JP2018079149A - Mammographic apparatus, imaging apparatus, image processing apparatus, image processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mammographic apparatus which appropriately displays a site of interest in a three-dimensional image even when CT imaging is performed with a breast held in a breast holding part.SOLUTION: There is provided a mammographic apparatus which comprises a gantry 30 including a radiation generation unit 10 for generating radiation and a radiation detection unit 12 for detecting radiation projected from the radiation generation unit 10, and which can rotate the radiation generation unit 10 and the radiation detection unit 12 with the radiation generation unit and the radiation detection unit facing each other. The gantry 30 includes an opening 20 through which a breast of a subject is inserted, and a breast holding part 34 which hold the breast of the subject inserted through the opening 20. A separation part 300 is provided between the subject's breast and the breast holding part 34 to separate the subject's breast and the breast holding part 34.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a mammography apparatus that performs mammography using radiation, an imaging apparatus, an image processing apparatus, and an image processing method.

  As a mammography apparatus, there is an apparatus for imaging a breast using a radiation generation unit that generates radiation and a radiation detection unit that detects radiation. There is a mammography apparatus capable of performing mammography and CT imaging. (For example, Patent Document 1)

Special table 2013-538668 gazette

  When performing CT imaging with the mammography apparatus of Patent Document 1, the breast of the subject is fixed between two plates. When CT imaging is performed with this mammography apparatus, volume data including breast holding portions of two plates is acquired. When a three-dimensional image is generated from volume data including a breast holder, the visibility of the region of interest may be deteriorated due to the influence of the breast holder.

  An object of the present invention is to provide a mammography apparatus, an imaging apparatus, and an image processing apparatus that can appropriately display a region of interest in a three-dimensional image even when CT imaging is performed with a breast held by a breast holding unit. And

  In order to achieve the object of the present invention, a gantry having a radiation generating unit for generating radiation and a radiation detecting unit for detecting radiation emitted from the radiation generating unit, the radiation generating unit and the radiation detection are provided. A mammography apparatus capable of rotating in a state where the parts face each other, wherein the gantry holds an opening for inserting the breast of the subject and the breast of the subject inserted from the opening A separation unit that separates the breast of the subject and the breast holding unit is provided between the breast of the subject and the breast holding unit.

  According to the present invention, it is possible to appropriately display a region of interest in a three-dimensional image even when CT imaging is performed with the breast held by the breast holding unit.

The figure which shows the external appearance of the mammography apparatus of this invention. The figure which shows the external appearance of the mammography apparatus of this invention seen from CT imaging | photography side. Sectional drawing of the mammography apparatus of this invention. The figure which shows the external appearance of the mammography apparatus of this invention seen from the mammography side. The figure which shows the structure of the mammography apparatus of this invention. The figure which shows the structure of the up-and-down drive part of the mammography apparatus of this invention. The figure which shows the rotation form by the rotation drive part of the mammography apparatus of this invention. The figure which shows the form by which the front cover was removed from the gantry of the mammography apparatus of this invention. The figure which shows the form by which the protective cover for protecting a breast was installed in the breast holding part. The flowchart which shows operation | movement of the mammography apparatus of this invention. The figure which shows the display form of a three-dimensional image. The figure which shows the display form of a two-dimensional image (tomographic image). The figure which shows the imaging | photography form of the subject who performs CT imaging | photography of this invention. The figure which shows the imaging | photography form of the subject who performs the mammography of this invention.

  FIG. 1 is a diagram illustrating an appearance of the mammography apparatus 100. The mammography apparatus 100 can perform mammography and CT imaging. When performing mammography and CT imaging, the subject is in a standing position. In the standing position, the subject stands on the floor with both feet placed on the floor. That is, the mammography apparatus 100 is a standing mammography apparatus.

  The mammography apparatus 100 rotates in a state where the radiation generation unit 10 that generates radiation, the radiation detection unit 12 that detects the radiation emitted from the radiation generation unit 10, and the radiation generation unit 10 and the radiation detection unit 12 face each other. It is possible to make it. The imaging unit 102 mainly includes a radiation generation unit 10 and a radiation detection unit 12.

  Then, imaging is performed in a state where the imaging target part (breast) of the subject is sandwiched between the compression plates 14 from the first side in the mammography apparatus 100. Here, the region to be imaged (breast) is sandwiched between the compression plate 14 and the radiation detection unit 12. In addition, a grid (not shown) may be provided on the upper surface of the radiation detection unit 12, and the imaging target region (breast) of the subject may be captured while being sandwiched between the compression plate 14 and the grid. That is, the mammography apparatus 100 has a first imaging unit in a mammography mode. Then, radiation is generated in a state where the imaging target region (breast) of the subject is inserted between the radiation generation unit 10 and the radiation detection unit 12 from the second side opposite to the first side in the mammography apparatus 100. The unit 10 and the radiation detection unit 12 are rotated and photographed. That is, the mammography apparatus 100 includes the second imaging unit in the CT imaging mode.

  The mammography apparatus 100 includes a gantry 30 that rotatably supports the radiation generation unit 10 and the radiation detection unit 12, and a support leg 40 that supports the gantry 30 with respect to the floor surface. That is, the gantry 30 supports the imaging unit 102 in a rotatable manner.

  When mammography is performed, imaging is performed in a state where the imaging target region (breast) of the subject is sandwiched between the compression plate 14 and the radiation detection unit 12 from the first side (right side in the figure) of the mammography apparatus 100. . The compression plate 14 is a transparent material and is a material that transmits radiation. Specifically, by moving the compression plate 14 up and down, the breast of the subject can be sandwiched between the compression plate 14 and the radiation detection unit 12. Radiation is generated by the radiation generation unit 10 with the subject's breast sandwiched between the compression plate 14 and the radiation detection unit 12. When the radiation detection unit 12 detects the radiation transmitted through the subject's breast, the subject's breast can be imaged. The mammography apparatus 100 can generate a mammo image based on the captured radiation data.

  When CT imaging is performed, a radiographic generation unit 10 and a radiation detection unit 12 capture a subject's imaging target region (breast) from a second side (left side in the figure) opposite to the first side in the mammography apparatus 100. Insert between. In this state, the radiation generation unit 10 and the radiation detection unit 12 are rotated by the rotating frame 38 to take an image. Specifically, the gantry 30 of the mammography apparatus 100 is provided with an opening 20 for inserting the breast of the subject. In a state where the breast of the subject is inserted into the opening 20, the radiation generation unit 10 and the radiation detection unit 12 are rotated by the rotating frame 38 and photographed. While the radiation generation unit 10 and the radiation detection unit 12 are rotated by the rotary frame 38, the radiation generation unit 10 generates radiation. The radiation detection unit 12 can photograph the subject's breast by detecting the radiation that has passed through the subject's breast. The mammography apparatus 100 can acquire volume data by reconstructing the captured projection data, and can generate a CT image based on the volume data.

  The first side of the mammography apparatus 100 is the mammography side, and the second side of the mammography apparatus 100 is the CT side. A line horizontally connecting the first side (mammography side) and the second side (CT side) is substantially parallel to the rotation axis of the rotary frame 38. Further, a line connecting the first side (mammography side) and the second side (CT side) horizontally is orthogonal to the plane of the substantially flat gantry 30 or the plane of the front cover 26.

