X-ray imaging aid, x-ray imaging apparatus, and x-ray imaging method

Abstract

To reduce a ratio of a shade of a shoulder blade being shown in a lung field in an X-ray image acquired by chest X-ray imaging.SOLUTION: An X-ray imaging aid is an aid for aiding X-ray imaging of the chest by being held between an X-ray detection part for standing position imaging opposed to an X-ray irradiation part and the chest of a subject. The aid includes a sponge member that can transmit an X-ray, and is formed so as to be compressed when held between the X-ray detection part and the chest.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to an X-ray imaging auxiliary tool, an X-ray imaging device, and an X-ray imaging method. [Background technology]

[0002] There is known a technique for performing a chest X-ray examination by irradiating a subject such as a patient with X-rays to obtain an image (see, for example, Patent Documents 1 and 2). In a chest X-ray examination, X-rays are irradiated from the back to the front (so-called PA direction) to the chest of a subject in a standing position, and a chest X-ray image is obtained. In this disclosure, imaging performed by irradiating X-rays in the PA direction to the chest of a subject in a standing position, i.e., standing, may be simply referred to as "chest X-ray imaging", and an image obtained by such chest X-ray imaging may be simply referred to as "chest X-ray image". [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-115384 A [Patent Document 2] JP 2020-48684 A Summary of the Invention [Problem to be solved by the invention]

[0004] In an X-ray image, the bones of a subject appear white due to X-ray absorption, and airy areas such as the lungs appear black. The main purpose of X-ray examinations, including chest X-ray imaging, is often to observe the lung fields in the chest of a subject. If the scapula is included in the field of view (the range in which X-rays are focused to generate an image) in chest X-ray photography, a shadow of the scapula will appear in the lung field in the chest X-ray image. This scapula shadow can be an obstacle to observing the lung field. For this reason, chest X-ray photography is generally performed in a posture that does not include the scapula in the field of view of X-ray photography. However, in more than half of actual clinical chest X-ray images, the scapula cannot be removed from the lung field on the X-ray image.

[0005] The present disclosure provides an X-ray imaging auxiliary tool, an X-ray imaging device, and an X-ray imaging method that can reduce the proportion of scapular shadows appearing in lung fields in X-ray images obtained by chest X-ray photography. [Means for solving the problem]

[0006] [1] An X-ray photography auxiliary device that assists in X-ray photography of the subject's chest by being sandwiched between an X-ray detection unit for upright photography facing an X-ray irradiation unit and the subject's chest, the X-ray photography auxiliary device having a sponge member that is transparent to X-rays and is formed so as to be compressed when sandwiched between the X-ray detection unit and the chest.

[0007] [2] The X-ray photography aid described in [1] above, wherein the sponge member has a flat surface that can come into contact with the X-ray detection unit, and the sponge member is formed so as to be compressed in a direction intersecting the flat surface when sandwiched between the X-ray detection unit and the chest.

[0008] [3] The volume of the sponge member is 400 cm 3 ~600cm 3 The X-ray photography auxiliary device according to the above [1] or [2].

[0009] [4] The X-ray photography aid described in any one of [1] to [3] above, wherein the sponge member is formed in a rectangular parallelepiped shape, the size of the sponge member in a thickness direction perpendicular to the surface of the sponge member that abuts the X-ray detection unit is 4.5 cm to 5.5 cm, the width of the surface is 9 cm to 11 cm, and the vertical width of the surface is 9 cm to 11 cm.

[0010] [5] The density of the sponge member is 20 kg / m 3 ~24kg / m 3 The X-ray photography auxiliary according to any one of the above [1] to [4],

[0011] [6] The X-ray photography auxiliary tool according to any one of [1] to [5] above, wherein the hardness of the sponge member measured by an Asker C-type hardness tester is 18 to 40.

[0012] [7] An X-ray imaging device comprising: an irradiation unit capable of irradiating X-rays; an X-ray detection unit for upright imaging that faces the irradiation unit and detects X-rays incident through a subject; and an X-ray imaging auxiliary device that is sandwiched between the X-ray detection unit and the subject's chest to assist in X-ray imaging of the chest, wherein the X-ray imaging auxiliary device is transparent to X-rays and has a sponge member that is formed to be compressed when sandwiched between the X-ray detection unit and the chest.

[0013] [8] A method for X-ray photography, comprising: a first step of emitting X-rays from an X-ray irradiation unit toward an X-ray detection unit with an X-ray-transmitting sponge member sandwiched between an X-ray detection unit for upright photography facing an X-ray irradiation unit and the subject's chest; and a second step of generating an X-ray image based on the X-rays detected by the X-ray detection unit, wherein in the first step, the sponge member is compressed by being sandwiched between the X-ray detection unit and the chest. Effect of the Invention

