Protective cover and biopsy unit

Abstract

To provide a protective cover and a biopsy unit which can suppress reduction in a contrast of mammography while suppressing vignetting of the radiation.SOLUTION: A protective cover comprises: a plate-shaped protective member which is detachably provided in a mammography apparatus having an imaging table and protects an imaging surface from a puncture needle; and a scattered ray removal grid which removes a scattered ray generated when the radiation passes through the breast. The scattered ray removal grid is the grid in which a plurality of transmission parts that transmits the radiation and a plurality of absorption parts that absorbs the radiation are alternately arrayed, and a boundary line between the transmission part and the absorption part extends in one direction. When a direction connecting a chest wall side on which the chest wall of a subject is located and an opposite side of the chest wall is a first direction and a direction orthogonal to the first direction is a second direction on the imaging surface, the scattered ray removal grid is arranged at an opposing position opposing to the imaging surface in such a posture that the direction in which the boundary line extends is in parallel to the second direction.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a protective cover and a biopsy unit.

Background Art

[0002] Patent Document 1 describes a mammography apparatus that forms a radiation image of a breast by arranging a radiation permeable body and a radiation impermeable body that constitute a grid so as to extend substantially parallel to the chest wall of the breast and irradiating a solid detector with radiation output from a radiation source through the grid.

[0003] Patent Document 2 describes an X-ray imaging device in which a scatter prevention grid having a plurality of partition walls can be configured to be positioned with respect to an X-ray imaging device such that each of the plurality of partition walls extends along a direction substantially parallel to the coronal plane of an object during imaging of the object using the X-ray imaging device. The X-ray imaging device can be operable in a tomosynthesis mode for imaging the chest of an object and can include a scatter prevention grid disposed between a chest platform and an X-ray detector.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Mammography equipment is sometimes used to locate the tissue to be collected within the breast when performing a biopsy (i.e., a biopsy, or biopsy) to collect tissue from lesions or other tissues within the breast. In this case, a biopsy unit is attached to the mammography equipment, and both breast imaging and tissue collection are performed. Since the biopsy unit has a puncture needle for collecting biopsy tissue, a protective cover is attached to the imaging table to protect the imaging surface from the puncture needle when using the biopsy unit.

[0006] In biopsies, to obtain a three-dimensional understanding of the tissue's position within the breast, stereo imaging or tomosynthesis imaging is sometimes performed, in which a C-arm to which a radiation source is attached is rotated along an axis of rotation approximately parallel to the depth direction of the imaging plane, and the radiation source is irradiated from multiple positions with different irradiation angles relative to the imaging plane. When performing such imaging (hereinafter referred to as pre-biopsy imaging), the contrast of the breast image may decrease due to the effects of scattered radiation. Using a scatter-removal grid is effective in suppressing the effects of scattered radiation. However, the scatter-removal grids that are standardly built into imaging tables do not have a boundary orientation between the radiation-absorbing part and the radiation-transmitting part that is suitable for pre-biopsy imaging, sometimes resulting in significant vignetting of the radiation.

[0007] The technology disclosed herein provides a protective cover and a biopsy unit that can suppress radiation vignetting and reduce the contrast of breast images during pre-biopsy imaging. [Means for solving the problem]

[0008] A first aspect of the technology of this disclosure comprises a mammography apparatus equipped with an imaging table on which the subject's breast is placed and which has an imaging surface into which radiation that has passed through the breast is incident, a flat protective member that is detachably attached to the imaging surface and protects the imaging surface from a puncture needle used to collect tissue from the breast, and a scattered radiation removal grid that removes scattered radiation generated when radiation passes through the breast, wherein the scattered radiation removal grid is a grid in which a plurality of transmitting parts that transmit radiation and a plurality of absorbing parts that absorb radiation are arranged alternately, and the boundary line between the transmitting parts and absorbing parts extends in one direction, and further, in the imaging surface, when the direction connecting the chest wall side where the subject's chest wall is located and the opposite side of the chest wall is defined as the first direction, and the direction perpendicular to the first direction is defined as the second direction, the scattered radiation removal grid is a protective cover positioned opposite the imaging surface in a posture in which the direction in which the boundary line extends is parallel to the second direction.

[0009] A second aspect of the technology of this disclosure is a protective cover according to the first aspect, wherein the scattered radiation removal grid is positioned between the protective member and the imaging surface.

[0010] A third aspect of the technology of this disclosure is a protective cover according to the first aspect, wherein the scattered radiation removal grid is provided on a protective member in a manner that allows it to be displaced between an opposing position facing the imaging surface and a retracted position moving away from the opposing position.

[0011] A fourth aspect of the technology of this disclosure is a protective cover according to the third aspect, wherein the protective member has a positioning portion that restricts the displacement of the scattered radiation removal grid at opposing positions.

[0012] A fifth aspect of the technology of this disclosure is a protective cover according to the third aspect, wherein the protective member is provided with a support shaft for supporting a scatter removal grid, and the scatter removal grid is rotatable about the support shaft.

[0013] A sixth aspect of the technology of this disclosure is a protective cover according to the fifth aspect, wherein the protective member is rectangular in shape, and the support shaft is located at one of the four corners of the protective member.

[0014] A seventh aspect of the technology of this disclosure is a protective cover according to the first aspect, wherein the scattered radiation removal grid is detachably attached to the protective member.

[0015] An eighth aspect of the technology of this disclosure is a protective cover according to the seventh aspect, wherein the protective member is provided with a guide portion that guides it to an opposing position by engaging with a scatter removal grid.

[0016] A ninth aspect of the technology of this disclosure is a protective cover according to the eighth aspect, wherein the guide portion is capable of receiving a scattered radiation removal grid from the opposite side of the chest wall where the subject's chest wall is located.

[0017] A tenth aspect of the technology of this disclosure is a protective cover according to the ninth aspect, wherein, when the direction along the first direction of the scattered radiation removal grid is the depth direction of the protective member and the direction along the second direction is the width direction of the protective member, the guide portion is a pair of guide rails provided at both ends in the width direction and extending in the depth direction.

[0018] An eleventh aspect of the technology of this disclosure is a protective cover according to the eighth aspect, wherein, when the direction along the first direction of the scattered radiation removal grid is the depth direction of the protective member and the direction along the second direction is the width direction of the protective member, the guide portion is capable of receiving the scattered radiation removal grid from the end in the width direction of the protective member.

[0019] A twelfth aspect of the technology of this disclosure is a protective cover according to the eleventh aspect, wherein the guide portion is provided only on the side opposite to the chest wall in the depth direction.

[0020] A thirteenth aspect of the technology of this disclosure is a protective cover according to the seventh aspect, which has a positioning unit that restricts a scattered radiation removal grid attached to a protective member to a position facing the imaging surface.

[0021] A fourteenth aspect of the technology of this disclosure is a protective cover according to the seventh aspect, wherein the scattered radiation removal grid is provided with a gripping portion.

[0022] The 15th aspect of the technology according to the present disclosure is a protective cover according to the 1st aspect, in which the scatter-ray removing grid is integrated with the protective member.

[0023] The 16th aspect of the technology according to the present disclosure is a biopsy unit that holds a puncture needle movably, and is a biopsy unit provided with the protective cover according to any one of the 1st aspect to the 15th aspect.

