CN111887883A

CN111887883A - X-ray imaging apparatus and X-ray imaging method

Info

Publication number: CN111887883A
Application number: CN201910369043.XA
Authority: CN
Inventors: 余文锐; 王飞
Original assignee: Hefei Yofo Medical Technology Co ltd
Current assignee: Hefei Yofo Medical Technology Co ltd
Priority date: 2019-05-05
Filing date: 2019-05-05
Publication date: 2020-11-06

Abstract

The application discloses an X-ray imaging apparatus and an X-ray imaging method. The X-ray imaging apparatus may include: an X-ray source configured to emit X-rays to irradiate a projection body, wherein the X-ray source has an exit port whose size can be adjusted; a detector configured to detect X-rays passing through the object to generate projection data; a rotating mechanism configured to be able to rotate the X-ray source and the detector around a rotation axis of a vertical direction around the projection body; and a calculation mechanism configured to calculate a size of an exit port of the X-ray source based on a size of the projection body, wherein the size of the exit port of the X-ray source is adjusted to the size calculated by the calculation mechanism.

Description

X-ray imaging apparatus and X-ray imaging method

Technical Field

The present application relates to the field of X-ray imaging.

Background

Imaging techniques, including for example X-ray imaging, CT (Computed Tomography), etc., have since been widely used in many fields, especially in the field of medical examinations. Generally, in order to enlarge the field of view, X-ray imaging apparatuses employ larger detectors. However, when a small object is photographed, a large portion of the X-rays become useless rays and are directly irradiated to the detector for imaging, and this also requires image removal through post-processing, which increases the amount of unnecessary calculation.

Disclosure of Invention

In view of at least one of the above technical problems, the present application provides an X-ray imaging apparatus and an X-ray imaging method.

According to an aspect of the present application, there is provided an X-ray imaging apparatus including: an X-ray source configured to emit X-rays to irradiate a projection body, wherein the X-ray source has an exit port whose size can be adjusted; a detector configured to detect X-rays passing through the object to generate projection data; a rotating mechanism configured to be able to rotate the X-ray source and the detector around a rotation axis of a vertical direction around the projection body; and a calculation mechanism configured to calculate a size of an exit port of the X-ray source based on a size of the projection body, wherein the size of the exit port of the X-ray source is adjusted to the size calculated by the calculation mechanism.

According to another aspect of the present application, there is provided an X-ray imaging method characterized by comprising: emitting X-rays by an X-ray source to irradiate the projection object; detecting, by a detector, X-rays passing through a projection volume to generate projection data; rotating the X-ray source and the detector around a rotation axis in the vertical direction around the projection body through a rotating mechanism; calculating the size of an exit port of the X-ray source based on the size of the projection body; and adjusting the size of the exit opening of the X-ray source to the calculated size of the exit opening of the X-ray source.

According to the X-ray imaging apparatus and the X-ray imaging method as described above, the size of the exit port of the X-ray source can be adjusted accordingly substantially in accordance with the size of the projection subject, and unnecessary calculations for eliminating the influence of the unnecessary X-rays in the post-processing can be reduced since unnecessary X-rays that directly irradiate the detector and are imaged are reduced.

Drawings

The above and other aspects, features and advantages of the present application will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which:

fig. 1 shows a schematic perspective view of an exemplary oral CT of the prior art.

Fig. 2 shows a schematic block diagram of an exemplary X-ray imaging device according to an exemplary embodiment of the present application.

Fig. 3 shows a schematic block diagram of an exemplary X-ray imaging device according to an exemplary embodiment of the present application.

Fig. 4 shows a schematic front view of a geometrical light path calculating a calculated size of a projection body in a vertical direction at a rotation center of a turning mechanism according to an exemplary embodiment of the present application.

Fig. 5 shows a schematic top view of a geometrical light path for calculating a calculated dimension of a projection volume in a horizontal direction at a rotation center of a turning mechanism according to an exemplary embodiment of the present application.

Fig. 6A and 6B show a front perspective view and a rear perspective view of an exit opening of an exemplary X-ray source according to an exemplary embodiment of the present application.

Fig. 7 shows a schematic flow diagram of an exemplary X-ray imaging method according to an exemplary embodiment of the present application.

Detailed Description

The present application will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments are shown. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art. Like reference numerals refer to like elements throughout the specification and throughout the drawings.

It will be understood that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements may be present. In contrast, when an element is referred to as being directly on another element, there are no intervening elements present.

It will be understood that, although the terms "first," "second," "third," etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings herein.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, including "at least one", unless the content clearly indicates otherwise. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.

Further, spatially relative terms such as "below … …" or "above … …" and "above … …" may be used herein to describe one element's relationship to another element as illustrated in the figures. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the figures. For example, if the device in one of the figures is turned over, elements described as "below" other elements would then be oriented "above" the other elements. The exemplary terms "below" or "beneath" can therefore encompass both an orientation of above and below.

