X-ray imaging system, X-ray attenuator, and X-ray imaging method

Abstract

The invention relates to the technical field of X-ray imaging, provides an X-ray imaging system, an X-ray attenuation piece and an X-ray imaging method, and can reduce a ghosting effect caused by non-uniform received doses in different areas of a detector. According to the invention, the X-ray attenuation part is used for attenuating part or all of the X-rays emitted by the X-ray source; the X-rays attenuated by the X-ray attenuation part at least comprise X-rays exposed to a non-target area of a working area of the detector; the non-target area belongs to the area, except the target area, of the working area, and the target area is the area, used for receiving X-rays penetrating through the detected object, of the working area.

Description

Technical Field

[0001] The present application relates to the field of X-ray imaging technology, and in particular to an X-ray imaging system, an X-ray attenuation element, an X-ray imaging method and apparatus, a processing device, a storage medium, and a computer program product. Background Art

[0002] In X-ray imaging technology, the exposure beam emitted by the X-ray source passes through the object being measured and is received by the detector. The collected data at each angle is reconstructed into an image to obtain the attenuation distribution of the object being measured, thereby identifying the structural items of the object being measured and conducting quantitative attenuation analysis.

[0003] In the exposure beam emitted by the radiation source, part of the exposure beam is exposed on the detector after passing through the object being measured, and part of the exposure beam is directly exposed on the detector without passing through the object being measured. The exposure dose in different areas of the detector varies greatly, and the detector receives uneven doses.

[0004] When the detector is an energy-integrating type, uneven exposure dose can cause regional variations in the detector's response sensitivity. This phenomenon is called the ghosting effect. The ghosting effect can distort the attenuation information in the reconstructed image, affecting quantitative attenuation analysis and even producing obvious artifacts that affect structural item recognition. Summary of the Invention

[0005] Based on this, it is necessary to provide an X-ray imaging system, an X-ray imaging method and apparatus, a processing device, a storage medium, a computer program product and a ray filter plate to address the above technical problems.

[0006] The present application provides an X-ray imaging system, the system comprising: an X-ray source and a detector, and an X-ray attenuation element;

[0007] In which, the X-ray attenuation component is used to attenuate part or all of the X-rays emitted by the X-ray source; the X-rays attenuated by the X-ray attenuation component include at least X-rays exposed to the non-target area of ​​the working area of ​​the detector; the non-target area belongs to the area on the working area except the target area, and the target area is the area on the working area for receiving X-rays passing through the object to be inspected.

[0008] In one embodiment, the X-ray attenuation component includes at least one pair of X-ray attenuation sub-components, and the same pair of X-ray attenuation sub-components are arranged on both sides of a target plane; the target plane is a plane formed by the bed entry direction and a central ray passing through a rotation center; the rotation center corresponds to the point around which the X-ray source and detector rotate as a whole.

[0009] In one embodiment, each X-ray attenuation sub-component is connected to a driving device; the driving device is used to change the spacing between the same pair of X-ray attenuation sub-components in a target direction; the target direction is a direction perpendicular to the target plane.

[0010] In one embodiment, the X-ray attenuation sub-component includes a portion of equal thickness and a portion of unequal thickness; relative to the portion of equal thickness, the portion of unequal thickness is closer to the target plane; among the portions of unequal thickness, the closer to the target plane, the smaller the thickness.

[0011] The present application provides an X-ray attenuation element, which is used to attenuate part or all of the X-rays emitted by an X-ray source;

[0012] The X-rays attenuated by the X-ray attenuation component include at least X-rays exposed to the non-target area of ​​the working area of ​​the detector; the non-target area belongs to the area on the working area other than the target area, and the target area is the area on the working area for receiving X-rays passing through the object to be inspected.

[0013] In one embodiment, the X-ray attenuation component includes at least one pair of X-ray attenuation sub-components, and the same pair of X-ray attenuation sub-components are arranged on both sides of a target plane; the target plane is a plane formed by the bed entry direction and a central ray passing through a rotation center; the rotation center corresponds to the point around which the X-ray source and detector rotate as a whole.

[0014] In one embodiment, each X-ray attenuation sub-component is connected to a driving device; the driving device is used to change the spacing between the same pair of X-ray attenuation sub-components in a target direction; the target direction is a direction perpendicular to the target plane.

[0015] The present application provides an X-ray imaging method, which is applied to the X-ray imaging system of the above embodiment or performed based on the X-ray attenuation element of the above embodiment, including:

[0016] Based on the estimation of the size of the projection area of ​​the object under inspection on the detector, the spacing between the same pair of X-ray attenuation components in the target direction is adjusted;

[0017] Control the X-ray source to emit X-rays.