[0014] According to the present disclosure, there is provided an X-ray imaging auxiliary tool, an X-ray imaging device, and an X-ray imaging method that are capable of reducing the proportion of scapular shadows appearing in the lung field in X-ray images obtained by chest X-ray photography. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic diagram showing an example of an X-ray imaging apparatus equipped with an X-ray imaging auxiliary tool. [Diagram 2] Fig. 2(a) is a schematic diagram showing an example of a cross-sectional view when radiography is performed in a standing position without using an X-ray imaging auxiliary tool, and Fig. 2(b) is an example of an X-ray image obtained without using an X-ray imaging auxiliary tool. [Diagram 3] Fig. 3(a) is a schematic cross-sectional view for explaining the problem when no X-ray imaging auxiliary is used, and Fig. 3(b) is a schematic cross-sectional view for explaining the desirable posture for removing the scapula from the lung field. [Figure 4] FIG. 4 is a perspective view that illustrates a schematic example of chest X-ray photography performed using the X-ray photography auxiliary tool. [Diagram 5] FIG. 5 is a perspective view that illustrates an example of an X-ray photography auxiliary tool. [Figure 6] Fig. 6(a) is a schematic diagram showing an example of a cross-sectional view during standing position radiography using an X-ray radiography auxiliary tool, and Fig. 6(b) is an example of an X-ray image obtained using the X-ray radiography auxiliary tool. [Figure 7] FIG. 7 is a set of photographs showing the posture of the subject when the sponge member material and size were changed. [Figure 8] FIG. 8 is a graph showing the results of evaluation of the presence or absence of a scapular shadow. [Figure 9] FIG. 9 is a graph showing the evaluation results by gender. [Figure 10] Figure 10 is a graph showing the evaluation results by age group. [Figure 11] FIG. 11 is a graph showing the evaluation results by BMI. [Figure 12] FIG. 12 is a graph showing the results of evaluating whether or not there is an increase or decrease in the scapular shadow. [Figure 13] FIG. 13 is a graph showing the results of evaluating the extent of reduction in the scapular shadow. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment will be described with reference to the drawings. In the description, the same elements or elements having the same functions are designated by the same reference numerals, and duplicated description will be omitted.

[0017] [X-ray equipment] FIG. 1 shows a schematic diagram of an X-ray imaging apparatus according to an embodiment. The X-ray imaging apparatus 1 shown in FIG. 1 is an apparatus for performing chest X-ray imaging in the PA direction on a subject S in a standing position. The subject S of the X-ray imaging apparatus 1 may be, for example, an inpatient, an outpatient, or a person undergoing a medical checkup. The chest, which is the subject of chest X-ray imaging, includes the lungs, heart, aorta, and spine. The X-ray imaging apparatus 1 may perform chest X-ray imaging while being operated by an operator such as a diagnostic radiologist. The X-ray imaging apparatus 1 may be configured to generate a chest X-ray image from a signal obtained by chest X-ray imaging.

[0018] The X-ray imaging device 1 includes, for example, an X-ray irradiation device 2, an upright imaging table 4, and an auxiliary tool 10. In the following, the positional relationship of each device and each member included in the X-ray imaging device 1 will be described based on a state in which a chest X-ray is taken.

[0019] The X-ray irradiator 2 functions as an irradiation unit capable of irradiating X-rays. The X-ray irradiator 2 can irradiate X-rays to the chest of the subject S. The X-ray irradiator 2 is also called an X-ray generator. The X-ray irradiator 2 has, for example, an X-ray tube built in, and emits X-rays upon receiving power supply. The X-rays emitted from the X-ray irradiator 2 may spread radially as they move away from the X-ray irradiator 2. The X-ray irradiator 2 may be provided movably, and when performing chest X-ray imaging, for example, the operator sets it to a position and posture suitable for X-ray imaging.

[0020] The upright radiography stand 4 is installed in an radiography room for performing X-ray radiography including chest X-ray radiography. The upright radiography stand 4 has an X-ray detection unit 6 for upright radiography. The X-ray detection unit 6 faces the X-ray irradiation device 2 and is a unit that detects X-rays incident through the subject S. The X-ray detection unit 6 for upright radiography is also called a upright reader or a bucky unit. The X-ray detection unit 6 has an X-ray detector such as a flat panel detector therein. The X-ray detection unit 6 may have a cassette containing intensifying screen instead of an X-ray detector such as a flat panel detector.

[0021] The X-ray detection unit 6 is provided on the upright imaging platform 4 so that it can be raised and lowered. For example, the height position of the X-ray detection unit 6 is adjusted by an operator according to the subject S. When taking a chest X-ray, the subject S is between the X-ray irradiator 2 and the X-ray detection unit 6. Even if the subject S is present, the X-ray detection unit 6 still faces the X-ray irradiator 2. The X-ray detection unit 6 and the X-ray irradiator 2 may face each other in one horizontal direction, and this one direction is defined as "direction D1" in the present disclosure.

[0022] In addition, in direction D1, the direction from the X-ray irradiator 2 to the X-ray detection unit 6 is defined as "front", and the direction from the X-ray detection unit 6 to the X-ray irradiator 2 is defined as "rear". In direction D1, the X-ray irradiator 2, subject S, and X-ray detection unit 6 are arranged in this order. In the following description, the horizontal direction perpendicular to direction D1 is defined as "direction D2", and the up-down direction perpendicular to directions D1 and D2 is defined as "direction D3".

[0023] The X-ray detection unit 6 includes a facing surface 6a facing the X-ray irradiator 2 (facing backward). The facing surface 6a intersects with the direction D1. The facing surface 6a may be a flat surface. The shape of the facing surface 6a may be a vertically long rectangle. In one example, the facing surface 6a has a size large enough to cover the entire chest of the subject S. In chest X-ray photography, the subject S stands facing forward and the chest of the subject S is directly facing the facing surface 6a of the X-ray detection unit 6, and X-ray photography is performed. Specifically, the subject S's chin is placed on the X-ray detection unit 6 (its housing part), and the subject S is maintained in a standing position so that at least a part of the subject S's chest or at least a part of the subject S's shoulders contacts the facing surface 6a, and X-ray photography is performed.