As used herein, "about" or "approximately" includes the stated value as well as the average value over an acceptable range of deviation for the specified value as determined by one of ordinary skill in the art taking into account the ongoing measurement and the error associated with the measurement of the specified quantity (i.e., the limitations of the measurement system).

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Fig. 1 shows a schematic perspective view of an exemplary oral CT of the prior art. It should be noted that, for convenience of explanation, the oral CT is taken as an example in the following description, but the X-ray imaging apparatus of the present application is not limited to the oral CT.

As shown in fig. 1, an exemplary oral CT of the prior art includes an X-ray source 100, a detector 200, and a rotation mechanism 300. The X-ray source 100 emits X-rays to irradiate the projection a, the detector detects the X-rays passing through the projection a, and the rotating mechanism 300 is capable of rotating the X-ray source 100 and the detector 200 around the projection a about a rotation axis in a vertical direction (i.e., a z direction in fig. 1). An exemplary underslung swivel mechanism 300 is shown in fig. 1, it being understood that swivel mechanism 300 may take other forms.

Fig. 2 shows a schematic block diagram of an exemplary X-ray imaging device according to an exemplary embodiment of the present application. As shown in fig. 2, an exemplary X-ray imaging apparatus according to an exemplary embodiment may include: x-ray source 100, detector 200, rotation mechanism 300. The X-ray source 100 may emit X-rays to irradiate the projection object a. The detector 200 may detect X-rays passing through the projection volume a to generate projection data. The rotation mechanism 300 is capable of rotating the X-ray source 100 and the detector 200 about the rotation axis in the vertical direction about the projection a. The above components have similar functions and functions to those of the prior art, and are not described in detail herein.

According to an exemplary embodiment of the present application, the X-ray source 100 has an exit port whose size can be adjusted, and thus the irradiation range of X-rays can be adjusted. It will be appreciated that, according to some embodiments, the exit opening may be replaced by a diaphragm or a similarly functioning component capable of adjusting the irradiation range of the X-rays. In order to make the structure more compact, exemplary embodiments of the present application employ exit ports that are adjustable in size, although the scope of the present application is not limited in this respect.

The exemplary X-ray imaging apparatus according to an exemplary embodiment may further include a computing mechanism 400.

The calculation mechanism 400 may calculate the size of the exit opening of the X-ray source. For example, in an exemplary embodiment, for an adult head, the calculation mechanism 400 will calculate that a larger exit opening size is to be used; for a child's head, the computing mechanism 400 will calculate that a smaller exit opening size is to be used. Wherein, after obtaining the size of the projection a, the calculation mechanism 400 may calculate the size of the exit opening of the X-ray source 100 according to, for example, a preset empirical formula, wherein the size of the projection a is positively correlated with the size of the exit opening of the X-ray source 100. For example, the size of the projection A may be linearly and positively correlated with the size of the exit aperture of the X-ray source 100. For example, in an exemplary embodiment, for an adult head, the computing mechanism 400 will determine the size of the exit aperture of the larger X-ray source 100 based on the larger projection size obtained; for a child's head, the computing mechanism 400 will determine the size of the exit opening of the smaller X-ray source 100 based on the smaller projection size obtained.

Then, the size of the exit opening of the X-ray source 100 can be adjusted to the size of the exit opening calculated (determined) by the calculation mechanism 400. For example, in some embodiments, the size of the exit port may be adjusted by an additional adjustment mechanism. According to an exemplary embodiment of the present application, the exit port of the X-ray source 100 can be automatically adjusted in size, which can be considered as integrating the exit port and the adjustment mechanism, thereby making the structure more compact, as described below (see fig. 6). It will be appreciated by those skilled in the art that the operator may also manually adjust the size of the exit port of the X-ray source 100 to achieve the function of automatically adjusting the exit port or adjustment mechanism, which is also within the scope of the present application.

It follows that with the exemplary X-ray imaging apparatus according to the exemplary embodiment, the size of the exit opening of the X-ray source 100 can be adjusted accordingly substantially according to the size of the projection a, and unnecessary calculations for eliminating the influence of unwanted X-rays in the post-processing can be reduced since unwanted X-rays that directly impinge on the detector and image are reduced.

An exemplary process by which the calculation mechanism 400 calculates the size of the exit opening of the X-ray source based on the size of the projection a is described below.

In certain exemplary embodiments, the calculation mechanism 400 may calculate the size of the exit port of the X-ray source in the vertical direction based on the size h of the projection volume a in the vertical direction (i.e., the size of the orthographic projection range of the projection volume a on the z-axis in fig. 1). In this way, the vertical dimension of the exit port of the X-ray source 100 can be adjusted based on the vertical dimension h of the projection a, so that the irradiation range of the X-ray source 100 in the vertical direction is positively correlated to the vertical dimension h of the projection a. The size of the exit opening of the X-ray source 100 in the horizontal direction may be set to correspond to the size of the detector 200 in the horizontal direction, for example. According to an exemplary embodiment, as described below, the size of the exit opening of the X-ray source 100 in the horizontal direction may be set to correspond to the size of the projection a in the horizontal direction, for example.

