X-ray imaging apparatus and method for controlling the X-ray imaging apparatus

Abstract

In an X-ray imaging system, the contours of objects within the volume data of scattered images are clarified. [Solution] The X-ray imaging apparatus 100 comprises a stage 10 on which an object W is placed, an X-ray generator 20 that irradiates the object with X-rays, a plurality of diffraction gratings 60, 70, 80, an X-ray detector 30, a control device 110, and a display device 130. The plurality of diffraction gratings are arranged so that X-rays can pass through them. The detector is provided opposite the X-ray generator, with the stage and the plurality of diffraction gratings in between, and detects changes in the object's self-image due to the plurality of diffraction gratings. The control device calculates multiple types of images of the object based on the changes in its self-image. The display device displays multiple types of images. The multiple types of images include an absorption image A and a scattering image S. The control device obtains the contour of the object from the absorption image and clarifies the contour of the object in the scattering image and displays it on the display device.

Description

Technical Field

[0001] The present disclosure relates to an X-ray imaging apparatus and a control method for an X-ray imaging apparatus, and more particularly to a technique for improving the display accuracy of a scatter image.

Background Art

[0002] In an X-ray imaging apparatus, in addition to generating an image based on general X-ray absorption, there is also a method of generating an image based on the phase of X-rays.

[0003] For example, Japanese Patent No. 4445397 (Patent Document 1) discloses an X-ray imaging apparatus that realizes X-ray imaging based on the phase of X-rays for a subject for which observation is difficult by a method based on X-ray absorption.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In X-ray imaging using a method based on the phase of X-rays, three types of images, an absorption image, a scatter image, and a refraction image, can be calculated from the data of one X-ray imaging. The three types of images are CT-reconstructed using, as projection data, values calculated from changes in the moire pattern generated in the self-image by overlapping diffraction gratings.

[0006] However, when CT reconstruction is performed, if the amplitude of the self-image disappears due to extreme attenuation of X-rays or the like and the amount of scatter cannot be accurately estimated, strong scatter artifacts (noise) that cause halation near the surface of the object may occur.

[0007] As a result, the scattered image may depict shapes that do not actually exist, causing the outermost surface of the object to appear slightly bulging. When this phenomenon occurs, users may not be able to correctly define the contour of the object in the scattered image.

[0008] This disclosure was made to solve the above-mentioned problems, and its purpose is to improve the display accuracy of scattered images in an X-ray imaging device. [Means for solving the problem]

[0009] An X-ray imaging apparatus according to a certain aspect of the present disclosure comprises a stage, an X-ray generator, a plurality of diffraction gratings, a detector, a control device, and a display device. The stage is on which an object is placed. The X-ray generator irradiates the object with X-rays. The plurality of diffraction gratings are arranged so that X-rays pass through them. The detector is provided opposite the X-ray generator, with the stage and the plurality of diffraction gratings in between, and detects changes in the object's self-image due to the plurality of diffraction gratings. The control device calculates multiple types of images of the object based on the changes in the self-image. The display device displays the multiple types of images. At least one of the plurality of diffraction gratings is provided between the X-ray generator and the stage, and at least one is provided between the stage and the detector. The multiple types of images include absorption images and scattering images. The control device obtains the contour of the object from the absorption image and clarifies the contour of the object in the scattering image and displays it on the display device.

[0010] A control method relating to another aspect of this disclosure relates to a control method for an X-ray imaging apparatus. The X-ray imaging apparatus comprises a stage, an X-ray generator, a plurality of diffraction gratings, a detector, and a display device. An object is placed on the stage. The X-ray generator irradiates the object with X-rays. The plurality of diffraction gratings are arranged so that X-rays pass through them. The detector is provided opposite the X-ray generator, with the stage and the plurality of diffraction gratings in between, and detects changes in the object's self-image due to the plurality of diffraction gratings. The display device displays multiple types of images of the object calculated based on the changes in the self-image. The plurality of diffraction gratings include at least one between the X-ray generator and the stage, and at least one between the stage and the detector. The multiple types of images include absorption images and scattering images. The control method includes the steps of obtaining the contour of the object from the absorption image and clarifying the contour of the object in the scattering image and displaying it on the display device. [Effects of the Invention]

[0011] In the X-ray imaging apparatus of this disclosure, the contour of an object can be obtained from the absorption image, and the obtained contour can be applied to the object in the scattered image, thereby clarifying the contour of the object in the scattered image. Therefore, the display accuracy of the scattered image can be improved. [Brief explanation of the drawing]

[0012] [Figure 1] This figure shows an example of the overall configuration of an X-ray imaging apparatus according to Embodiment 1. [Figure 2] This diagram shows the configuration of the control unit in an X-ray imaging system. [Figure 3] This diagram shows the configuration of each diffraction grating. [Figure 4] This figure shows the change in the moiré pattern of the self-image. [Figure 5] This diagram illustrates a method for outputting an image from changes in moiré patterns. [Figure 6] This is a functional block diagram of the control system in an X-ray imaging device. [Figure 7] This figure shows the result of applying the contour of the absorption image to the scattering image. [Figure 8] It is a flowchart showing the processing procedure of the X-ray imaging apparatus. [Figure 9] It is a diagram showing an example of the overall configuration of the X-ray imaging apparatus according to Modification 1. [Figure 10] It is a diagram showing a method of displaying an image on a display device by the control device according to Embodiment 2.