[0024] (X-ray photography aids) Here, in order to facilitate understanding of the role of the auxiliary tool 10 (X-ray imaging auxiliary tool) provided in the X-ray irradiation device 2, a problem when the auxiliary tool 10 is not provided, i.e., when the auxiliary tool 10 is not used in chest X-ray imaging, will be described. FIG. 2(a) shows a schematic cross section (cut surface in a plane perpendicular to the direction D3) of the chest of the subject S when chest X-ray imaging is performed. In FIG. 2(a), "92R" represents the right lung field of the subject S, and "92L" represents the left lung field of the subject S. In addition, "94R" represents the right scapula of the subject S, and "94L" represents the left scapula of the subject S.

[0025] The cross section shown in Fig. 2(a) is in a state where the subject S naturally faces the opposing surface 6a. Fig. 2(b) shows an X-ray image P1 obtained in the state shown in Fig. 2(a). A part of the X-rays emitted from the X-ray irradiator 2, passing through the lung field 92R and entering the X-ray detection unit 6 also passes through the scapula 94R, and the remaining part does not pass through the scapula 94R. A part of the X-rays emitted from the X-ray irradiator 2, passing through the lung field 92L and entering the X-ray detection unit 6 also passes through the scapula 94L, and the remaining part does not pass through the scapula 94L.

[0026] 2(a), the two dashed lines whose distance from each other increases as they approach the X-ray detection unit 6 indicate the boundary between the part that passes through the lung field via the scapula and the part that passes through the lung field without passing through the scapula within the field of view imaged by the X-ray detection unit 6. "R" indicates the range in which X-rays enter the X-ray detection unit 6 without passing through the scapula.

[0027] A part of the X-rays enters the X-ray detection unit 6 through the scapula 94R and the lung field 92R, and a part of the X-rays enters the X-ray detection unit 6 through the scapula 94L and the lung field 92L, causing a shadow of the scapula to appear in the part of the X-ray image P1 corresponding to the lung field 92R and the lung field 92L. In FIG. 2(b), the shadow of the scapula is the part indicated by the white arrow. Masses and the like that may be formed in the lung field are often observed as a shadow (a part that appears white). Therefore, the shadow of the scapula can be an obstacle to observation of the lung field during a chest X-ray examination.

[0028] In order to remove the shadows of the scapula 94R and scapula 94L from the lung field on the X-ray image, it is necessary to push the shoulder (clavicle and humerus) of the subject S forward. As shown in FIG. 3(a), by pushing the shoulder forward, the scapula 94R and scapula 94L move forward. As a result, it can be seen that the region R is expanded compared to the state shown in FIG. 2(a). In this case, the shadows of the scapula 94R and scapula 94L included in the lung field on the X-ray image may become smaller. However, even if the shoulder is pushed forward, the X-ray detection unit 6 becomes a physical barrier and the shoulder cannot be pushed forward any further, and the X-rays that pass through the lung field via the scapula and enter the X-ray detection unit 6 remain.

[0029] It is known that the scapula moves around the sternoclavicular joint as an axis. The inventors came up with the idea that, as shown in FIG. 3(b), if the sternum (indicated by "96" in FIG. 3(b)) can be pulled backward while the shoulder is in contact with the X-ray detection unit 6 in chest X-ray photography, the scapula 94R and scapula 94L can be brought forward further. If the sternum 96 is moved backward while the front of the shoulder is in contact with the opposing surface 6a of the X-ray detection unit 6, the scapula 94R and scapula 94L will be brought forward relatively when the position of the sternum 96 is used as a reference. It can be seen that when the sternum 96 is pulled backward and the scapula 94R and scapula 94L are brought forward further (rotated further outward), the region R is wider than the state shown in FIG. 3(a). In this case, the shadows of the scapula 94R and scapula 94L may be removed from the lung field or may be smaller on the X-ray image.

[0030] In chest X-ray photography, the posture shown in Fig. 3(b) is ideal from the viewpoint of removing the shadow of the scapula from the lung field on the X-ray image, but it is not easy for all people who can be the subject S to take this posture in chest X-ray photography. Therefore, the inventors of the present invention have further studied and have come up with the idea that if a member that has an appropriate hardness, changes shape, and transmits X-rays is placed between the chest of the subject S (more specifically, the area where the sternum is located) and the X-ray detection unit 6, it will be possible to easily take the ideal posture (hereinafter referred to as the "ideal posture") for removing the shadow of the scapula as shown in Fig. 3(b).

[0031] As shown in FIG. 4, the auxiliary tool 10 (X-ray photography auxiliary tool) provided in the X-ray photography device 1 is a member that assists chest X-ray photography by being sandwiched between the X-ray detection unit 6 and the chest of the subject S. Specifically, the auxiliary tool 10 is a member that assists the subject S in taking the above-mentioned ideal posture. By using the auxiliary tool 10, the posture of the subject S can be made closer to the above-mentioned ideal posture when performing chest X-ray photography. As shown in FIG. 5, the auxiliary tool 10 includes a sponge member 20 (sponge cushion). The auxiliary tool 10 is made of, for example, the sponge member 20.

