 12), as a feature quantity 31 (see Figure 1). In addition, in this embodiment, the feature acquisition unit 21 is configured to acquire the position of the specific direction fiber region 50 as a feature quantity 31, along with its size. The position of the specific direction fiber region 50 refers to the coordinates of the center of the specific direction fiber region 50 in the tensor image 42.

[0061] Specifically, the feature acquisition unit 21 is configured to acquire the size of the binarized region 51, which is a specific direction fiber region 50 in the binarized image 43, as a feature 31. In this embodiment, the feature acquisition unit 21 is configured to acquire the feature 31 based on the binarized region 51, which is a region having pixel values ​​greater than the threshold 32.

[0062] The binarized image 43 shown in Figure 13 contains the first binarized region 51a, the second binarized region 51b, and the third binarized region 51c. The feature acquisition unit 21 acquires the size and position of each of the first binarized region 51a, the second binarized region 51b, and the third binarized region 51c.

[0063] Here, a specific direction fiber region 50 (see Figure 11) that appears as a single region in the orientation analysis image 41 (see Figure 11) may appear as a discontinuous binarized region 51 in the binarized image 43. In this case, if the area of ​​the binarized region 51 is obtained as a feature quantity 31, the obtained value will be smaller than the actual area of ​​the specific direction fiber region 50, resulting in an inaccurate feature quantity 31. Therefore, in this embodiment, the feature quantity acquisition unit 21 is configured to perform a smoothing process on the binarized image 43.

[0064] In this embodiment, the feature acquisition unit 21 is configured to perform morphological processing, for example, by repeatedly performing shrinkage and dilation processing on the image as a smoothing process. In morphological processing, by performing shrinkage and dilation processing the same number of times, discontinuous points in the image can be connected. This makes it possible to connect the binarized regions 51, which have become discontinuous regions due to the binarization process, into a single region.

[0065] Furthermore, in this embodiment, the feature acquisition unit 21 is configured to acquire the area of ​​the binarized region 51 after smoothing as the feature quantity 31.

[0066] In this embodiment, the feature quantity 31 (see Figure 1) includes the ratio of the area of ​​the largest binarization region 51, which is the maximum binarization region 52, to the total area of ​​the subject 90 (see Figure 1) (total area of ​​the first region 90b), and the position of the maximum binarization region 52. That is, the feature quantity acquisition unit 21 acquires the ratio and position of the area of ​​the largest of the first binarization region 51a, which is the first binarization region 51a, the second binarization region 51b, and the third binarization region 51c, as the ratio and position of the area of ​​the maximum binarization region 52.

[0067] (Prediction of the location of the area of ​​reduced strength) Furthermore, in this embodiment, the feature acquisition unit 21 (see Figure 1) is configured to predict the location of the strength reduction area 53, which is a portion of the material 90 whose mechanical strength is relatively reduced due to the orientation of the fibers 91a (see Figure 7), based on the feature quantities 31. Specifically, the feature acquisition unit 21 is configured to predict the location of the strength reduction area 53 based on the ratio of the area of ​​the maximum binarization region 52 and the location of the maximum binarization region 52.

[0068] Table 31a, shown in Figure 14, is a table showing the area ratio of the binarized regions 51 (see Figure 13) acquired by the feature acquisition unit 21 (see Figure 1), the centroid position of the binarized regions 51, and the fracture position when an actual tensile test was performed. The area ratio is the ratio of the area of ​​each binarized region 51 to the area of ​​the subject 90 (see Figure 1). In Table 31a, "Region No." is a virtual number set according to the position of each binarized region 51. In this embodiment, "Region No." is set in order of increasing centroid position value.

[0069] As shown in Table 31a, the fracture point of the subject 90 during the actual tensile test and the location of the maximum binarization region 52 (region No. 3) are close to each other. Therefore, we confirmed whether a similar trend was observed in various parts of the subject 90 by performing similar analyses and tests on various parts of the subject 90.

[0070] Graph 34, shown in Figure 15, is a graph that shows the position (centroid) of the maximum binarization region 52 in various parts of the subject 90 and the fracture position when an actual tensile test was performed. In Graph 34, the horizontal axis represents the fracture position when an actual tensile test was performed, and the vertical axis represents the centroid of the maximum binarization region 52. When performing the tensile test, the subject 90 was physically divided, test specimens were created from various parts, and a tensile test was performed on each test specimen.

[0071] When the position of the maximum binarization region 52 (see Figure 13) and the point 34a indicating the fracture position during the actual tensile test were plotted for each part of the subject 90 (see Figure 1), it was confirmed that the fracture position falls approximately between the dashed lines 34b and 34c. The dashed lines 34b and 34c indicate the range where the difference between the fracture position and the position of the maximum binarization region 52 is plus or minus 10 mm. In other words, it was confirmed that the predicted position of the strength reduction area 53 (see Figure 13) falls within a 20 mm width range of the fracture position during the actual tensile test.

[0072] Therefore, it was confirmed that it is possible to accurately predict the fracture location when a tensile test is performed on the subject 90 based on the position (center of gravity) of the maximum binarization region 52.

[0073] (Prediction of overall intensity of the subject) Furthermore, the feature acquisition unit 21 (see Figure 1) is configured to predict the overall mechanical strength of the subject 90 (see Figure 1) based on the feature quantities 31 (see Figure 1) of the intensity reduction areas 53 (see Figure 13) included in the entire subject 90 (see Figure 1). Specifically, the feature acquisition unit 21 is configured to acquire an index value of the overall mechanical strength of the subject 90 based on the ratio of the area of ​​all binarized regions 51 (see Figure 13) to the total area of ​​the subject 90.