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and their descriptions are not repeated.

[0014] [Embodiment 1] FIG. 1 is a diagram showing an example of the overall configuration of an X-ray imaging apparatus 100 according to Embodiment 1. The X-ray imaging apparatus 100 performs CT (Computed Tomography) imaging using X-rays. As shown in FIG. 1, the X-ray imaging apparatus 100 includes a stage 10, an X-ray generator 20, an X-ray detector 30, diffraction gratings 60, 70, 80, a control device 110, an input device 120, and a display device 130.

[0015] The X-ray generator 20 is controlled by the control device 110 and irradiates an object W placed on the stage 10 with an X-ray beam X. The X-ray beam X is a bundle of X-rays that expands in a conical shape with the focal point as the apex. The X-ray generator 20 is, for example, an X-ray tube.

[0016] The X-ray detector 30 is provided facing the X-ray generator 20 with the stage 10 interposed therebetween. The X-ray detector 30 is controlled by the control device 110 and detects the X-ray intensity attenuated according to the transmission path of the X-rays. The X-ray detector 30 is composed of, for example, a flat panel detector (FPD) in which detection elements are arranged in a two-dimensional array. In this case, the X-ray detector 30 can acquire a two-dimensional distribution of the X-ray intensity. Note that the X-ray detector 30 may be configured to be movable in the X-axis direction.

[0017] In the following description, the direction connecting the X-ray generator 20 and the X-ray detector 30 is referred to as the X-axis direction. Also, the direction that is perpendicular to the X-axis direction and parallel to the surface of the stage 10 is referred to as the Y-axis direction. Further, the direction perpendicular to the X-axis direction and the Y-axis direction, that is, the normal direction of the stage 10, is referred to as the Z-axis direction.

[0018] The stage 10 is disposed between the X-ray generator 20 and the X-ray detector 30. The object W placed on the stage 10 is exposed to the X-ray beam X traveling from the X-ray generator 20 toward the X-ray detector 30. The stage 10 is configured to be rotatable by a motor and rotates about the rotation axis in the Z-axis direction under the control of the control device 110 with the object W placed thereon.

[0019] When the stage 10 rotates, the X-ray imaging apparatus 100 can acquire an X-ray image by imaging the object W from the horizontal direction and reconstruct a CT image from the obtained plurality of X-ray images.

[0020] Also, the stage 10 can be translated in the X-axis direction, the Y-axis direction, and the Z-axis direction by driving the motor under the control of the control device 110. By moving the stage 10 in the X-axis direction, the Y-axis direction, and the Z-axis direction and then rotating it, the X-ray imaging apparatus 100 can move a part of the object W to the center of the region where X-ray imaging is to be performed and then perform X-ray imaging after changing the magnification. By doing so, the user can obtain a more magnified image of a part of the object W that the user is particularly interested in.

[0021] The diffraction grating 60 is provided between the X-ray generator 20 and the stage 10 so as to face the X-ray generator 20. A number of slits are formed in a certain direction on the diffraction grating 60, and the wavefront of the X-ray is aligned by diffraction of the X-ray emitted from the X-ray generator 20 by the slits.

[0022] The diffraction grating 70 is positioned between the diffraction grating 60 and the stage 10, parallel to the diffraction grating 60. The diffraction grating 70 has numerous slits formed in a certain direction, through which the X-ray beam X that has passed through the diffraction grating 60 passes. Alternatively, the diffraction grating 70 may be positioned between the stage 10 and the X-ray detector 30, parallel to the diffraction grating 60.

[0023] The diffraction grating 80 is positioned between the stage 10 and the X-ray detector 30, parallel to the diffraction gratings 60 and 70. The diffraction grating 80 has numerous slits formed in a certain direction, through which the X-ray beam X that has passed through the diffraction grating 70 passes. The diffraction grating 80 is configured to be movable in the Y-axis and Z-axis directions under the control of the control device 110.

[0024] The control device 110 controls the stage 10, the X-ray generator 20, the X-ray detector 30, and the diffraction grating 80.

[0025] The input device 120 receives operation input from the user and transmits it to the control device 110. The input device 120 may be, for example, a keyboard, a touch panel, or a mouse. The input device 120 may be located outside the X-ray imaging apparatus 100.

[0026] The display device 130 receives images and other data generated based on X-ray imaging from the control device 110 and displays them. The display device 130 is, for example, a display or a printer.