Advantages of the Invention

[0024] The technology of the present disclosure can provide a protective cover and a biopsy unit capable of suppressing a decrease in contrast of an image obtained by imaging a breast while suppressing blooming of radiation.

Brief Description of the Drawings

[0025] [Figure 1] It is an external perspective view showing an example of the configuration of a breast imaging apparatus. [Figure 2] It is an external perspective view showing an example of a state where a protective cover and a biopsy unit are attached to and detached from a breast imaging apparatus. [Figure 3] It is an external side view showing an example of the configuration of a breast imaging apparatus. [Figure 4] It is an external front view showing an example of the configuration of a breast imaging apparatus. [Figure 5] It is an external plan view showing an example of the state of displacement of an external grid. <� [Figure 6] It is an external side view showing an example of a state where radiation is irradiated in a breast imaging apparatus. [Figure 7] It is a diagram summarizing the proper use of grids in a breast imaging apparatus. [Figure 8] It is an external side view showing an example of the configuration of a breast imaging apparatus as a comparative example. [Figure 9] It is an external front view showing an example of the configuration of a breast imaging apparatus as a comparative example. [Figure 10] It is an external plan view showing another example of the state of displacement of an external grid. [Figure 11]This is an external plan view showing another example of the displacement of the external grid. [Figure 12] This is an external plan view showing another example of the displacement of the external grid. [Figure 13] This is an external view plan showing another example of a protective cover. [Modes for carrying out the invention]

[0026] Embodiments of this disclosure will be described in detail below with reference to the drawings.

[0027] For the purposes of this explanation, the height, width, and front-to-back (also called depth) directions of the mammography device 10 will be indicated by three arrows: X, Y, and Z. First, the height direction is indicated by arrow Z, with the direction indicated by arrow Z being the upward direction of the mammography device 10 and the opposite direction being the downward direction. The height direction is vertical. The width direction is indicated by arrow X, which is perpendicular to arrow Z, with the direction indicated by arrow X being the rightward direction of the mammography device 10 and the opposite direction being the leftward direction. The front-to-back direction is indicated by arrow Y, which is perpendicular to both arrow Z and arrow X, with the direction indicated by arrow Y being the frontward direction of the mammography device 10 and the opposite direction being the rearward direction. In other words, the side of the mammography device 10 facing the stand 20 is the rearward direction, and the opposite side where the subject A stands (see Figure 2) is the frontward direction. Furthermore, in the following, expressions using "side," such as "upper side," "lower side," "left side," "right side," "front side," and "back side," have the same meaning as expressions using "direction."

[0028] Furthermore, in this embodiment, "vertical direction" refers to the vertical direction including not only a perfectly vertical direction but also an error that is generally acceptable in the art to which the disclosed technology belongs, and that does not contradict the spirit of the disclosed technology. Similarly, "horizontal direction" refers to the horizontal direction including not only a perfectly horizontal direction but also an error that is generally acceptable in the art to which the disclosed technology belongs, and that does not contradict the spirit of the disclosed technology.

[0029] Furthermore, in this embodiment, "match" refers not only to a perfect match but also to a match that includes errors that are generally acceptable in the technical field to which the disclosed technology belongs, and that do not contradict the spirit of the disclosed technology.

[0030] (First Embodiment) As shown in Figures 1 and 2, the mammography apparatus 10 according to the first embodiment is a radiography apparatus that irradiates the breast M of a subject A with radiation and takes a radiographic image of the breast M. The radiation is X-rays as an example, but gamma rays may also be used. Subject A is positioned in front of the mammography apparatus 10. The mammography apparatus 10 is an example of a "mammography apparatus" according to the technology of this disclosure.

[0031] The mammography apparatus 10 is connected to a console (not shown). The console has a setting function to configure the mammography apparatus 10 according to the imaging order, as well as a function to acquire the radiographic images taken by the mammography apparatus 10 and display the acquired radiographic images. The console is connected to an image database server (not shown) via a network (not shown), such as a LAN (Local Area Network), and is capable of communication with the image database server (not shown).

[0032] The mammography apparatus 10 comprises a stand 20 and an arm 21. The stand 20 consists of a base 20A installed on the floor of the radiography room and a support column 20B extending in the height direction from the base 20A. The arm 21 is roughly C-shaped when viewed from the left side and is connected to the support column 20B via a pivot axis. The arm 21 is movable in the height direction relative to the support column 20B, allowing for height adjustment according to the height of the subject A. The arm 21 is also rotatable around a pivot axis perpendicular to the support column 20B.

[0033] The arm 21 consists of a radiation source housing 22, a main body 23, and an imaging table 24. The radiation source 25 is housed in the radiation source housing 22. The radiation source housing 22 has, for example, a housing structure with a longitudinal direction in the front-to-back direction. The breast M of subject A is placed on the imaging table 24. A radiation detector 26 is housed in the imaging table 24. The main body 23 integrally connects the radiation source housing 22 and the imaging table 24. The main body 23 holds the radiation source housing 22 and the imaging table 24 in opposing positions. Handrails 27 for subject A to grasp are provided on both sides of the main body 23.

[0034] The breast M of subject A is placed on the imaging table 24. The imaging table 24 has an imaging surface 24A into which radiation that has passed through the breast M is incident. A radiation detector 26 is housed in the imaging table 24. The imaging table 24 is an example of an "imaging table" according to the technology of this disclosure.

[0035] The radiation source 25 irradiates the breast M, which is placed on the imaging table 24, with radiation. The radiation emitted from the radiation source 25 passes through the compression plate 30 and then enters the breast M. The radiation detector 26 detects the radiation that has passed through the breast M and outputs a radiation image. The radiation detector 26 is called an FPD (Flat Panel Detector). The radiation detector 26 has a scintillator that converts radiation into visible light, and may be an indirect conversion type that converts the visible light emitted by the scintillator into an electrical signal, or a direct conversion type that directly converts radiation into an electrical signal.

[0036] A field limiter 31 is provided between the radiation source 25 and the imaging table 24. The field limiter 31, also called a collimator, defines the field of radiation irradiation to the imaging table 24.

[0037] A face guard 32 is attached to the radiation source housing 22. The face guard 32 is made of or coated with a material that does not transmit radiation, and protects the face of subject A from radiation.

[0038] A compression plate 30 is provided between the imaging table 24 and the irradiation field limiter 31 to compress the breast M between the imaging table 24 and the compression plate 30. The compression plate 30 is made of a material that allows radiation to pass through. The compression plate 30 is positioned opposite the imaging table 24. In this embodiment, the compression plate 30 is box-shaped with an open top.

[0039] The moving mechanism 35 supports the compression plate 30 so that it can move between the radiation source 25 and the imaging table 24. The movable part 34 is positioned between the compression plate 30 and the moving mechanism 35. The movable part 34 is slidably held on a rail 28 provided on the moving mechanism 35. The rail 28 extends in the vertical direction.

[0040] The moving mechanism 35 includes, for example, a motor (not shown), a motor driver (not shown), and a lead screw mechanism (not shown). The motor rotates in response to an electrical drive signal output by the motor driver, and moves the compression plate 30 via the lead screw mechanism.