[0074] Graph 35 shown in Figure 16 has the specimen number on the horizontal axis, the maximum stress (MPa: megapascals) on the left vertical axis, and the total area ratio (%) of the binarized region 51 (see Figure 13) on the right vertical axis. As shown in legend 35a, the broken line 35b, indicated by a circle on a dashed line, shows the total area ratio, and the broken line 35c, indicated by a square on a solid line, shows the maximum stress. The total area ratio is the sum of the ratios of the area of ​​each binarized region 51 to the total area of ​​the subject 90 captured in the binarized image 43 (see Figure 13). In other words, the total area ratio is the ratio of the area of ​​all binarized regions 51 to the total area of ​​the subject 90 captured in the binarized image 43.

[0075] As shown in Graph 35, it was confirmed that when the total area ratio is large, the maximum stress tends to be small, and when the total area ratio is small, the maximum stress tends to be large. In other words, a high correlation was confirmed between the total area ratio for each test specimen and the maximum stress. Therefore, the sum of the area ratios of all binarized regions 51 can be used as an index value for the overall mechanical strength of the subject 90 (see Figure 1).

[0076] (Tendency towards bias in fiber orientation) The example shown in Figure 17(A) is a binarized image 43a when the orientation bias of the fibers 91a (see Figure 7) within the subject 90 (see Figure 1) is strong. The example shown in Figure 17(B) is a binarized image 43b when the orientation bias of the fibers 91a within the subject 90 is weak.

[0077] As shown in Figure 17(A), when the orientation bias of the fibers 91a is strong, the size (area) of the binarization region 51 tends to increase and the number of binarization regions 51 tends to decrease compared to when the orientation bias of the fibers 91a is weak. In other words, when the orientation bias of the fibers 91a is strong, the size (area) of the specific direction fiber region 50 (see Figure 11) tends to increase and the number of regions tends to decrease.

[0078] On the other hand, as shown in Figure 17(B), when the orientation bias of the fibers 91a is weak, the size (area) of the binarization region 51 tends to decrease and the number of binarization regions 51 tends to increase compared to when the orientation bias of the fibers 91a is strong. In other words, when the orientation bias of the fibers 91a is weak, the size (area) of the specific direction fiber region 50 tends to decrease and the number of regions tends to increase.

[0079] If the orientation of the fibers 91a within the subject 90 is strongly biased, areas where the mechanical strength is reduced may occur due to the orientation of the fibers 91a. On the other hand, if the orientation of the fibers 91a within the subject 90 is weak, the fibers 91a are arranged in random directions, thus reducing the likelihood of areas where the mechanical strength is reduced due to the orientation of the fibers 91a.

[0080] Therefore, in this embodiment, the feature acquisition unit 21 (see Figure 1) is configured to acquire the tendency of orientation bias of the fibers 91a within the subject 90 based on the size and number of binarized regions 51 in the binarized image 43. In this embodiment, the feature acquisition unit 21 is configured to acquire the tendency of orientation bias of the fibers 91a within the subject 90 based on the area and number of binarized regions 51.

[0081] (Display of dark-field images, binarized images, and feature quantities) Next, referring to Figure 18, we will describe the configuration in which the control unit 2b (see Figure 1) displays the dark-field image 40c, the binarized image 43, the feature quantity 31, the fracture prediction position 36, and the total area ratio 31b on the display unit 3.

[0082] The control unit 2b is configured to display the dark-field image 40c, the binarized image 43, the feature quantity table 31a, the fracture prediction position 36, and the total area ratio 31b side by side on the display unit 3.

[0083] Furthermore, although not shown in the diagram, if the orientation bias of the fibers 91a is weak, the control unit 2b will not display the feature quantity table 31a, the fracture prediction position 36, and the total area ratio 31b, and will instead display on the display unit 3 that the subject 90 is not suitable for analysis according to this embodiment.

[0084] Next, referring to Figure 19, the process by which the control unit 2b (see Figure 1) according to this embodiment displays the feature quantity 31 (see Figure 1) on the display unit 3 (see Figure 1) will be described.

[0085] In step 101, the control unit 2b controls the X-ray source 10 (see Figure 1) and the rotation mechanism 15 (see Figure 1) to image the subject 90 (see Figure 1) and the multiple gratings placed between the X-ray source 10 and the X-ray detector 11 (see Figure 1) at multiple imaging angles while rotating them relative to each other in a rotational direction around the direction of the X-ray irradiation axis 70 (see Figure 1).

[0086] In step 102, the image processing unit 2a (see Figure 1) generates multiple X-ray phase contrast images 40 (see Figure 1) for each orientation of the subject 90 relative to multiple gratings, based on the intensity distribution of X-rays detected by the X-ray detector 11. In this embodiment, the image processing unit 2a generates at least multiple dark-field images 40c (see Figure 6) as multiple phase contrast images.

[0087] In step 103, the feature acquisition unit 21 (see Figure 1) acquires orientation information 30 (see Figure 9) regarding the orientation of fibers 91a contained in the subject 90 based on a plurality of X-ray phase contrast images 40. In this embodiment, the control unit 2b acquires the orientation information 30 based on a plurality of dark-field images 40c.

[0088] In step 104, the feature acquisition unit 21 (see Figure 1) acquires feature quantities 31 related to the mechanical strength of the subject 90 based on the orientation information 30 acquired in step 103. In this embodiment, in step 104, the feature acquisition unit 21 acquires the area ratio of the maximum binarization region 52 (see Figure 13), the position of the maximum binarization region 52, and the area ratio of all binarization regions 51 (see Figure 13) as feature quantities 31.

[0089] In step 105, the control unit 2b determines whether the size (area) and number of binarization regions 51 having pixel values ​​greater than or equal to the threshold 32 (see Figure 1) are greater than or equal to a predetermined size (area) and number. If the size (area) and number of binarization regions 51 having pixel values ​​greater than or equal to the threshold 32 are greater than or equal to the predetermined size (area) and number, the process proceeds to step 106. If the size (area) and number of binarization regions 51 having pixel values ​​greater than or equal to the threshold 32 are not greater than or equal to the predetermined size (area) and number, the process proceeds to step 107.