In general, when imaging is performed with an X-ray imaging apparatus, the projection a is positioned substantially at a preset position, and thus the distance from the X-ray source 100 to the projection a is substantially determined, in which case it is understood that the relationship between the vertical dimension of the exit port of the X-ray source 100 and the vertical dimension h of the projection a can be determined by the geometric relationship between the positions thereof. In other words, after obtaining the dimension h of the projection a in the vertical direction (and the calculated dimension in the vertical direction, the dimension in the horizontal direction, and the calculated dimension in the horizontal direction), the calculation mechanism 400 may calculate the dimension in the vertical direction of the exit port from the distance from the X-ray source 100 to the projection a, the distance from the exit port to the projection a, and the like. In some exemplary embodiments, the mapping relationship between the size of the exit port (including the vertical and horizontal directions) and the size of the projector a (and the calculated size) may be preset empirically (e.g., the previously set empirical formula described above). This can reduce the amount of calculation by the calculation means 400 and increase the speed. According to an exemplary embodiment of the present application, the vertical dimension of the exit opening of the X-ray source 100 may be set such that the X-rays exactly illuminate the edge of the projection a in the vertical direction (e.g. tangent), i.e. exactly cover the dimension h of the projection a in the vertical direction. For the calculated dimension H and the like described below, similar processing to that for the dimension H can also be performed based on similar principles. It will be appreciated by those skilled in the art that in practice certain tolerances may be set, which are also within the scope of the present application. Similar arrangements can be made for dimensions in other directions, which are not described in detail here.

Further, in general, when imaging is performed with an X-ray imaging apparatus, the projection a is generally required to be disposed at a preset fixed position at which the projection a is substantially symmetrically disposed. Thus, in the following, merely for the sake of clear expression of the concept of the present application, the exemplary embodiments herein assume a symmetrical arrangement of the projector a, for example in the vertical or horizontal direction, respectively an increase or decrease of the vertical or horizontal dimension of the exit opening of the X-ray source 100. However, it will be understood by those skilled in the art that when the projection a is arranged asymmetrically in the vertical direction, for example, at the predetermined position, it is sufficient to arrange the size of the vertical direction of the exit opening of the X-ray source 100 asymmetrically accordingly so that the X-ray can cover the size h of the projection a in the vertical direction, which is also within the scope of the present application.

In certain exemplary embodiments, the dimension h of the projector a in the vertical direction may be input by the operator.

In certain exemplary embodiments, referring to fig. 3, the X-ray imaging apparatus further includes a visible light imaging unit 500, and a size h of the projector a in the vertical direction may be obtained by pre-photographing the projector a by the visible light imaging unit 500. As shown in fig. 3, the visible light imaging unit 500 may be provided in the rotating mechanism 300. However, it is understood that the visible light imaging unit 500 may be disposed at other positions. With the visible light imaging unit 500, the radiation to the projection subject a can be reduced.

According to an exemplary embodiment, the calculation mechanism 400 may calculate the size of the exit opening of the X-ray source 100 based on a calculated size H of the projection a in the vertical direction at the rotation center of the rotation mechanism 300, wherein it should be noted that the calculated size H of the projection a in the vertical direction at the rotation center of the rotation mechanism 300 does not refer to an actual size of the projection a in the vertical direction at the rotation center of the rotation mechanism 300, but refers to a size calculated by an algorithm according to an exemplary embodiment, and is referred to herein as a calculated size.

Fig. 4 shows a schematic front view of a geometrical light path calculating a calculated size of a projection body in a vertical direction at a rotation center of a turning mechanism according to an exemplary embodiment of the present application. As shown in fig. 4, O denotes a rotation center of the rotation mechanism 300, SAD denotes a distance from the X-ray source 100 to the rotation center, and SID denotes a distance from the X-ray source 100 to the detector 200, which are known parameters for the X-ray imaging apparatus. The X-ray source 100 may pre-photograph the projection subject, i.e., the X-ray source 100 may emit X-rays to irradiate the projection subject. As will be appreciated by those skilled in the art, after the X-rays are emitted, the detector 200 will receive the X-rays, both with and without the X-rays passing through the projection volume. If the X-rays pass through the object, the intensity of the X-rays is reduced and the detector 200 is able to detect the intensity of the received X-rays. Therefore, the effective area of the detector 200, which is referred to herein as an area receiving the X-rays passing through the object, can be determined according to the intensity of the X-rays detected by the detector 200. For example, in some exemplary embodiments, the intensity S of the X-rays emitted by the X-ray source 100 is known, and a region in which the intensity of the X-rays detected by the detector 200 is lower than the intensity S may be determined as the effective region, but the scope of the present application is not limited thereto. As shown in fig. 4, the size of the effective area in the vertical direction (i.e., the size of the projection range on the z-axis in fig. 1) is denoted by L, and can be determined by the detector 200 after the pre-photographing. Then, the calculation means 400 can calculate the calculation size H of the projection in the vertical direction at the rotation center of the rotation means 300 as SAD/SID × L based on the geometric relationship of the triangle. In actual practice, for example, the size of the exit opening of the X-ray source 100 in the vertical direction may be first adjusted to the maximum position to make the determination of the effective area. After the calculated dimension H of the projector in the vertical direction is determined, the corresponding dimension of the exit opening of the X-ray source 100 in the vertical direction may be calculated based on H and then adjusted accordingly.