  The first side (mammography side) and the second side (CT side) in the mammography apparatus 100 are divided by the substantially flat gantry 30, the front cover 26, and the imaging unit 102 of the mammography apparatus 100. It is an area.

  Here, the mammography apparatus 100 will be specifically described with reference to FIGS. FIG. 2 is a diagram illustrating an appearance of the mammography apparatus 100 as viewed from the CT imaging side. FIG. 3 is a cross-sectional view of the mammography apparatus 100. The cross-sectional view of the mammography apparatus 100 is a cross-sectional view taken along a center line (dashed line) extending in the vertical direction of the mammography apparatus 100 in FIG. FIG. 4 is a diagram illustrating an appearance of the mammography apparatus 100 as viewed from the mammography side.

  As shown in FIG. 2, the gantry 30 on the CT imaging side is provided with a radiation generation unit 10 that rotates during CT imaging and a front cover 26 that protects the subject from the radiation detection unit 12. The front cover 26 has an opening 20 for inserting a breast of a subject who performs CT imaging. The gantry 30 on the CT imaging side is provided with a plurality of gripping portions 22a, 22b, 22c, and 22d to be held by a subject who performs CT imaging. The plurality of gripping portions 22a, 22b, 22c, and 22d are formed in a concave shape. The support leg 40 on the CT imaging side is provided with a notch 48 for inserting a subject's foot for CT imaging.

  As shown in FIG. 4, the gantry 30 on the mammography side is provided with a compression plate 14 that compresses the breast of the subject performing mammography. A protective plate 4 for protecting the subject from unnecessary exposure is installed on the gantry 30 on the mammography side. In addition, the gantry 30 on the mammography side is provided with a gripping unit 70 for a subject to perform mammography. The grip part 70 is formed in a convex shape. Further, the support leg 40 on the mammography side is not provided with a notch 48 for inserting a subject's foot for mammography.

  FIG. 5 shows a configuration diagram of the mammography apparatus 100. The mammography apparatus 100 includes a rotation drive unit 112 that rotates the radiation generation unit 10 and the radiation detection unit 12 in a state where the radiation generation unit 10 and the radiation detection unit 12 face each other. The mammography apparatus 100 includes a compression plate drive unit 114 that moves the compression plate 14 up and down, and a vertical drive unit 116 that moves the gantry 30 up and down relative to the support leg 40.

  The mammography apparatus 100 includes a control unit 110 that controls the radiation generation unit 10, the radiation detection unit 12, the rotation drive unit 112, the compression plate drive unit 114, and the vertical drive unit 116, respectively. The mammography apparatus 100 includes operation units 50 and 52 that transmit instructions to the control unit 110 and an operation console 90. An operation unit 50 that operates the mammography apparatus 100 is installed in the gantry 30, and an operation unit 52 that has the same function as the operation unit 50 is installed on the support base 2 that supports the radiation detection unit 12. The console 90 is installed outside the photographing room.

  The mammography apparatus 100 includes an image processing unit 200 that generates a CT image based on volume data by reconstructing projection data imaged by the radiation detection unit 12, and a reconstructed CT image as a two-dimensional image or a three-dimensional image. A display unit 202 that displays images is provided. The display unit 202 may be integrated with the console 90.

  In addition, on the support 2, a display unit that displays any one of the information of the subject, the height information of the radiation detection unit 12 b, the dose information of the radiation generation unit 10 b, and the compression information (N) by the compression plate 14. May be installed.

  Although not shown, the radiation generation unit 10 includes an electron emission source and a target that mainly generate electrons. Electrons generated from the electron emission source are emitted to the target side due to a potential difference between the cathode and the anode. The target is a member that generates radiation by electron collision. The radiation radiated from the target is shaped into a cone beam shape and irradiated outward. The control unit 110 can control the imaging conditions of the radiation generation unit 10.

  The radiation detection part 12 detects the radiation which permeate | transmitted the subject with a photoelectric conversion element, and outputs it as an electrical signal. For example, the radiation detection unit 12 includes a conversion panel that detects radiation that has passed through the subject, a power storage unit, an I / F (interface) that outputs information converted from radiation to electrical signals, and the like. An electrical signal is output to the control unit 110 by an I / F (interface).

<Gantry>
As shown in FIGS. 2 to 4, the gantry 30 supports a ring-shaped rotating frame 38 for rotating the radiation generating unit 10 and the radiation detecting unit 12 facing each other, and the rotating frame 38 rotatably. And a ring-shaped fixed frame 30a. The fixed frame 30a has an arc shape, and a part of the rotating frame 38 may be rotatably supported. The gantry 30 has a long cylindrical portion 30b having a long cylindrical shape connected to the fixed frame 30a. The rotating frame 38 and the fixed frame 30 a can also be referred to as a rotating unit that rotates the radiation generating unit 10 and the radiation detecting unit 12. The fixed frame 30a and the long cylindrical portion 30b are integrally formed. The fixed frame 30a is positioned above the long cylindrical portion 30b. The long cylindrical portion 30b is connected to a support leg 40 that supports the gantry 30 with respect to the floor surface.

  The gantry 30 is erected in the vertical direction so that the subject can perform standing position imaging. The rotation axis of the rotating unit (the rotating frame 38 in the gantry 30) that rotates the radiation generating unit 10 and the radiation detecting unit 12 is the horizontal direction.

  The long cylindrical portion 30 b covers the outer periphery of the long cylindrical portion 42 in the support leg portion 40. That is, the long cylindrical portion 42 of the support leg 40 is incorporated in the long cylindrical portion 30b of the gantry 30, and the long cylindrical portion 42 of the support leg 40 and the long cylindrical portion 30b of the gantry 30 are nested. ing.

  The mammography apparatus 100 includes a vertical drive unit 116 that moves the long cylindrical part 30 b up and down with respect to the support leg 40. That is, the mammography apparatus 100 includes a vertical drive unit 116 that moves the gantry 30 up and down.

  FIG. 6 is a diagram illustrating a configuration of the vertical drive unit 116 that moves the gantry 30 up and down. The inside of the gantry 30 and the inside of the support leg 40 are hollow from each other. Inside the gantry 30, a circular gear 82 and a support portion 80 that supports the circular gear 82 rotatably are installed. The rotational axis of the circular gear 82 is parallel to the horizontal plane. The support unit 80 supports the circular gear 82 such that the rotation axis of the circular gear 82 is parallel to the horizontal plane. Although not shown, the gantry 30 includes a drive unit (motor) that rotates the circular gear 82.

  In addition, a flat bar member 84 and a support portion 86 that supports the bar member 84 are installed inside the support leg 40. The flat bar member 84 is installed along the longitudinal direction (vertical direction) of the support leg 40. The longitudinal direction of the support leg 40 is a direction orthogonal to the horizontal plane. The flat bar member 84 is installed across the inside of the support leg 40 and the inside of the gantry 30. The mammography apparatus 100 fills a gap between the long cylindrical portion 30b of the gantry 30 and the long cylindrical portion 42 of the support leg 40, and the long cylindrical portion 30b of the gantry 30 and the long cylindrical portion 42 of the support leg 40 are in contact with each other. You may provide the shock absorbing material 88 for suppressing rattling.