[0090] In step 106, the control unit 2b displays the feature quantities 31 on the display unit 3. In this embodiment, the control unit 2b displays the area ratio of the maximum binarization region 52, the position of the maximum binarization region 52, and the area ratio of all binarization regions 51 as the feature quantities 31. The control unit 2b also displays the dark-field image 40c and the binarized image 43 (see Figure 13) on the display unit 3 along with the feature quantities 31. After that, the process ends.

[0091] If the process proceeds from step 105 to step 107, in step 107, the control unit 2b notifies that the subject 90 is not suitable for analysis by the X-ray phase imaging device 100. Specifically, the control unit 2b displays a message on the display unit 3 indicating that the subject 90 is not suitable for analysis by the X-ray phase imaging device 100. After that, the process ends.

[0092] (Effects of this embodiment) In this embodiment, the following effects can be obtained.

[0093] In this embodiment, as described above, the X-ray phase imaging apparatus 100 is an X-ray phase imaging apparatus that predicts the location where the mechanical strength of a subject 90 including fibers 91a is decreasing, and comprises an X-ray source 10 that irradiates with X-rays, an X-ray detector 11 that detects X-rays irradiated from the X-ray source 10, a plurality of gratings arranged between the X-ray source 10 and the X-ray detector 11, a rotation mechanism 15 that rotates the subject 90 and the plurality of gratings relative to each other in a rotational direction about the X-ray irradiation axis 70, and the rotation mechanism 15 rotates the subject 90 and the plurality of gratings relative to each other, and the target of the plurality of gratings The system includes an image processing unit 2a that generates multiple X-ray phase contrast images 40 for each orientation of the subject 90 relative to a plurality of grids based on the intensity distribution of X-rays detected by the X-ray detector 11 by changing the orientation of the subject 90 and imaging it, and a control unit 2b (orientation information acquisition unit 20 and feature acquisition unit 21) that acquires orientation information 30 regarding the orientation of fibers 91a contained in the subject 90 based on the plurality of X-ray phase contrast images 40, and acquires feature quantities 31 regarding the mechanical strength of the subject 90 based on the acquired orientation information 30.

[0094] This allows the user to confirm the feature quantities 31 related to the mechanical strength of the subject 90, which are obtained based on the orientation information 30. As a result, it is easy to identify the parts of the subject 90 where the mechanical strength is reduced due to the orientation of the fibers 91a.

[0095] Furthermore, in this embodiment, as described above, the X-ray phase imaging image analysis method is an X-ray phase imaging image analysis method for predicting the location where the mechanical strength of a subject 90 including fibers 91a is reduced, and comprises the steps of: imaging the subject 90 and a plurality of gratings arranged between the X-ray source 10 and the X-ray detector 11 at a plurality of imaging angles while relatively rotating them in a rotational direction about the direction of the X-ray irradiation axis 70; generating a plurality of X-ray phase contrast images 40 for each orientation of the subject 90 with respect to the plurality of gratings based on the intensity distribution of X-rays detected by the X-ray detector 11; acquiring orientation information 30 regarding the orientation of fibers 91a included in the subject 90 based on the plurality of X-ray phase contrast images 40; and acquiring feature quantities 31 regarding the mechanical strength of the subject 90 based on the acquired orientation information 30.

[0096] This makes it possible to provide an X-ray phase imaging method that, similar to the X-ray phase imaging apparatus 100 described above, can easily identify areas in the subject 90 where the mechanical strength is reduced due to the orientation of the fibers 91a.

[0097] Furthermore, in the above embodiment, the following additional effects can be obtained by configuring it as follows.

[0098] In other words, in this embodiment, as described above, the control unit 2b (feature acquisition unit 21) is configured to acquire feature quantities 31 of the direction of force acting on the object 90 based on the direction of force acting on the object 90 and orientation information 30 in a direction intersecting the direction of force acting on the object 90. As a result, the user can easily grasp the mechanical strength in the direction of force acting on the object 90 by checking the feature quantities 31.

[0099] Furthermore, in this embodiment, as described above, the control unit 2b (strength reduction prediction unit 22) is configured to predict the location of strength reduction areas 53, which are parts in the object 90 whose mechanical strength is relatively reduced due to the orientation of the fibers 91a, based on the feature quantity 31. As a result, the location of strength reduction areas 53 is predicted, so for example, by discarding the strength reduction areas 53 and using the parts other than the strength reduction areas 53 in the product, it is possible to suppress a decrease in product yield. In addition, based on the prediction result of the location of strength reduction areas 53, it is possible to identify regions in the object 90 where fibers 91a oriented in a specific direction are concentrated (specific direction fiber region 50). As a result, it is possible to improve the product manufacturing process, for example, by changing the manufacturing process to one that can suppress the concentration of fibers 91a oriented in a specific direction in a specific region in an object 90 manufactured by arranging fibers 91a in a random direction.

[0100] Furthermore, in this embodiment, as described above, the control unit 2b (intensity reduction prediction unit 22) is configured to predict the overall mechanical strength of the object 90 based on the feature quantity 31 of the intensity reduction portion 53 included in the entire object 90. As a result, by predicting the overall mechanical strength of the object 90 based on the feature quantity 31, the quality of the object 90 in terms of mechanical strength can be easily grasped. Consequently, quality control regarding the mechanical strength of the object 90 can be easily performed.