[0032] The sponge member 20 is a member that is permeable to X-rays. The sponge member 20 may be a single-cell sponge or an open-cell sponge. In one example, the sponge member 20 is formed using polyurethane foam (urethane foam) or polyethylene foam. Being permeable to X-rays means that the sponge member 20 transmits X-rays to an extent that it does not cause a shadow (does not appear white) on an X-ray image, similar to lung fields and the like. The sponge member 20 is formed so as to be compressed when sandwiched between the X-ray detection unit 6 and the chest of the subject S. The sponge member 20 is sandwiched between the X-ray detection unit 6 and the chest of the subject S, and is compressed so that its size in the direction D1 is not small by receiving contact forces from both the X-ray detection unit 6 and the chest.

[0033] The sponge member 20 may be provided independently from other members such as the X-ray detection unit 6. In other words, the operator or the like may be able to carry only the sponge member 20. When the sponge member 20 is provided independently, in chest X-ray photography, for example, with the assistance or instruction of the operator, the sponge member 20 is sandwiched between the chest of the subject S and the X-ray detection unit 6 to the extent that it is compressed and deformed, and is held in a compressed state between the chest of the subject S and the X-ray detection unit 6.

[0034] The sponge member 20 may include a flat surface 20a (flat surface) that can come into contact with the X-ray detection unit 6 (more specifically, the facing surface 6a of the X-ray detection unit 6). The sponge member 20 is formed so as to be compressed in a direction intersecting the surface 20a when sandwiched between the X-ray detection unit 6 and the chest of the subject S.

[0035] If the volume of the sponge member 20 is too small or too large, it becomes difficult to bring the posture of the subject S closer to the ideal state. 3 More than 420cm 3 or more, or 450cm 3 From the viewpoint of bringing the posture of the subject S closer to the ideal posture, the volume of the sponge member 20 is set to 600 cm 3 Below, 580cm3 or less than 550cm 3 In one example, the volume of the sponge member 20 may be 400 cm 3 ~600cm 3 , or 450cm 3 ~550cm 3 It is.

[0036] If the hardness of the sponge member 20 is too low (if the sponge member 20 is too soft), the sternum 96 cannot be lowered backward, making it difficult to bring the posture of the subject S closer to the ideal state. If the hardness of the sponge member 20 is too high (if the sponge member 20 is too hard), it becomes difficult to move the shoulders forward to contact the X-ray detection unit 6, making it difficult to bring the posture of the subject S closer to the ideal state.

[0037] The hardness of the sponge member 20 may be measured by an Asker C type hardness meter. The hardness of the sponge member 20 measured by the Asker C type hardness meter may be 18 or more, 20 or more, 22 or more, or 24 or more from the viewpoint of bringing the posture of the subject S closer to the ideal posture. The hardness of the sponge member 20 measured by the Asker C type hardness meter may be 40 or less, 38 or less, 36 or less, or 34 or less from the viewpoint of bringing the posture of the subject S closer to the ideal posture. In one example, the hardness of the sponge member 20 measured by the Asker C type hardness meter is 18 to 40, 20 to 38, or 22 to 36. The hardness of the sponge member 20 measured by the Asker C type hardness meter is defined as the arithmetic average of the measured values ​​obtained by measuring five or more times under the same conditions.

[0038] The density of the sponge member 20 affects the hardness of the sponge member 20. From the viewpoint of obtaining a hardness that brings the posture of the subject S closer to the above-mentioned ideal posture, the density of the sponge member 20 is set to 20 kg / m 3 More than 20.5kg / m 3 or more than 21kg / m 3 The density of the sponge member 20 is set to 24 kg / m from the viewpoint of obtaining a hardness that brings the posture of the subject S closer to the ideal posture. 3 Below, 23.5kg / m 3 or less than 23 kg / m3 In one example, the density of the sponge member 20 may be 20 kg / m 3 ~24kg / m 3 , or 21 kg / m 3 ~23kg / m 3 It is.

[0039] The sponge member 20 may be formed in a rectangular parallelepiped shape. In this case, of the six flat surfaces included in the sponge member 20, any one of two surfaces facing in opposite directions functions as a surface that contacts the X-ray detection unit 6. The thickness T, horizontal width L1, and vertical width L2 of the sponge member 20 may be within the following ranges. Thickness: 4.5cm~5.5cm ·Width L1: 9cm~11cm Length L2: 9cm~11cm

[0040] The thickness T is the size of the sponge member 20 in the thickness direction perpendicular to the surface 20a of the sponge member 20 that contacts the X-ray detection unit 6. The thickness direction corresponds to the direction D1 when the sponge member 20 is sandwiched between the subject S and the X-ray detection unit 6. Regarding the width L1 and the length L2, the width L1 of the surface 20a is measured and the length L2 of the surface 20a is measured in a state in which one arbitrarily selected side of the surface 20a is horizontal and the surface 20a is vertical.

[0041] The various dimensions, hardness, and density of the sponge member 20 are set so that the size of the sponge member 20 in direction D1 can be compressed to about 2 cm to 3 cm without forcing the subject S when the sponge member 20 is sandwiched between the subject S and the X-ray detection unit 6. The sponge member 20 may be formed from a commercially available sponge cushion.