[0018] In one embodiment, adjusting the spacing between the same pair of X-ray attenuation sub-components in the target direction based on an estimation of the size of the projection area of ​​the object under inspection on the detector includes:

[0019] Obtaining the size of a chamber for accommodating the sample body;

[0020] determining a magnification ratio for imaging the sample body;

[0021] determining a target setting spacing based on the cabin size and the magnification ratio;

[0022] Adjust the spacing between the same pair of X-ray attenuation components in the target direction to be consistent with the target set spacing.

[0023] In one embodiment, after controlling the X-ray source to emit X-rays, the method further includes:

[0024] Acquiring projection data of the object detected by the detector;

[0025] Acquiring air exposure data associated with the target set interval;

[0026] Air correction is performed on the projection data based on the air exposure data.

[0027] The present application provides an X-ray imaging device, which is applied to the X-ray imaging system of the above embodiment or is implemented based on the X-ray attenuation element of the above embodiment, including:

[0028] A spacing adjustment module, configured to adjust the spacing between the same pair of X-ray attenuation sub-components in the target direction based on an estimate of the size of the projection area of ​​the inspected object on the detector;

[0029] The ray control module is used to control the X-ray source to emit X-rays.

[0030] The present application provides a processing device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the above method.

[0031] The present application provides a computer-readable storage medium having a computer program stored thereon, and the computer program is used by a processor to execute the above method.

[0032] The present application provides a computer program product having a computer program stored thereon, wherein the computer program is used by a processor to execute the above method.

[0033] In the solution provided in the present application, the working area of ​​the detector includes a target area and a non-target area, wherein the target area is an area for receiving X-rays passing through the object to be inspected, and the non-target area belongs to the area on the working area other than the target area; for X-rays exposed to the non-target area, the X-ray attenuation component can attenuate them, thereby reducing the exposure dose of the non-target area, and narrowing the exposure dose difference between the non-target area and the target area, improving the uneven dose received by the detector, and reducing the ghost effect caused by the uneven dose received by the detector. This solution can reduce or even eliminate the ghost effect to a certain extent without the need for additional modification to the detector, and weaken or even avoid the artifacts and attenuation distortion problems that may be caused by the ghost effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 is a schematic diagram of an X-ray imaging system in one embodiment;

[0036] Figure 2 is a partial schematic diagram of an X-ray imaging system at a z-axis viewing angle in one embodiment;

[0037] Figure 3 Schematic diagram of exposure dose distribution in one embodiment;

[0038] Figure 4 A schematic diagram of exposure dose distribution changes when the spacing becomes smaller in one embodiment;

[0039] Figure 5 A schematic diagram of exposure dose distribution changes when the spacing becomes smaller in another embodiment;

[0040] Figure 6 Schematic diagram of exposure dose distribution of unequal thickness parts of an X-ray attenuation sub-element in different structures in one embodiment;

[0041] Figure 7 1 is a flow chart of an X-ray imaging method according to an embodiment;

[0042] Figure 8 FIG. 4 is a diagram showing the internal structure of a processing device in one embodiment. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0044] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0045] In X-ray imaging technology, certain X-ray imaging systems can be used to capture multiple projection images of an object under inspection and perform image reconstruction based on the multiple projection images. During the capture of the multiple projection images, a detector may exhibit a ghosting effect, resulting in distortion of the attenuation information of the reconstructed image. Therefore, such X-ray imaging systems that reconstruct images based on multiple projection images have high requirements for detector performance variations. Applying the solution provided in this application to such X-ray imaging systems can minimize ghosting effects. Such X-ray imaging systems are, for example, computed tomography (CT); CT may include, but is not limited to, industrial CT, cone beam CT (CBCT), and microCT. Taking micro-CT as an example, micro-CT is generally used in scientific research scenarios. The number of projection images captured by micro-CT is close to the number of clinical images, which places high demands on image quality and is more sensitive to changes in detector performance. The size range of the objects being inspected varies greatly, and the size of the projected area of ​​the object on the detector varies with the object and the magnification ratio. The uneven X-ray dose has a greater impact on the changing projected area. In addition, micro-CT has a certain pursuit of high resolution, which itself places higher demands on detector performance changes. Applying the solution provided in this application to micro-CT can better meet the requirements of micro-CT for detector performance changes.

[0046] Reference Figure 1 The X-ray imaging system includes an X-ray source 101 and a detector 102. When imaging an object under examination, the object is located between the X-ray source 101 and the detector 102. Generally, the bed advancing direction (the direction in which the scanning bed advances) can be set as the z-axis, the direction in which the X-ray source emits X-rays can be set as the y-axis, and another direction perpendicular to the bed advancing direction and the X-ray emission direction can be set as the x-axis. The X-ray source can emit X-rays, and the X-rays can be exposed to the working area of ​​the detector 102 after passing through the object under examination.