In this way, it is possible to realize the corresponding adjustment of the size of the exit port of the X-ray source 100 in the vertical direction based on the calculated size of the projection object in the vertical direction only by the components of the X-ray imaging apparatus itself, such as the X-ray source 100 and the detector 200, without using an additional component.

According to an exemplary embodiment, the calculation means 400 may calculate the size of the exit opening of the X-ray source in the horizontal direction from the size of the projection in the horizontal direction. In certain exemplary embodiments, the horizontal dimension w of the projector may be input by the operator. For example, if the vertical direction is the Z-axis of a cartesian coordinate system and the horizontal plane includes the X-axis and the Y-axis of the cartesian coordinate system, and the three-dimensional size of the projection is Z, X, and Y, respectively, the horizontal size of the projection can be set

With this arrangement, the X-ray emitted from the X-ray source 100 can cover most of the shapes of the projection objects by using the calculated size of the exit of the X-ray source 100 in the horizontal direction.

According to an exemplary embodiment, as shown in fig. 3, the X-ray imaging apparatus may further include a visible light imaging unit 500, and the size of the horizontal direction of the object may be obtained by pre-photographing the object by the visible light imaging unit 500. With the visible light imaging unit 500, radiation to the projection subject can be reduced.

In some exemplary embodiments, the visible light imaging unit 500 photographs a subject at a first position to obtain a first horizontal direction dimension x; thereafter, the visible light imaging unit 500 photographs the projection subject at a second position where a perpendicular line from the first position to the rotation axis and a perpendicular line from the second position to the rotation axis are at right angles to obtain a second horizontal direction dimension y. For example, the visible light imaging unit 500 may be disposed on the rotating mechanism 300, and after the visible light imaging unit 500 pre-photographs the projection object at the first position, the rotating mechanism 300 rotates 90 degrees around the rotation axis to the second position, and then pre-photographs the projection object again, it is understood that the scope of the present application is not limited theretoHere, the process is repeated. Thereafter, the calculating means 400 may be based on the horizontal dimension of the projector

And calculating to obtain w.

For ease of understanding, it may be assumed that the vertical direction is the Z-axis in a cartesian coordinate system, and the horizontal plane includes the X-axis and the Y-axis in the cartesian coordinate system. The three-dimensional size of the projection volume can be obtained by the visible light imaging unit 500 through the following steps:

the visible light imaging unit 500 photographs the projection subject to obtain a projection range Z of the projection subject on the Z axis;

the visible light imaging unit 500 photographs the projection subject along the Y axis to obtain a projection range X of the orthographic projection image on the X axis;

the visible light imaging unit 500 photographs the projection subject along the X-axis to obtain a projection range Y of the orthographic projection image in the Y-axis; and

the calculating means 400 may calculate the horizontal dimension of the projection object

As described above, according to an exemplary embodiment of the present application, the size of the exit port of the X-ray source 100 may be set based only on the size H of the projector in the vertical direction, the calculated size H of the projector in the vertical direction at the rotation center of the rotation mechanism, or the size w of the projector in the horizontal direction, respectively. It should be noted that the size of the exit port of the X-ray source 100 may be set based on the size H of the projection body in the vertical direction and the size w of the projection body in the horizontal direction, or based on the calculated size H of the projection body in the vertical direction at the rotation center of the rotating mechanism and the size w of the projection body in the horizontal direction.

Fig. 5 shows a schematic top view of a geometrical light path for calculating a calculated dimension of a projection volume in a horizontal direction at a rotation center of a turning mechanism according to an exemplary embodiment of the present application. As will be seen from the following, similarly to fig. 4, according to the geometrical optical path shown in fig. 5, the calculated dimension W of the projector in the horizontal direction (including the calculated dimension x in the first horizontal direction and the calculated dimension y in the second horizontal direction) can be calculated by the dimension K of the effective area in the horizontal direction (including the K1 in the first horizontal direction and the K2 in the second horizontal direction), respectively.