[0042] FIG. 6(a) shows a schematic cross section of the auxiliary tool 10 (sponge member 20) sandwiched between the subject S and the X-ray detection unit 6. FIG. 6(b) shows an X-ray image P2 obtained in the state shown in FIG. 6(a). When the sponge member 20 of the auxiliary tool 10 is sandwiched between the part of the chest of the subject S where the sternum is located and the X-ray detection unit 6, the posture of the subject S becomes the above-mentioned ideal state, and it can be seen that the region R includes the entire lung field 92R and the lung field 92L. That is, it can be seen that in the entire lung field 92R and the lung field 92L, the X-rays that pass through these lung fields and are detected by the X-ray detection unit 6 do not pass through the scapula 94R and the scapula 94L. In this case, the shadow of the scapula is not formed in the lung field on the X-ray image P2. For example, the shadow of the scapula is formed outside the outer edge of the lung field on the X-ray image P2.

[0043] [X-ray method] Next, as an example of an X-ray imaging method, a description will be given of various steps executed using the X-ray imaging apparatus 1. The X-ray imaging method includes, for example, a preparation step, an irradiation step, and an image generation step.

[0044] The preparation process is a process for preparing a state in which chest X-ray photography is possible using the X-ray photography device 1. The preparation process includes preparing a sponge member 20 as the auxiliary tool 10. The preparation process includes an operator setting the X-ray irradiation device 2 of the X-ray photography device 1 in a position and posture suitable for chest X-ray photography. In the preparation process, the subject S assumes a posture with his / her shoulders forward with the sponge member 20 sandwiched between the chest of the subject S and the X-ray detection unit 6.

[0045] The irradiation step (first step) is a step of irradiating X-rays from the X-ray irradiator 2 toward the X-ray detection unit 6 in a state in which the sponge member 20 of the auxiliary tool 10 is sandwiched between the X-ray detection unit 6 and the chest of the subject S. In this irradiation step (while this irradiation step is being performed), the sponge member 20 is compressed by being sandwiched between the X-ray detection unit 6 and the chest of the subject S. In the irradiation step, an operator operates the X-ray irradiator 2, so that X-rays are irradiated from the X-ray irradiator 2 toward the chest of the subject S. The image generation step (second step) is a step of generating an X-ray image based on the X-rays (signals) detected by the X-ray detection unit 6 in the irradiation step. The generation of the X-ray image may be performed by any of various known methods.

[0046] [Variations] The shape of the sponge member 20 is not limited to the shape of the above-mentioned example, so long as it is possible to bring the posture of the subject S closer to the ideal posture. In addition, the various dimensions, hardness, and density of the sponge member 20 are not limited to the ranges of the above-mentioned example, so long as it is possible to bring the posture of the subject S closer to the ideal posture. The sponge member 20 may have a shape other than a rectangular parallelepiped. For example, the sponge member 20 may be formed in a hemisphere including one flat surface, a cylindrical shape, a truncated polygonal pyramid shape (for example, a quadrangular pyramid truncated) or a truncated cone shape.

[0047] In the X-ray imaging device 1, the sponge member 20 may be detachably attached to the X-ray detection unit 6. In the X-ray imaging device 1, the sponge member 20 may be permanently provided on the X-ray detection unit 6. In one example among the various examples described above, at least a part of the matters described in the other examples may be combined.

[0048] [Verification of dimensions and hardness] Regarding the dimensions and hardness of the sponge member 20, the range in which the subject S can approach the ideal posture exemplified in Fig. 3 was examined. Sponge members whose dimensions were obviously too large, whose dimensions were obviously too small, and soft sponge members (for example, those with a hardness of less than 18 as measured by an Asker C-type hardness tester) were excluded from the examination because, based on the experience of the present inventors, they are unable to bring the posture of the subject S into the ideal posture.

[0049] Also, it is desirable to use as the evaluation criterion whether or not the shadow of the scapula falls outside the lung field on the X-ray image, but in chest X-ray photography, the subject S is exposed to radiation, even if only in small amounts, and it is not necessarily desirable to obtain X-ray images primarily for the purpose of verifying dimensions, etc. For this reason, multiple types of sponge members 20 with different dimensions and hardness were prepared, and the posture of the subject S when the sponge members 20 were held in front of the chest was used as the evaluation criterion.

[0050] The posture of subject S was evaluated for each of Comparative Example, Verification Example 1, Verification Example 2, and Verification Example 3. In the Comparative Example, the posture was evaluated in a state where the sponge member (auxiliary tool) was not sandwiched between the X-ray detection unit 6 and the chest of subject S. In each of Verification Examples 1, 2, and 3, the posture was evaluated in a state where a sponge member made of polyurethane foam was sandwiched between the X-ray detection unit 6 and the chest of subject S.

[0051] In verification example 1, posture was evaluated using a sponge member having medium hardness, width L1 = 10 cm, length L2 = 10 cm, and thickness T = 5 cm. In verification example 2, posture was evaluated using a sponge member having a harder hardness than the sponge member in verification example 1, width L1 = 10 cm, length L2 = 10 cm, and thickness T = 5 cm. In verification example 3, posture was evaluated using a sponge member having the same hardness as the sponge member in verification example 1, width L1 = 20 cm, length L2 = 10 cm, and thickness T = 5 cm.

[0052] 7 shows images of the postures in each of the comparative example, verification example 1, verification example 2, and verification example 3. In verification example 1, verification example 2, and verification example 3, the position of the scapula relative to the sternum was more forward than in the comparative example. In verification example 1, the thickness T of the sponge member was reduced to about 2.5 cm, in verification example 2, the thickness T of the sponge member was reduced to about 3.3 cm, and in verification example 3, the thickness T of the sponge member was reduced to about 3.0 cm.