[0041] The compression plate 30 is attached to the movable part 34 via a pair of support arms 33. The movable part 34 moves vertically together with the compression plate 30 by a moving mechanism 35. Functionally, the vertical direction is the direction in which the compression plate 30 moves toward the imaging table 24 (i.e., downward) and the direction in which the compression plate 30 moves away from the imaging table 24 (i.e., upward). In this way, the compression plate 30 is configured to be movable in a manner that changes the distance between it and the imaging table 24.

[0042] A biopsy unit 39 is attached to the mammography apparatus 10. The biopsy unit 39 is a unit for collecting tissue from the breast M for biopsy. The biopsy unit 39 comprises a main body 40, an adjustment unit 41, a needle holder 42, and a puncture needle 43. The adjustment unit 41 is movable relative to the main body 40, thereby adjusting the insertion position, insertion angle, and insertion amount of the puncture needle 43 into the breast M. The needle holder 42 holds the puncture needle 43. The puncture needle 43 has a double structure, for example, an outer needle and an inner needle. The procedure for tissue collection using such a puncture needle 43 is as follows as an example: The puncture needle 43 is inserted into the breast M, and when the tip of the puncture needle 43 reaches the location of the tissue to be collected, the inner needle is extended from the outer needle, and tissue is collected in the tissue collection area formed on the inner needle. After collecting tissue on the inner needle, the inner needle is retracted into the outer needle, and the puncture needle 43 is withdrawn from the breast 43. This allows the target tissue to be collected from the breast M to be harvested. The compression plate 30 also has an opening on its bottom surface, and the puncture needle 43 is inserted into the breast M through this opening. The puncture needle 43 is an example of a "puncture needle" according to the technology of this disclosure.

[0043] When a biopsy is performed using the biopsy unit 39, a protective cover 37 is placed on the imaging table 24. The protective cover 37 protects the imaging surface 24A from the puncture needle 43. That is, the protective cover 37 prevents the puncture needle 43 from contacting the imaging surface 24A. The protective cover 37 comprises a flat protective member 37A and a front wall 37B that is bent from the front end of the protective member 37A. The breast M is placed on the protective member 37A. The protective member 37A is made of a material that can transmit radiation (for example, acrylic resin). The size of the protective member 37A is such that it can support the breast M, and the thickness of the protective member 37A has sufficient strength to support the breast M. The protective member 37A is an example of a "protective member" according to the technology of this disclosure.

[0044] As shown in Figure 2, the biopsy unit 39 and protective cover 37 are attached to the mammography apparatus 10 when a biopsy is performed. In other words, the biopsy unit 39 and protective cover 37 are detachable from the mammography apparatus 10. The protective cover 37 is attached to the imaging table 24 of the mammography apparatus 10, for example, by magnetic attraction using a magnet. Specifically, a magnet is attached to the protective cover 37, and the protective cover 37 is attached to the imaging table 24 by magnetic attraction of the magnet to a magnetizing plate provided on the imaging table 24. This is merely one example; for example, the protective cover 37 may be attached to the imaging table 24 via an adhesive sheet, or a part of the protective cover 37 may be fitted into a recess provided on the imaging table 24 to attach it to the imaging table 24.

[0045] The biopsy unit 39 is placed on the imaging table 24 after the protective cover 37 has been attached to the imaging table 24. Specifically, the main body 40 of the biopsy unit 39 is placed above the rear end 37C of the protective cover 37. The biopsy unit 39 may also be controlled to operate only when the protective cover 37 is attached to the imaging table 24.

[0046] Furthermore, the compression plate 30 is also a compression plate for the biopsy unit 39, and can be attached to the mammography device 10 by replacing it with the compression plate for mammography when a biopsy is not performed (not shown).

[0047] As shown in Figure 3, for example, when a biopsy is performed, the breast M is compressed by the compression plate 30, and the puncture needle 43 is inserted into the breast M. In this case, it is necessary to accurately identify the location of the tissue to be harvested from the breast M (e.g., lesional tissue). For this reason, as will be described later, when a biopsy is performed, pre-biopsy imaging may be performed to three-dimensionally identify the location of the tissue to be harvested from the breast M. In this embodiment, stereo imaging is performed by irradiating the breast with radiation R from two directions, left and right, with different irradiation angles relative to the imaging table 24.

[0048] Here, the imaging table 24 may have a built-in scatter-removing grid, such as a built-in grid 45. As is well known, the scatter-removing grid removes scattered radiation generated when radiation passes through the breast M. The built-in grid 45 is located inside the imaging table 24, on the radiation source 25 side of the radiation detector 26. The built-in grid 45 is a flat plate-shaped member and comprises an absorbing portion 46 that transmits radiation R and a transmitting portion 47 that absorbs radiation. The absorbing portion 46 and the transmitting portion 47 are arranged alternately, and the boundary line 48 between the absorbing portion 46 and the transmitting portion 47 is arranged inside the imaging table 24 so as to extend in the front-to-back direction (i.e., the direction connecting the chest wall side and the anti-chest wall side of the subject A on the imaging surface 24A). In other words, the absorbing portion 46 and the transmitting portion 47 are arranged alternately in the left-to-right direction. Here, the front-to-back direction is an example of the "first direction" related to the technology of this disclosure.

[0049] Examples of materials for the absorption section 46 include a thin film of lead. Examples of materials for the permeation section 47 include aluminum, paper, and carbon fiber.

[0050] When stereo imaging is performed, the mammography apparatus 10 performs imaging with the built-in grid 45 moved towards the anti-chest wall side (i.e., towards the main body 23 side) inside the imaging table 24. The boundary line 48 of the absorbent part 46 and the transmitted part 47 of the built-in grid 45 extends in a direction perpendicular to the direction of movement of the tube 25A. Therefore, when imaging is performed by moving the tube 25A using the built-in grid 45, the central axis of the radiation beam R and the boundary line 48 become perpendicular, resulting in increased vignetting of the radiation.

[0051] Therefore, in stereo imaging, an external grid 44, which is a scatter removal grid integrated into a protective cover 37, is used instead of the built-in grid 45. The external grid 44 refers to a scatter removal grid positioned outside the imaging table 24, and is used here to distinguish it from the built-in grid 45 that is built into the imaging table 24. The external grid 44, like the built-in grid 45, is equipped with an absorbing section 46 and a transmitting section 47. In the external grid 44, the absorbing section 46 and the transmitting section 47 are arranged alternately, and the boundary line 48 between the absorbing section 46 and the transmitting section 47 extends in the left-right direction. In other words, the absorbing section 46 and the transmitting section 47 are arranged alternately in the front-back direction. As a result, in the external grid 44, the central axis of the radiation beam R and the direction in which the boundary line 48 extends are approximately coincident, so that vignetting of radiation is suppressed in stereo imaging. Here, the left-right direction is an example of the "second direction" related to the technology of this disclosure. The absorption section 46 is an example of an "absorption section" relating to the technology of this disclosure, and the transmission section 47 is an example of a "transmission section" relating to the technology of this disclosure. The boundary line 48 is an example of a "boundary line" relating to the technology of this disclosure. The external grid 44 is an example of a "scatter removal grid" relating to the technology of this disclosure.