  The circular gear 82 and the rod member 84 mesh with each other. When a rotational force is applied to the circular gear 82 by the drive unit (motor), the bar member 84 can be moved up and down. Specifically, when the circular gear 82 is rotated counterclockwise by the drive unit (motor), the bar member 84 can be moved downward with respect to the gantry 30. When the circular gear 82 is rotated counterclockwise, the distance between the support portion 80 that supports the circular gear 82 and the support portion 86 that supports the rod member 84 increases. As described above, when the circular gear 82 in the vertical drive unit 116 is rotated counterclockwise, the gantry 30 can be moved upward.

  Further, when the circular gear 82 is rotated clockwise by the drive unit (motor), the bar member 84 can be moved upward with respect to the gantry 30. When the circular gear 82 is rotated clockwise, the distance between the support portion 80 that supports the circular gear 82 and the support portion 86 that supports the bar member 84 is reduced. Thus, when the circular gear 82 in the vertical drive unit 116 is rotated clockwise, the gantry 30 can be moved downward.

  As described above, the mammography apparatus 100 can move the gantry 30 up and down by the vertical drive unit 116. By moving the gantry 30 up and down, the height of the opening 20 can be adjusted according to the height of the breast of the subject.

  Further, by moving the gantry 30 up and down, the height sandwiched between the compression plate 14 and the radiation detection unit 12 can be adjusted according to the height of the breast of the subject.

  In addition, although the vertical drive part 116 showed an example of the rack and pinion system as mentioned above, other forms, such as a combination of a cam follower and a guide rail, may be sufficient.

<Radiation generator and radiation detector>
The mammography apparatus 100 includes a radiation generation unit 10 that generates radiation and a radiation detection unit 12 that detects radiation emitted from the radiation generation unit 10, and the radiation generation unit 10 and the radiation detection unit 12 face each other. It is possible to rotate with.

  The radiation generation unit 10 and the radiation detection unit 12 are installed on a rotating frame 38 that rotates with respect to the fixed frame 30 a of the gantry 30. Here, as shown in FIG. 3, the mammography apparatus 100 includes a radiation generation unit 10a and a radiation detection unit 12a for CT imaging, and a radiation generation unit 10b and a radiation detection unit 12b for mammography. . The gantry 30 includes a radiation generation unit 10a and a radiation detection unit 12a for CT imaging, and a radiation generation unit 10b and a radiation detection unit 12b for mammography. That is, the mammography apparatus 100 includes two sets of radiation generation units and radiation detection units for CT imaging and mammography.

  The gantry 30 has a ring-shaped rotating frame 38 for rotating the CT imaging radiation generator 10a and the radiation detector 12a facing each other and rotating the mammography radiation generator 10b and the radiation detector 12b facing each other. have.

  Specifically, the radiation generating unit 10a and the radiation detecting unit 12a are installed on the rotary frame 38 for CT imaging. The radiation detection unit 12a is installed on the rotary frame 38 via the support base 2 that supports the radiation detection unit 12a.

  For mammography, the rotary frame 38 is provided with a radiation generation unit 10b and a radiation detection unit 12b. The radiation detection unit 12 b is installed on the rotating frame 38 via the support base 2.

  The rotating frame 38 is connected to the fixed frame 30a of the gantry 30 through a bearing having a bearing structure. The fixed frame 30a is in a stationary state and is a stationary frame. The rotating frame 38 can be rotated by the rotation driving unit 112. The rotation drive unit 112 is installed inside the gantry 30 so that the rotation axis of the rotation frame 38 is in the horizontal direction.

  A compression plate 14 is installed on the support base 2 so as to be movable up and down. The support 2 is provided with a rotary knob 54 that moves the compression plate 14 up and down. By rotating the rotary knob 54 and lowering the compression plate 14, the breast of the subject can be sandwiched between the compression plate 14 and the radiation detection unit 12b. The rotary knob 54 may have a two-stage dial for moving the breast compression plate 14 up and down. The rotary knob 54 includes a rotary knob with a large diameter and a rotary knob with a small diameter. The rotary knob 54 is a rotary knob with a large diameter on the inner side (support base 2 side), and a rotary knob with a small diameter on the outer side (rotary frame 38 side). Even if the rotary knob with a large diameter and the rotary knob with a small diameter are rotated by the same angle, the moving amount (stroke) of the compression plate 14 is different. The amount of movement of the compression plate 14 is larger when the rotary knob having a larger diameter is rotated than the rotary knob having a smaller diameter.

  The rotary knob with a large diameter can move the compression plate 14 up and down more greatly than the rotary knob with a small diameter. When the rotary knob with a large diameter is turned, the compression plate 14 can be moved up and down greatly. When the rotary knob with a small diameter is turned, the compression plate 14 can be moved up and down small. Thus, a rotary knob with a large diameter can be used for coarse adjustment, and a rotary knob with a small diameter can be used for fine adjustment.

  As described above, the support base 2 is installed on the rotating frame 38, and the support base 2 supports the radiation detection unit 12 a, the radiation detection unit 12 b, and the compression plate 14. By rotating the rotary frame 38 together with the support base 2 by the rotation driving unit 112, the radiation detection unit 12a and the radiation detection unit 12b can be rotated. Further, by rotating the rotating frame 38 by the rotation driving unit 112, the radiation generating unit 10a and the radiation generating unit 10b can be rotated.

  As shown in FIG. 3, the radiation generating unit 10a and the radiation generating unit 10b are installed at substantially the same height. The radiation detection unit 12a is installed at a position higher than the radiation detection unit 12b.

  In other words, the radiation generating unit 10a and the radiation generating unit 10b are installed so that the radiation generating unit 10a and the radiation generating unit 10b are at the same position (same distance) with respect to the rotation axis of the rotating unit (the rotating frame 38). ing.

  In addition, the radiation detection unit 12a and the radiation detection unit 12b are installed so that the radiation detection unit 12b is positioned outside the radiation detection unit 12a with respect to the rotation axis of the rotation unit (the rotation frame 38). .

  The distance between the radiation generator 10a and the radiation detector 12a used when performing CT imaging is shorter than the distance between the radiation generator 10b and the radiation detector 12b used when performing mammography.

  When mammography is performed, the breast of the subject is sandwiched between the compression plate 14 and the radiation detection unit 12b. Since the subject's breast is crushed and flattened due to the compression, the area to be irradiated with radiation must be increased to secure a field of view (FOV). Therefore, the radiation detection unit 12b used when performing mammography is installed at a position lower than the radiation detection unit 12a used when performing CT imaging.

  The irradiation field 8 is an irradiation field by the radiation generator 10b for mammography. The radiation generation unit 10b and the radiation detection unit 12b are installed so that the irradiation field 8 from the radiation generation unit 10b includes the compression plate 14. The irradiation field 8 has a quadrangular pyramid shape (cone beam shape) that spreads with the focal point of the radiation generating unit 10b as a vertex. As shown in FIG. 3, one side end (left side) of the irradiation field 8 is in the vertical direction, and the other side end (right side) of the irradiation field 8 is in the oblique direction. In order to image the subject's breast circumference (axillary area), the end (irradiation field end, irradiation field end surface) of the irradiation field 8 on the subject side (left side) performing mammography is in the vertical direction. The irradiation field 8 of the radiation generator 10b is set.

  On the other hand, when performing CT imaging, the radiation generation unit 10a and the radiation detection unit 12a are installed so that the size of the rotating frame 38 and the size of the mammography apparatus 100 (gantry 30) as a whole are compact. Specifically, the distance between the radiation generation unit 10a and the radiation detection unit 12a is set as short as possible. The radiation detection unit 12 a is installed directly below the breast holding unit 34. Even if the radiation detection unit 12 a is rotated by the rotating frame 38, the radiation detection unit 12 a is installed at a position where the radiation detection unit 12 a does not contact the breast holding unit 34.