[0053] In verification examples 2 and 3, a gap g was formed between the facing surface 6a of the X-ray detection unit 6 and the front surface of the shoulder of the subject S. On the other hand, in verification example 1, the front surface of the shoulder of the subject S came into contact with the facing surface 6a of the X-ray detection unit 6. From the above, it can be seen that, compared to verification examples 2 and 3, when the sponge member of verification example 1 was used, the posture of the subject S was closer to the ideal posture.

[0054] (Hardness measurement) The hardness of each of the test piece 1 made of the same material as the sponge member used in the verification example 1 and the test piece 2 made of the same material as the sponge member used in the verification example 2 was measured. Specifically, a digital hardness tester (C type) manufactured by TOPINCN was used as an Asker C-type hardness tester (C-type hardness tester) to perform 10 measurements on each of the test piece 1 and the test piece 2. The arithmetic average of the 10 measurements was calculated as the measurement value of the hardness of the test piece 1 and the test piece 2. The 10 measurements were performed in an environment with an air temperature of 24 degrees and a humidity of 52%, and the hardness tester was pressed against the test piece by hand. Table 1 below shows the measured values ​​of the digital hardness tester for each measurement and the arithmetic average value.

[0055] [Table 1]

[0056] Test piece 1 is formed in a rectangular parallelepiped shape, and its size is 10 cm × 10 cm × 5 cm. Test piece 2 is formed in a rectangular parallelepiped shape, and its size is 11 cm × 10 cm × 4.5 cm. The density of the sponge member of test piece 1 (verification example 1) is 22 kg / m3 From the results shown in Table 1 above and the posture evaluation results in various verification examples shown in Fig. 7, it can be seen that when the sponge members have similar dimensions, the posture of the subject S can be brought closer to the ideal state when the sponge member has an Asker C-type hardness of 40 or less.

[0057] [Evaluation of scapular shadows on X-ray images] Next, the shadow of the scapula on the X-ray image obtained when the sponge member according to the verification example 1 was used and the above-mentioned X-ray imaging method was executed was evaluated. In this case, the evaluation was performed by comparing with the X-ray image obtained by performing chest X-ray imaging without using the sponge member. As described above, since it is not appropriate to unnecessarily expose the subject S to radiation, the X-ray image used for comparison when the sponge member was not used was one obtained when chest X-ray imaging was performed in the same imaging room in the past. The X-ray image to be evaluated was obtained by the above-mentioned X-ray imaging method using the sponge member, taking advantage of the opportunity to perform a chest X-ray examination.

[0058] The equipment and auxiliary tools used in the evaluation are as follows: Sponge material: Polyurethane foam, size 10cm x 10cm x 5cm, density 22kg / m 3 Standing camera stand: MS Microreader (Made by Mitaya Shoji) X-ray irradiation equipment: UP150L-30L (Shimadzu Corporation) Image processing device: FCR (manufactured by Fujifilm Medical) Image viewer: EV Insite (PSP)

[0059] The X-ray images of 704 cases were evaluated, which allowed for a comparative evaluation between the "previous" chest X-ray taken without using a sponge member and the "current" chest X-ray taken with a sponge member. As part of the evaluation, the presence or absence of a scapula shadow in each of the left and right lung fields on the X-ray images was evaluated. The evaluation results are shown in Figure 8. The graph in Figure 8 shows the ratio of the number of cases in which a scapula shadow was seen in the lung field on the X-ray image to the total number of cases (n=704). The presence or absence of a scapula shadow in the lung field was judged by visual inspection of the X-ray images.

[0060] "Previous right scapula" is the percentage of cases in which the shadow of the right scapula (scapula 94R) was seen in the right lung field on the X-ray image obtained in the previous chest X-ray without using a sponge member. "Previous left scapula" is the percentage of cases in which the shadow of the left scapula (scapula 94L) was seen in the left lung field on the X-ray image obtained in the previous chest X-ray. "Current right scapula" is the percentage of cases in which the shadow of the right scapula (scapula 94R) was seen in the right lung field on the X-ray image obtained in the current chest X-ray with a sponge member. "Current left scapula" is the percentage of cases in which the shadow of the left scapula (scapula 94L) was seen in the left lung field on the X-ray image obtained in the current chest X-ray.

[0061] The proportion of cases where a shadow was cast on the right scapula in the previous test was 60.4%, whereas the proportion of cases where a shadow was cast on the right scapula this time was 30.4%, meaning that the proportion of cases where a shadow was cast was reduced to about half. The proportion of cases where a shadow was cast on the left scapula in the previous test was 77.3%, whereas the proportion of cases where a shadow was cast on the right scapula this time was 46.2%, meaning that the proportion of cases where a shadow was cast was reduced to about 0.6 times. From the above results, it can be seen that in chest X-ray photography, by sandwiching the sponge member 20 between the chest of the subject S and the X-ray detection unit 6, the proportion of cases where a shadow of the scapula is cast in the lung field on the X-ray image is reduced.

[0062] Figure 9 shows the results of evaluating the proportion of cases in which the shadow of the scapula was seen in the lung field on the X-ray image, broken down by gender. The results shown in Figure 9 show that the proportion of cases in which the shadow of the scapula was seen in the lung field on the X-ray image has decreased compared to the previous study, regardless of gender.

[0063] Figure 10 shows the results of evaluating the proportion of cases in which a scapular shadow was seen in the lung field on an X-ray image by age group.The results shown in Figure 10 show that the proportion of cases in which a scapular shadow was seen in the lung field on an X-ray image has decreased compared to the previous time in all generations (regardless of age).