[0052] As shown in Figure 4, the mammography apparatus 10 has a function for performing contrast-enhanced imaging. As the contrast agent used for contrast-enhanced imaging, a contrast agent using iodine with a k-absorption edge of 33 keV (hereinafter simply referred to as "contrast agent") is generally used. The mammography apparatus 10 uses the breast M to which the contrast agent has been administered as the subject, and irradiates it with radiation R of a first energy lower than the k-absorption edge of the contrast agent to capture a low-energy image with the radiation detector 26, and also irradiates it with radiation R of a second energy higher than the k-absorption edge of the contrast agent to capture a high-energy image with the radiation detector 26. The specific first and second energies are determined in addition to the k-absorption edge of the contrast agent, taking into account the specifications of the mammography apparatus 10, the desired image quality of the radiation image, and the subject's exposure to radiation, and are generally preferably between 22 keV and 49 keV.

[0053] The contrast agent and tissues such as breast tissue have different radiation absorption characteristics (R). Therefore, high-energy images acquired in the manner described above show not only body tissues such as breast tissue and fat, but also the contrast agent clearly. Conversely, low-energy images show almost no contrast agent, while body tissues such as breast tissue are clearly visible. Consequently, a difference image showing the difference between the low-energy and high-energy images can be obtained as an image in which the breast tissue structure has been removed and the contrast agent is clearly visible. This type of imaging is called contrast-enhanced energy subtraction imaging.

[0054] Furthermore, as mentioned above, stereotactic imaging is sometimes performed during a biopsy to obtain a three-dimensional understanding of the location of the tissue to be biopsied within the breast M. In stereotactic imaging, multiple images are taken by changing the irradiation angle of radiation R by changing the irradiation position R in the left-right direction. At each irradiation angle in the left-right direction of stereotactic imaging, imaging with radiation R of different energy levels (i.e., contrast-enhanced energy subtraction imaging) is performed. This makes the tissue to be biopsied clearer in the image and makes it easier to understand its three-dimensional location.

[0055] Stereo imaging is performed with the breast M compressed between the compression plate 30 and the protective cover 37. The protective cover 37 has a spacer 38, which creates a gap between the imaging table 24 and the protective cover 37. An external grid 44 is provided between the protective cover 37 and the imaging surface 24A of the imaging table 24. Radiation R, from which scattered radiation has been removed by the external grid 44, is incident on the radiation detector 26. High-energy and low-energy images are obtained at each irradiation angle in the left and right directions. After the three-dimensional position of the tissue to be biopsied within the breast M is determined by stereo imaging, a puncture needle 43 is inserted into the breast M and the tissue to be biopsied is collected.

[0056] As shown in Figure 5, the protective member 37A of the protective cover 37 has an arc-shaped recess 52 at its rear end 37C. The main body 40 of the biopsy unit 39 is provided with a pair of bases 51. The bases 51 are cylindrical, and the recess 52 is shaped to match the outer circumference of the bases 51. After the protective cover 37 is placed on the imaging table 24, the biopsy unit 39 is placed on the imaging table 24 from above. In this case, the bases 51 are positioned to match the recess 52. As a result, even if the protective cover 37 moves in the front-to-back or left-to-right direction, the recess 52 contacts the base 51, thus preventing the protective cover 37 from shifting significantly. A gap is provided between the outer circumference of the base 51 and the inner circumference of the recess 52, allowing the protective cover 37 to move slightly. This prevents the biopsy unit 39 from moving as the protective cover 37 moves, thus preventing the position of the puncture needle 43 provided on the biopsy unit 39 from shifting.

[0057] The external grid 44 is integrated with the protective member 37A. In this embodiment, "integrated" means that the protective member 37A and the external grid 44 are separate components and are integrated by fixing the external grid 44 to the protective member 37A in a way that makes it impossible to remove them, and that the protective member 37A and the external grid 44 are integrated in a way that makes it impossible to separate them, for example by processing the surface of the external grid 44. In the example shown in Figure 5, the external grid 44 is the former, that is, the protective member 27A and the external grid 44 are separate components and are integrated with the protective member 37A by fixing the external grid 44 to the protective member 37A in a way that makes it impossible to remove them.

[0058] Specifically, the external grid 44 is attached to the protective member 37A of the protective cover 37 via a support shaft 49. The support shaft 49 is provided on the protective member 37A and rotatably supports the external grid 44. In other words, the external grid 44 is rotatable around the support shaft 49. In the example shown in Figure 5, the support shaft 49 is located in the lower right corner when the rectangular protective member 37A is viewed from above (i.e., viewed from the Z direction shown in Figure 5). This is merely one example, and the support shaft 49 may also be located in the upper right corner, upper left corner, or lower left corner when the protective member 37A is viewed from above. The support shaft 49 is an example of a "support shaft" related to the technology of this disclosure.

[0059] The external grid 44 also comprises a grid body 44A having an absorbent portion 46 and a permeable portion 47, and an extension portion 44B extending from the grid body 44A toward the support shaft 49. The grid 44 is rotatably mounted on the support shaft 49 via the extension portion 44B. One end of the support shaft 49 is attached to a protective member 37A, and an enlarged diameter portion 50 is provided at the other end of the support shaft 49. The enlarged diameter portion 50 supports the extension portion 44B from below. Here, the extension portion 44B may be reinforced with a material having higher strength than the grid body 44A. Alternatively, the extension portion 44B may be reinforced by attaching a metal plate to its surface. With this configuration, the durability of the extension portion 44B against loads generated on the extension portion 44B by rotational operation is improved.

[0060] Thus, the external grid 44 is capable of being displaced between a position facing the imaging surface 24A and a retracted position by rotating around the support shaft 49. The external grid 44's displacement is restricted in the facing position. In other words, the external grid 44 is positioned in the facing position. In the example shown in Figure 5, the external grid 44, having rotated from the retracted position to the facing position, is positioned in the facing position by contacting the front wall 37B of the protective cover 37. The front wall 37B is an example of a "positioning part" related to the technology of this disclosure.

[0061] As shown in Figure 6, in the opposing position, the external grid 44 is positioned at the chest wall side on the imaging table 24. For example, the external grid 44 is positioned so that its front end surface 44A1 coincides with the front end surface 24B of the imaging table 24. The focal point of the tube 25A is positioned above the front end surface 24B of the imaging table 24. This allows imaging to be performed on the chest wall side (i.e., the front side) of the breast M placed on the imaging table 24. Furthermore, because the external grid 44 is positioned at the chest wall side of the imaging table 24, scattered radiation can be removed up to the chest wall side of the breast M being imaged.

[0062] Furthermore, the external grid 44 is a so-called focusing grid. That is, in the external grid 44, the multiple interface surfaces of the absorbing section 46 and the transmitting section 47 are not parallel, and the surfaces extending from each of the multiple interface surfaces are inclined in such a way that they pass through the focal position F of the tube 25A and converge into a single straight line parallel to the interface surfaces. In this example, since the focal position F of the tube 25A is located on the front end surface 44A1 side of the external grid 44, the inclination angle of the multiple interface surfaces gradually increases as you move from the front end surface 44A1 to the rear. By making the external grid 44 such a focusing grid, vignetting of radiation R is suppressed more effectively compared to a parallel grid where the multiple interface surfaces are parallel.