  The irradiation field 6 is an irradiation field by the radiation generator 10a for CT imaging. The breast of the subject who performs CT imaging is held on the breast holder 34 and is not compressed. The radiation generation unit 10 a and the radiation detection unit 12 a are installed so that the irradiation field 6 from the radiation generation unit 10 a includes the distal end portion of the breast holding unit 34.

  The irradiation field 6 has a quadrangular pyramid shape (cone beam shape) that spreads with the focal point of the radiation generating unit 10a as a vertex. As shown in FIG. 3, one side end (right side) of the irradiation field 6 is in the vertical direction, and the other side end (left side) of the irradiation field 6 is in the oblique direction. In order to image the breast circumference (axillary area) of the subject, the end (irradiation field end, irradiation field end surface) of the irradiation field 6 on the subject side (right side) performing CT imaging is in the vertical direction. Is set.

  In this way, the end of the irradiation field 8 (irradiation field end, irradiation field end face) on the subject side (left side) performing mammography is set to be in the vertical direction, and the subject performing CT imaging. The (right side) irradiation field 6 end (irradiation field end, irradiation field end surface) is set to be in the vertical direction. In breast cancer, metastases around the breast (axilla) can occur. An irradiation field 6 of the radiation generation unit 10a for CT imaging and an irradiation field 8 of the radiation generation unit 10b for mammography are set so that the circumference of the breast (axillary) of the subject can be imaged. .

  When performing CT imaging, the radiation generator 10a for CT imaging may be installed at a higher position than the radiation generator 10b for mammography in order to ensure a field of view (FOV). . When performing CT imaging, the radiation generation unit 10a rotates the radiation generation unit 10a and the radiation detection unit 12a while generating radiation from the focal point.

  As described above, the mammography apparatus 100 of the present invention includes the first radiation generation unit 10a that generates radiation and the second radiation generation unit 10b that generates radiation. The mammography apparatus 100 also includes a first radiation detection unit 12a that detects radiation emitted from the first radiation generation unit 10a and a second radiation that detects radiation emitted from the second radiation generation unit 10b. Radiation detector 12b.

  The first radiation generation unit 10a and the first radiation generation unit 10a and the first radiation detection unit 12a are sandwiched between the imaging target region of the subject from the first side in the mammography apparatus 100. Photographing is performed using the radiation detector 12a. In addition, a state in which the imaging target region of the subject is inserted between the second radiation generation unit 10b and the second radiation detection unit 12b from the second side opposite to the first side in the mammography apparatus 100 Then, the second radiation generation unit 10b and the second radiation detection unit 12b are rotated and photographed.

  Thus, the mammography apparatus 100 includes two sets of radiation generation units and radiation detection units for CT imaging and mammography. Therefore, it is possible to secure an FOV (Field of view) suitable for each of the breast of the subject performing CT imaging and the breast of the subject performing mammography.

<Rotating frame>
The mammography apparatus 100 includes a rotation drive unit 112 that rotates the radiation generation unit 10 and the radiation detection unit 12 via a rotation frame 38. The radiation generation unit 10 includes therein a radiation generation unit 10b for mammography and a radiation generation unit 10a for CT imaging.

  FIG. 4 shows a mode in which the mammography apparatus 100 performs mammography of CC (Caranio Caudal view). The position of the rotary frame 38 is set so that the radiation generator 10b, the compression plate 14, and the radiation detector 12b are arranged in the vertical direction.

  By rotating the rotary knob 54, the compression plate 14 can be moved, and the distance between the compression plate 14 and the radiation detection unit 12b can be adjusted. By moving the compression plate 14, the subject's breast can be compressed. In the mammography of CC shown in FIG. 4, the breast disposed between the compression plate 14 and the radiation detection unit 12 b is compressed between the compression plate 14 and the radiation detection unit 12 b and is radiographed.

  The rotation drive unit 112 is installed inside the fixed frame 30a. A rotating frame 38 is rotatably connected to the rotation driving unit 112 via a connecting member (for example, a belt). A bearing is set in the gap between the fixed frame 30 a and the rotating frame 38. The rotation frame 38 rotates with respect to the fixed frame 30a by the drive of the rotation driving unit 112.

  FIG. 7 is a diagram illustrating a rotation form in which the radiation generation unit 10 b and the radiation detection unit 12 b are rotated by the rotation driving unit 112 of the mammography apparatus 100. When the mammography apparatus 100 performs mammography in MLO (internal and external oblique view), as shown in FIG. 7, the rotating frame 38 is rotated from the state of FIG. 4 by a predetermined angle (for example, about 65 degrees). The state is stopped. The stop state of the rotating frame 38 may be maintained by a servo or a brake. In the MLO mammography shown in FIG. 7, the breast disposed between the compression plate 14 and the radiation detection unit 12 b is compressed between the compression plate 14 and the radiation detection unit 12 b to be radiographed.

  Further, when performing CT imaging, the rotation frame 38 is rotated with respect to the fixed frame 30 a by driving the rotation driving unit 112. Specifically, the rotating frame 38 is rotated at least 180 degrees. When the rotating frame 38 is rotated, the radiation generation unit 10a generates radiation, and the radiation detection unit 12a detects radiation. The radiation detection unit 12 can perform CT imaging on the subject's breast by detecting radiation that has passed through the subject's breast. The mammography apparatus 100 can generate a CT image based on the volume data by reconstructing the captured projection data.

<Front cover>
A front cover 26 is detachably installed on the gantry 30 of the mammography apparatus 100. In other words, the front cover 26 is detachably installed on the ring-shaped fixed frame 30a. Specifically, the front cover 26 is attached to the fixed frame 30a by fitting the protrusion of the front cover 26 into the frame (groove) of the fixed frame 30a.

  FIG. 2 shows a form in which the front cover 26 is attached to the gantry 30 of the mammography apparatus 100. FIG. 8 shows a form in which the front cover 26 is removed from the gantry 30 of the mammography apparatus 100.

  As shown in FIG. 8, when the front cover 26 is removed from the gantry 30, the operator accesses the breast of the subject performing mammography through the hollow portion of the rotating frame 38 from the CT imaging side. Can do. In mammography, position adjustment and compression adjustment can be performed on the breast disposed between the radiation detection unit 12b and the compression plate 14 of the mammography apparatus 100.

  Since the fixed frame 30a in the gantry 30 is ring-shaped, the front cover 26 is circular. The front cover 26 only needs to be fixed to a member that does not move with respect to the rotation of the radiation generation unit 10 and the radiation detection unit 12.

  The front cover 26 is provided with an opening 20 for inserting the subject's breast. Specifically, as shown in FIG. 2, a circular opening 20 for inserting the subject's breast is provided at the center of the front cover 26.

  The front cover 26 is composed of a shielding member that shields radiation. Scattered radiation is prevented from passing through the front cover 26 during CT imaging or mammography. That is, scattered radiation does not reach the CT imaging side. The front cover 26 is a translucent member. Since the front cover 26 is translucent, even if the front cover 26 is installed on the gantry 30, the positions of the radiation generating unit 10 and the radiation detecting unit 12 can be confirmed from the CT imaging side.

