JP6362320B2 - Breast tomography equipment - Google Patents

Description

  The present invention relates to a tomography apparatus that performs computed tomography (CT imaging), and more particularly to a mammography tomography apparatus (mammo CT apparatus) used for imaging a breast.

  Conventionally, breast cancer examinations have been performed using palpation and ultrasonic diagnosis, but mammo CT apparatuses capable of performing mammography using three-dimensional (3D) images using CT imaging have been developed.

Patent Document 1 discloses an example of a mammo CT apparatus. The mammo CT apparatus disclosed in Patent Document 1 includes a top plate with an open / closed breast entrance, a measurement device that rotates horizontally around the breast entrance / exit, an X-ray generator, and an X-ray detector. It is configured. When CT imaging, the test person Nesoberi prone to the top plate, shot while inserting the breast the breast receiving portion from the breast inlet and outlet is made. The X-ray generator and X-ray detector with a built-in collimator that defines the X-ray irradiation area are rotated at a predetermined angular position while rotating around the rotation axis passing through the breast housing, and viewed from each direction. An X-ray transmission image of the subject is acquired. In addition, an X-ray shield for blocking leakage of X-rays to the human body is attached to the lower surface of the top plate.

US Pat. No. 6,987,831

In breast CT apparatus of Patent Document 1, the breast while applying a sternum of the test person on the top plate upper surface for inserting the breast inlet and outlet to the breast receiving portion. As a result, the breast overlaps within the X-ray irradiation area irradiated to the breast storage section, so that an X-ray transmission image can be projected and photographed on the X-ray detector. In the mammo CT apparatus, it is preferable to place the X-ray detector as close to the top plate as possible so that the breast (root) on the sternum side can be imaged as much as possible.

By the way, the X-ray detector has a detection area at the center where X-ray detection is performed by the X-ray detection element, and a non-detection area at the periphery where a wiring circuit and the like cannot be laid out and cannot be detected. In order to be able to image the base of the breast, it is necessary to bring the detection area close to the top plate. In order to prevent the leakage of X-ray to the test side, the X-ray shield is provided inside of the top plate. When the X-ray detector is brought close to the top plate, it interferes with this, so the X-ray detector cannot be brought closer than a certain level.

An object of the present invention is in breast CT apparatus using the radiation represented by X-ray, the detection area of the radiation detector to enable the radiation imaging to breast base portion by approaching to the test side is there.

The first of the present invention includes a gantry having a front plate breast insertion opening is provided to the breast is inserted, a breast insertion portion continuous to the breast insertion opening, and
An X-ray generating tube disposed inside the gantry and having an X-ray emitting portion;
An X-ray detector disposed inside the gantry and opposed to the X-ray emission part between the breast insertion part;
A rotation drive unit that rotates the X-ray generation tube and the X-ray detector synchronously around a rotation axis that passes through the breast insertion unit;
A breast tomography apparatus that irradiates X-rays from the X-ray emission part to the X-ray detector via the breast insertion part,
An annular X-ray shielding portion provided on the front plate surrounding the breast insertion portion;
The X-ray detector, have a portion overlapping with the X-ray shielding section in a radial direction perpendicular to the rotating shaft,
The X-ray shielding part has an inner circumferential X-ray shielding part located on the inner circumferential side of the front plate, and an outer circumferential X-ray shielding part located outside the inner circumferential X-ray shielding part via a gap. , within the gap, as viewed from the X-ray emitting portion, the X-ray detector you characterized in that overlaps the X-ray shielding portion.
According to a second aspect of the present invention, a gantry having a front plate provided with a breast insertion opening into which a breast is inserted, and a breast insertion section connected to the breast insertion opening,
An X-ray generating tube disposed inside the gantry and having an X-ray emitting portion;
An X-ray detector disposed inside the gantry and opposed to the X-ray emission part between the breast insertion part;
A rotation drive unit that rotates the X-ray generation tube and the X-ray detector synchronously around a rotation axis that passes through the breast insertion unit;
A breast tomography apparatus that irradiates X-rays from the X-ray emission part to the X-ray detector via the breast insertion part,
An annular X-ray shielding portion provided on the front plate surrounding the breast insertion portion;
The X-ray detector has a portion overlapping the X-ray shielding portion in a radial direction orthogonal to the rotation axis;
A gap is provided between the outer peripheral edge of the X-ray shielding part and the outer peripheral edge of the front plate, and the X-ray detector is connected to the X-ray shielding part in the gap as viewed from the X-ray emission part. It is characterized by overlapping.
According to a third aspect of the present invention, a gantry having a front plate provided with a breast insertion opening into which a breast is inserted, and a breast insertion section connected to the breast insertion opening,
An X-ray generating tube disposed inside the gantry and having an X-ray emitting portion;
An X-ray detector disposed inside the gantry and opposed to the X-ray emission part between the breast insertion part;
A rotation drive unit that rotates the X-ray generation tube and the X-ray detector synchronously around a rotation axis that passes through the breast insertion unit;
A breast tomography apparatus that irradiates X-rays from the X-ray emission part to the X-ray detector via the breast insertion part,
An annular X-ray shielding portion provided on the front plate surrounding the breast insertion portion;
The X-ray detector has a portion overlapping the X-ray shielding portion in a radial direction orthogonal to the rotation axis;
The X-ray detector has a portion that overlaps in front of the X-ray shielding portion when viewed from the X-ray emission portion.
A fourth aspect of the present invention is a gantry having a front plate provided with a breast insertion opening into which a breast is inserted, and a breast insertion section connected to the breast insertion opening,
An X-ray generating tube disposed inside the gantry and having an X-ray emitting portion;
An X-ray detector disposed inside the gantry and opposed to the X-ray emission part between the breast insertion part;
A rotation drive unit that rotates the X-ray generation tube and the X-ray detector synchronously around a rotation axis that passes through the breast insertion unit;
A breast tomography apparatus that irradiates X-rays from the X-ray emission part to the X-ray detector via the breast insertion part,
An annular X-ray shielding portion provided on the front plate surrounding the breast insertion portion;
The X-ray detector has a portion overlapping the X-ray shielding portion in a radial direction orthogonal to the rotation axis;
The X-ray detector is convexly curved outward in the radial direction, and the center of curvature of the X-ray detector is positioned so as to overlap the rotation axis.