Referring to fig. 4 and 5, according to an exemplary embodiment, the calculation mechanism 400 may calculate the size of the exit opening of the X-ray source in the horizontal direction from the calculated size W of the projection body in the horizontal direction at the rotation center of the rotation mechanism 300. The calculated dimension W of the horizontal direction of the projection body at the rotation center of the rotation mechanism 300 can be obtained by:

the X-ray source 100 emits X-rays to irradiate the projection subject;

the detector 200 detects X-rays to determine a dimension K1 (see fig. 5) of the effective region in the vertical direction (i.e., a dimension of the projection in the first horizontal direction (i.e., a size of a projection range of the projection in the horizontal direction of the surface of the detector 200);

the calculation mechanism 400 calculates X according to the calculation size X of the projection body in the first horizontal direction, which is SAD/SID × K1, wherein SAD is the distance from the X-ray source 100 to the rotation center, and SID is the distance from the X-ray source 100 to the detector 200;

the rotation mechanism 300 rotates 90 degrees around the rotation axis (it is understood that the rotation mechanism 300 rotates the X-ray source 100 and the detector 200 90 degrees around the rotation axis), and the X-ray source 100 emits X-rays to irradiate the projection subject;

the detector 200 detects the X-rays to determine a dimension K2 of the active area in a second horizontal direction (i.e., the size of the projection range of the projection volume in the horizontal direction of the surface of the detector 200);

the calculation means 400 calculates y from the calculated size y of the projection in the second horizontal direction, which is SAD/SID × K2; and

the calculation means 400 calculates the size of the projection body in the horizontal direction at the rotation center of the rotation means

W is obtained by calculation.

As described above, according to the exemplary embodiments of the present application, the size of the exit port of the X-ray source 100 may be set based only on the size H of the projector in the vertical direction, the calculated size H of the projector in the vertical direction at the rotation center of the rotation mechanism, the size W of the projector in the horizontal direction, or the calculated size W of the projector in the horizontal direction at the rotation center of the rotation mechanism, respectively. It should be noted that the size of the exit port of the X-ray source 100 may also be set based on the size H of the projector in the vertical direction (or the calculated size H of the projector in the vertical direction at the rotation center of the rotating mechanism) and the size W of the projector in the horizontal direction (or the calculated size W of the projector in the horizontal direction at the rotation center of the rotating mechanism).

For ease of understanding, it may be assumed that the vertical direction is the Z-axis in a cartesian coordinate system, and the horizontal plane includes the X-axis and the Y-axis in the cartesian coordinate system. For example, a three-dimensional calculated dimension of the projection body (including a calculated dimension H of the projection body in the vertical direction and a calculated dimension W in the horizontal direction) at the rotation center of the rotation mechanism 300 can be obtained by:

the X-ray source 100 emits X-rays to irradiate the projection subject;

the detector 200 detects X-rays to determine a dimension L (see fig. 4) of the effective region in the vertical direction (i.e., a size of a projection range of the projection of the object in the vertical direction on the surface of the detector 200) and a dimension K1 (see fig. 5) in the first horizontal direction (i.e., a size of a projection range of the projection of the object in the horizontal direction on the surface of the detector 200);

the calculating mechanism 400 calculates H, X according to the calculated size H of the projection in the vertical direction, SAD/SID × L, and the calculated size X of the projection in the first horizontal direction, SAD/SID × K1, wherein SAD is the distance from the X-ray source 100 to the rotation center, and SID is the distance from the X-ray source 100 to the detector 200;

W is obtained by calculation.

Fig. 6A and 6B show a rear perspective view and a front perspective view of an exit opening of an exemplary X-ray source according to an exemplary embodiment of the present application.

As shown in fig. 6A and 6B, the exit port of the X-ray source may include an upper horizontal barrier 6, a lower horizontal barrier 7, and a first motor (vertical movement motor) 1, wherein the first motor 1 may drive the upper horizontal barrier 6 and the lower horizontal barrier 7 to move in the vertical direction to adjust the size of the exit port of the X-ray source in the vertical direction; the exit opening of the X-ray source may further comprise a left vertical baffle 12, a right vertical baffle 13 and a second motor (horizontal movement motor) 8, wherein the second motor 8 drives the left vertical baffle 12 and the right vertical baffle 13 to move in the horizontal direction to adjust the size of the exit opening of the X-ray source in the vertical direction. As shown in fig. 6A, the exit opening of the X-ray source may also comprise a holder 2 for assembling the various components. The exit port of the X-ray source may further include a vertical sliding table 3, a vertical screw 4, and a vertical moving fixing block 5 for cooperating with the first motor 1, the upper horizontal barrier 6, and the lower horizontal barrier 7. The exit port of the X-ray source may further include a horizontal movement fixing block 9, a horizontal movement sliding table 10, and a horizontal screw 11 for cooperating with a second motor 8, a left vertical baffle 12, and a right vertical baffle 13. It will be appreciated by those skilled in the art that the specific structure described above is merely exemplary and the scope of the present application is not limited thereto.

As described above, merely for the sake of clear expression of the concept of the present application, the exemplary embodiment herein assumes a symmetrical arrangement of the projector a in the vertical direction or the horizontal direction, and thus the first motor 1 can symmetrically drive the upper horizontal barrier 6 and the lower horizontal barrier 7 to move in the vertical direction, and the second motor 8 can symmetrically drive the left vertical barrier 12 and the right vertical barrier 13 to move in the horizontal direction, respectively. It will be appreciated by those skilled in the art that when the projector a is disposed asymmetrically in the vertical direction, for example, at the predetermined position, it is possible to move in the vertical direction by driving the upper and lower horizontal barriers asymmetrically accordingly (e.g., by disposing two motors driving the upper and lower horizontal barriers, respectively) so that the X-ray can cover the dimension h of the projector a in the vertical direction, which is also within the scope of the present application.