[0047] In some scenarios, X-ray exposure in front of the detector can be limited by a collimator arranged symmetrically along the xy plane. The collimator may include two parts, one part is located at the z1 position and the other part is located at the z2 position. At this time, the working area of ​​the detector 102 can be the X-ray detection area corresponding to the detector 102 after being limited by the collimator at the z1 and z2 positions.

[0048] In some scenarios, when the X-rays are not limited by the collimator, the entire area of ​​the detector 102 can be used as the working area of ​​the detector 102 .

[0049] A portion of the working area of ​​the detector 102 receives attenuated X-rays generated by X-rays emitted by the X-ray source 101 and penetrating the object under examination. This area corresponds to the projection area of ​​a particular object under examination and is also referred to as the object projection area. This projection area receives X-rays transmitted through the object and matches the area projected onto the detector 102 by the X-ray source 101. The object projection area may vary for different objects, with its size determined by the object's dimensions and magnification ratio. In some embodiments, the target area is the area of ​​the working area that receives X-rays transmitted through the object, i.e., the object projection area. In micro-CT, the specimen body is typically placed in a chamber. The chamber containing the specimen body is irradiated by the X-ray source, and the detector detects the corresponding projection data. In some embodiments, the object projection area includes the projection area formed by the chamber and the specimen body, with the chamber being used to house the specimen body. In some embodiments, the main structure of the chamber is cylindrical. In this case, the area projected onto the detector 102 by the X-ray source 101 (hereinafter referred to as the chamber projection area) can be used as the target area. The area outside the target area of ​​the detector 102's working area can be referred to as the non-target area. By using the capsule's projected area as the target area, the size of the object's projected area can be directly determined based on the capsule's size and magnification ratio. Of course, in some embodiments, the object's projected area is the projected area formed by the sample itself. The projected area formed by the sample itself does not include the capsule. In this embodiment, the projected area formed by the sample itself can be used as the target area, and the size of the object's projected area can be directly determined based on the sample's size and magnification ratio.

[0050] The X-ray imaging system provided in the present application also includes an X-ray attenuation component, which is used to attenuate part or all of the X-rays emitted by the X-ray source. The X-rays attenuated by the X-ray attenuation component include at least X-rays exposed to non-target areas of the working area of ​​the detector.

[0051] As a result, the exposure dose of the non-target area of ​​the detector 102 is reduced, thereby reducing the difference in exposure dose between the non-target area and the target area, improving the unevenness of the dose received by the detector 102, and reducing the ghost effect caused by the uneven dose received by the detector 102; without the need for additional modification to the detector 102, the ghost effect can be reduced or even eliminated to a certain extent, and the artifacts and attenuation distortion problems that may be caused by the ghost effect can be weakened or even avoided.

[0052] In one embodiment, the X-ray attenuation element includes at least one pair of X-ray attenuation sub-elements, and the same pair of X-ray attenuation sub-elements are arranged on both sides of a target plane; the target plane is a plane formed by the bed approach direction and a central ray passing through the rotation center; the rotation center corresponds to the point around which the X-ray source and the detector rotate as a whole.

[0053] Refer again Figure 1 The X-ray attenuation component 103 may include at least a pair of X-ray attenuation sub-components, wherein the pair of X-ray attenuation sub-components may be respectively denoted as 103a and 103b.

[0054] Among the X-rays emitted by X-ray source 101, one ray passes through the center of rotation. This ray can be referred to as the central ray. The center of rotation corresponds to the point about which the X-ray source and detector rotate as a whole. The plane formed by the bed approach direction (i.e., the z-axis direction) and the central ray can be referred to as the target plane, with the x-axis being the normal direction of the target plane. Arranging the same pair of X-ray attenuation sub-components on both sides of the target plane means providing one X-ray attenuation sub-component on each side of the target plane. Of course, since the spacing of the X-ray attenuation sub-components in the target direction is adjustable, each X-ray attenuation sub-component may intersect the target plane. The position of the X-ray attenuation sub-components may pass through the target plane.

[0055] In some embodiments, the X-ray attenuation sub-components 103a and 103b are symmetrically arranged along the target plane.

[0056] In some embodiments, the X-ray attenuation sub-components 103a and 103b are centrally symmetrically arranged along the center point on the target plane.

[0057] In one embodiment, the X-ray attenuation sub-component includes a portion of equal thickness and a portion of unequal thickness; the portion of unequal thickness is closer to the target plane than the portion of equal thickness; and among the portions of unequal thickness, the closer to the target plane, the smaller the thickness.

[0058] In the unequal thickness portion, the X-rays transmitted through the object under inspection attenuated by the portion with greater thickness are closer to the edge of the object under inspection, while the X-rays transmitted through the object under inspection attenuated by the portion with less thickness are closer to the center of the object under inspection.