In the present invention, the radiation shield is provided with an annular gap corresponding to the rotational movement path of the radiation detector, and the end on the side facing the front plate of the radiation detector is located inside the gap. I'm stuck in. In other words, since the end of the radiation detector facing the front plate enters the front plate side from the surface of the radiation shield, compared with the case where the radiation detector is provided in contact with the radiation shield. However, the radiation detector can be brought closer to the front plate by the thickness of the radiation shield at the maximum. Accordingly, the detection area of the radiation detector can be brought close to the test person, it is possible to radiography to breast base portion. Moreover, leakage of excess radiation to the subject can be prevented by the radiation shield.

It is a whole perspective view of a mammography apparatus (mammo CT apparatus). It is sectional drawing of the mammo CT apparatus of the 1st example of this invention, (a) is sectional drawing seen from the X direction in FIG. 1, (b) is sectional drawing seen from the Y direction in FIG. FIG. 3 is an enlarged view around the collimator from the radiation generating tube in FIG. It is a block diagram of the imaging | photography system of the mammo CT apparatus of this invention. It is sectional drawing of the mammo CT apparatus of the 2nd example of this invention, (a) is sectional drawing seen from the X direction in FIG. 1, (b) is sectional drawing seen from the Y direction in FIG. It is sectional drawing of the mammo CT apparatus of the 3rd example of this invention, (a) is sectional drawing seen from the X direction in FIG. 1, (b) is sectional drawing seen from the Y direction in FIG. It is sectional drawing of the mammo CT apparatus of the 4th example of this invention, (a) is sectional drawing seen from the X direction in FIG. 1, (b) It is sectional drawing seen from the Y direction. FIG. 6 is a cross-sectional view of a mammo CT apparatus according to a fifth example of the present invention, where (a) is a cross-sectional view seen from the X direction in FIG. 1, and (b) is a cross-sectional view seen from the Y direction in FIG.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the drawings referred to below, the same reference numerals indicate the same components.

[First example]
<Outline of mammo CT system>
As shown in FIGS. 1 to 3, a mammographic tomography apparatus (mammo CT apparatus) 1 has a gantry 2 constituting a room in which a radiation source, a radiation detector 11 and the like are housed. Also, the gantry 2, at the center thereof, and a breast receiving portion 3 for the test person P inserts the breast 15. In addition, 4 is a support part.