[0063] Figure 7 summarizes the imaging modes and grids used in the mammography apparatus 10 according to this embodiment. As shown in Figure 7, when imaging is performed when the radiation source 25 is positioned vertically opposite the imaging table 24 (i.e., normal imaging), the built-in grid 45 is used. As described above, the built-in grid 45 is built inside the imaging table 24. In the built-in grid 45, the boundary line 48 between the absorption section 46 and the transmission section 47 extends in the front-to-back direction.

[0064] On the other hand, in the case of stereo imaging, an external grid 44 attached to the protective cover 37 is used. The external grid 44 is provided between the protective cover 37 and the imaging surface 24A. In the external grid 44, the boundary line 48 between the absorption section 46 and the transmission section 47 extends in the left-right direction (in this example, the direction of movement of the tube 25A).

[0065] As described above, in the mammography apparatus 10 according to this embodiment, a protective cover 37 is used when a biopsy is performed. In addition to the protective member 37A, the protective cover 37 includes an external grid 44, which is an example of a scatter-removing grid suitable for stereo imaging.

[0066] In other words, when performing a biopsy, stereo imaging is sometimes performed to grasp the three-dimensional position of the tissue to be biopsied within the breast M. In stereo imaging, multiple images are taken by changing the irradiation angle of radiation R by changing the irradiation position of radiation R in the left-right direction. With this configuration, the external grid 44 can be positioned in a posture in which the direction in which the boundary line 48 of the absorption part 46 and the transmission part 47 of the external grid 44 extends is parallel to the left-right direction. Therefore, compared to the case in which the boundary line 48 extends is parallel to the front-back direction, vignetting of effective radiation R (radiation other than scattered radiation) that is incident at an angle from the radiation source 25 toward the imaging surface 24A can be suppressed. This is because, when the external grid 44 is positioned in a posture in which the direction in which the boundary line 48 extends is parallel to the front-back direction, the absorption part 46 extending parallel to the boundary line 48 and the central axis of the radiation beam connecting the focal point of the tube 25A and the imaging surface 24A intersect. In other words, since the direction of movement of the tube 25A and the direction of extension of the absorption section 46 are perpendicular, vignetting occurs due to the absorption section 46 in relation to the radiation R irradiated from the tube 25A.

[0067] Furthermore, during biopsy, stereo imaging and contrast-enhanced energy subtraction imaging are sometimes combined to obtain breast images that highlight the biopsy target where neovascularization is dense. This configuration is particularly effective in such cases. This is because contrast-enhanced energy subtraction imaging takes the difference between two images taken with radiation of different energies, which tends to reduce contrast. In this configuration, the incidence of scattered radiation is suppressed by using an external grid 44, thus suppressing the reduction in contrast. As a method to suppress the reduction in contrast, it is also possible to increase the gain of the signal output by the radiation detector 26 during image correction processing, but since increasing the gain also increases noise, the method using the external grid 44 is preferred.

[0068] For example, as shown in Figure 8 as a comparative example, consider the case where stereo imaging and contrast-enhanced energy subtraction imaging are performed in combination with the internal grid 45 retracted, without using the external grid 44. In this case, since the internal grid 45 is retracted, vignetting of radiation R caused by the orthogonality of the direction of movement of the tube 25A and the direction in which the boundary line 48 extends does not occur. On the other hand, as shown in Figure 9, since the external grid 44 is not used, scattered radiation caused by radiation R transmitted through the breast M is directly incident on the radiation detector 26. As a result, the contrast in the breast image decreases. As mentioned above, in contrast-enhanced energy subtraction imaging, the difference between two images taken with radiation of different energies is taken, so the contrast tends to decrease, and the contrast in the breast image decreases even further. As a result, it becomes difficult to determine the location of the tissue to be biopsied in the breast M. In this configuration, by using the external grid 44, the incidence of scattered radiation is suppressed, and therefore the decrease in contrast can be suppressed.

[0069] Furthermore, in the comparative example, the protective cover for a typical biopsy does not anticipate the provision of an external grid 44. Therefore, even if there were a grid to be attached externally to the imaging table 24, it would be impossible to place the grid on the imaging table 24 because the imaging table 24 is already covered by the protective cover. In the protective cover 37 according to this embodiment, an external grid 44 is provided, so the effect of removing scattered radiation by the external grid 44 can be obtained while using the protective cover 37.

[0070] Furthermore, in the protective cover 37 according to this embodiment, the external grid 44 is positioned between the protective member 37A and the imaging surface 24A. This protects the external grid 44 and the imaging surface 24A from the puncture needle 43 by the protective member 37A. In addition, compared to the case where the external grid 44 is positioned on the opposite side of the protective member 37A (i.e., the upper side), the distance between the external grid 44 and the imaging surface 24A is narrower, so scattered radiation can be effectively removed.

[0071] Furthermore, in the protective cover 37 according to this embodiment, the external grid 44 is provided on the protective member 37A in such a manner that it can be displaced between a position facing the imaging surface 24A and a retracted position moving away from the facing position. Because the external grid 44 can be displaced between the facing position and the retracted position, user convenience is improved compared to a case where the external grid 44 cannot be displaced, for example, by allowing the user to decide whether or not to position the external grid 44 in the facing position.

[0072] Furthermore, in the protective cover 37 according to this embodiment, the protective member 37A has a front wall 37B that restricts the displacement of the external grid 44 at opposing positions. Since the external grid 44 is restricted at opposing positions by the front wall 37B, the positioning accuracy of the external grid 44 is improved compared to the case where the external grid 44 is not restricted.

[0073] Furthermore, in the protective cover 37 according to this embodiment, the protective member 37A is provided with a support shaft 49 that supports the external grid 44, and the external grid 44 is rotatable around the support shaft 49. As the external grid 44 rotates around the support shaft 49, the external grid 44 is displaced to the opposite position, making the work required for displacement easier.

[0074] Furthermore, in the protective cover 37 according to this embodiment, the protective member 37A is rectangular in shape, and the support shaft 49 is located in the lower left corner of the protective member 37A. Because the support shaft 49 is located in the lower left corner, it has less impact on the radiation incident on the imaging surface 24A compared to the case where the support shaft 49 is located in the center of the protective member 37A.

[0075] Furthermore, in the protective cover 37 according to this embodiment, the external grid 44 is integrated with the protective member 37A. Since the external grid 44 is integrated with the protective member 37A and is positioned together with the protective cover 37, the positioning of the external grid 44 is simpler compared to the case where the external grid 44 is separate from the protective cover 37.

[0076] Furthermore, in the biopsy unit 39 according to this embodiment, the puncture needle 43 is held movably, and the biopsy unit 39 is equipped with a protective cover 37. When a biopsy is performed using the biopsy unit 39, the protective cover 37 is used. In addition to the protective member 37A, the protective cover 37 is equipped with an external grid 44 suitable for stereo imaging. In this configuration, by using the external grid 44, the incidence of scattered radiation is suppressed, so a decrease in contrast can be suppressed.

[0077] (First variation) In the first embodiment described above, an example was given in which the external grid 44 is displaced between the opposing position and the retracted position by rotating around the support shaft 49, but the technology of this disclosure is not limited thereto. In this first modification, the external grid 44 is displaced between the opposing position and the retracted position by sliding in the front-rear direction relative to the protective member 37A.