  As shown in FIGS. 3 and 4, the front cover 26 is provided with a breast holding portion 34 as a holding base for holding the breast inserted from the opening 20. The breast holding part 34 is a transparent member and a member that transmits radiation. The breast holding part 34 is formed along the periphery of the opening 20 of the front cover 26. The breast holding part 34 is formed so as to protrude from the opening 20 of the front cover 26 to the photographing part 102 side.

  The breast holding part 34 is hollow and is curved in accordance with the shape of the breast. A part (lower side) of the breast holding part 34 has a bowl shape, and a part (upper side) of the breast holding part 34 is open. The breast holding part 34 has an opening 34a for an operator to access the breast from the mammography side.

  The breast holding part 34 has a shape that holds the lower side of the breast. The breast holder 34 can hold the breast while maintaining the shape of the breast. The breast holding unit 34 does not compress the breast.

  As shown in FIG. 4, a part (upper side) of the breast holding unit 34 is open, so that the operator can access the breast of the subject performing CT imaging from the mammography side. It has become. That is, the operator can access the breast of the subject held by the breast holding unit 34 from the mammography side.

  The breast holding part 34 can be attached to and detached from the front cover 26. Here, breast holders 34 of various sizes can be prepared. That is, the operator can prepare a plurality of breast holders 34. For example, the breast holder 34 can be replaced according to the size of the breast of the subject.

  The front cover 26 and the breast holder 34 fixed to the gantry 30 separate the subject's space from the radiation generator 10 and the radiation detector 12 that rotate during CT imaging. Since the breast of the subject is held by the breast holding unit 34, it is fixed during imaging.

  Although the example in which the breast holding part 34 is connected along the periphery of the opening 20 of the front cover 26 is shown, the present invention is not limited to this. For example, the breast holder 34 may be connected to the fixed frame 30 a of the gantry 30.

  The gantry 30 is provided with an insertion portion 24a and an insertion portion 24b. The insertion portion 24 a and the insertion portion 24 b are places where an operator's hand is inserted when removing the front cover 26, and are installed along the fixed frame 30 a of the gantry 30. The insertion portion 24a and the insertion portion 24b are installed at two places on the left and right of the fixed frame 30a of the gantry 30. The insertion portion 24 a and the insertion portion 24 b are installed so as to be line-symmetric with respect to the center line (one-dot chain line) of the gantry 30.

  The operator can remove the front cover 26 by putting his hands in the insertion portion 24a and the insertion portion 24b and pulling the front cover 26 toward the front side. By removing the front cover 26 during mammography, the subject's breast can be easily accessed.

  On the contrary, the operator can attach the front cover 26 to the gantry 30 by pushing the front cover 26 backward with respect to the fixed frame 30 a of the gantry 30.

  The front cover 26 may be opaque from the subject side who performs CT imaging and transparent from the operator side of the mammography side. By making the front cover 26 opaque from the subject side, fear of moving the radiation generating unit 10 and the radiation detecting unit 12 over the front cover 26 can be avoided.

  As shown in FIGS. 2 and 8, the front cover 26 is provided with a first illumination unit 120 that irradiates light to the CT imaging side. For example, the first illumination unit 120 is installed along the circumferential direction of the front cover 26. That is, the first illumination unit 120 is installed along the outer edge of the front cover 26. That is, the 1st illumination part 120 is installed in ring shape with respect to the front cover 26, and irradiates light in a ring shape. Moreover, the 1st illumination part 120 may be installed in ring shape with respect to the gantry 30 (fixed frame 30a, long cylindrical part 30b) by the side of CT imaging. That is, the 1st illumination part 120 is installed so that light may be irradiated from the mammography apparatus 100 by the side of CT imaging. It suffices that the front side of the mammography apparatus 100 shown in FIG. 2 is irradiated with light. The light emitted from the first illumination unit 120 may be either a lighting form or a blinking form. The illumination unit is controlled by the control unit 110, although not shown.

  Prior to CT imaging, the control unit 110 emits light from the first illumination unit 120. Prior to CT imaging, the first illumination unit 120 irradiates light to the CT imaging side. Therefore, the subject who is scheduled to perform CT imaging can recognize which side of the mammography apparatus is to perform imaging.

  During CT imaging, the control unit 110 extinguishes the light irradiated to the CT imaging side by the first illumination unit 120. CT imaging is a period during which CT imaging is performed by rotating the radiation generation unit 10 and the radiation detection unit 12. That is, during CT imaging, light is not emitted from the first illumination unit 120 when the radiation generation unit 10 and the radiation detection unit 12 are rotating. Light is emitted from the first illumination unit 120 when the radiation generation unit 10 and the radiation detection unit 12 are stationary.

  The radiation generation unit 10 is provided with a second illumination unit 122 that irradiates light on the CT imaging side. During the CT imaging, the control unit 110 emits light from the second illumination unit 122. That is, light is emitted from the second illumination unit 122 when CT imaging is being performed and the radiation generation unit 10 and the radiation detection unit 12 are rotating. When the radiation generation unit 10 and the radiation detection unit 12 are stationary, no light is emitted from the second illumination unit 122. The light irradiated from the 2nd illumination part 122 is a lighting form. Since the light emitted from the second illumination unit 122 is in the lighting form, the positions of the radiation generation unit 10 and the radiation detection unit 12 can be confirmed even when the radiation generation unit 10 and the radiation detection unit 12 are rotating. ing.

  Further, since the front cover 26 is translucent, the light emitted from the second illumination unit 122 passes through the front cover 26. The light emitted from the second illumination unit 122 is emitted to the CT imaging side. During CT imaging in which the radiation generation unit 10 and the radiation detection unit 12 are rotating, the radiation generation unit 10 generates radiation and irradiates light from the second illumination unit 122. The operator and the subject can confirm the positions of the rotating radiation generator 10 and the radiation detector 12 from the CT imaging side. Therefore, the operator and the subject recognize the position of the radiation generation unit 10 and the radiation detection unit 12 from the CT imaging side, thereby recognizing how much further the radiation generation unit 10 is rotated to complete the CT imaging. be able to.

  Specifically, from the state shown in FIGS. 4 and 8, the radiation generation unit 10 and the radiation detection unit 12 make one clockwise rotation to perform CT imaging. Before performing CT imaging, the radiation generation unit 10 is positioned on the upper side of the mammography apparatus, and the radiation detection unit 12 is positioned on the lower side of the mammography apparatus. When CT imaging is started, the radiation generation unit 10 located on the upper side of the mammography apparatus rotates clockwise. Then, light is emitted from the second illumination unit 122 at the same time as the radiation generation unit 10 rotates clockwise. The operator and the subject can recognize how much the radiation generation unit 10 is further rotated and the radiation generation unit 10 is positioned on the upper side, that is, how much further the radiation generation unit 10 is to be rotated to complete the CT imaging.

  In addition, although the radiation generation part 10 showed the form with which the 2nd illumination part 122 which irradiates light to CT imaging side was installed, you may install the 2nd illumination part 122 in the radiation detection part 12. FIG.

  When the radiation generation unit 10 and the radiation detection unit 12 rotate and CT imaging is completed, the control unit 110 causes the first illumination unit 120 to emit light. The first illumination unit 120 emits light to the CT imaging side. Therefore, the operator and the subject can recognize that the CT imaging has been completed.