[0027] Figure 2 shows the configuration of the control device 110 in the X-ray imaging apparatus 100. As shown in Figure 2, the control device 110 comprises a memory 112, a processor 114, and a communication interface 116, all connected to each other via a common communication bus.

[0028] The communication interface 116 receives setting values ​​for various parameters of the X-ray imaging apparatus 100, sensor measurements, and other data from the input device 120. The communication interface 116 also transmits signals to the stage 10, the X-ray generator 20, the X-ray detector 30, the diffraction grating 80, and the display device 130.

[0029] Memory 112 stores various programs and data. Memory 112 includes, for example, ROM (Read Only Memory) and RAM (Random Access Memory).

[0030] The processor 114 controls each device of the X-ray imaging apparatus 100 based on various data stored in the memory 112 and various data obtained from the communication interface 116. The processor 114 is, for example, a processing unit such as a CPU (Central Processing Unit) and an MPU (Micro Processing Unit).

[0031] Figure 3 shows the configuration of each diffraction grating. The slits of diffraction gratings 60, 70, and 80 are positioned in the same direction. Since X-rays are a type of electromagnetic wave, when X-rays pass through each diffraction grating, interference fringes of light and dark called self-images are generated. Changes in the self-image are acquired when the object W is placed on stage 10, and by comparing these with changes in the self-image when the object W is not placed, absorption, refraction, and scattering images of the X-rays are detected.

[0032] As shown in the upper diagram (A) of Figure 3, the smaller the focal spot size of the X-ray generator 20, the more aligned the wavefront of the X-ray beam X can be output, resulting in a clearer self-image. However, this has the problem of requiring a relatively long imaging time because the amount of X-rays output per unit time is small.

[0033] To increase the amount of X-rays output per unit time, it is necessary to increase the voltage applied to the X-ray generator 20, thereby increasing the amount of electrons that strike the target within the X-ray generator 20. Since electrons repel each other, increasing the amount of electrons increases the focal spot size of the X-ray generator, which is the area of ​​electrons that strike the target.

[0034] However, if the focal size is large, X-rays will be incident on the object W from various angles, making it difficult to align the wavefronts of the X-rays. This impairs the clarity of the self-image, making it impossible to capture absorption, refraction, and scattering images with high contrast. Therefore, as shown in the lower diagram (B) of Figure 3, a diffraction grating 60 is installed. The X-ray beam X is emitted from the X-ray generator 20 and passes through the diffraction grating 60, creating a virtual array of X-ray generators with small focal sizes.

[0035] Thus, the inclusion of the diffraction grating 60 allows for a higher output of X-ray beam X per unit time, thereby shortening the imaging time of the object W, while simultaneously outputting X-rays with aligned wavefronts. As a result, a clear self-image can be acquired in a short time.

[0036] Figure 4 shows the change in the moiré pattern of the self-image. The X-ray beam X, emitted from the X-ray generator 20 and whose wavefronts are aligned after passing through the diffraction grating 60, then passes through the diffraction grating 70. The self-image 202 immediately after the X-ray beam X passes through the diffraction grating 70 shows only interference fringes of bright and dark areas, because it has not yet passed through the object W, and the slits in the diffraction grating 70 have generated them.

[0037] Subsequently, when the X-ray beam X passes through the object W, the object W causes a phase change in the incident X-rays, so the self-image 202 changes to the self-image 204. However, the change in the self-image from self-image 202 to self-image 204 is small and difficult to distinguish. Therefore, by superimposing the diffraction grating 80 in addition to the diffraction gratings 60 and 70, moiré interference fringes (hereinafter also referred to as "moiré pattern") are generated in the self-image 206. The control device 110 changes the moiré pattern by gradually moving the diffraction grating 80 perpendicular to the slits of the diffraction gratings 60 and 70. The X-ray detector 30 detects the change in the moiré pattern.

[0038] Figure 5 illustrates a method for outputting an image from changes in the moiré pattern. This method uses stepping imaging (striping method) in which the diffraction grating 80 is moved perpendicular to the slits of the other diffraction gratings 60 and 70. As the diffraction grating 80 moves, the moiré pattern of the self-image 206 detected by the X-ray detector 30 changes. When the grayscale value of the self-image is obtained as the movement distance of the diffraction grating 80 is changed, a graph like the one in Figure 5 is obtained. The horizontal axis of the graph represents the step, which is the distance the diffraction grating 80 moves. The vertical axis of the graph represents the grayscale value of the self-image.

[0039] Line GR shows the change in the grayscale value of the self-image when X-ray imaging is performed without the object W. Line GS shows the change in the grayscale value of the self-image when X-ray imaging is performed with the object W placed on the stage 10. The control device 110 outputs an absorption image from the rate of change of the average grayscale value (Cs / Cr) calculated using the average grayscale value Cr of line GR and the average grayscale value Cs of line GS.