As shown in fig. 7, an exemplary X-ray imaging method according to an exemplary embodiment of the present application may include the steps of:

s10 irradiating the projection object with X-rays emitted from the X-ray source;

s20 detecting the X-ray passing through the projection body through the detector to generate projection data;

s30 rotating the X-ray source and the detector around the rotation axis of the vertical direction around the projection body through a rotating mechanism;

s40 calculating the size of the exit of the X-ray source based on the size of the projection body; and

s50 adjusts the size of the exit aperture of the X-ray source to the calculated size.

The above method may be accomplished by the X-ray source 100, the detector 200, the rotation mechanism 300, and the calculation mechanism 400 as shown in fig. 2. For example, S40 may be performed by the computing mechanism 400, and S50 may be performed by additional adjustment mechanisms. However, it is understood that the above steps may be performed by other means or by a person, for example, in S40, the size of the projection object may be input and the size of the exit port of the X-ray source may be calculated by an operator, and in S50, the size of the exit port of the X-ray source 100 may be manually adjusted by the operator.

According to an exemplary embodiment of the present application, the size of the exit opening of the X-ray source 100 may be calculated according to, for example, a preset empirical formula, wherein the size of the projector a is positively correlated to the size of the exit opening of the X-ray source 100. For example, in an exemplary embodiment, for an adult head, the size of the exit aperture of the X-ray source 100 will be determined to be larger based on the larger projector size; whereas for a child's head, the size of the exit opening of the X-ray source 100 will be determined to be smaller based on the smaller projection size.

As described above, according to the exemplary X-ray imaging method according to the exemplary embodiment of the present application, the size of the exit port of the X-ray source 100 can be adjusted accordingly substantially according to the size of the object a, and unnecessary calculations for eliminating the influence of unnecessary X-rays in the post-processing can be reduced since unnecessary X-rays directly irradiated onto the detector and imaged are reduced.

According to an exemplary embodiment, S40 may include calculating a dimension h of the projector in a vertical direction. In certain exemplary embodiments, the dimension h of the projector in the vertical direction may be input by the operator.

In certain exemplary embodiments, the X-ray imaging method may further include obtaining a dimension h of the projection in a vertical direction by pre-photographing the projection through a visible light imaging unit 500 as shown in fig. 3. As previously mentioned, with the visible light imaging unit, the radiation to the object can be reduced.

According to an exemplary embodiment, S40 may include a calculated dimension H of the projector in the vertical direction at the center of rotation of the swivel mechanism. As described previously, the calculated dimension H of the projector in the vertical direction at the rotation center of the rotation mechanism 300 does not refer to the actual dimension of the projector in the vertical direction at the rotation center of the rotation mechanism 300, but refers to a dimension calculated by an algorithm according to an exemplary embodiment, and is referred to herein as a calculated dimension.

In certain exemplary embodiments, calculating the calculated dimension H of the projector in the vertical direction at the center of rotation of the swivel mechanism comprises:

emitting X-rays by an X-ray source to irradiate the projection object;

detecting X-rays through a detector to determine the size L of the effective area in the vertical direction;

h is calculated from H ═ SAD/SID × L, where SAD is the distance of the X-ray source to the center of rotation and SID is the distance of the X-ray source to the detector.

As described above, referring to fig. 4, O denotes the rotation center of the rotation mechanism 300, and SAD and SID are known parameters for the X-ray imaging apparatus. The X-ray source 100 may pre-photograph the projection subject, i.e., the X-ray source 100 may emit X-rays to irradiate the projection subject. As will be appreciated by those skilled in the art, after the X-rays are emitted, the detector 200 will receive the X-rays, both with and without the X-rays passing through the projection volume. If the X-rays pass through the object, the intensity of the X-rays is reduced and the detector 200 is able to detect the intensity of the received X-rays. Therefore, the effective area of the detector 200 can be determined according to the intensity of the X-rays detected by the detector 200. For example, in some exemplary embodiments, the intensity S of the X-rays emitted by the X-ray source 100 is known, and a region in which the intensity of the X-rays detected by the detector 200 is lower than the intensity S may be determined as the effective region, but the scope of the present application is not limited thereto. As shown in fig. 4, the size of the effective area in the vertical direction (i.e., the size of the projection range on the z-axis in fig. 1) is denoted by L, and can be determined by the detector 200 after the pre-photographing. Then, from the geometric relationship of the triangle, the calculated dimension H of the projection body in the vertical direction at the rotation center of the rotation mechanism 300 can be calculated as SAD/SID × L.