[0078] As shown in Figure 10, the external grid 44 is attached to the protective member 37A via a pair of guide rails 53. The pair of guide rails 53 are rail-shaped members that extend in the front-rear direction. Each of the pair of guide rails 53 is positioned in the left-right direction at a distance corresponding to the width of the external grid 44. Each of the pair of guide rails 53 has an L-shape in cross-section when viewed from the front-rear direction. Each of the pair of guide rails 53 has a side wall 53A that protrudes downward from the protective member 37A and a support portion 53B that is bent from the tip of the side wall 53A. The side wall 53A faces the left-right side of the external grid 44 and restricts the left-right movement of the external grid 44. The support portion 53B supports the lower surface of the external grid 44 from below.

[0079] An elongated hole 53C is provided in the side wall 53A along the front-rear direction. A gripping portion 44C provided on the external grid 44 is inserted through the elongated hole 53C. The gripping portion 44C is a rod-shaped part that protrudes from the grid body 44A along the left-right direction. When the gripping portion 44C is grasped by the user and moved in the front-rear direction, the external grid 44 moves in the front-rear direction. As a result, the external grid 44 moves between a retracted position and an opposing position. In this case, the external grid 44 is guided by a pair of guide rails 53.

[0080] As described above, in the mammography apparatus 10 according to this first modified example, a protective cover 37 is used when a biopsy is performed. In addition to the protective member 37A, the protective cover 37 is equipped with an external grid 44 suitable for stereo imaging. In this configuration, by using the external grid 44, the incidence of scattered radiation is suppressed, so the decrease in contrast can be suppressed.

[0081] Furthermore, in the protective cover 37 according to this first modified example, the external grid 44 is integrated with the protective member 37A. Since the external grid 44 is integrated with the protective member 37A and is positioned together with the protective cover 37, the positioning of the external grid 44 is simpler compared to the case where the external grid 44 is separate from the protective cover 37.

[0082] (Second Embodiment) In the first embodiment described above, an example was given in which the external grid 44 is integrated with the protective cover 37, but the technology of this disclosure is not limited thereto. In this second embodiment, the external grid 44 is detachably attached to the protective cover 37.

[0083] As shown in Figure 11, the protective member 37A of the protective cover 37 is provided with a pair of guide rails 55. The pair of guide rails 55 are rail-shaped members provided on the lower surface of the protective member 37A. The pair of guide rails 55 extend along the front-rear direction and are arranged at a distance corresponding to the width of the external grid 44 in the left-right direction. The pair of guide rails 55 are provided at positions facing the side surfaces of the external grid 44. The pair of guide rails 55 are an example of the "guide part" and "guide rail" according to the technology of this disclosure.

[0084] The external grid 44 is provided with a gripping portion 44D. The gripping portion 44D is an L-shaped member in plan view, with one end attached to the rear end surface of the grid body 44A. The other end of the gripping portion 44D is also made possible to grip it with the user's hand H. When the gripping portion 44D is grasped by the user and the external grid 44 moves, the external grid 44 is inserted between the protective cover 37 and the imaging surface 24A from the rear end 37C side of the protective cover 37. The external grid 44 is also inserted between a pair of guide rails 55. In other words, the pair of guide rails 55 are made capable of receiving the external grid 44 from the rear. The external grid 44 then moves from the rear to the front of the protective cover 37, guided by the pair of guide rails 55. The pair of guide rails 55 engage with the sides of the external grid 44, guiding the external grid 44 to its opposing position. The external grid 44 is positioned in the opposing position when it comes into contact with the front wall 37B of the protective cover 37. The gripping portion 44D is an example of a "gripping portion" according to the technology of this disclosure. The front wall 37B is an example of a "positioning portion" according to the technology of this disclosure.

[0085] Furthermore, when the gripping part 44D is grasped by the user and the external grid 44 moves, the external grid 44 moves backward from its opposing position. Then, the external grid 44 is removed from between the protective cover 37 and the imaging surface 24A. In this way, the external grid 44 is detachably attached to the protective cover 37.

[0086] Before the external grid 44 is attached to the protective cover 37, or after it has been removed, the external grid 44 may be handled directly by the user's hands H. In this case, the surface of the external grid 44 is reinforced. For example, reinforcement may be provided by attaching a thin sheet of carbon fiber reinforced resin to the surface of the external grid 44.

[0087] As described above, in the protective cover 37 according to this second embodiment, the external grid 44 is detachably attached to the protective member 37A. Therefore, when the external grid 44 is not needed (for example, in the case of shooting where the tube 25A is not moved in the left-right direction), the protective cover 37 can be used even with the external grid 44 removed.

[0088] Furthermore, in the protective cover 37 according to this second embodiment, a pair of guide rails 55 are provided on the protective member 37A. The pair of guide rails 55 guide the external grid 44 to the opposing position by engaging with the external grid 44. The presence of the guide rails 55 makes it easier to position the external grid 44 in the opposing position compared to when the guide rails 55 are not present.

[0089] Furthermore, in the protective cover 37 according to this second embodiment, the pair of guide rails 55 are designed to accept the external grid 44 from the rear. Since the subject A is in front of the mammography apparatus 10, and the external grid 44 is designed to accept it from the rear, the external grid 44 can be positioned opposite the subject A even when the subject A is present.

[0090] Furthermore, in the protective cover 37 according to this second embodiment, the external grid 44 is guided by a pair of guide rails 55 extending in the front-rear direction of the protective member 37A. That is, since there is no member for guiding on the front side of the protective member 37A, the external grid 44 is inserted up to the front side of the protective member 37A. Since the chest wall of the subject A is on the front side of the protective member 37A, the external grid 44 is positioned up to the chest wall side.

[0091] Furthermore, in the protective cover 37 according to this second embodiment, the external grid 44 is positioned at the opposing position by contacting the front wall 37B of the protective cover 37. As a result, the external grid 44 is restricted to the opposing position, improving positioning accuracy compared to the case where the external grid 44 is not restricted.

[0092] Furthermore, in the protective cover 37 according to this second embodiment, the external grid 44 is provided with a gripping portion 44D, which simplifies the operation of displacing the external grid 44.

[0093] In the second embodiment described above, an example was given in which a gripping portion 44D is attached to the external grid 44, but the technology of this disclosure is not limited thereto. The external grid 44 may not have a gripping portion 44D, and the external grid 44 may be moved by being pushed from behind by a separate rod-shaped member. Alternatively, the external grid 44 may be moved by pulling a string-shaped member attached to the front end surface 44A1 of the external grid 44 forward. Furthermore, the external grid 44 may be directly grasped or moved by the user's hand H.

[0094] (Second variation) In the second embodiment described above, an example was given in which the external grid 44 is inserted from the rear of the protective cover 37, but the technology of this disclosure is not limited thereto. In this second modification, the external grid 44 is inserted from the left-right direction (i.e., the width direction) of the protective cover 37.