[0101] Furthermore, in this embodiment, as described above, the orientation information 30 includes an orientation angle 30a, which is the angle in the direction in which the fibers 91a included in the subject 90 extend, and an orientation degree 30b, which is an index indicating how well the fibers 91a are aligned in the same direction. The image processing unit 2a is configured to generate a tensor image 42, which is an image based on the orientation degree 30b at a specific orientation angle 30a. The control unit 2b (feature acquisition unit 21) is configured to acquire feature quantities 31 based on the tensor image 42. As a result, by generating a tensor image 42 at an orientation angle 30a desired by the user, feature quantities 31 relating to the mechanical strength of the subject 90 in the direction desired by the user can be acquired. Consequently, by checking the feature quantities 31, the user can easily grasp the mechanical strength of the subject 90 in the direction desired by the user.

[0102] Furthermore, in this embodiment, as described above, the control unit 2b (feature acquisition unit 21) is configured to acquire the size of the specific direction fiber region 50, which is the region of fibers 91a oriented in a direction along a specific orientation angle 30a as depicted in the tensor image 42, as a feature quantity 31. Here, the larger the proportion of fibers 91a oriented in a direction intersecting the direction of the force acting on the subject 90, the greater the reduction in the mechanical strength of the subject 90. That is, the larger the size of the specific direction fiber region 50, the greater the reduction in the mechanical strength of the subject 90. Therefore, by acquiring the size of the specific direction fiber region 50 as a feature quantity 31, the size of the specific direction fiber region 50 can be presented to the user as a feature quantity 31. As a result, the user can easily grasp the degree to which the mechanical strength of the subject 90 has decreased by checking the size of the specific direction fiber region 50. In addition, the mechanical strength of the subject 90 can be quantitatively grasped by the size of the specific direction fiber region 50.

[0103] Furthermore, in this embodiment, as described above, the control unit 2b (feature acquisition unit 21) is configured to acquire the size of the specific direction fiber region 50 and the position of the specific direction fiber region 50 as feature quantities 31. This allows the user to understand the degree to which the mechanical strength of the object 90 has decreased and the location of the decrease in mechanical strength. As a result, the user can easily understand the location of the strength-reduced portion 53, which is a location in the object 90 where damage may occur.

[0104] Furthermore, in this embodiment, as described above, the image processing unit 2a is configured to generate a binarized image 43 by binarizing the pixel values ​​of the tensor image 42, and the control unit 2b (feature acquisition unit 21) is configured to acquire the size of the binarized region 51, which is the specific direction fiber region 50 in the binarized image 43, as a feature 31. Here, in an image (tensor image 42) where the pixel values ​​are based on the orientation degree 30b of a specific orientation angle 30a, the boundary of the specific direction fiber region 50 becomes unclear in the region where the orientation degree 30b gradually changes. When the boundary of the specific direction fiber region 50 becomes unclear, it may not be possible to accurately acquire the size of the specific direction fiber region 50. Therefore, as described above, by obtaining the size of the binarized region 51, which is the specific direction fiber region 50 in the binarized image 43, as a feature quantity 31, the size of the specific direction fiber region 50 can be obtained with greater accuracy compared to a configuration in which the size of the specific direction fiber region 50 in an image of pixel values ​​based on the degree of orientation 30b of a specific orientation angle 30a (tensor image 42) is obtained as a feature quantity 31. As a result, the feature quantity 31 can be obtained with greater accuracy.

[0105] Furthermore, in this embodiment, as described above, the control unit 2b (feature acquisition unit 21) is configured to perform smoothing processing on the binarized image 43 and to acquire the area of ​​the binarized region 51 after the smoothing processing as a feature quantity 31. Here, a specific direction fiber region 50, which is a single region in the orientation analysis image 41, may become a discontinuous binarized region 51 in the binarized image 43. In this case, if the area of ​​the binarized region 51 is acquired as a feature quantity 31, a value smaller than the actual area of ​​the specific direction fiber region 50 will be acquired as the feature quantity 31, thus reducing the accuracy of the feature quantity 31. Therefore, by acquiring the area of ​​the binarized region 51 after the smoothing processing as the feature quantity 31, the binarized region 51 that has become a discontinuous region due to the binarization processing can be treated as a single region. As a result, the reduction in the accuracy of the feature quantity 31 can be suppressed.

[0106] Furthermore, in this embodiment, as described above, the feature quantity 31 includes the ratio of the area of ​​the largest binarization region 51, which is the maximum binarization region 52, to the total area of ​​the subject 90, and the position of the maximum binarization region 52. The control unit 2b (feature quantity acquisition unit 21) is configured to predict the position of the intensity reduction region 53 based on the ratio of the area of ​​the maximum binarization region 52 and the position of the maximum binarization region 52. Here, a region with a large ratio of the area of ​​the binarization region 51 is a region with a large proportion of fibers 91a with a specific orientation angle 30a, and therefore is a region where the mechanical strength is reduced. Thus, by configuring it as described above, the position of the subject 90 with the greatest reduction in mechanical strength can be easily predicted.

[0107] Furthermore, in this embodiment, as described above, the feature quantity 31 includes the ratio of the area of ​​all binarized regions 51 to the total area of ​​the subject 90, and the control unit 2b (feature quantity acquisition unit 21) is configured to acquire an index value of the mechanical strength of the entire subject 90 based on the ratio of the area of ​​all binarized regions 51 to the total area of ​​the subject 90. As a result, the user can easily grasp the mechanical strength of the entire subject 90 by checking the index value of the mechanical strength of the entire subject 90, which is acquired based on the ratio of the area of ​​all binarized regions 51 to the total area of ​​the subject 90.