The gantry 2 includes an inner peripheral plate 5 that surrounds the breast storage unit 3, an outer peripheral plate 6 that surrounds the outer periphery, a front plate 7 that connects the inner peripheral plate 5 and the outer peripheral plate 6 on the front side, and a back side that is not shown. It is a hollow disk-shaped member which has a back plate. The front plate 7 has an annular shape in which a breast entrance / exit 17 for entering / exiting the breast 15 into / from the breast accommodating part 3 is opened at the center. Inside the gantry 2, a radiation generating tube 8 and a radiation detector 11 are supported by a rotating plate (not shown), and are rotated together by a rotation drive unit 101 (see FIG. 4) during CT imaging. It is the composition which becomes. This rotation is performed around a rotation axis D that extends in the direction in which the breast 15 enters and exits the breast storage unit 3 (Z direction) through the inside of the breast storage unit 3. The radiation generating tube 8 and the radiation detector 11 are rotated in the same direction at the same angular velocity. When shooting in breast CT apparatus 1, from the surface side of the front plate 7 of the test person P gantry 2, from the breast inlet and outlet 17 to the breast receiving portion 3 by inserting the breast 15, a CT imaging while maintaining this posture Do. The mammo CT apparatus 1 of this example is of a type in which the front plate 7 is installed vertically and the subject P stands in front of the front plate 7 for examination. However, the mammo CT apparatus 1 according to the present invention is a type in which the front plate 7 is placed sideways and the front plate 7 is used as the top plate described in the background art, and the subject lies on the front plate 7 and is inspected. It can also be. In this case, the inner peripheral plate 5 can be omitted.

<Radiation tube>
As shown in FIGS. 2 and 3, the radiation generating tube 8 is a transmissive radiation generating tube, and includes an electron gun 9 that generates an electron beam and a radiation emitting unit 10. As the electron gun 9, for example, a hot filament type electron generation source can be used. The radiation emitting unit 10 includes a transmission type target in which a target layer that generates radiation by irradiating an electron beam from an electron gun 9 is laminated on a radiation transmissive support substrate. The material constituting the support substrate is preferably a material having a strength capable of supporting the target layer, a low absorption of radiation generated in the target layer, and a high thermal conductivity so that heat generated in the target layer can be quickly dissipated. For example, diamond, silicon carbide, aluminum nitride, or the like can be used. The material constituting the target layer is preferably a material having a high melting point and high radiation generation efficiency. For example, tungsten, tantalum, molybdenum and alloys thereof can be used.

The radiation emitting unit 10 has a collimating function for defining a radiation emission region generated by the electron beam irradiation to the target as a predetermined radiation irradiation region 13. The emitted radiation is irradiated to the radiation detector 11 while being defined in a predetermined radiation irradiation region 13 by this collimating function. At this time, since the breast 15 of the test person P enters the irradiation region 13, mammary gland radiation transmission image of the breast 15 reaches the radiation detector 11, contained within the breast 15, the transmitted image such as fat can get.

  The radiation generating tube 8 is supported by a rotating plate (not shown) that is rotated by a rotation driving unit 101 (see FIG. 4), and a rotating shaft that extends in the direction in which the breast 15 enters and exits the breast storage unit 3 by the rotation of the rotating plate. It rotates around D.

<Radiation detector>
The radiation detector 11 has a central detection area 11a where radiation can be detected and a peripheral non-detection area 11b where radiation cannot be detected. The radiation detector 11 of this embodiment, the detection area 11a are arranged a plurality of radiation detecting elements, the non-detection area 11b is configured to signal wiring connected to a plurality of radiation detecting elements are arranged ing. The detection area 11a in this example has a size that matches the radiation irradiation region 13 defined by the collimating function of the radiation emitting unit 10, and the planar shape of the detection area 11a in this example is a quadrangle. The radiation detection element is not particularly limited as long as it is an element that converts the intensity of incident radiation to an electric signal, but is configured by a photoelectric conversion element such as a CMOS and a phosphor. Further, the radiation detector 11 may be a digital sensor type radiation detector provided with an AD converter from the viewpoint of compatibility with the imaging system.

  The radiation detector 11 is provided at a position facing the radiation emitting portion 10 of the radiation generating tube 8 with the breast accommodating portion 3 interposed therebetween. The radiation detector 11 is supported by a rotating plate (not shown) that is rotated together with the radiation generating tube 8 by a rotation driving unit 101 (see FIG. 4). The radiation detector 11 rotates in the same direction at the same angular velocity as that of the radiation generating tube 8 around the rotation axis D extending in the direction in which the breast 15 enters and exits the breast housing 3 by the rotation of the rotating plate. .