[0040] Furthermore, the control device 110 calculates the average amplitude (Ar / Cr) of line GR from the amplitude Ar of line GR and the average grayscale value Cr of line GR. The control device 110 calculates the average amplitude (As / Cs) of line GS from the amplitude As of line GS and the average grayscale value Cs of line GS. Then, the control device 110 outputs a scattering image from the rate of change of the average amplitude (As / Cs) / (Ar / Cr) calculated using the average amplitude (Ar / Cr) of line GR and the average amplitude (As / Cs) of line GS.

[0041] Furthermore, the control device 110 outputs a refracted image from the shift in the peak positions of line GR and line GS (constant × ΔΦ) calculated using the difference ΔΦ between the peak positions of line GR and line GS. In this way, the X-ray imaging device 100 can acquire three types of images—absorption images, scattering images, and refracted images—in a single X-ray imaging session.

[0042] The X-ray imaging device 100, which generates images based on the phase of X-rays, enables imaging and analysis that was not possible with methods based on X-ray absorption. Specifically, the X-ray imaging device 100 enables high-contrast imaging of light elements such as polymer materials and biological tissues, and fiber orientation analysis of fiber-reinforced resins such as carbon fiber reinforced polymers (CFRP) by visualizing the scattering of X-rays by fiber bundles.

[0043] However, when CT reconstruction is performed, if the amplitude of the self-image disappears due to extreme attenuation of the X-rays, making it impossible to accurately estimate the amount of scattering, noise such as halation may occur near the surface of the object.

[0044] As a result, shapes that do not actually exist may be projected, and the outermost surface of the object may appear slightly bulging. When this phenomenon occurs, users may not be able to correctly define the contour of the object in the scattered image.

[0045] Therefore, the X-ray imaging apparatus 100 acquires the region and contour of the object W from the absorption image, and either trims the object W in the scattered image to match the shape of the region or superimposes the contour onto the object W in the scattered image. By doing so, the contour of the object in the volume data of the scattered image is clarified, and the display accuracy of the scattered image can be improved.

[0046] Figure 6 is a functional block diagram of the control device 110 in the X-ray imaging apparatus 100. The control device 110 includes a self-image acquisition unit 151, an absorption image calculation unit 152, a scattering image calculation unit 154, a refraction image calculation unit 156, a contour acquisition unit 153, a contour application unit 155, and an output unit 157.

[0047] The self-image acquisition unit 151 acquires a self-image from the X-ray detector 30 for each movement distance of the diffraction grating 80. The absorption image calculation unit 152 calculates the absorption image from the rate of change of the average grayscale value of the displacement of the moiré pattern of the self-image input from the self-image acquisition unit 151.

[0048] Similarly, the scattering image calculation unit 154 calculates the scattering image from the grayscale average amplitude change rate of the displacement of the moiré pattern of the self-image input from the self-image acquisition unit 151. Similarly, the refraction image calculation unit 156 calculates the refraction image from the grayscale peak position shift of the displacement of the moiré pattern of the self-image input from the self-image acquisition unit 151.

[0049] The contour acquisition unit 153 acquires the region of the object W and the contour of the object W within the absorption image input from the absorption image calculation unit 152. Specifically, the contour acquisition unit 153 identifies the region of the object W as the region of the object W, and extracts the contour of the object W.

[0050] The contour application unit 155 superimposes the contour of the object W in the absorption image input from the contour acquisition unit 153 onto the object W in the scattered image input from the scattering image calculation unit 154. Alternatively, the contour application unit 155 trims the object W in the scattered image with the shape of the region of the object W in the absorption image input from the contour acquisition unit 153. By doing so, the contour of the object W in the scattered image becomes clearer, allowing for more accurate measurement of the size of the object W. In addition, because the surface of the object W becomes clearer, the distance from the surface of the object W to defects within the object W can be measured more accurately.

[0051] Subsequently, the control device 110 recognizes the area outside the contour as the background region. The control device 110 can also delete or hide the data in the background region that is outside the contour of the object W in the scattered image. This makes it easier for the user to see the surface of the object W. Furthermore, contrast adjustment can be performed only on the data within the contour of the object W in the scattered image. This makes it easier for the user to observe the object W.

[0052] The output unit 157 displays on the display device 130 a scattered image on which the contour of the object W in the absorption image input from the contour application unit 155 is clearly defined. In addition to the scattered image, the output unit 157 may also display on the display device 130 the absorption image input from the absorption image calculation unit 152 and / or the refractive image input from the refractive image calculation unit 156.

[0053] Figure 7 shows the result of applying the contour of the absorption image to the scattering image. Note that Figure 7 is a processed version of an actual image generated by X-ray imaging, which has been modified for illustrative purposes. In the actual image, the orientation of the fibers of the object W (hereinafter also referred to as "fiber orientation") and the surface irregularities of the object W are represented in color or grayscale.