[0059] In a micro-CT scenario, the sample body is placed in a cabin for X-ray irradiation. At this time, the thickness of the X-ray attenuation component at each position along the x-axis can be designed based on the attenuation characteristics of the cabin containing the sample body. For example, among the parts of the inspected object including the cabin and the sample body along the x-axis, if the middle part has a greater attenuation effect on X-rays and the edge part has a smaller attenuation effect on X-rays, then the closer the position of the X-ray attenuation component is to the target plane, the smaller the corresponding thickness. In some extreme cases, the thickness can be 0.

[0060] In the above micro-CT scenario, if Figure 1 The darker quadrilateral area in the detector 102 shown is the cabin projection area. The darker quadrilateral area is also the target area, and the lighter quadrilateral area is the non-target area. When the central portion of the object under inspection has a greater attenuation effect on X-rays than the edges, an X-ray attenuation component can be used to attenuate X-rays received at the edges of the target area and X-rays received in the non-target area, thereby achieving a more uniform dose distribution on the detector. Specifically, the unequal thickness portions of the X-ray attenuation component can be used to attenuate X-rays received at the edges of the target area, while the uniform thickness portions of the X-ray attenuation component can be used to attenuate X-rays received in the non-target area.

[0061] Reference Figure 2 , Figure 2 For the z-axis perspective Figure 1 wherein the X-ray attenuation sub-element 103a includes an equal thickness portion and an unequal thickness portion, wherein, compared with the equal thickness portion, the unequal thickness portion is closer to the target plane, and, in the unequal thickness portion, the closer to the target plane, the smaller the thickness of the portion.

[0062] It should be noted that Figure 1 and Figure 2 In the embodiment, the structure of the unequal thickness parts of the X-ray attenuating sub-component 103a and the X-ray attenuating sub-component 103b is an oblique cut structure with opposite cutting angles, which is only one example. The structure of the unequal thickness parts of the X-ray attenuating sub-component 103a and the X-ray attenuating sub-component 103b can also be an oblique cut structure with the same cutting angle, such as Figure 3 It is understandable that the structures of the unequal thickness parts of the X-ray attenuation sub-component 103a and the X-ray attenuation sub-component 103b may also be other symmetrical structures with monotonically varying thicknesses.

[0063] In some embodiments, the X-ray attenuation sub-component 103a and the X-ray attenuation sub-component 103b can be designed as an arc-shaped structure, and the center of the arc-shaped structure of the X-ray attenuation sub-component 103a and the X-ray attenuation sub-component 103b can coincide with the focus of the X-ray source to ensure that the penetration depth of the filters corresponding to different emission angles is consistent.

[0064] The following combination Figure 3 The following describes the exposure dose distribution of the detector 102 along the x-axis:

[0065] In the case where no X-ray attenuation element is provided and the object to be inspected is not placed between the X-ray source 101 and the detector 102, when the X-rays emitted by the X-ray source 101 are directly exposed to the detector 102, the exposure dose distribution formed is as follows: Figure 3As shown in FIG. 110 , it can be seen based on FIG. 110 that the exposure dose is relatively uniform along the x-axis direction on the detector 102 .

[0066] In the case where no X-ray attenuation element is provided and the object to be inspected is placed between the X-ray source 101 and the detector 102, when the X-rays emitted by the X-ray source 101 are exposed to the detector 102, the exposure dose distribution formed is as follows: Figure 3 As shown in 111, it can be seen based on 111 that the exposure dose is relatively uneven along the x-axis direction of the detector 102. Since the target area is the area that receives X-rays that pass through the object to be inspected, the exposure dose of the target area of ​​the detector 102 is lower, and the exposure dose of the non-target area is higher.

[0067] In one embodiment, each X-ray attenuation sub-component is connected to a driving device; the driving device is used to change the spacing between the same pair of X-ray attenuation sub-components in a target direction; the target direction is a direction perpendicular to the target plane.

[0068] The direction perpendicular to the target plane can be referred to as the target direction. The spacing between the X-ray attenuating sub-components 103a and 103b along the target direction can be adjusted by a drive device so that the spacing between the X-ray attenuating sub-components 103a and 103b along the target direction is adapted to the target area. The drive device can be, but is not limited to, a motor, and the motor can be, but is not limited to, a stepping motor or a transmission motor. The spacing between the X-ray attenuating sub-components 103a and 103b along the target direction is adapted to the target area, specifically as follows:

[0069] Take the X-ray attenuation components 103a and 103b including equal thickness parts and unequal thickness parts as an example for description:

[0070] When the X-ray attenuation sub-components 103a and 103b include equal-thickness portions and unequal-thickness portions, the spacing between the X-ray attenuation sub-components 103a and 103b along the target direction can be characterized by: the spacing between the target dividing plane of the X-ray attenuation sub-component 103a and the target dividing plane of the X-ray attenuation sub-component 103b (hereinafter referred to as the dividing plane spacing of the X-ray attenuation sub-components 103a and 103b), where the target dividing plane is the dividing plane between the equal-thickness portion and the unequal-thickness portion of the X-ray attenuation sub-component.