<Radiation shield>
As shown in FIGS. 2 and 3, a double annular radiation shield 14 is provided inside the front plate 7 of the gantry 2 so as to surround the breast entrance / exit 17. The radiation shield 14 is divided into an inner peripheral radiation shield 14b on the inner peripheral side (a peripheral edge on the breast entrance / exit 17 side) and an outer peripheral radiation shield 14a on the outer peripheral side (the peripheral edge on the outer peripheral plate 6 side). It is provided with an annular gap 14c between them. The gap 14c is formed corresponding to the rotational movement path of the radiation detector 11, and the radiation detector 11 is provided at a position corresponding to the interval 14c and faces the front plate 7 of the radiation detector 11. The end on the side to be inserted enters the inside of the gap 14c. In other words, the end of the radiation detector 11 on the side facing the front plate 7 enters the front plate 7 side from the surfaces of the inner radiation shield 14b and the outer radiation shield 14a. The radiation detector 11 rotates around the rotation axis D in a state where the end on the side facing the front plate 7 enters the gap 14c.

Radiation shield 14 made of an outer peripheral radiation shield 14a and the inner circumferential radiation shield 14b from the radiation-emitting portion 10 direct irradiation or radiation to the test person P, occurs when radiation strikes the radiation detector 11 scattered radiation is used to prevent leakage of the subject test person P such. As the material of the radiation shield 14, heavy metals such as lead, tungsten, tantalum, and rhenium having high radiation shielding ability are suitable. The radiation shield 14 (outer peripheral radiation shield 14a and inner peripheral radiation shield 14b) is generally annular, but may be elliptical, rectangular, or the like.

  With the arrangement as in this example, when viewed from the Z direction, the end of the radiation detector 11 on the side facing the front plate 7 enters the thickness of the radiation shield 14. For this reason, the radiation detector 11 can be brought close to the front plate 7 of the gantry 2 without being obstructed by the radiation shield 14, and the detection area 11 a can be brought close to the front plate 7 to widen the root of the breast 15. CT imaging of a range becomes possible. In addition, as described above, since the end of the radiation detector 11 facing the front plate 7 overlaps with the thickness of the radiation shield 14 when viewed from the Z direction, the radiation detector 11 and the radiation shield are overlapped. Leakage of radiation from between the body 14 can also be suppressed.

<Mammo CT system imaging system>
FIG. 4 is a configuration diagram of an imaging system of the mammo CT apparatus of the present invention.

  The system control apparatus 100 controls the radiation generating apparatus 103 including the radiation generating tube 8 and its driving circuit 102, the radiation detector 11, and the rotation driving unit 101 in cooperation with each other. The drive circuit 102 outputs various control signals to the radiation generation tube 8 under the control of the radiation tube control unit 108 of the system control apparatus 100. The rotation drive control unit 107 of the system control apparatus 100 sends a drive control signal to the rotation drive unit 101 based on position information from the position detection sensor 104 for detecting the rotation position of the rotary plate that supports the radiation generating tube 8 and the like. Output. The emission state of radiation emitted from the radiation generator 103 is controlled while rotating the rotation drive unit 101 by a predetermined amount by this drive control signal. The radiation emitted from the radiation generator 103 is partially shielded by a collimator or the like, passes through the breast 15 and is detected by the radiation detector 11. The radiation detector 11 converts the detected radiation into an image signal and outputs it to the signal processing unit 105. The signal processing unit 105 performs predetermined signal processing on the image signal and sends the image signal to the image processing unit 106 under the control of the system control apparatus 100. The image processing unit 106 in the system control device 100 forms a CT image from image information captured at each rotational position, and stores this in the image storage unit 109. The display unit 111 generates a stereoscopic image by synthesizing a CT image obtained by capturing a plurality of images of the radiation generating tube 8 and the radiation detector 11 while rotating around the breast 15 by the image synthesis unit 110. An image can be displayed.

[Second example]
FIG. 5 shows a mammo CT apparatus according to the second example. In the present example, one annular radiation shield 14 is provided on the inner surface of the front plate 7 with a gap 14 c between the outer peripheral edge of the front plate 7. The radiation detector 11 is provided at a position corresponding to the gap 14c, and the end on the side facing the front plate 7 enters the inside of the gap 14c. That is, the end of the radiation detector 11 on the side facing the front plate 7 enters the front plate 7 side from the surface of the radiation shield 14. Except for these points, the second example is the same as the first example.

By the above configuration, since the irradiation region 13 can be configured to substantially traverse the gap 14c, reliable leakage of radiation to the test person P than the first example described above Prevention can be performed.