[0064] Figure 11 shows the results of evaluating the proportion of cases in which a scapular shadow was seen in the lung field on an X-ray image by BMI (BMI range). The results shown in Figure 11 show that the proportion of cases in which a scapular shadow was seen in the lung field on an X-ray image has decreased compared to the previous time, regardless of BMI. It can also be seen that the degree of decrease in the above proportion is relatively large in the BMI range of 18.5 to 25.

[0065] As an evaluation separate from the presence or absence of a scapula shadow, we evaluated the change in the width of the scapula shadow in the lung field on X-ray images for cases in which a scapula shadow was present in the lung field on the previous X-ray image. The number of cases (n) in which a scapula shadow was included in the right lung field on the previous X-ray image was 425, and the number of cases (n) in which a scapula shadow was included in the left lung field on the previous X-ray image was 544. The maximum width Wm between the outer edge of the lung field and the inner edge of the scapula in the lateral direction on the X-ray image was measured as the width of the scapula shadow in the lung field (see Figure 2(b)). When a scapula shadow was not present in the lung field, the maximum width Wm was set to zero.

[0066] In the graph shown in Figure 12, "reduced" indicates the number of cases in which the maximum width Wm in the current X-ray image decreased compared to the previous X-ray image. "No change" indicates the number of cases in which the maximum width Wm in the current X-ray image did not change compared to the previous X-ray image, and "increased" indicates the number of cases in which the maximum width Wm in the current X-ray image increased compared to the previous X-ray image. From the evaluation results shown in Figure 12, it can be seen that the width of the scapula shadow in the lung field decreased in more than 90% of cases.

[0067] In FIG. 13, the width of the scapula shadow in the lung field was evaluated in the cases that were the subject of the evaluation shown in FIG. 12. The average maximum width Wm in the cases in which the scapula shadow was included in the right lung field on the previous X-ray image was 12.4 mm, and the average maximum width Wm in the cases in which the scapula shadow was included in the left lung field on the previous X-ray image was 14.4 mm. In contrast, the average maximum width Wm of the right scapula on the current X-ray image in the same subject case was 4.0 mm, a decrease of 8.4 mm. In other words, the average maximum width Wm of this time decreased to about 0.3 times the average maximum width Wm of the previous maximum width Wm. The average maximum width Wm of the left scapula on the current X-ray image in the same subject case was 5.8 mm, a decrease of 8.7 mm. In other words, the average maximum width Wm of this time decreased to about 0.4 times the average maximum width Wm of the previous maximum width Wm.

[0068] [Effects of the embodiment] The above-described auxiliary tool 10 is an X-ray photography auxiliary tool that assists in X-ray photography of the chest of subject S by being sandwiched between the X-ray detection unit 6 for standing position photography facing the X-ray irradiator 2 and the chest of subject S. This auxiliary tool 10 is capable of transmitting X-rays and includes a sponge member 20 that is formed to be compressed when sandwiched between the X-ray detection unit 6 and the chest of subject S.

[0069] The shadow of the scapula on the X-ray image obtained by chest X-ray photography can be an obstacle to the observation of the lung field. In chest X-ray photography, if the sternum 96 can be pulled backward while the shoulder is in contact with the X-ray detection unit 6, the scapula can be pushed forward further, and if a compressible sponge member is sandwiched between the chest of the subject S and the X-ray detection unit 6, the subject S can easily take an ideal posture (the above-mentioned ideal posture) for removing the shadow of the scapula from the lung field. Since the sponge member 20 provided in the above-mentioned auxiliary tool 10 transmits X-rays, the sponge member 20 does not become a shadow on the X-ray image. In addition, since the sponge member 20 is deformed so as to be compressed when sandwiched between the X-ray detection unit 6 and the chest of the subject S, it can help the posture of the subject S to approach the above-mentioned ideal posture. From the above, the above-mentioned auxiliary tool 10 can reduce the ratio of the shadow of the scapula reflected in the lung field in the X-ray image obtained by chest X-ray photography.

[0070] The sponge member 20 may have a flat surface (surface 20a) that can come into contact with the X-ray detection unit 6. The sponge member 20 may be formed so as to be compressed in a direction intersecting the flat surface when sandwiched between the X-ray detection unit 6 and the chest of the subject S. In this case, in the preparation stage for chest X-ray photography, the flat surface can be attached to the X-ray detection unit 6, and the sponge member 20 can be sandwiched between the X-ray detection unit 6 and the chest of the subject S. This makes it possible to simultaneously suppress disorders caused by shadows of the scapula in X-ray images and simplify the work of preparation using an auxiliary tool.

[0071] The volume of the sponge member 20 is 400 cm 3 ~600cm 3 If the volume of the sponge member 20 is large, the shoulders of the subject S do not contact the X-ray detection unit 6, and if the volume of the sponge member 20 is small, the sternum 96 cannot be lowered backward, and it is difficult for the posture of the subject S to approach the ideal posture. 3 ~600cm 3 By using the sponge member 20 having the above-mentioned structure, it is easy to bring the posture of the subject S closer to the ideal posture.