[0054] The scattered image of the object W in the XY plane calculated by the control device 110 based on the displacement of the moiré pattern has noise N around the contour of the object W, making the contour of the object W unclear. After applying the contour of the absorption image, the scattered image of the object W in the XY plane is free of noise N, the contour of the object W is clear, and the display accuracy of the scattered image is improved. It is preferable to eliminate the noise N, but even if the noise N is not eliminated, the contour of the object W becomes clearer, allowing for accurate measurement of the distance of defects from the contour of the object W.

[0055] Similarly, the scattering image of the object W in the YZ plane calculated by the control device 110 based on the displacement of the moiré pattern shows line-like noise N in the Z-axis direction and band-like noise N extending in the Y-axis direction on the upper contour of the object W. In addition, semicircular noise N of varying strengths is generated on the lower contour of the object W. As a result, the contour of the object W is unclear. After applying the contour of the absorbed image, the scattering image of the object W in the YZ plane is free of the noise that was present on the upper and lower surfaces of the object W, the contour of the object W is clearer, and the display accuracy of the scattering image is improved.

[0056] Figure 8 is a flowchart showing the processing procedure of the X-ray imaging apparatus 100. First, the user places the object W on the stage 10 (step S1). Next, the control device 110 moves the stage 10 so that the object W is within the area where X-ray imaging is possible, then rotates it, and in that state emits X-rays from the X-ray generator 20 to image the object W with X-rays (step S2).

[0057] The control device 110 gradually moves the diffraction grating 80 in a direction perpendicular to the slit, detecting and storing changes in the self-image from the X-ray detector 30 (step S3). As explained in Figure 5, the control device 110 compares the change in the grayscale value of the self-image when X-ray imaging is performed without the previously measured and stored object W, with the change in the grayscale value of the self-image when X-ray imaging is performed with the stored object W present.

[0058] Based on the displacement of the moiré pattern of the self-image, the absorption image is calculated from the rate of change of the average grayscale value (Cs / Cr), the scattering image is calculated from the rate of change of the average amplitude (As / Cs) / (Ar / Cr), and the refractive image is calculated from the shift in the peak positions of the lines GR and GS (constant × ΔΦ) (Step S4).

[0059] The control device 110 identifies any region in the absorption image with a brightness above a certain level as the object W, and acquires the region and contour of the object W (step S5). The control device 110 superimposes the contour of the absorption image onto the object W in the scattering image (step S6). Alternatively, the control device 110 trims the object W in the scattering image to match the shape of the object W's region. It also recognizes the area outside the contour as the background and deletes or hides the data for the background area.

[0060] Finally, the control device 110 causes the display device 130 to display a scattered image on which the contour of the object W is clearly defined and no background data outside the contour exists (step S7). The control device 110 also causes the display device 130 to display at least one of the absorption image, the scattered image before the contour is defined, and the refraction image.

[0061] Thus, the X-ray imaging apparatus 100 according to Embodiment 1 can acquire the region and contour of an object from the absorption image, superimpose the obtained contour onto the object in the scattered image, or trim the object in the scattered image by the shape of the object's region, thereby clarifying the contour of the object in the scattered image. Therefore, the display accuracy of the scattered image can be improved.

[0062] [Example 1] In Modification 1, a configuration in which the direction of the rotation axis of the object is different will be described. Figure 9 is a diagram showing an example of the overall configuration of the X-ray imaging apparatus 100 according to Modification 1. The X-ray imaging apparatus 100 according to Modification 1 comprises a stage 15, an X-ray generator 20, an X-ray detector 30, diffraction gratings 60, 70, 80, a control device 110, an input device 120, and a display device 130. In Figure 9, the description of the same configuration as in Embodiment 1 will not be repeated.

[0063] Stage 15 is positioned between the X-ray generator 20 and the X-ray detector 30. The object W placed on Stage 15 is exposed to the X-ray beam X directed from the X-ray generator 20 to the X-ray detector 30. Stage 15 rotates around its axis of rotation in the X-axis direction while gripping the object W, by driving a motor under the control of the control device 110.

[0064] The X-ray imaging apparatus 100 can acquire X-ray images by rotating the stage 15 and performing X-ray imaging of the same plane of the object W at different rotation angles, and can reconstruct a CT image from the obtained multiple X-ray images. Depending on the direction of the fibers of the object W, the direction of scattering of X-rays irradiated onto the object W differs, and the intensity of the X-rays detected by the X-ray detector 30 also changes. Therefore, the X-ray imaging apparatus 100 according to Modified Example 1 can detect the fiber orientation of the object W by performing X-ray imaging of the object W using the stage 15.

[0065] Furthermore, the stage 15 can be moved in the X-axis, Y-axis, and Z-axis directions by driving a motor under the control of the control device 110, thereby changing the observation range of the object W within the field of view. By moving and then rotating the stage 15 in the X-axis, Y-axis, and Z-axis directions, the X-ray imaging apparatus 100 can magnify a portion of the object W and perform X-ray imaging.