[Third example]
As shown in FIG. 6, the radiation detector 11 of this example has a three-dimensionally curved shape. Specifically, it is convexly curved toward the rotation outer periphery side in the rotation direction around the rotation axis D shown in FIG. The rest is the same as the first example described above.

  By doing in this way, the width | variety of the clearance gap 14c opened between the outer periphery radiation shield 14a and the inner periphery radiation shield 14b can be made small, and the leakage of the radiation from this area | region can be suppressed. Since the width of the gap 14c can be minimized, it is most preferable that the center of curvature of the radiation detector 11 coincides with the rotation axis D.

[Fourth example]
As shown in FIG. 7, in this example, the radiation detector 11 in the second example described above is curved convexly toward the outer periphery of the rotation in the rotation direction around the rotation axis D. The rest is the same as the second example described above.

  In this example, the width of the gap 14c opened between the outer peripheral edge of the front plate 7 can be reduced, and radiation leakage from this region can be suppressed. Since the width of the gap 14c can be made the smallest, it is most preferable that the center of curvature of the radiation detector 11 coincides with the rotation axis D, as in the third example.

[Fifth example]
As shown in FIG. 8, the region of the gap 14c overlapping the radiation irradiation region 13 from the radiation emitting unit 10 to the breast storage unit 3 is filled, and the periphery of the rotation axis D is synchronized with the radiation detector 11 in the same direction. A rotating radiation sub-shield 16 is provided. Except this point, the second embodiment is the same as the first example.

  By doing in this way, the leakage of the radiation from especially the clearance gap 14c located between the radiation emission part 10 and the breast accommodating part 3 can be suppressed. It is effective to provide the radiation sub-shield 16 at least in the region of the gap 14c that overlaps the radiation irradiation region 13 from the radiation emitting unit 10 to the breast storage unit 3, and by providing it in a wider region, the effect of preventing radiation leakage is provided. It can also be improved.

  1: mammography apparatus (mammography CT apparatus), 2: gantry, 3: breast housing part, 4: support part, 5: inner peripheral plate, 6: outer peripheral plate, 7: front plate, 8: radiation generating tube, 9 : Electron gun, 10: radiation emitting part, 11: radiation detector, 11a: detection area, 11b: detected area, 12: collimator, 13: radiation irradiation region, 14: radiation shield, 14a: outer peripheral radiation shield, 14b: inner peripheral radiation shield, 14c: gap, 15: breast, 16: radiation auxiliary shield, 100: system controller, 101: rotation drive unit, 102: drive circuit, 103: radiation generator, 104: position detection Sensor: 105: Signal processing unit 106: Image processing unit 107: Rotation drive control unit 108: Radiation generation tube control unit 109: Image storage unit 110: Image composition unit 111: Display unit P: Test Person, : Axis of rotation

Claims (14)