[0108] Furthermore, in this embodiment, as described above, the control unit 2b (feature acquisition unit 21) is configured to acquire feature quantities 31 based on a binarization region 51 which is a region having a value greater than a preset threshold 32. Here, in the tensor image 42, regions with small pixel values ​​are regions where the proportion of fibers 91a oriented in directions other than the specific orientation angle 30a is greater than in regions with large pixel values. In other words, in the tensor image 42, regions with small pixel values ​​have a smaller degree of decrease in mechanical strength in the direction intersecting the specific orientation angle 30a than in regions with large pixel values. Therefore, as described above, by acquiring regions having a value greater than the threshold 32 as the binarization region 51, the prediction accuracy of the portion of the subject 90 with reduced mechanical strength can be improved.

[0109] Furthermore, in this embodiment, as described above, the control unit 2b is configured to acquire the tendency of orientation bias of the fibers 91a within the subject 90 based on the size and number of binarized regions 51 in the binarized image 43. Here, if the orientation bias of the fibers 91a is weak, the size of the specific direction fiber region 50 becomes smaller. In this case, even if binarization processing is performed using the threshold 32, the binarized region 51 may not be obtained. Therefore, as described above, by acquiring the tendency of orientation bias of the fibers 91a within the subject 90, the threshold 32 can be set according to the orientation bias of the fibers 91a. As a result, the binarized region 51 can be reliably acquired. Also, if the orientation bias of the fibers 91a is weak, a decrease in mechanical strength due to the orientation of the fibers 91a may not occur. Therefore, by acquiring the tendency of orientation bias of the fibers 91a within the subject 90, the user can determine whether or not the subject is suitable for analysis performed by the X-ray phase imaging apparatus 100 according to this embodiment. As a result, user convenience (usability) can be improved.

[0110] [Differentiation] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims rather than by the description of the embodiments above, and further includes all modifications (exceptions) within the meaning and scope of the claims.

[0111] For example, in the above embodiment, an example was shown in which the X-ray phase imaging apparatus 100 is equipped only with a rotation mechanism 15 that rotates the subject 90 and a plurality of gratings relative to each other, but the present invention is not limited thereto. As shown in the modified X-ray phase imaging apparatus 200 in Figure 20, the present invention may further be equipped with a second rotation mechanism 17 that rotates the subject 90 and an imaging system including an X-ray source 10, a plurality of gratings and an X-ray detector 11 relative to each other.

[0112] The modified X-ray phase imaging apparatus 200 shown in Figure 20 differs from the X-ray phase imaging apparatus 100 according to the above embodiment in that it includes an X-ray imaging unit 201 instead of an X-ray imaging unit 1, and a computer 202 instead of a computer 2.

[0113] The modified X-ray imaging unit 201 differs from the X-ray imaging unit 1 in the above embodiment in that it further includes a second rotation mechanism 17.

[0114] The second rotation mechanism 17 is configured to rotate the subject 90 relative to the imaging system, which includes the X-ray source 10, multiple gratings, and the X-ray detector 11. Details of how the second rotation mechanism 17 rotates the subject 90 relative to the imaging system, which includes the X-ray source 10, multiple gratings, and the X-ray detector 11, will be described later.

[0115] Furthermore, the modified computer 202 differs from the computer 2 in the above embodiment in that it includes an image processing unit 202a and a control unit 202b instead of an image processing unit 2a and a control unit 2b.

[0116] The image processing unit 202a is configured to generate a three-dimensional phase contrast image by performing imaging while changing the angle between the subject 90 and the imaging system using the second rotation mechanism 17, and changing the orientation with respect to multiple grids using the rotation mechanism 15.

[0117] As shown in Figure 21, the second rotation mechanism 17 is configured to rotate the subject 90 and the imaging system relative to each other in a rotational direction about an axis 72 perpendicular to the X-ray irradiation axis 70. Specifically, the second rotation mechanism 17 is configured to rotate the subject 90 and the imaging system relative to each other by rotating the subject 90 in a rotational direction about an axis 72 perpendicular to the X-ray irradiation axis 70. The second rotation mechanism 17 includes a mounting section (not shown) on which the subject 90 is placed, and a drive section (not shown) that generates a driving force to rotate the mounting section.

[0118] Therefore, as shown in Figure 22, the image processing unit 202a can generate binarized images 43 (first binarized image 43c to fifth binarized image 43g) of each cross-section in the thickness direction (X direction) of the subject 90 (see Figure 20).

[0119] The example shown in Figure 22 illustrates the first binarized image 43c to the fifth binarized image 43g arranged along the thickness direction (X direction) of the subject 90. As shown in Figure 22, the binarized region 51 of the first binarized image 43c and the binarized region 51 of the second binarized image 43d overlap in the thickness direction of the subject 90. Also, the binarized region 51 of the second binarized image 43d and the binarized region 51 of the third binarized image 43e overlap in the thickness direction of the subject 90. Furthermore, the binarized region 51 of the third binarized image 43e and the binarized region 51 of the fourth binarized image 43f overlap in the thickness direction of the subject 90. Also, the binarized region 51 of the fourth binarized image 43f and the binarized region 51 of the fifth binarized image 43g overlap in the thickness direction of the subject 90. In other words, in the example shown in Figure 22, the specific directional fiber region 50 (see Figure 11) is continuous along the thickness direction of the subject 90. Therefore, when a force in direction B is applied to the subject 90, fracture is likely to occur.

[0120] In the modified X-ray phase imaging apparatus 200, the distribution in the thickness direction (X direction) of the specific fiber region 50 can be understood in detail by acquiring tomographic images. As a result, areas where mechanical strength is reduced can be understood in more detail.

[0121] Furthermore, while the above embodiment shows an example in which the control unit 2b predicts the portion where the tensile strength has decreased, the present invention is not limited to this. For example, the control unit 2b may be configured to predict the fracture location in a three-point bending test.