[0066] The X-ray imaging apparatus 100 according to Modification 1, for example, superimposes 16-bit grayscale scattered image volume data for each rotation angle of the stage 15 and converts it into 8-bit RGB volume data for various rotation angles of the stage 15. In this way, the fiber orientation obtained from the scattered image at each rotation angle can be represented by a different color for each fiber orientation. Therefore, the user can analyze the fiber orientation of the object W by observing only one scattered image, without having to compare multiple scattered images at each rotation angle.

[0067] Furthermore, when performing X-ray CT imaging of an object rather than analyzing fiber orientation, the X-ray imaging apparatus 100 according to Modified Example 1 may, when performing X-ray imaging of the object W, rotate the diffraction gratings 60, 70, and 80 simultaneously around the same axis of rotation as the stage 15, without rotating the stage 15, so that each slit of the diffraction gratings 60, 70, and 80 faces the same direction.

[0068] Furthermore, the control device 110 can generate scattering images for each rotation angle of the diffraction gratings 60, 70, and 80 around their rotation axes by changing the rotation angles of the diffraction gratings 60, 70, and 80 around their rotation axes and performing X-ray imaging. In this case, the rotation angles of the three diffraction gratings 60, 70, and 80 are kept the same.

[0069] In the X-ray imaging apparatus 100 according to Embodiment 1 and Modification 1, the diffraction grating 70 may be installed on the X-ray generator 20 side of the object W as shown in Figure 1, or on the X-ray detector 30 side of the object W as shown in Figure 9.

[0070] [Embodiment 2] In Embodiment 2, the method of display by the display device 130 will be described. Figure 10 is a diagram showing the method of displaying an image on the display device 130 by the control device 110 according to Embodiment 2. The configuration of the X-ray imaging apparatus 100 according to Embodiment 2 is the same as the configuration of the X-ray imaging apparatus 100 according to Embodiment 1.

[0071] Conventionally, even when an X-ray imaging device 100 generates multiple types of images from a single volume data, it is common practice to display the images one by one sequentially on the display device 130. In this case, if a user wants to compare the same part of an object W in multiple types of images, a problem may arise in that they have to observe while switching between screens. Therefore, the X-ray imaging device 100 according to Embodiment 2 is configured to be able to display multiple types of images simultaneously on the display device 130.

[0072] The control device 110 displays, for example, an absorption image A, a scattering image S, and a refraction image R. Note that the images to be displayed are not limited to the three images described above; any two of the absorption image A, scattering image S, and refraction image R may be displayed. Alternatively, multiple scattering images different for each angle of the diffraction grating may be displayed. The control device 110 displays multiple images simultaneously on the display device 130 such that the displayed areas of the object W coincide.

[0073] For example, if the depth of the absorption image changes in response to the user rotating the mouse wheel, the control device 110 will also change the depth of the scattering and refraction images in the same way as the absorption image. Furthermore, even if the depth of the scattering or refraction image is changed by the control device 110, the depth of all displayed images will change accordingly.

[0074] Furthermore, the control device 110 provides a pointer P on each image simultaneously displayed on the display device 130. The control device 110 displays the pointer P on the display device 130 so that it points to the same location on the object W within each image. For example, as the user moves the mouse cursor, the pointer P moves in conjunction to the same position in each image: the absorption image A, the scattering image S, and the refraction image R.

[0075] This allows for easy comparison of specific parts of the object W within multiple images. Therefore, it makes it easier for the user to observe the object W. [Pattern] Those skilled in the art will understand that the above-described exemplary embodiments are specific examples of the following embodiments.

[0076] (Section 1) An X-ray imaging apparatus according to one embodiment comprises a stage, an X-ray generator, a plurality of diffraction gratings, a detector, a control device, and a display device. The stage is on which an object is placed. The X-ray generator irradiates the object with X-rays. The plurality of diffraction gratings are arranged so that X-rays can pass through them. The detector is provided opposite the X-ray generator, with the stage and the plurality of diffraction gratings in between, and detects changes in the object's self-image due to the plurality of diffraction gratings. The control device calculates multiple types of images of the object based on the changes in its self-image. The display device displays multiple types of images. At least one of the plurality of diffraction gratings is provided between the X-ray generator and the stage, and at least one is provided between the stage and the detector. The multiple types of images include absorption images and scattering images. The control device obtains the contour of the object from the absorption image and clarifies the contour of the object in the scattering image and displays it on the display device.

[0077] The X-ray imaging apparatus described in paragraph 1 provides a technique that makes it possible to clarify the contours of objects within the volume data of scattered images.

[0078] (Article 2) In the X-ray imaging apparatus described in Article 1, the control device acquires the region of the absorption image with a brightness of a predetermined level or higher as the region of the object, and acquires the contour of the region of the object as the contour of the object.