In this way, it is possible to realize the corresponding adjustment of the size of the exit port of the X-ray source 100 based on the calculated size of the projection body in the vertical direction only by the components of the X-ray imaging apparatus itself, such as the X-ray source 100 and the detector 200, without using an additional component.

According to an exemplary embodiment, S40 may include calculating a horizontal dimension of the projector. In some exemplary embodiments, the size of the projector in the horizontal direction may be input by an operator.

In certain exemplary embodiments, calculating the horizontal dimension of the projector includes obtaining the horizontal dimension of the projector by pre-photographing the projector by the visible light imaging unit. As previously described, with a visible light imaging unit (e.g., visible light imaging unit 500 as shown in fig. 4), radiation to the projector may be reduced.

In some exemplary embodiments, obtaining the horizontal dimension of the projection by pre-photographing the projection by the visible light imaging unit includes:

shooting a projection object at a first position through a visible light imaging unit to obtain a dimension x in a first horizontal direction;

photographing the projection object at a second position by the visible light imaging unit to obtain a dimension y of a second horizontal direction, wherein a perpendicular to the rotation axis from the first position and a perpendicular to the rotation axis from the second position are at right angles; and

according to the size in the horizontal direction

And calculating to obtain w.

For example, the visible light imaging unit 500 photographs the projection subject at a first position to obtain a first horizontal direction dimension x; the visible light imaging unit 500 photographs the projection subject at a second position where a perpendicular line from the first position to the rotation axis and a perpendicular line from the second position to the rotation axis are at right angles to obtain a second horizontal direction dimension y. For example, as shown in fig. 3, the visible light imaging unit 500 may be disposed on the rotating mechanism 300, and after the visible light imaging unit 500 pre-photographs the projection object at the first position, the rotating mechanism 300 rotates by 90 degrees around the rotation axis to the second position and then pre-photographs the projection object again, it is understood that the scope of the present application is not limited thereto. Thereafter, it may be according to the size in the horizontal direction

And calculating to obtain w.

According to an exemplary embodiment, S40 may include calculating a calculated dimension W of the horizontal direction of the projector at the center of rotation of the swivel mechanism.

In some embodiments, calculating the calculated dimension W in the horizontal direction of the projector at the center of rotation of the rotating mechanism may include:

emitting X-rays by an X-ray source to irradiate the projection object;

detecting the X-rays by a detector to determine a dimension K1 of the active area in a first horizontal direction;

calculating X according to the calculated size X of the projection body in the first horizontal direction, namely SAD/SID multiplied by K1, wherein SAD is the distance from the X-ray source to the rotation center, and SID is the distance from the X-ray source to the detector;

rotating the rotating mechanism about the axis of rotation by 90 degrees;

emitting X-rays by an X-ray source to irradiate the projection object;

detecting the X-rays by the detector to determine a dimension K2 of the active area in the second horizontal direction;

calculating y according to the calculated size y of the projection body in the second horizontal direction, namely SAD/SID multiplied by K2; and

calculated size according to horizontal direction

W is obtained by calculation.

It should be noted that the above-mentioned exemplary X-ray imaging method according to the exemplary embodiment of the present application corresponds generally to the aforementioned exemplary X-ray imaging apparatus according to the exemplary embodiment of the present application, and thus some descriptions thereof are omitted for brevity.

While certain exemplary embodiments and examples have been described herein, other embodiments and modifications will be apparent from the above description. Various changes and modifications to the embodiments of the present application may be made by those skilled in the art without departing from the teachings of the present application. The inventive concept is therefore not limited to the embodiments but is to be defined by the appended claims along with their full scope of equivalents.

Claims

1. An X-ray imaging apparatus, characterized by comprising:

an X-ray source configured to emit X-rays to irradiate a projection body, wherein the X-ray source has an exit port whose size can be adjusted;

a detector configured to detect X-rays passing through the object to generate projection data;

a rotating mechanism configured to be able to rotate the X-ray source and the detector around a rotation axis of a vertical direction around the projection body; and

a calculation mechanism configured to calculate a size of an exit port of the X-ray source based on a size of the projection body,

wherein the size of the exit opening of the X-ray source is adjusted to the size calculated by the calculation means.

2. The X-ray imaging apparatus according to claim 1, wherein the calculation mechanism is configured to calculate a size of the exit port of the X-ray source in a vertical direction based on a size h of the projection body in the vertical direction,

preferably, the X-ray imaging apparatus further includes a visible light imaging unit, and the dimension h of the projection in the vertical direction is obtained by pre-photographing the projection by the visible light imaging unit.

3. The X-ray imaging apparatus according to claim 1, wherein the calculation mechanism is configured to calculate a size of the exit port of the X-ray source based on a calculated size H of the projection body in a vertical direction at a rotation center of the rotation mechanism,

preferably, the calculated dimension H of the projection body in the vertical direction at the rotation center of the rotation mechanism is obtained by:

the X-ray source emits X-rays to irradiate the projection body;

the detector detects the X-ray to determine the size L of the effective area in the vertical direction;

the calculation mechanism calculates H according to H ═ SAD/SID multiplied by L, wherein SAD is the distance from the X-ray source to the rotation center, and SID is the distance from the X-ray source to the detector.