[0122] Furthermore, while the above embodiment shows an example in which the control unit 2b predicts both the location of the strength-reduced portion 53, which is the part of the subject 90 whose mechanical strength is reduced, and the overall mechanical strength of the subject 90, the present invention is not limited to this. At least the location of the strength-reduced portion 53, which is the part of the subject 90 whose mechanical strength is reduced, can be predicted, and it is not necessary to predict the overall mechanical strength of the subject 90.

[0123] Furthermore, although the above embodiment shows an example in which the feature acquisition unit 21 acquires the size of the specific direction fiber region 50 and the position of the specific direction fiber region 50, the present invention is not limited to this. For example, if the feature acquisition unit 21 is configured to acquire the size of the specific direction fiber region 50 for each region obtained by dividing the dark-field image 40c into predetermined sizes (widths), it is not necessary to acquire the position of the specific direction fiber region 50.

[0124] Furthermore, while the above embodiment shows an example in which the feature acquisition unit 21 acquires the ratio of the area of ​​the binarized region 51 as the feature quantity 31, the present invention is not limited thereto. For example, the feature acquisition unit 21 may be configured to acquire the value of the area of ​​the binarized region 51 as the feature quantity 31. Alternatively, the feature acquisition unit 21 may be configured to acquire the length of the outer perimeter of the binarized region 51 as the feature quantity 31. Alternatively, the feature acquisition unit 21 may be configured to acquire the circumscribing rectangle of the binarized region 51 and acquire the length of the longest side of the circumscribing rectangle as the feature quantity 31. Alternatively, the feature acquisition unit 21 may be configured to ellipse-fit the binarized region 51 and acquire a value based on the ratio of the long side to the short side of the fitted ellipse as the feature quantity 31. The method for which the feature acquisition unit 21 acquires the size of the binarized region 51 is not limited.

[0125] Furthermore, although the above embodiment shows an example in which the feature acquisition unit 21 performs morphological processing as a smoothing process for the binarized image 43, the present invention is not limited to this. The feature acquisition unit 21 may perform any processing as long as it is possible to connect the discontinuous binarized regions 51. For example, the feature acquisition unit 21 may be configured to perform processing using a Gaussian filter as a smoothing process for the binarized image 43. However, in the case of smoothing processing using a Gaussian filter, the accuracy when connecting the binarized regions 51 may decrease. Therefore, it is preferable that the feature acquisition unit 21 be configured to perform morphological processing as a smoothing process.

[0126] Furthermore, although the above embodiment shows an example configuration in which the control unit 2b displays the feature quantities 31 (Table 31a), the dark-field image 40c, the binarized image 43, the fracture prediction position 36, and the total area ratio 31b on the display unit 3, the present invention is not limited to this. The control unit 2b does not need to display the dark-field image 40c, the binarized image 43, the fracture prediction position 36, and the total area ratio 31b, as long as it displays at least the feature quantities 31. Also, although the control unit 2b displays Table 31a of the feature quantities 31, it may be configured to display only the area ratio of the maximum binarized region 52 and the numerical data of the position of the maximum binarized region 52.

[0127] Furthermore, while the above embodiment shows an example in which the feature acquisition unit 21 binarizes the pixel values ​​of the tensor image 42 using a preset threshold 32, the present invention is not limited to this. For example, the feature acquisition unit 21 may be configured to binarize the pixel values ​​of the tensor image 42 using a threshold input by the user.

[0128] Furthermore, although the above embodiment shows an example in which the feature acquisition unit 21 acquires the tendency of orientation bias of the fibers 91a, the present invention is not limited to this. For example, the feature acquisition unit 21 does not need to acquire the tendency of orientation bias of the fibers 91a.

[0129] Furthermore, in the above embodiment, as shown in Figure 3, an example configuration of the rotation mechanism 15 comprising a grating holding part 15a, a drive part 15b, and a housing part 15c was shown, but the present invention is not limited thereto. The configuration of the rotation mechanism 15 is not limited as long as multiple gratings can be rotated in a rotational direction around the X-ray irradiation axis 70.

[0130] Furthermore, while the above embodiment shows an example in which the rotation mechanism 15 rotates the subject 90 relative to the multiple grids by rotating the multiple grids, the present invention is not limited to this. For example, the rotation mechanism 15 may be configured to rotate the subject 90 relative to the multiple grids by rotating the subject 90.

[0131] Furthermore, although the above embodiment shows an example in which the X-ray phase imaging apparatus 100 images CFRP as the subject 90, the present invention is not limited thereto. For example, the X-ray phase imaging apparatus 100 may be configured to image GFRP (glass fiber reinforced plastic) as the subject. Any fiber composite material may be imaged as the subject.

[0132] Furthermore, although the above embodiment shows an example in which the subject 90 is divided into first region 90b to seventh region 90h and imaged in each region, the present invention is not limited to this. If it is possible to image the entire subject 90, it is not necessary to divide the subject 90 into multiple regions for imaging.

[0133] Furthermore, while the above embodiment shows an example in which the grid position adjustment mechanism 16 is configured to move the first grid 12 in the X direction, Y direction, Z direction, rotation direction Rz, rotation direction Rx, and rotation direction Ry, the present invention is not limited to this. In the present invention, the grid position adjustment mechanism 16 may be configured to move in only one or more of the X direction, Y direction, Z direction, rotation direction Rz, rotation direction Rx, and rotation direction Ry. Also, the grid position adjustment mechanism 16 may be configured to move the second grid 13 or the third grid 14. Note that when performing fringe scanning, the grid position adjustment mechanism 16 must be configured to move the grid in the direction in which fringe scanning is performed.

[0134] Furthermore, in the above embodiment, an example was shown in which the multiple gratings are configured to include a third grating 14 for increasing the coherence of X-rays irradiated from the X-ray source 10, but the present invention is not limited thereto. If the coherence of the X-rays irradiated from the X-ray source 10 is high, the configuration may not include the third grating 14.