[0071] The distance between the dividing surfaces of the X-ray attenuation components 103a and 103b is denoted as dis_1, the length of the target area along the target direction is denoted as dis_2, the distance from the X-ray source 101 to the surface where the X-ray attenuation components are located is denoted as dis_3, and the distance from the X-ray source 101 to the surface where the detector 102 is located is denoted as dis_4. In some embodiments, these distances are set to satisfy the following relationship: dis_1 / dis_2=dis_3 / dis_4, that is, dis_1=(dis_3 / dis_4)×dis_2. In this case, the unequal thickness portions of the X-ray attenuation components 103a and 103b will attenuate the X-rays exposed to the edge of the target area. Figure 3 Introduce the situation.

[0072] The target area of ​​the detector 102 includes a center and an edge, wherein the center of the target area corresponds to the area where the central part of the object is projected onto the detector 102 , and the edge of the target area corresponds to the area where the edge part of the object is projected onto the detector 102 .

[0073] In the case where no X-ray attenuation element is provided and the object to be inspected is located between the X-ray source 101 and the detector 102, when the X-rays emitted by the X-ray source 101 are exposed to the detector 102, the exposure dose distribution is as follows: Figure 3 As shown in 111, the center of the object under inspection is generally thicker than the edge. When the density of the object under inspection is relatively uniform and the main material composition is relatively consistent, Figure 3 Taking the water phantom as an example, the greater the penetration depth of X-rays when passing through the object under inspection, the greater the attenuation. The attenuation of rays passing through the center of the object is the greatest. The exposure dose corresponding to the center part of the 111 is lower than the exposure dose corresponding to the edge part. In this case, there will be a large difference in exposure dose between the center and the edge of the target area, which will make the ghosting effect more obvious.

[0074] The X-ray attenuation component provided in this application can also attenuate X-rays exposed to the edge of the target area. In this case, the size of the separation distance dis_1 between the dividing surfaces of the X-ray attenuation components 103a and 103b can meet the following requirements: dis_1 = (dis_3 / dis_4) × dis_2.

[0075] When an X-ray attenuator is set and dis_1 = (dis_3 / dis_4) × dis_2, and the object under inspection is not placed between the X-ray source 101 and the detector 102, the exposure dose distribution formed when the X-rays emitted by the X-ray source 101 are exposed to the detector 102 is as follows: Figure 3 As shown in 112.

[0076] When an X-ray attenuator is set and dis_1 = (dis_3 / dis_4) × dis_2, the object to be inspected is placed between the X-ray source 101 and the detector 102. When the X-rays emitted by the X-ray source 101 are exposed to the detector 102, the exposure dose distribution formed is as follows: Figure 3 As shown in 113.

[0077] It can be seen from 113 that the difference in exposure dose between the target area and the non-target area of ​​the detector 102 is small; compared with 111, the difference in exposure dose between the center and the edge of the target area is smaller, and the exposure dose distribution at the center and the edge of the target area is more uniform, thereby reducing the ghost effect. To a certain extent, the sensitivity difference caused by the ghost effect can be reduced, so as not to cause image artifacts or attenuation distortion.

[0078] For smaller objects, the target area may become smaller. In this case, when the X-rays emitted by the radiation source 101 are exposed to the detector 102, the exposure dose distribution formed is as follows: Figure 4 In the example 111_1, the distance between the pair of X-ray attenuation components in the target direction can be reduced. After the reduction, when the object under inspection is not placed between the X-ray source 101 and the detector 102, the X-rays emitted by the X-ray source 101 are exposed to the detector 102, and the exposure dose distribution formed is as follows: Figure 4 In the case where the object to be inspected is placed between the X-ray source 101 and the detector 102, when the X-rays emitted by the X-ray source 101 are exposed to the detector 102, the exposure dose distribution formed is as follows Figure 4 As shown in 113_1.

[0079] Figure 5 The figure shows that when the object under inspection is not placed between the X-ray source 101 and the detector 102, the distance dis_1 between the dividing planes of the same pair of X-ray attenuation components gradually decreases. Three states, dis_1_a, dis_1_b, and dis_1_c, are selected as examples for description. In these three states, the exposure dose distributions formed when the X-rays emitted by the X-ray source 101 are exposed to the detector 102 are respectively as follows: Figure 5 112_2, 112_3 and 112_4 are shown in FIG.

[0080] When the spacing between the splitting planes of a pair of X-ray attenuating components is dis_1_c, the area corresponding to the center of the exposure dose distribution and with higher exposure dose accounts for a smaller proportion than that of dis_1_b, and the maximum exposure dose is lower. This is because the same pair of X-ray attenuating components overlap, and the overlapping area is equivalent to a thinner attenuating component of uniform thickness. When the spacing between the splitting planes of a pair of X-ray attenuating components, dis_1, is close to 0, it is equivalent to a whole X-ray attenuating component of uniform thickness.