[0079] The X-ray imaging apparatus described in paragraph 2 provides a technique for extracting the region and contour of an object within an absorption image.

[0080] (Clause 3) In the X-ray imaging apparatus described in paragraph 2, the control device clarifying the contour of an object in the scattered image includes superimposing the contour of an object obtained from the absorbed image onto the object in the scattered image.

[0081] According to the X-ray imaging apparatus described in paragraph 3, a technique is provided for clarifying the outline of an object in the scattered image.

[0082] (Article 4) In the X-ray imaging apparatus described in Articles 1 to 3, the control device deletes or hides data outside the contour.

[0083] According to the X-ray imaging apparatus described in paragraph 4, a technique is provided to display only the region in which an object is located within the volume data of the scattered image.

[0084] (Clause 5) In the X-ray imaging apparatus described in paragraph 1 or 2, the control device clarifying the contour of an object in the scattered image includes trimming the object in the scattered image to the shape of the region of the object obtained from the absorbed image.

[0085] According to the X-ray imaging apparatus described in paragraph 5, a technique is provided for clarifying the contours of objects in scattered images.

[0086] (Section 6) In the X-ray imaging apparatus described in Sections 1 to 5, the control device performs contrast adjustment only on data within the contour.

[0087] The X-ray imaging apparatus described in paragraph 6 provides a technique for performing contrast adjustment only on objects within the volume data of the scattered image.

[0088] (Section 7) The X-ray imaging apparatus described in any one of Sections 1 to 6 further comprises a first rotation mechanism for rotating the stage around a rotation axis in the normal direction.

[0089] The X-ray imaging apparatus described in paragraph 7 provides a technique for imaging an object from all directions.

[0090] (Clause 8) The X-ray imaging apparatus described in any one of paragraphs 1 to 7 further comprises a second rotation mechanism for rotating the stage around a rotation axis in the direction connecting the X-ray generator and the detector.

[0091] According to the X-ray imaging apparatus described in paragraph 8, a technique for obtaining information on fiber orientation is provided. (Section 9) The X-ray imaging apparatus described in any one of Sections 1 to 8 further comprises a third rotation mechanism for changing the angle of multiple diffraction gratings around the rotation axis in the direction connecting the X-ray generator and the detector.

[0092] According to the X-ray imaging apparatus described in paragraph 9, a technique for changing the angle of the diffraction grating is provided.

[0093] (Item 10) In the X-ray imaging apparatus described in Item 9, the control device calculates a scattered image for each angle of the third rotation mechanism.

[0094] According to the X-ray imaging apparatus described in paragraph 10, a technique is provided for outputting scattering images for each angle of the diffraction grating.

[0095] (Item 11) In the X-ray imaging apparatus described in any one of items 1 to 10, the display device displays the absorption image and the scattering image side by side on the screen.

[0096] The X-ray imaging apparatus described in paragraph 11 provides a technique that allows the user to compare absorption and scattering images relatively easily.

[0097] (Item 12) In the X-ray imaging apparatus described in any one of items 1 to 11, the multiple types of images further include refracted images.

[0098] According to the X-ray imaging apparatus described in paragraph 12, a technology is provided that allows for the output of refractive images as well. (Clause 13) In the X-ray imaging apparatus described in paragraph 12, the display device displays at least two images from among the absorption image, the scattering image, and the refraction image side by side on the screen.

[0099] The X-ray imaging apparatus described in paragraph 13 provides a technique for simultaneously displaying at least two or more images on the screen of a single display device.

[0100] (Paragraph 14) In the X-ray imaging apparatus described in paragraph 13, the control device displays the same region as shown in the first image for the second image.

[0101] According to the X-ray imaging apparatus described in paragraph 14, a technique is provided in which objects in multiple images simultaneously displayed on the screen of a single display device show the same region.

[0102] (Paragraph 15) In the X-ray imaging apparatus described in any one of paragraphs 1 to 14, the control device displays a pointer on the display device that indicates a predetermined point on the image, and in the second image, displays a pointer at a position corresponding to the position shown in the first image.

[0103] The X-ray imaging apparatus described in paragraph 15 provides a technique that allows a user to compare identical points within an object in multiple images simultaneously displayed on the screen of a single display device.

[0104] (Section 16) A control method relating to one embodiment relates to a control method for an X-ray imaging apparatus. The X-ray imaging apparatus comprises a stage, an X-ray generator, a plurality of diffraction gratings, a detector, and a display device. An object is placed on the stage. The X-ray generator irradiates the object with X-rays. The plurality of diffraction gratings are arranged so that X-rays pass through them. The detector is provided opposite the X-ray generator, with the stage and the plurality of diffraction gratings in between, and detects changes in the self-image of the object due to the plurality of diffraction gratings. The display device displays multiple types of images of the object calculated based on the changes in the self-image. At least one of the plurality of diffraction gratings is included between the X-ray generator and the stage, and at least one is included between the stage and the detector. The multiple types of images include absorption images and scattering images. The control method includes the steps of obtaining the contour of the object from the absorption image and clarifying the contour of the object in the scattering image and displaying it on the display device.