[0135] Furthermore, in the above embodiment, an example was shown in which the first grating 12 was a phase grating in order to form a self-image due to the Talbot effect, but the present invention is not limited to this. In the present invention, the self-image only needs to be a striped pattern, so an absorption grating may be used instead of a phase grating. When an absorption grating is used, depending on optical conditions such as distance, there will be a region where a simple striped pattern is generated (non-interferometer) and a region where a self-image due to the Talbot effect is generated (interferometer).

[0136] [Aspect] Those skilled in the art will understand that the exemplary embodiments described above are specific examples of the following embodiments.

[0137] (Item 1) An X-ray phase imaging apparatus for predicting the location where the mechanical strength of a subject containing fibers is reduced, An X-ray source that emits X-rays, An X-ray detector for detecting X-rays irradiated from the aforementioned X-ray source, A plurality of gratings are arranged between the X-ray source and the X-ray detector, A rotation mechanism that rotates the subject and the plurality of grids relative to each other in a rotational direction about the X-ray irradiation axis, An image processing unit generates multiple X-ray phase contrast images for each orientation of the subject relative to the multiple grids, based on the intensity distribution of X-rays detected by the X-ray detector, by rotating the subject and the multiple grids relative to each grid using the rotation mechanism and taking images while changing the orientation of the subject with respect to the multiple grids. An X-ray phase imaging apparatus comprising: a control unit that acquires orientation information relating to the orientation of fibers contained in a subject based on the plurality of X-ray phase contrast images, and acquires characteristic quantities relating to the mechanical strength of the subject based on the acquired orientation information.

[0138] (Item 2) The X-ray phase imaging apparatus according to item 1, wherein the control unit is configured to acquire the characteristic quantity of the direction of force acting on the subject based on the direction of force acting on the subject and the orientation information in a direction intersecting the direction of force acting.

[0139] (Item 3) The X-ray phase imaging apparatus according to item 1 or 2, wherein the control unit is configured to predict the location of a strength reduction portion, which is a portion in the subject where the relative mechanical strength is reduced due to the orientation of the fibers, based on the feature quantities.

[0140] (Item 4) The X-ray phase imaging apparatus according to item 3, wherein the control unit is configured to predict the mechanical strength of the entire subject based on the characteristic quantities of the intensity reduction portion included in the entire subject.

[0141] (Item 5) The orientation information includes an orientation angle, which is the angle in the direction in which the fibers contained in the subject extend, and an orientation degree, which is an indicator of how well the fibers are aligned in the same direction. The image processing unit is configured to generate an orientation information image, which is an image based on the degree of orientation at a specific orientation angle. The X-ray phase imaging apparatus according to item 3 or 4, wherein the control unit is configured to acquire the feature quantities based on the orientation information image.

[0142] (Item 6) The X-ray phase imaging apparatus according to item 5, wherein the control unit is configured to acquire as a feature quantity the size of a specific direction fiber region, which is a region of the fibers facing in a direction along a specific orientation angle captured in the orientation information image.

[0143] (Item 7) The X-ray phase imaging apparatus according to item 6, wherein the control unit is configured to acquire the size of the specific direction fiber region and the position of the specific direction fiber region as the feature quantities.

[0144] (Item 8) The image processing unit is configured to generate a binarized image by binarizing the pixel values ​​of the orientation information image, The X-ray phase imaging apparatus according to item 6 or 7, wherein the control unit is configured to acquire the size of the binarized region, which is the specific direction fiber region in the binarized image, as the feature quantity.

[0145] (Item 9) The X-ray phase imaging apparatus according to item 8, wherein the control unit is configured to perform a smoothing process on the binarized image and to acquire the area of ​​the binarized region after the smoothing process as the feature quantity.

[0146] (Item 10) The aforementioned feature quantity includes the ratio of the area of ​​the largest of the binarized regions, which is the maximum binarized region, to the total area of ​​the subject, and the position of the maximum binarized region. The X-ray phase imaging apparatus according to item 8 or 9, wherein the control unit is configured to predict the position of the intensity reduction portion based on the ratio of the area of ​​the maximum binarization region and the position of the maximum binarization region.

[0147] (Item 11) The aforementioned feature quantity includes the ratio of the area of ​​all the binarized regions to the area of ​​the entire subject, The X-ray phase imaging apparatus according to item 8 or 9, wherein the control unit is configured to obtain an index value of the mechanical strength of the entire subject based on the ratio of the area of ​​all the binarization regions to the area of ​​the entire subject.

[0148] (Item 12) The X-ray phase imaging apparatus according to any one of items 8 to 11, wherein the control unit is configured to acquire the feature quantity based on the binarization region, which is a region having a value greater than a preset threshold.

[0149] (Item 13) The X-ray phase imaging apparatus according to any one of items 8 to 12, wherein the control unit is configured to acquire the tendency of bias in the orientation of the fibers within the subject based on the size and number of the binarized regions in the binarized image.