A gantry having a front plate provided with a breast insertion slot into which a breast is inserted, and a breast insertion section connected to the breast insertion slot;
An X-ray generating tube disposed inside the gantry and having an X-ray emitting portion;
An X-ray detector disposed inside the gantry and opposed to the X-ray emission part between the breast insertion part;
A rotation drive unit that rotates the X-ray generation tube and the X-ray detector synchronously around a rotation axis that passes through the breast insertion unit;
A breast tomography apparatus that irradiates X-rays from the X-ray emission part to the X-ray detector via the breast insertion part,
An annular X-ray shielding portion provided on the front plate surrounding the breast insertion portion;
The X-ray detector, have a portion overlapping with the X-ray shielding section in a radial direction perpendicular to the rotating shaft,
The X-ray shielding part has an inner circumferential X-ray shielding part located on the inner circumferential side of the front plate, and an outer circumferential X-ray shielding part located outside the inner circumferential X-ray shielding part via a gap. In the gap, the X-ray detector overlaps with the X-ray shielding unit as viewed from the X-ray emission unit . A gantry having a front plate provided with a breast insertion slot into which a breast is inserted, and a breast insertion section connected to the breast insertion slot;
An X-ray generating tube disposed inside the gantry and having an X-ray emitting portion;
An X-ray detector disposed inside the gantry and opposed to the X-ray emission part between the breast insertion part;
A rotation drive unit that rotates the X-ray generation tube and the X-ray detector synchronously around a rotation axis that passes through the breast insertion unit;
A breast tomography apparatus that irradiates X-rays from the X-ray emission part to the X-ray detector via the breast insertion part,
An annular X-ray shielding portion provided on the front plate surrounding the breast insertion portion;
The X-ray detector has a portion overlapping the X-ray shielding portion in a radial direction orthogonal to the rotation axis;
A gap is provided between the outer peripheral edge of the X-ray shielding part and the outer peripheral edge of the front plate, and the X-ray detector is connected to the X-ray shielding part in the gap as viewed from the X-ray emission part. Breast tufts tomograph it said overlap. A gantry having a front plate provided with a breast insertion slot into which a breast is inserted, and a breast insertion section connected to the breast insertion slot;
An X-ray generating tube disposed inside the gantry and having an X-ray emitting portion;
An X-ray detector disposed inside the gantry and opposed to the X-ray emission part between the breast insertion part;
A rotation drive unit that rotates the X-ray generation tube and the X-ray detector synchronously around a rotation axis that passes through the breast insertion unit;
A breast tomography apparatus that irradiates X-rays from the X-ray emission part to the X-ray detector via the breast insertion part,
An annular X-ray shielding portion provided on the front plate surrounding the breast insertion portion;
The X-ray detector has a portion overlapping the X-ray shielding portion in a radial direction orthogonal to the rotation axis;
When viewed from the X-ray emitting section, milk tufts tomograph you characterized by having a portion where the X-ray detector overlap in front of the X-ray shielding portion. A gantry having a front plate provided with a breast insertion slot into which a breast is inserted, and a breast insertion section connected to the breast insertion slot;
An X-ray generating tube disposed inside the gantry and having an X-ray emitting portion;
An X-ray detector disposed inside the gantry and opposed to the X-ray emission part between the breast insertion part;
A rotation drive unit that rotates the X-ray generation tube and the X-ray detector synchronously around a rotation axis that passes through the breast insertion unit;
A breast tomography apparatus that irradiates X-rays from the X-ray emission part to the X-ray detector via the breast insertion part,
An annular X-ray shielding portion provided on the front plate surrounding the breast insertion portion;
The X-ray detector has a portion overlapping the X-ray shielding portion in a radial direction orthogonal to the rotation axis;
The X-ray detector is curved convexly outwardly in the radial direction, the center of curvature of the X-ray detector, it milk humor tomograph you characterized lying overlaps the rotation axis. The X-ray detector includes a detection area having a plurality of X-ray detection elements and capable of detecting X-rays, and a non-detection area where the X-rays are not detected and are located at the periphery of the detection area, breast tomography apparatus according to any one of claims 1 to 4 wherein the portion overlapping the X-ray shielding portions of the X-ray detector, characterized in that said non-detection area. The X-ray blocking portion includes the rotating shaft thick portion having a thickness in the direction, either of claims 1 to 5, characterized in that it has a portion overlapping with the X-ray detector in the thick portion or breast tomography apparatus according to item 1. The X-ray shielding part has an inner circumferential X-ray shielding part located on the inner circumferential side of the front plate, and an outer circumferential X-ray shielding part located outside the inner circumferential X-ray shielding part via a gap. 5. The mammography apparatus according to claim 3, wherein the X-ray detector overlaps with the X-ray shielding unit when viewed from the X-ray emission unit in the gap. An X-ray sub-shielding unit that is located in the gap in contact with the X-ray irradiation region from the X-ray emitting unit to the breast insertion unit and rotates in the same direction around the rotation axis in synchronization with the X-ray detector. breast tomography apparatus according to 請 Motomeko 1 or 7 you, comprising. The breast tomography apparatus according to claim 8 , wherein the X-ray sub-shielding unit is located on the opposite side of the X-ray detector with the breast insertion opening interposed therebetween. A gap is provided between the outer peripheral edge of the X-ray shielding part and the outer peripheral edge of the front plate, and the X-ray detector is connected to the X-ray shielding part in the gap as viewed from the X-ray emission part. The breast tomography apparatus according to claim 3, wherein the breast tomography apparatuses overlap. The mammography apparatus according to any one of claims 1 to 6 , wherein the X-ray shielding unit has a portion overlapping in front of the X-ray detector as viewed from the X-ray emission unit. The breast tomography apparatus according to claim 4, wherein the X-ray detector has a portion overlapping in front of the X-ray shielding unit when viewed from the X-ray emission unit. The X-ray detector, breast tomography apparatus according to any one of claims 1 to 12, characterized in that at the end of the front plate opposite to the side overlapping the X-ray shielding portion. The breast tomography apparatus according to any one of claims 1 to 3 , wherein the X-ray detector is convexly curved outward in the radial direction.

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