  Further, as shown in FIG. 7, the radiation generation unit 10, the radiation detection unit 12, and the compression plate 14 are provided with a third illumination unit 124 that irradiates light to the mammography side. Moreover, the 3rd illumination part 124 may be installed in the gantry 30 (fixed frame 30a, long cylindrical part 30b) by the side of mammography. That is, the third illumination unit 124 is installed so that light is emitted from the mammography apparatus on the mammography side. It suffices that light is irradiated on the front side of the mammography apparatus shown in FIG. The light emitted from the third illumination unit 124 may be either in a lighting form or a blinking form.

  When performing mammography, the control unit 110 emits light from the third illumination unit. When performing mammography, light is irradiated to the mammography side by the third illumination unit 124. Therefore, a subject who is planning to take mammography can recognize which side of the mammography apparatus is to be used for imaging.

  As described above, in the gantry 30 of the mammography apparatus 100 of the present invention, the front cover 26 that protects the subject from the radiation generation unit 10 and the radiation detection unit 12 that rotate during CT imaging is detachably installed. The front cover 26 has an opening 20 for inserting the breast of the subject and a breast holding unit 34 for holding the breast of the subject inserted through the opening 20. The gantry 30 is detachably installed with a front cover 26 that protects the subject from the radiation generation unit 10 and the radiation detection unit 12 that rotate during CT imaging and has a function of holding the breast of the subject. Yes. Therefore, the subject can be protected from the radiation generation unit 10 and the radiation detection unit 12 that rotate during CT imaging. CT imaging can be performed with the patient's breast properly held.

<Separation part>
FIG. 9 shows the form of the breast holder 34 in the mammography apparatus 100 of the present invention. The left diagram in FIG. 9 is an external view of the breast holder 34, and the right diagram in FIG. 9 is a cross-sectional view at the center of the breast holder 34. The right view of FIG. 9 is the same cross section as the cross section taken along the center line (dashed line) extending in the vertical direction of the mammography apparatus 100 of FIG.

  As shown in FIG. 9, the breast holder 34 has an opening for an operator to access the breast. The upper side of the breast holder 34 is open. In the opening of the breast holding unit 34, a separation unit 300 having properties different from those of the breast holding unit 34 is installed. The separation unit 300 has a property different from that of the subject's breast. The separation unit 300 is a separation layer for separating the breast holding unit 34 and the breast of the subject. Specifically, the separation unit 300 is installed on the side of the breast holding unit 34 that holds the breast. The separating unit 300 may have an attachment function and be detachable from the breast holding unit 34.

  The thickness of the separation unit 300 may be any thickness that allows the breast holding unit 34 and the subject's breast to be separated on the volume data in the three-dimensional image. The thickness of the separation unit 300 is 1 mm to 3 mm, for example.

  The radiation absorption rate of the separation unit 300 is different from the radiation absorption rate of the breast of the subject. The separation unit 300 is a substance having a lower radiation absorption rate than the subject's breast. Further, the radiation absorption rate of the separation unit 300 is different from the radiation absorption rate of the breast holding unit 34. The separation unit 300 is a substance having a lower radiation absorption rate than the breast holding unit 34. The separation unit 300 is, for example, a highly porous material such as a sponge. A larger amount of radiation transmitted through the separation unit 300 is advantageous for the image quality of the CT image in the breast of the subject.

  In addition, the separating unit 300 may have a shape and a material that improve the fixation of the subject's breast. It is a material that prevents the subject's breast from slipping. The separation unit 300 can fix and maintain the breast of the subject on the breast holding unit 34.

<Operation unit>
As shown in FIGS. 2 and 4, the operation unit 50 for operating the mammography apparatus is installed in the gantry 30. The operation unit 50 is installed in a component that does not rotate in the mammography apparatus. The operation unit 50 is installed on each of the left and right side surfaces of the fixed frame 30a in the gantry 30. Specifically, the operation unit 50 includes an operation unit 50a and an operation unit 50b. The operation unit 50a and the operation unit 50b are installed at the right end and the left end of the fixed frame 30a, respectively. As shown in FIG. 5, the operation unit 50 (the operation unit 50 a and the operation unit 50 b) is connected to the control unit 110.

  As shown in FIG. 4, the operation unit 52 (operation unit 52 a and operation unit 52 b) for operating the mammography apparatus is installed on the support base 2 installed on the rotating frame 38. That is, the operation unit 52 is installed on a rotating component in the mammography apparatus. In the present embodiment, the operation unit 52 is installed on the left and right side surfaces of the support base 2. Specifically, the operation unit 52 includes an operation unit 52a and an operation unit 52b. The operation unit 52 a and the operation unit 52 b are respectively installed on the left and right side surfaces of the support base 2. As shown in FIG. 5, the operation unit 52 (the operation unit 52 a and the operation unit 52 b) is connected to the control unit 110.

  The operation unit 50 installed on the gantry 30 and the operation unit 52 installed on the support base 2 have the same button configuration. The operation unit 50 and the operation unit 52 have the same function. The operation unit 50 and the operation unit 52 include a button for moving the compression plate 14 up and down and a button for rotating the radiation generation unit 10 and the radiation detection unit 12. These buttons are buttons that the operator presses with a finger.

<Image processing>
When the mammography apparatus 100 performs CT imaging, the radiation detection unit 12 can perform CT imaging on the breast of the subject by detecting radiation that has passed through the breast of the subject. Specifically, the mammography apparatus 100 acquires volume data by reconstructing projection data imaged by the radiation detection unit 12. The mammography apparatus 100 generates a three-dimensional image or a two-dimensional CT image based on the volume data.

  The image processing unit 200 reconstructs projection data around the breast of the subject output from the radiation detection unit 12 (radiation detection unit 12a), and acquires volume data. The image processing unit 200 generates a three-dimensional image by rendering the volume data. Rendering is a process of expressing three-dimensional volume data in two dimensions in order to display it on the screen of the display unit 202. Rendering performs coordinate conversion from three-dimensional coordinates of volume data to two-dimensional coordinates, and shading processing is performed to produce a three-dimensional effect. Rendering includes volume rendering and surface rendering.

  The image processing unit 200 generates a two-dimensional image (tomographic image) by cutting out one cross section from the reconstructed volume data. The image processing unit 200 can also generate a plurality of two-dimensional images (tomographic images) having orthogonal cross sections. For example, the image processing unit 200 can also generate a two-dimensional image (tomographic image) of an axial section, a sagittal section, and a coronal section. Further, the image processing unit 200 can generate a two-dimensional image (tomographic image) in a desired cross section by setting the coordinates of the cross section with the console 90. The operator sets the coordinates of the cross section so that the region of interest (eg, mammary gland) of the subject's breast is displayed via the console 90, thereby including the two-dimensional region including the region of interest (eg, mammary gland). An image (tomographic image) can be generated.

  At this time, the image processing unit 200 separates the reconstructed volume data into volume data of the subject's breast, breast holding unit 34, and separation unit 300. That is, the image processing unit 200 separates the reconstructed volume data into volume data of the subject's breast and volume data other than the breast.

  An image processing technique called segmentation can be used as a method for separating the volume data into the breast of the subject, the breast holding unit 34, and the separation unit 300. Specifically, the image processing unit 200 separates the subject's breast, the breast holding unit 34, and the separation unit 300 in the volume data based on the pixel values (CT values) constituting the reconstructed volume data. To do. That is, the volume data is separated into a breast area and a non-breast area of the subject based on the pixel value (CT value). The breast of the subject and the breast holder 34 may be separated using a region expansion method (region growing method) based on pixel values (CT values) or the like.