[0095] As shown in Figure 12, the protective member 37A of the protective cover 37 is provided with a guide section 56. The guide section 56 comprises a first rail 56A, a second rail 56B, and a third rail 56C. The first rail 56A is a straight rail-shaped member extending in the left-right direction. The second rail 56B and the third rail 56C are L-shaped rail-shaped members when the protective member 37A is viewed from above. The distance between the first rail 56A and the second rail 56B is a distance corresponding to the front-rear distance of the external grid 44. Similarly, the distance between the first rail 56A and the third rail 56C is a distance corresponding to the front-rear distance of the external grid 44. The guide section 56 and the first rail 56A are examples of the "guide section" according to the technology of this disclosure.

[0096] The first rail 56A and the second rail 56B allow the external grid 44 to be received from the right between the protective cover 37 and the imaging surface 24A. Furthermore, the first rail 56A and the third rail 56C allow the external grid 44 to be received from the left.

[0097] The distance between the second rail 56B and the third rail 56C is determined to correspond to the lateral distance of the external grid 44. The second rail 56B and the third rail 56C guide the forward and backward movement of the external grid 44.

[0098] In the example shown in Figure 12, the gripping portion 44D is grasped by the user, causing the external grid 44 to move. As a result, the external grid 44 is inserted between the protective cover 37 and the imaging surface 24A from the right side of the protective cover 37. First, the external grid 44 moves to the left, guided by the first rail 56A and the second rail 56B. Next, the external grid 44 moves forward, guided by the second rail 56B and the third rail 56C. Finally, the external grid 44 is positioned in the opposite position when it comes into contact with the front wall 37B of the protective cover 37.

[0099] Furthermore, when the gripping part 44D is grasped by the user and the external grid 44 moves, the external grid 44 moves backward from its opposing position. Then, the external grid 44 moves to the right. After that, the external grid 44 is removed from between the protective cover 37 and the imaging surface 24A. In this way, the external grid 44 is detachably attached to the protective cover 37.

[0100] As explained above, in the protective cover 37 of this second modified example, the external grid 44 can be received from the left and right directions by the guide portion 56. Since the subject A is in front of the mammography device 10, the external grid 44 can be received from the left and right directions, so even if the subject A is in front, the external grid 44 is positioned opposite.

[0101] Furthermore, in the protective cover 37 according to this second modified example, the external grid 44 is guided by the first rail 56A, the second rail 56B, and the third rail 56C. In the protective cover 37, only the first rail 56A is provided within the range of movement of the external grid 44 in the front-rear direction. That is, within the range of movement of the external grid 44 in the front-rear direction, there is no member on the front side of the protective member 37A that restricts the movement of the external grid 44 in the front-rear direction, so the external grid 44 is inserted up to the front side of the protective member 37A. As a result, since the chest wall of subject A is on the front side of the protective member 37A, the external grid 44 is positioned towards the chest wall.

[0102] (Third embodiment) In the first and second embodiments described above, the external grid 44 was described as being movable relative to the protective cover 37, but the technology of this disclosure is not limited thereto. In this third embodiment, the external grid 44 is fixed to the protective cover 37.

[0103] As shown in Figure 13, the external grid 44 is fixed to the protective cover 37. The external grid 44 is fixed by being attached to the protective cover 37 via an adhesive, but this is only one example. For example, it may be fixed by fastening members that fasten the protective cover 37 and the external grid 44 together, or the protective cover 37 and the external grid 44 may be fixed by magnetic attraction using magnets.

[0104] The fixing position of the external grid 44 to the protective cover 37 is pre-adjusted so that when the protective cover 37 is placed on the imaging table 24, the external grid 44 is in a position opposite it. When the user places the protective cover 37 on the imaging table 24, the external grid 44 is also positioned opposite it.

[0105] As described above, in the protective cover 37 according to this third embodiment, the external grid 44 is integrated with the protective member 37A. Since the external grid 44 is integrated with the protective member 37A and the external grid 44 is arranged together with the protective cover 37, the arrangement of the external grid 44 is simpler compared to the case where the external grid 44 is separate from the protective cover 37.

[0106] In the third embodiment described above, an example was given in which the external grid 44 is fixed to the protective member 37A, but the technology of this disclosure is not limited thereto. For example, the external grid 44 may be embedded inside the protective member 37A of the protective cover 37, or a protective coating may be formed on the surface of the external grid 44 so that it functions as a protective cover 37.

[0107] In the embodiments described above, examples of configurations in which stereo imaging and contrast-enhanced energy subtraction imaging are combined were given, but the technology of this disclosure is not limited to these. For example, a configuration in which only stereo imaging is performed may also be described.

[0108] Furthermore, although the above embodiments have described examples of stereo imaging being performed by moving the radiation source 25 in the left-right direction, the technology of this disclosure is not limited thereto. For example, the radiation source 25 may be a so-called multi-source, comprising a plurality of tubes 25A arranged along the left-right direction, with each tube 25A irradiating with radiation R. In a multi-source, since the plurality of tubes 25A are arranged in the left-right direction, stereo imaging can be performed, for example, by using the tubes 25A at both ends in the left-right direction.

[0109] Furthermore, although stereo imaging in the case of biopsy has been described in each of the above embodiments, the technology of this disclosure is not limited thereto. For example, so-called tomosynthesis imaging, in which the breast M is photographed from multiple irradiation positions with different irradiation angles in order to obtain a tomographic image of the breast M, may be performed as a pre-biopsy imaging. The projected images of the breast M from the multiple irradiation positions obtained by tomosynthesis imaging are subjected to image reconstruction processing and used to generate a tomographic image of the breast M.

[0110] Furthermore, although the above embodiments have described examples in which the biopsy unit 39 and the protective cover 37 are separate components, the technology of this disclosure is not limited thereto. For example, the protective cover 37 may be fixed to the biopsy unit 39.

[0111] The descriptions and illustrations presented above are detailed explanations of the technical aspects of this disclosure and are merely examples of the technical aspects. For example, the above descriptions of the structure, function, operation, and effect are examples of the structure, function, operation, and effect of the technical aspects of this disclosure. Therefore, it goes without saying that you may delete unnecessary parts, add new elements, or replace elements in the descriptions and illustrations presented above, as long as you do not deviate from the essence of the technical aspects of this disclosure. Furthermore, in order to avoid confusion and facilitate understanding of the technical aspects of this disclosure, explanations of common technical knowledge and the like that do not require special explanation to enable the implementation of the technical aspects of this disclosure have been omitted from the descriptions and illustrations presented above.

[0112] All documents, patent applications, and technical standards described herein are incorporated by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted as being incorporated by reference.

[0113] The following additional information is disclosed regarding the above embodiment.