[0105] The X-ray imaging apparatus described in paragraph 16 provides a technique that makes it possible to clarify the contours of objects within the volume data of scattered images.

[0106] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the description of the embodiments above, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of symbols]

[0107] 10,15 Stage, 20 X-ray generator, 30 X-ray detector, 60,70,80 Diffraction grating, 100 X-ray imaging device, 110 Control device, 112 Memory, 114 Processor, 116 Communication interface, 120 Input device, 130 Display device, 151 Self-image acquisition unit, 152 Absorption image calculation unit, 153 Contour acquisition unit, 154 Scattering image calculation unit, 155 Contour application unit, 156 Refraction image calculation unit, 157 Output unit, 202,204,206 Self-image, A Absorption image, Cr,Cs Average grayscale value, GR,GS Line, N Noise, P Pointer, R Refraction image, S Scattering image, W Object, XX-ray beam.

Claims

1. A stage on which the object is placed, An X-ray generator that irradiates the aforementioned object with X-rays, Multiple diffraction gratings arranged so that X-rays can pass through, A detector is provided opposite the X-ray generator, with the stage and the plurality of diffraction gratings in between, to detect changes in the self-image of the object due to the plurality of diffraction gratings, A control device that calculates multiple types of images of the object based on the changes in the self-image, The system includes a display device that displays multiple types of images, The plurality of diffraction gratings are At least one is provided between the X-ray generator and the stage, At least one is provided between the stage and the detector, The aforementioned multiple types of images include absorption images and scattering images. The control device is The contour of the object is obtained from the absorption image, An X-ray imaging apparatus that clarifies the outline of the object in the scattered image and displays it on the display device.

2. The control device is The region of the absorption image with a predetermined brightness or higher is acquired as the region of the object. The X-ray imaging apparatus according to claim 1, which acquires the contour of the region of the object as the contour of the object.

3. The X-ray imaging apparatus according to claim 2, wherein clarifying the contour of the object in the scattered image includes superimposing the contour of the object obtained from the absorption image onto the object in the scattered image.

4. The X-ray imaging apparatus according to claim 3, wherein the control device deletes or hides data outside the contour.

5. The X-ray imaging apparatus according to claim 2, wherein clarifying the contour of the object in the scattered image includes trimming the object in the scattered image to the shape of the region of the object obtained from the absorption image.

6. The X-ray imaging apparatus according to any one of claims 1 to 5, wherein the control device performs contrast adjustment only for data within the contour.

7. The X-ray imaging apparatus according to claim 6, further comprising a first rotation mechanism for rotating the stage around a rotation axis in the normal direction.

8. The X-ray imaging apparatus according to claim 7, further comprising a second rotation mechanism for rotating the stage about a rotation axis in the direction connecting the X-ray generator and the detector.

9. The X-ray imaging apparatus according to claim 8, further comprising a third rotation mechanism for changing the angle of the plurality of diffraction gratings around a rotation axis in the direction connecting the X-ray generator and the detector.

10. The control device is The X-ray imaging apparatus according to claim 9, wherein the scattered image is calculated for each angle of the third rotation mechanism.

11. The X-ray imaging apparatus according to claim 10, wherein the display device displays the absorption image and the scattering image side by side on a screen.

12. The X-ray imaging apparatus according to claim 11, wherein the aforementioned multiple types of images further include refracted images.

13. The X-ray imaging apparatus according to claim 12, wherein the display device displays at least two or more images, including the absorption image, the scattering image, and the refraction image, side by side on a screen.

14. The X-ray imaging apparatus according to claim 13, wherein the control device displays the same region as shown in the first image for the second image.

15. The control device is The display device displays a pointer that indicates a predetermined point on the image, The X-ray imaging apparatus according to claim 14, wherein a pointer is displayed in the second image at a position corresponding to the position shown in the first image.

16. A method for controlling an X-ray imaging device, The aforementioned X-ray imaging apparatus, A stage on which the object is placed, An X-ray generator that irradiates the aforementioned object with X-rays, Multiple diffraction gratings arranged so that X-rays can pass through, A detector is provided opposite the X-ray generator, with the stage and the plurality of diffraction gratings in between, to detect changes in the self-image of the object due to the plurality of diffraction gratings, The system includes a display device that displays multiple types of images of the object calculated based on the changes in the self-image, The plurality of diffraction gratings are At least one is included between the X-ray generator and the stage, At least one is included between the stage and the detector, The aforementioned multiple types of images include absorption images and scattering images. The control method described above is A step of obtaining the contour of the object from the absorption image, A method for controlling an X-ray imaging apparatus, comprising the steps of clarifying the contour of the object in the scattered image and displaying it on the display device.

Images