  In the case of volume data in CT imaging, it is generally known that a pixel value (CT value) corresponding to fat is about −200 to −20. It is known that the pixel value (CT value) corresponding to soft tissue is about 50. Here, it is assumed that the breast of the subject has a property close to a pixel value (CT value) corresponding to fat. The breast holding unit 34 in this embodiment has a property close to a pixel value (CT value) corresponding to fat. That is, the breast holding unit 34 is made of a material that can obtain the same pixel value (CT value) as that of the subject's breast.

  On the other hand, the separating unit 300 is different from the nature of the subject's breast and the breast holding unit 34. The separation unit 300 in this embodiment has a property close to a pixel value (CT value) corresponding to soft tissue. That is, the separation unit 300 is made of a material that can obtain a pixel value (CT value) different from that of the subject's breast and the breast holding unit 34.

  As described above, the image processing unit 200 separates the subject's breast in the volume data, the breast holding unit 34, and the separation unit 300 based on the pixel values (CT values) constituting the volume data. Then, the image processing unit 200 removes the volume data of the breast holding unit 34 and the separation unit 300 from the reconstructed volume data, and generates volume data of the subject's breast. If the separation unit 300 is set as a reference, the volume data is divided into two regions with the separation unit 300 as a boundary. As described above, the volume data is divided into the breast region of the subject and the breast holding unit 34 with the separation unit 300 as a boundary.

  The image processing unit 200 generates a three-dimensional image by rendering the breast volume data of the subject from which the breast holding unit 34 and the separation unit 300 have been deleted. The image processing unit 200 generates a three-dimensional image by rendering volume data of the subject's breast from which volume data other than the subject's breast has been deleted. Here, a three-dimensional image from which the breast holding unit 34 and the separation unit 300 are deleted is generated. Accordingly, the display unit 202 can display the three-dimensional image of only the breast of the subject without the breast holding unit 34 and the separation unit 300 being deleted.

  FIG. 10 shows an operation procedure of the mammography apparatus of the present invention.

  S100: When performing CT imaging, the rotating frame 38 is rotated together with the radiation generator 10a and the radiation detector 12a. When the rotating frame 38 is rotated, the radiation generation unit 10a generates radiation, and the radiation detection unit 12a detects radiation. The radiation detection unit 12a can perform CT imaging on the subject's breast by detecting radiation that has passed through the subject's breast.

  S102: The mammography apparatus 100 generates volume data by reconstructing projection data detected by the radiation detection unit 12a.

  S104: The operator sets whether or not to delete the volume data corresponding to the breast holding unit 34 from the entire volume data via the console 90. When deleting the volume data of the breast holding unit 34 from the entire volume data, the process proceeds to S106. When the volume data of the breast holding unit 34 is not deleted from the entire volume data, the image processing unit 200 generates a three-dimensional image by rendering the entire volume data. The image processing unit 200 generates a two-dimensional image (tomographic image) by cutting out one cross section from the volume data. Then, the operation ends.

  S106: When deleting the volume data of the breast holding unit 34 from the entire volume data, a threshold is set for the volume data. The threshold value is a value based on a pixel value (CT value) for separating the breast of the subject in the volume data, the breast holding unit 34, and the separation unit 300. Here, the volume data is separated into three areas. The breast holding unit 34 is made of a material that can obtain the same pixel value (CT value) as that of the subject's breast, and the separation unit 300 is different in pixel value (CT value) from the subject's breast and breast holding unit 34. It is comprised with the material which can be obtained. Therefore, the threshold is determined in advance so that these regions can be segmented (separated). The operator can also set a threshold value via the console 90. The operator can set the threshold according to the characteristics of the breast of the subject.

  S108: The image processing unit 200 performs a labeling process of the subject's breast, the breast holding unit 34, and the separation unit 300 in the volume data separated according to the threshold value. Specifically, the image processing unit 200 sets the volume data area of the subject's breast to “1”, sets the volume data area of the breast holding unit 34 to “2”, and The volume data area is set to “3”. Usually, since the breast of the subject, the separation unit 300, and the breast holding unit 34 are arranged from the inside of the volume data, the image processing unit 200 sets “1”, “3”, and “2” in order from the inside of the volume data, It may be set. Further, the image processing unit 200 may set an area (for example, an air layer) other than the breast of the subject, the breast holding unit 34, and the separation unit 300 as “4”.

  In this way, the image processing unit 200 separates the subject's breast in the volume data, the breast holding unit 34, and the separation unit 300 based on the pixel values (CT values) constituting the reconstructed volume data. .

  S110: The image processing unit 200 performs a deletion process based on the labeled label. The image processor 200 leaves the volume data set as “1” and deletes the volume data set as “2” and “3”. In this manner, the image processing unit 200 removes the volume data of the breast holding unit 34 and the volume data of the separation unit 300 from the entire volume data, thereby generating volume data of the subject's breast. When the region other than the subject's breast, breast holding unit 34, and separation unit 300 is set as “4”, the image processing unit 200 may delete the volume data set as “4”.

  Then, the image processing unit 200 generates a three-dimensional image by rendering the volume data of the subject's breast from which the volume data of the breast holding unit 34 and the volume data of the separation unit 300 are deleted. Therefore, a three-dimensional image from which the breast holding unit 34 and the separation unit 300 are deleted is generated. Therefore, the display unit 202 can display a three-dimensional image of only the breast of the subject from which the breast holding unit 34 and the separation unit 300 are deleted.

  FIG. 11 is a diagram illustrating a three-dimensional image displayed on the display unit 202. FIG. 11A is a three-dimensional image when the image processing of the present invention is not applied, and FIG. 11B is a three-dimensional image when the image processing of the present invention is applied.

  As shown in FIG. 11A, the three-dimensional image 306 of the subject's breast includes a region of interest 310. The region of interest 310 is a region including the mammary gland. When the image processing according to the present invention is not applied, the volume data of the subject's breast is rendered including the volume data of the breast holder 34, so that the three-dimensional image 308 of the breast holder 34 is displayed on the breast of the subject. Covered and displayed by a three-dimensional image 306. Therefore, a part of the region of interest 310 in the three-dimensional image 306 of the subject's breast is hidden by the three-dimensional image 308 of the breast holder 34. The visibility of the region of interest 310 in the three-dimensional image 306 is poor.

  As shown in FIG. 11B, the region of interest 310 is included in the three-dimensional image 306 of the subject's breast. When the image processing of the present invention is applied, since the volume data of the subject's breast is rendered without including the volume data of the breast holding unit 34, the display unit 202 has the breast holding unit 34 and the separation unit 300 deleted. It is possible to display a three-dimensional image of only the breast of the subject who has been subjected. The region of interest 310 in the three-dimensional image 306 of the subject's breast is displayed without being hidden by the three-dimensional image 308 of the breast holder 34. The visibility of the region of interest 310 in the three-dimensional image 306 is improved.

  FIG. 12 is a diagram illustrating a two-dimensional image displayed on the display unit 202. The image processing unit 200 generates a two-dimensional image (tomographic image) by cutting out one cross section from the reconstructed volume data. The display unit 202 displays a two-dimensional image (tomographic image) 302 of the subject's breast, a two-dimensional image 304 of the breast holding unit 34, and a two-dimensional image 312 of the separation unit 300.