[0081] The structure of the same pair of X-ray attenuation components can also be set to other structures, refer to Figure 6 (a) to (c) in the text, Figure 6 The structure shown in (a) is another beveled structure with the cutting angle in the opposite direction. Figure 6 The structure shown in (b) is a parabolic section structure. Figure 6 The structure shown in (c) is a stepped cross-section structure.

[0082] exist Figure 6 In the case of the structure shown in (a), when the object to be inspected is not placed between the X-ray source 101 and the detector 102, the exposure dose distribution formed when the X-rays emitted by the X-ray source 101 are exposed to the detector 102 is as follows: Figure 6 112_5 in the.

[0083] exist Figure 6 In the case of the structure shown in (b), when the object to be inspected is not placed between the X-ray source 101 and the detector 102, the exposure dose distribution formed when the X-ray emitted by the X-ray source 101 is exposed to the detector 102 is as follows: Figure 6 112_6 in the.

[0084] exist Figure 6 In the case of the structure shown in (c), when the object to be inspected is not placed between the X-ray source 101 and the detector 102, the exposure dose distribution formed when the X-rays emitted by the X-ray source 101 are exposed to the detector 102 is as follows: Figure 6 112_7 in the.

[0085] The material used for the X-ray attenuation element may be, but is not limited to, metals or non-metals such as PMMA, Al, Cu, Sn, and metal compounds, which have an X-ray attenuation effect.

[0086] Based on the same inventive concept, embodiments of the present application further provide an X-ray attenuation component. The solution provided by this X-ray attenuation component is similar to the solution described in the aforementioned X-ray imaging system. Therefore, the specific limitations of one or more of the following X-ray attenuation component embodiments can be found in the aforementioned limitations on the X-ray imaging system and will not be further elaborated here.

[0087] An embodiment of the present application also provides an X-ray attenuation component, which is used to attenuate part or all of the X-rays emitted by the X-ray source; the X-rays attenuated by the X-ray attenuation component include at least X-rays exposed to the non-target area of ​​the working area of ​​the detector; the non-target area belongs to the area on the working area except the target area, and the target area is the area on the working area used to receive X-rays passing through the object under inspection.

[0088] In one embodiment, the X-ray attenuation element includes at least one pair of X-ray attenuation sub-elements, and the same pair of X-ray attenuation sub-elements are arranged on both sides of a target plane; the target plane is a plane formed by the bed approach direction and a central ray passing through the rotation center; the rotation center corresponds to the point around which the X-ray source and the detector rotate as a whole.

[0089] In one embodiment, each X-ray attenuation sub-component is connected to a driving device; the driving device is used to change the spacing between the same pair of X-ray attenuation sub-components in a target direction; the target direction is a direction perpendicular to the target plane.

[0090] The present application provides an X-ray imaging method, which is applied to the above-mentioned X-ray imaging system or is performed based on the above-mentioned X-ray attenuation element, including: Figure 7 The steps shown are:

[0091] Step S701 : Based on the estimation of the size of the projection area of ​​the inspected object on the detector, the distance between the same pair of X-ray attenuation components in the target direction is adjusted.

[0092] Specifically, the target setting spacing can be determined based on the estimation of the size of the projection area of ​​the inspected object on the detector, and the driving device can be controlled to operate according to the target setting spacing so that the spacing between the same pair of X-ray attenuation components in the target direction remains consistent with the target setting spacing.

[0093] In some embodiments, during current use, the size of the projection area of ​​the current object under inspection on the detector can be estimated, and the length of the projection area of ​​the object under inspection along the x-axis (hereinafter referred to as the x-axis length of the projection area) can be determined based on the estimation result; according to the distance between the X-ray source 101 and the detector 102 and the distance between the X-ray source 101 and the X-ray attenuation element 103, a distance ratio is obtained, and a spacing whose ratio to the x-axis length of the projection area satisfies the distance ratio is determined, and the spacing is used as the target setting spacing.

[0094] In some embodiments, the projection area sizes of multiple common types of objects on the detector can be pre-calculated, and the projection area sizes of each type of object can be classified to form multiple projection ranges. For each projection range, the spacing of the X-ray attenuation sub-components along the target direction is set. This set spacing can be referred to as a set spacing. Based on this, during current use, the projection area size of the current object on the detector can be estimated, thereby determining a target set spacing from the multiple set spacings.

[0095] After the target set distance is determined, the driving device can be controlled to move the X-ray attenuation sub-components so that the distance between the same pair of X-ray attenuation sub-components in the target direction is equal to the target set distance.

[0096] Step S702: Control the X-ray source to emit X-rays.

[0097] After adjusting the spacing between the same pair of X-ray attenuation components in the target direction, when the current object to be inspected is placed between the X-ray source and the detector, the X-ray source can be controlled to emit X-rays, thereby obtaining projection data detected by the detector and obtaining the corresponding projection map for image reconstruction.