4. The X-ray imaging apparatus according to any one of claims 1 to 3, wherein the calculation mechanism is configured to calculate a size of an exit port of the X-ray source based on a size w of the projection body in a horizontal direction,

preferably, the X-ray imaging apparatus further comprises a visible light imaging unit, the size of the horizontal direction of the object is obtained by pre-photographing the object by the visible light imaging unit,

preferably, the horizontal dimension of the projector is obtained by:

the visible light imaging unit shoots a projection object at a first position to obtain a dimension x in a first horizontal direction;

the visible light imaging unit photographs the projection body at a second position to obtain a dimension y in a second horizontal direction, wherein a perpendicular line from the first position to the rotation axis and a perpendicular line from the second position to the rotation axis are at a right angle; and

the calculating means is based on the horizontal dimension of the projector

And calculating to obtain w.

5. The X-ray imaging apparatus according to any one of claims 1 to 3, wherein the calculation mechanism is configured to calculate the size of the exit opening of the X-ray source based on a calculated size W of the projection body in the horizontal direction at the rotation center of the rotation mechanism, wherein the calculated size W of the projection body in the horizontal direction at the rotation center of the rotation mechanism is obtained by:

the X-ray source emits X-rays to irradiate the projection body;

the detector detects the X-rays to determine a dimension K1 of the active area in the first horizontal direction;

the calculating mechanism calculates X according to the calculated size X of the projection body in the first horizontal direction, namely SAD/SID multiplied by K1, wherein SAD is the distance from the X-ray source to the rotation center, and SID is the distance from the X-ray source to the detector;

the rotating mechanism rotates for 90 degrees around the rotating axis;

the X-ray source emits X-rays to irradiate the projection body;

the detector detects the X-rays to determine a dimension K2 of the active area in the second horizontal direction;

the calculating mechanism calculates y according to the calculated size y of the projection body in the second horizontal direction, namely SAD/SID multiplied by K2; and

the calculating means calculates the size of the projection body in the horizontal direction at the rotation center of the rotating means

W is obtained by calculation.

6. The X-ray imaging apparatus of claim 1,

the exit port comprises an upper transverse baffle plate, a lower transverse baffle plate and a first motor, wherein the first motor drives the upper transverse baffle plate and the lower transverse baffle plate to move in the vertical direction, and/or

The exit port comprises a left vertical baffle, a right vertical baffle and a second motor, wherein the second motor drives the left vertical baffle and the right vertical baffle to move in the horizontal direction.

7. An X-ray imaging method, comprising:

emitting X-rays by an X-ray source to irradiate the projection object;

detecting, by a detector, X-rays passing through a projection volume to generate projection data;

rotating the X-ray source and the detector around a rotation axis in the vertical direction around the projection body through a rotating mechanism;

calculating the size of an exit port of the X-ray source based on the size of the projection body; and

the size of the exit opening of the X-ray source is adjusted to the calculated size of the exit opening of the X-ray source.

8. The X-ray imaging method as defined in claim 7,

calculating the size of the exit opening of the X-ray source based on the size of the projection comprises calculating the size h of the projection in the vertical direction,

preferably, calculating the dimension h of the projector in the vertical direction comprises pre-shooting the projector by the visible light imaging unit to obtain the dimension h of the projector in the vertical direction; or

Calculating the size of the exit opening of the X-ray source based on the size of the projection includes calculating a calculated size H of the projection in a vertical direction at a center of rotation of the rotating mechanism,

preferably, calculating the calculated dimension H of the projection body in the vertical direction at the rotation center of the rotation mechanism includes:

emitting X-rays by an X-ray source to irradiate the projection object;

9. The X-ray imaging method according to claim 7 or 8, wherein calculating the size of the exit port of the X-ray source based on the size of the projection body comprises calculating the size of the projection body in the horizontal direction,

preferably, the calculating of the horizontal dimension of the projector comprises obtaining the horizontal dimension of the projector by pre-photographing the projector by the visible light imaging unit,

preferably, the obtaining of the horizontal-direction size of the projection object by pre-photographing the projection object by the visible light imaging unit includes:

according to the size in the horizontal direction

And calculating to obtain w.

10. The X-ray imaging method according to claim 7 or 8, wherein calculating the size of the exit port of the X-ray source based on the size of the projection body comprises calculating a calculated size W of the projection body in the horizontal direction at the rotation center of the rotation mechanism,

preferably, calculating the calculated dimension W of the horizontal direction of the projection body at the rotation center of the rotation mechanism includes:

emitting X-rays by an X-ray source to irradiate the projection object;

rotating the rotating mechanism about the axis of rotation by 90 degrees;

emitting X-rays by an X-ray source to irradiate the projection object;

calculated size according to horizontal direction

W is obtained by calculation.