[0072] The sponge member 20 may be formed in a rectangular parallelepiped shape. The size (thickness T) of the sponge member 20 in the thickness direction perpendicular to the surface (surface 20a) of the sponge member 20 that contacts the X-ray detection unit 6 may be 4.5 cm to 5.5 cm. The horizontal width L1 of the surface may be 9 cm to 11 cm. The vertical width L2 of the surface may be 9 cm to 11 cm. In this case, when the sponge member 20 is sandwiched between the X-ray detection unit 6 and the chest of the subject S, the size of the sponge member 20 in the thickness direction may be compressed to an amount (for example, about 2 cm to 3 cm) that is necessary to lower the sternum 96 to achieve the ideal posture. Therefore, it is easy to bring the posture of the subject S closer to the ideal posture.

[0073] The density of the sponge member 20 is 20 kg / m 3 ~24kg / m 3 In this case, the sponge member 20 has a hardness within an appropriate range for taking the above-mentioned ideal posture, so that it is easy to bring the posture of the subject S closer to the above-mentioned ideal posture.

[0074] The hardness of the sponge member 20 measured by an Asker C type hardness meter may be 18 to 40. If the sponge member 20 is too hard, the shoulders of the subject S will not contact the X-ray detection unit 6, and if the sponge member 20 is too soft, the sternum 96 will not be able to be lowered back, making it difficult for the posture of the subject S to approach the ideal posture. In contrast, by using a sponge member 20 with an Asker C type hardness of 18 to 40, it is easy to bring the posture of the subject S closer to the ideal posture.

[0075] The X-ray imaging device 1 described above includes an X-ray irradiator 2 capable of irradiating X-rays, an X-ray detection unit 6 for upright imaging that faces the X-ray irradiator 2 and detects X-rays incident through the subject S, and an auxiliary tool 10 that assists in X-ray imaging of the subject S's chest by being sandwiched between the X-ray detection unit 6 and the chest of the subject S. The auxiliary tool 10 has a sponge member 20 that is permeable to X-rays and is formed so as to be compressed when sandwiched between the X-ray detection unit 6 and the chest of the subject S. This X-ray imaging device 1, like the auxiliary tool 10, can reduce the proportion of scapular shadows reflected in the lung field in an X-ray image obtained by chest X-ray imaging.

[0076] The X-ray imaging method described above includes a first step (irradiation step) of emitting X-rays from the X-ray irradiator 2 toward the X-ray detection unit 6 in a state where the sponge member 20 capable of transmitting X-rays is sandwiched between the X-ray detection unit 6 for upright position imaging facing the X-ray irradiator 2 and the chest of the subject S, and a second step (image generation step) of generating an X-ray image based on the X-rays detected by the X-ray detection unit 6. In the first step, the sponge member 20 is compressed by being sandwiched between the X-ray detection unit 6 and the chest of the subject S. This X-ray imaging method, like the above-mentioned auxiliary tool 10, can reduce the proportion of scapular shadows reflected in the lung field in an X-ray image obtained by chest X-ray imaging. [Explanation of symbols]

[0077] 1...X-ray imaging device, 2...X-ray irradiation device, 4...standing imaging table, 6...X-ray detection unit, 10...auxiliary tool, 20...sponge member, 20a...surface, S...subject, 92R, 92L...lung field, 94R, 94L...scapula, 96...sternum.

Claims

1. 1. An X-ray photography auxiliary device that is sandwiched between an X-ray detection unit for standing position photography facing an X-ray irradiation unit and a chest of a subject, and that assists in X-ray photography of the chest, An X-ray photography auxiliary device comprising a sponge member that is capable of transmitting X-rays and is formed so as to be compressed when sandwiched between the X-ray detection unit and the chest.

2. the sponge member has a flat surface that can come into contact with the X-ray detection unit, 2. The X-ray photography auxiliary device according to claim 1, wherein the sponge member is formed so as to be compressed in a direction intersecting the flat surface when sandwiched between the X-ray detection unit and the chest.

3. The volume of the sponge member is 400 cm ３ ~600cm ３ 3. The X-ray photography aid according to claim 1 or 2,

4. The sponge member is formed in a rectangular parallelepiped shape, The size of the sponge member in a thickness direction perpendicular to a surface of the sponge member that contacts the X-ray detection unit is 4.5 cm to 5.5 cm; The width of the surface is 9 cm to 11 cm; 3. The X-ray photography aid according to claim 1, wherein the vertical width of said surface is 9 cm to 11 cm.

5. The density of the sponge member is 20 kg / m ３ ~24kg / m ３ 3. The X-ray photography aid according to claim 1 or 2,

6. 3. The X-ray photography auxiliary tool according to claim 1, wherein the hardness of the sponge member measured by an Asker C type hardness tester is 18 to 40.

7. An irradiation unit capable of irradiating X-rays; an X-ray detection unit for upright position radiography, which faces the irradiation unit and detects X-rays incident through a subject; an X-ray photography auxiliary tool that is sandwiched between the X-ray detection unit and a chest of the subject to assist in X-ray photography of the chest, The X-ray imaging aid of the X-ray imaging device has a sponge member that is transparent to X-rays and is formed so as to be compressed when sandwiched between the X-ray detection unit and the chest.

8. a first step of emitting X-rays from an X-ray irradiation unit toward an X-ray detection unit in a state where an X-ray-transmittable sponge member is sandwiched between an X-ray detection unit for standing position radiography facing an X-ray irradiation unit and a chest of a subject; A second step of generating an X-ray image based on the X-rays detected by the X-ray detection unit, In the first step, the sponge member is compressed by being sandwiched between the X-ray detection unit and the chest.

Images