[0114] <Note 1> A flat protective member is detachably attached to a mammography apparatus, which is equipped with an imaging table on which the subject's breast is placed and which has an imaging surface into which radiation that has passed through the breast is incident, and which protects the imaging surface from a puncture needle used to collect tissue from the breast. The system includes a scatter-removing grid that removes scattered radiation generated when the above-mentioned radiation passes through the above-mentioned breast, The above-mentioned scattered radiation removal grid is a grid in which multiple transmission parts that transmit the radiation and multiple absorption parts that absorb the radiation are arranged alternately, and the boundary line between the transmission parts and the absorption parts extends in one direction. Furthermore, in the above-mentioned imaging surface, if the direction connecting the chest wall side where the subject's chest wall is located and the opposite side of the chest wall is defined as the first direction, and the direction perpendicular to the first direction is defined as the second direction, then the scattered radiation removal grid is positioned opposite the imaging surface in a orientation such that the direction in which the boundary line extends is parallel to the second direction. Protective cover. <Note 2> The above-mentioned scattered radiation removal grid is positioned between the protective member and the imaging surface. The protective cover described in Appendix 1. <Note 3> The above-mentioned scattered radiation removal grid is provided on the protective member in a manner that allows it to be displaced between a position facing the imaging surface and a retracted position moving away from the facing position. The protective cover described in Appendix 1 or Appendix 2. <Note 4> The protective member has a positioning portion that restricts the displacement of the scattered radiation removal grid at the opposing position. The protective cover described in Appendix 3. <Note 5> The protective member is provided with a support shaft that supports the scattered radiation removal grid. The above-mentioned scatter removal grid is rotatable around the above-mentioned support axis. The protective cover described in Appendix 3 or Appendix 4. <Note 6> The protective member described above is rectangular in shape, and the support shaft is positioned at one of the four corners of the protective member. The protective cover described in Appendix 5. <Note 7> The above-mentioned scattered radiation removal grid is detachably attached to the above-mentioned protective member. The protective cover described in Appendix 1. <Note 8> The protective member is provided with a guide portion that guides it to the opposing position by engaging with the scattered radiation removal grid. The protective cover described in Appendix 7. <Note 9> The guide section described above is capable of receiving the scattered radiation removal grid from the side opposite to the chest wall where the subject's chest wall is located. The protective cover described in Appendix 8. <Note 10> When the direction along the first direction of the above-mentioned scattered radiation removal grid is defined as the depth direction of the protective member, and the direction along the second direction is defined as the width direction of the protective member, The above-mentioned guide section is a pair of guide rails provided at both ends in the width direction and extending in the depth direction. The protective cover described in Appendix 9. <Note 11> When the direction along the first direction of the above-mentioned scattered radiation removal grid is defined as the depth direction of the protective member, and the direction along the second direction is defined as the width direction of the protective member, The guide portion described above is capable of receiving the scattered radiation removal grid from the end of the protective member in the width direction. The protective cover described in Appendix 8. <Note 12> The above-mentioned guide section is provided only on the side opposite to the chest wall in the depth direction. The protective cover described in Appendix 11. <Note 13> The protective member has a positioning unit that restricts the scatter removal grid to a position facing the imaging surface. A protective cover as described in any one of the notes 7 through 12. <Note 14> The above-mentioned scatter removal grid is provided with a gripping portion. A protective cover as described in any one of the notes 7 through 13. <Note 15> The above-mentioned scattered radiation removal grid is integrated with the above-mentioned protective member. A protective cover as described in any one of the notes 1 through 6. <Note 16> A biopsy unit that movably holds the above-mentioned puncture needle, A biopsy unit equipped with a protective cover as described in one of the appendices 1 through 15. [Explanation of Symbols]

[0115] 10. Mammography device 20 stands 20A Base 20B Post 21 Arms 22 Source housing 23 Main body 24 Shooting platform 24A Imaging surface 24B Front end surface 25 Radiation source 25A tube 26 Radiation detectors 27 Handrail 28 rails 30 Compression plate 31 Irradiation field limiter 32 Face Guards 33 Support Arm 34 Moving parts 35 Moving mechanism 37 Protective cover 37A Protective component 37B Front wall 37C Rear end 38 Spacers 39 Biopsy Unit 40 Main body 41 Adjustment part 42 Needle holding part 43 Puncture needle 44 External Grid 44A Grid Unit 44A1 Front end surface 44B Extension 44C,44D Grip part 45 Built-in grid 46 Absorbent part 47 Transparent part 48 Boundary Line 49 Support shaft 50 Expanded diameter part 51 Base 52 recess 53, 55 Guide rails 53A side wall 53B Support part 53C long hole 56 Guide section 56A First Rail 56B Second Rail 56C Third Rail A Subject F Focus position H hand R radiation M Breast X, Y, Z arrows

Claims

1. A flat protective member is detachably attached to a mammography apparatus, which is equipped with an imaging table on which the subject's breast is placed and which has an imaging surface into which radiation that has passed through the breast is incident, and which protects the imaging surface from a puncture needle used to collect tissue from the breast. The system includes a scatter-removing grid that removes scattered radiation generated when the aforementioned radiation passes through the breast, The aforementioned scattered radiation removal grid is a grid in which a plurality of transmitting portions that transmit radiation and a plurality of absorbing portions that absorb radiation are arranged alternately, and the boundary line between the transmitting portions and the absorbing portions extends in one direction. Furthermore, in the imaging surface, if the direction connecting the chest wall side where the subject's chest wall is located and the opposite side of the chest wall is defined as the first direction, and the direction perpendicular to the first direction is defined as the second direction, then the scattered radiation removal grid is positioned opposite the imaging surface in a orientation where the direction in which the boundary line extends is parallel to the second direction. Protective cover.

2. The scattered radiation removal grid is positioned between the protective member and the imaging surface. The protective cover according to claim 1.

3. The scattered radiation removal grid is provided on the protective member in a manner that allows it to be displaced between a position facing the imaging surface and a retracted position moving away from the facing position. The protective cover according to claim 1.

4. The protective member has a positioning portion that restricts the displacement of the scattered radiation removal grid at the opposing position. The protective cover according to claim 3.

5. The protective member is provided with a support shaft that supports the scattered radiation removal grid. The scattered radiation removal grid is rotatable around the support axis. The protective cover according to claim 3.

6. The protective member is rectangular in shape, and the support shaft is positioned at one of the four corners of the protective member. The protective cover according to claim 5.

7. The scattered radiation removal grid is detachably attached to the protective member. The protective cover according to claim 1.

8. The protective member is provided with a guide portion that guides it to the opposing position by engaging with the scattered radiation removal grid. The protective cover according to claim 7.

9. The guide section is capable of receiving the scattered radiation removal grid from the side opposite to the chest wall where the subject's chest wall is located. The protective cover according to claim 8.

10. When the direction along the first direction of the scattered radiation removal grid is defined as the depth direction of the protective member, and the direction along the second direction is defined as the width direction of the protective member, The guide portion is a pair of guide rails provided at both ends in the width direction and extending in the depth direction. The protective cover according to claim 9.

11. When the direction along the first direction of the scattered radiation removal grid is defined as the depth direction of the protective member, and the direction along the second direction is defined as the width direction of the protective member, The guide portion is capable of receiving the scattered radiation removal grid from the end of the protective member in the width direction. The protective cover according to claim 8.

12. The guide portion is provided only on the side opposite to the chest wall in the depth direction. The protective cover according to claim 11.

13. The protective member has a positioning unit that restricts the scatter removal grid to a position facing the imaging surface. The protective cover according to claim 7.

14. The aforementioned scatter removal grid is provided with a gripping portion. The protective cover according to claim 7.

15. The aforementioned scatter removal grid is integrated with the protective member. The protective cover according to claim 1.

16. A biopsy unit that movably holds the aforementioned puncture needle, A biopsy unit comprising a protective cover according to any one of claims 1 to 15.

Images