[0098] In one embodiment, after controlling the X-ray source to emit X-rays, the method provided in the present application further includes: obtaining projection data of the inspected object detected by the detector; obtaining air exposure data associated with the target set distance; and performing air correction on the projection data based on the air exposure data.

[0099] After obtaining multiple set intervals in advance, corresponding air exposure data can also be obtained; illustratively, taking one of the multiple set intervals as an example, the driving device is controlled to work and move the X-ray attenuation sub-components so that the spacing between the same pair of X-ray attenuation sub-components in the target direction is equal to the set interval; then, when there is no object to be inspected between the X-ray source and the detector, the X-ray source is controlled to emit X-rays, and the data detected by the detector at this time is used as air exposure data, and the air exposure data is associated with the set interval; in this way, the air exposure data corresponding to other set intervals can be obtained and associated.

[0100] During current use, air exposure data associated with the target set spacing may be acquired, and air correction may be performed on the projection data obtained in step S703.

[0101] The method of the above embodiment can be applied to micro-CT. In this case, adjusting the spacing between the pair of X-ray attenuating sub-components in the target direction based on the estimated size of the projection area of ​​the inspected object on the detector in step S701 may include: obtaining the size of a chamber for accommodating the sample body; determining the magnification ratio used for imaging the sample body; determining a target set spacing based on the chamber size and the magnification ratio; and adjusting the spacing between the pair of X-ray attenuating sub-components in the target direction to be consistent with the target set spacing;

[0102] In micro-CT, the specimen is typically placed in a chamber fixed to the scanning bed. This chamber, containing the specimen, can serve as the object being examined. The specimen can be a laboratory mouse, ex vivo tissue, or other specimen. The distance from the X-ray source to the object being examined (or the center of the chamber) is denoted as SOD (source to object distance), and the distance from the X-ray source to the detector plane is denoted as SDD (source to detector distance). SDD / SOD is also known as the magnification ratio.

[0103] After the sample body is placed in the cabin, the cabin is fixed on the scanning bed and the magnification ratio is adjusted, the X-ray source can be controlled to emit X-rays. Some X-rays pass through the cabin containing the sample body and are exposed on the detector to obtain projection data detected by the detector.

[0104] In micro-CT, the size of the projection area of ​​the current object under inspection on the detector is estimated to determine the target set interval among multiple set intervals. This can be achieved by the following methods:

[0105] Various cabin sizes can be associated with different magnification ratios in advance. For any cabin size and its associated magnification ratio, the spacing of the X-ray attenuation sub-components along the target direction is set. The set spacing can be called a set spacing. The set spacing is associated with the cabin size and the magnification ratio. In this way, multiple association relationships can be obtained, each association relationship includes the set spacing, the cabin size and the magnification ratio, and at least one of the cabin size and the magnification ratio associated with different set spacings is different.

[0106] During current use, the size of the chamber for accommodating the current sample body and the magnification ratio for imaging the current sample body may be determined, and a target set interval may be determined from a plurality of set intervals based on the current chamber size and the current magnification ratio.

[0107] It should be understood that, although the various steps in the flowcharts involved in the above embodiments are shown in sequence as indicated by the arrows, these steps are not necessarily performed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be performed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily performed at the same time, but can be performed at different times, and the execution order of these steps or stages is not necessarily performed in sequence, but can be performed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0108] Based on the same inventive concept, embodiments of the present application further provide an X-ray imaging device for implementing the aforementioned X-ray imaging method. The solution provided by this device is similar to the solution described in the aforementioned method. Therefore, the specific limitations of one or more of the following X-ray imaging device embodiments can be found in the above-described limitations of the X-ray imaging method and are not further elaborated here.

[0109] In one embodiment, an X-ray imaging device is provided, which is applied to the above-mentioned X-ray imaging system or is implemented based on the above-mentioned X-ray attenuation element, including:

[0110] A spacing adjustment module, configured to adjust the spacing between the same pair of X-ray attenuation sub-components in the target direction based on an estimation of the size of the projection area of ​​the inspected object on the detector;

[0111] The ray control module is used to control the X-ray source to emit X-rays.

[0112] In one embodiment, the spacing adjustment module is further used to: obtain the size of a chamber for accommodating the sample body; determine the magnification ratio used for imaging the sample body; determine the target setting spacing based on the chamber size and the magnification ratio; and adjust the spacing of the same pair of X-ray attenuation components in the target direction to be consistent with the target setting spacing.

[0113] In one embodiment, the device further includes a correction module for acquiring projection data of the inspected object detected by the detector; acquiring air exposure data associated with the target set distance; and performing air correction on the projection data based on the air exposure data.