[0150] (Item 14) An X-ray phase imaging image analysis method for predicting the location where the mechanical strength of a fiber-containing subject is reduced, The steps include imaging the subject and multiple gratings placed between the X-ray source and the X-ray detector at multiple imaging angles while rotating them relative to each other in a rotational direction about the direction of the X-ray irradiation axis, The steps include generating a plurality of X-ray phase contrast images for each orientation of the subject relative to the plurality of gratings based on the intensity distribution of X-rays detected by the X-ray detector, The steps include obtaining orientation information regarding the orientation of the fibers contained in the subject based on the plurality of X-ray phase contrast images, An X-ray phase imaging image analysis method comprising the step of obtaining feature quantities relating to the mechanical strength of a subject based on the orientation information obtained. [Explanation of Symbols]

[0151] 2a, 202a Image Processing Unit 2b, 202b Control Unit 10 X-ray source 11 X-ray detectors 15 Rotation mechanism 30 Orientation Information 30a Orientation angle 30b Degree of orientation 31. Feature quantities (Feature quantities related to the mechanical strength of the subject) 32 thresholds 40 X-ray phase contrast images 42 Tensor Images (Orientation Information Images) 43. Binarized image 50 Specific Directional Fiber Region 51 Binarization Region 52 Maximum binarization region 53 Decreased strength part 70 X-ray irradiation axis 90 Subjects 91a Fiber 100, 200 X-ray imaging devices

Claims

1. An X-ray phase imaging apparatus for predicting the location where the mechanical strength of a subject containing fibers is reduced, An X-ray source that emits X-rays, An X-ray detector for detecting X-rays irradiated from the aforementioned X-ray source, A plurality of gratings are arranged between the X-ray source and the X-ray detector, A rotation mechanism that rotates the subject and the plurality of grids relative to each other in a rotational direction about the X-ray irradiation axis, An image processing unit generates multiple X-ray phase contrast images for each orientation of the subject relative to the multiple grids, based on the intensity distribution of X-rays detected by the X-ray detector, by rotating the subject and the multiple grids relative to each grid using the rotation mechanism and taking images while changing the orientation of the subject with respect to the multiple grids. The system includes a control unit that performs the following: control to acquire orientation information, including the orientation angle which is the angle in the direction in which the fibers contained in the subject extend, and the degree of orientation which is an indicator of how well the fibers are aligned in the same direction, based on the dark-field images in the plurality of X-ray phase contrast images; and control to acquire a feature quantity relating to the direction of force acting on the subject, based on the direction of force acting on the subject and the orientation information in a direction intersecting the direction of force acting on the subject, wherein the system includes a control unit that performs the following: The image processing unit is configured to generate an orientation information image, which is an image based on the degree of orientation at the orientation angle in a direction intersecting the direction of force application, and to generate a binarized image by binarizing the pixel values ​​of the generated orientation information image. The control unit is configured to acquire the feature quantities from the binarized region in the binarized image, in an X-ray phase imaging apparatus.

2. The X-ray phase imaging apparatus according to claim 1, wherein the control unit is configured to predict the location of a strength reduction portion, which is a portion in the subject where the relative mechanical strength is reduced due to the orientation of the fibers, based on the feature quantities.

3. The X-ray phase imaging apparatus according to claim 2, wherein the control unit is configured to predict the mechanical strength of the entire subject based on the characteristic quantities of the intensity reduction portion included in the entire subject.

4. The X-ray phase imaging apparatus according to claim 1, wherein the control unit is configured to acquire as a feature quantity the size of a specific direction fiber region, which is a region of the fiber facing in a direction along the orientation angle that intersects with the direction of force applied as seen in the orientation information image.

5. The X-ray phase imaging apparatus according to claim 4, wherein the control unit is configured to acquire the size of the specific direction fiber region and the position of the specific direction fiber region as the feature quantities.

6. The X-ray phase imaging apparatus according to claim 5, wherein the control unit is configured to acquire the size of the binarized region, which is the specific direction fiber region in the binarized image, as the feature quantity.

7. The X-ray phase imaging apparatus according to claim 6, wherein the control unit is configured to perform a smoothing process on the binarized image and to acquire the area of ​​the binarized region after the smoothing process as the feature quantity.

8. The aforementioned feature quantity includes the ratio of the area of ​​the largest of the binarized regions, which is the maximum binarized region, to the total area of ​​the subject, and the position of the maximum binarized region. The X-ray phase imaging apparatus according to claim 7, wherein the control unit is configured to predict the location of a reduced-strength portion, which is a portion in the subject where the mechanical strength is relatively reduced due to the orientation of the fibers, based on the ratio of the area of ​​the maximum binarization region and the position of the maximum binarization region.

9. The aforementioned feature quantity includes the ratio of the area of ​​all the binarized regions to the area of ​​the entire subject, The X-ray phase imaging apparatus according to claim 7, wherein the control unit is configured to obtain an index value of the mechanical strength of the entire subject based on the ratio of the area of ​​all the binarization regions to the total area of ​​the subject.

10. The X-ray phase imaging apparatus according to claim 7, wherein the control unit is configured to acquire the feature quantity based on the binarization region, which is a region having a value greater than a preset threshold.

11. The X-ray phase imaging apparatus according to claim 10, wherein the control unit is configured to acquire the tendency of bias in the orientation of the fibers within the subject based on the size and number of the binarized regions in the binarized image.

12. An X-ray phase imaging image analysis method for predicting the location where the mechanical strength of a subject containing fibers is reduced, The steps include imaging the subject and multiple gratings placed between the X-ray source and the X-ray detector at multiple imaging angles while rotating them relative to each other in a rotational direction about the direction of the X-ray irradiation axis, The steps include generating a plurality of X-ray phase contrast images for each orientation of the subject relative to the plurality of gratings based on the intensity distribution of X-rays detected by the X-ray detector, The steps include obtaining orientation information, which includes the orientation angle, which is the angle in the direction in which the fibers contained in the subject extend, and the degree of orientation, which is an indicator of how well the fibers are aligned in the same direction, based on the dark-field images in the plurality of X-ray phase contrast images, The method includes the step of obtaining a characteristic quantity of the direction of force acting on the subject, based on the direction of force acting on the subject and the orientation information in a direction intersecting the direction of force acting, In the step of obtaining the aforementioned feature quantities, An orientation information image is generated, which is an image based on the degree of orientation at the orientation angle in a direction intersecting the direction of the force applied, and a binarized image is generated by binarizing the pixel values ​​of the generated orientation information image. An X-ray phase imaging image analysis method for obtaining the feature quantities from the binarized region in the binarized image.

Images