[0114] Each module in the aforementioned X-ray imaging device may be implemented in whole or in part through software, hardware, or a combination thereof. Each module may be embedded in or independent of a processor in a processing device in the form of hardware, or may be stored in a memory in the processing device in the form of software, so that the processor can call and execute the corresponding operations of each module.

[0115] In an exemplary embodiment, a processing device is provided. The processing device can be regarded as a part of an X-ray imaging system. The internal structure diagram of the processing device can be shown as follows: Figure 8 As shown. The processing device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O) and a communication interface. The processor, memory and input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the processing device is used to provide computing and control capabilities. The memory of the processing device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The database of the processing device is used to store data related to the X-ray imaging method. The input / output interface of the processing device is used to exchange information between the processor and an external device. The communication interface of the processing device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, an X-ray imaging method is implemented.

[0116] Those skilled in the art will understand that Figure 8The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the processing device to which the solution of the present application is applied. The specific processing device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0117] In one embodiment, a processing device is provided, including a memory and a processor. The memory stores a computer program, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0118] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0119] In one embodiment, a computer program product is provided, on which a computer program is stored. The computer program is used by a processor to execute the steps in the above-mentioned various method embodiments.

[0120] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the above-mentioned embodiments. In particular, any reference to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processors involved in the various embodiments provided herein may be, but are not limited to, general-purpose processors, central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), programmable logic devices (PLDs), data processing logic devices based on quantum computing, and the like.

[0121] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0122] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. An X-ray imaging system, characterized in that: The system includes: an X-ray source and a detector, and an X-ray attenuation element; In which, the X-ray attenuation component is used to attenuate part or all of the X-rays emitted by the X-ray source; the X-rays attenuated by the X-ray attenuation component include at least X-rays exposed to the non-target area of ​​the working area of ​​the detector; the non-target area belongs to the area on the working area except the target area, and the target area is the area on the working area for receiving X-rays passing through the object to be inspected.

2. The system according to claim 1, wherein: The X-ray attenuation component includes at least one pair of X-ray attenuation sub-components, and the same pair of X-ray attenuation sub-components are arranged on both sides of a target plane; the target plane is a plane formed by the bed entry direction and the central ray passing through the rotation center; the rotation center corresponds to the point around which the X-ray source and detector rotate as a whole.

3. The system according to claim 2, characterized in that Each X-ray attenuation sub-component is connected to a driving device; the driving device is used to change the spacing between the same pair of X-ray attenuation sub-components in a target direction; the target direction is a direction perpendicular to the target plane.

4. The system according to claim 2 or 3, characterized in that The X-ray attenuation sub-component includes a portion of equal thickness and a portion of unequal thickness; relative to the portion of equal thickness, the portion of unequal thickness is closer to the target plane; among the portions of unequal thickness, the closer to the target plane, the smaller the thickness.

5. An X-ray attenuating element, characterized in that: The X-ray attenuating member is used to attenuate part or all of the X-rays emitted by the X-ray source; The X-rays attenuated by the X-ray attenuating member include at least X-rays that are exposed to a non-target area of ​​the working area of ​​the detector; The non-target area is an area on the working area except the target area. The target area is an area on the working area for receiving X-rays that pass through the object to be inspected.

6. The X-ray attenuating element according to claim 5, wherein: The X-ray attenuation component includes at least one pair of X-ray attenuation sub-components, and the same pair of X-ray attenuation sub-components are arranged on both sides of a target plane; the target plane is a plane formed by the bed entry direction and the central ray passing through the rotation center; the rotation center corresponds to the point around which the X-ray source and detector rotate as a whole.

7. The X-ray attenuating element according to claim 6, wherein: Each X-ray attenuation sub-component is connected to a driving device; the driving device is used to change the spacing between the same pair of X-ray attenuation sub-components in a target direction; the target direction is a direction perpendicular to the target plane.

8. An X-ray imaging method, characterized in that: The method is applied to the X-ray imaging system of claim 2 or 3 or is performed based on the X-ray attenuation element of claim 6 or 7, and includes: Based on the estimation of the size of the projection area of ​​the object under inspection on the detector, the spacing between the same pair of X-ray attenuation components in the target direction is adjusted; Control the X-ray source to emit X-rays.

9. The method according to claim 8, characterized in that Based on the estimation of the size of the projected area of ​​the inspected object on the detector, the spacing between the same pair of X-ray attenuation components in the target direction is adjusted, including: Obtaining the size of a chamber for accommodating the sample body; determining a magnification ratio for imaging the sample body; determining a target setting spacing based on the cabin size and the magnification ratio; Adjust the spacing between the same pair of X-ray attenuation components in the target direction to be consistent with the target set spacing.

10. The method according to claim 9, characterized in that After controlling the X-ray source to emit X-rays, the method further includes: Acquiring projection data of the object detected by the detector; Acquiring air exposure data associated with the target set interval; Air correction is performed on the projection data based on the air exposure data.

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