  A region of interest 314 is included in the two-dimensional image 302 of the subject's breast. The region of interest 314 is a region including the mammary gland. Since the two-dimensional image (tomographic image) 302 of the subject's breast is cut out from the volume data and displayed, the two-dimensional image 304 of the breast holding unit 34 and the two-dimensional image 312 of the separating unit 300 are displayed. It is not covered by the two-dimensional image 312 of the breast. In the two-dimensional image (tomographic image) 302 of the subject's breast, the visibility of the region of interest 314 does not deteriorate.

  Therefore, in S104, when generating a two-dimensional image (tomographic image) by cutting out one cross section from the volume data, the image processing unit 200 may set in advance that the volume data of the breast holding unit 34 is not deleted. Good. This is because the two-dimensional image 304 of the breast holder 34 does not become an obstacle to the two-dimensional image 302 of the subject's breast.

  In S110, the operator can set a label to be deleted from the volume data via the console 90. For example, the volume data set as “1” and “2” can be left and the volume data set as “3” can be deleted. This is because the separation unit 300 is a relatively thin material and thus is less likely to become an obstacle in the three-dimensional image of the subject's breast.

  As described above, the mammography apparatus 100 of the present invention has the opening 20 for inserting the breast of the subject and the breast holding unit 34 for holding the breast of the subject inserted from the opening 20. A separation unit 300 for separating the breast of the subject and the breast holding unit 34 is installed between the breast of the person and the breast holding unit 34.

  As described above, the separation unit 300 can physically separate the breast holding unit 34 and the breast of the subject in the three-dimensional image. Even if CT imaging is performed with the breast held by the breast holding unit, the region of interest can be appropriately displayed in the three-dimensional image.

  In addition, although the mammography apparatus 100 of the present invention has been described as an example including two sets of radiation generation units and radiation detection units for CT imaging and mammography, one set of radiation generation unit and radiation detection unit is provided. It is also possible to realize CT imaging and mammography. Specifically, the mammography apparatus 100 includes a moving mechanism (not shown) that moves the radiation generation unit and the radiation detection unit by CT imaging and mammography. For example, in CT imaging, the radiation generation unit is moved to the position 10a shown in FIG. 3, and the radiation detection unit is moved to the position 12a. In mammography, the radiation generation unit is moved to the position 10b, and the radiation detection unit is moved to the position 12b shown in FIG. Also, there is no need to have a function for photographing mammo.

  In the present embodiment, the mammography apparatus has been described specifically for imaging a subject's breast, but the imaging target may be other than the breast, for example, the extremities. Therefore, the imaging apparatus of the present invention has an opening for inserting a target part of the subject and a holding unit that holds the target part of the subject inserted from the opening, and the target part of the subject In other words, a separation unit that separates the target region of the subject and the holding unit is installed between the holding unit and the holding unit.

  Further, the image processing unit 200 separates the reconstructed volume data into volume data of a subject's target region, a holding unit, and a separation unit. The image processing unit 200 separates the reconstructed volume data into volume data of the subject site of the subject and volume data other than the target site. Then, the image processing unit 200 generates a three-dimensional image by rendering the volume data of the subject part of the subject from which the volume data other than the subject part of the subject has been deleted.

  That is, the image processing unit 200 includes a generation unit that generates volume data from the projection data detected by the radiation detection unit in a state where the radiation generation unit and the radiation detection unit are rotated. A separation means for separating the volume data and the volume data other than the target site, and rendering the volume data of the target site of the subject from which the volume data other than the target site of the subject has been deleted. A generating means for generating is provided. The details of the image processing unit 200 are as described above.

<Grip part>
As shown in FIG. 2, the gantry 30 on the CT imaging side is formed with a plurality of gripping portions 22a, 22b, 22c, and 22d to be held by a subject who performs CT imaging. Specifically, the plurality of gripping portions 22a, 22b, 22c, and 22d are respectively formed along the circumferential direction of the outer edge of the ring-shaped fixed frame 30a that rotatably supports the rotating frame 38 in the gantry 30. . A plurality of gripping portions 22a, 22b, 22c, and 22d are formed in the vicinity of the joint portion between the fixed frame 30a and the front cover 26 installed on the fixed frame 30a.

  In the fixed frame 30a, the grip 22a is installed on the upper right, the grip 22b is on the lower right, the grip 22c is on the upper left, and the grip 22d is on the lower left. Although not shown, in the fixed frame 30a, the grip portion may be installed directly above.

  The plurality of gripping portions 22a, 22b, 22c, and 22d are concave gripping portions and are formed on a ring-shaped fixed frame 30a. The grasping part 22 is depressed to such an extent that the fingertip of the subject is caught.

  FIG. 13 is a diagram illustrating an imaging mode of the subject P who performs CT imaging. The subject P grips at least one gripping portion among the plurality of gripping portions 22a, 22b, 22c, and 22d. As shown in FIG. 11, the subject P can grip the grip portion 22 a and the grip portion 22 d on the upper side of the gantry 30. At this time, the tip (toe) of the foot of the subject P is inserted into the notch 48. The subject P can support the body of the subject P by attracting the body of the subject P to the gantry 30 side.

  As shown in FIG. 14, the gantry 30 on the mammography side is provided with a gripping unit 70 for a subject to perform mammography. The holding part 70 is installed along the circumferential direction of the outer edge of the ring-shaped fixed frame 30a. Specifically, the gripping portion 70 is formed so as to protrude from two support points in the fixed frame 30a. The support point is located below the fixed frame 30a. The distance between the two support points in the gripping unit 70 is longer than the width of the radiation generating unit 10b or the radiation detecting unit 12b. Further, the distance between the two support points in the grip portion 70 is longer than the width of the support base 2.

  The gripping part 70 is a rod-shaped member and is installed so as to have an arch shape connecting two support points in the fixed frame 30a. The grip 70 is a so-called handrail-like member. The grip part 70 is curved. Specifically, the grip part 70 is curved downward. This is to prevent the radiation generation unit 10 and the radiation detection unit 12 from interfering (collision) with the gripping unit 70 even if the radiation generation unit 10 and the radiation detection unit 12 are rotated.

  There is also a gap between the fixed frame 30a and the grip portion 70 of the arch portion. This gap is about several centimeters. Since there is a gap between the fixed frame 30a and the grip portion 70 of the arch portion, the subject can grip the grip portion 70 with both hands.

  FIG. 14 is a diagram illustrating a photographing form of the subject P performing mammography. The subject P holds the holding part 70 with both hands. The body of the subject P can be supported by attracting the body of the subject P toward the gantry 30 side.

  Since the distance between the two support points in the grip 70 is longer than the width of the radiation generator 10b or the radiation detector 12b, even if the radiation generator 10 and the radiation detector 12 are rotated, the grip 70 is separated from the radiation generator 10. It is not hidden by the radiation detector 12. In addition, even when the radiation generation unit 10 and the radiation detection unit 12 rotate, the subject can hold the holding unit 70.

  The plurality of grip portions 22a, 22b, 22c, and 22d on the CT imaging side and the grip portion 70 on the mammography side are different in shape. The CT imaging side gripping portions 22 a, 22 b, 22 c, and 22 d are recessed with respect to the gantry 30, while the mammography side gripping portion 70 is protruding with respect to the gantry 30. .

  On the CT imaging side, it is necessary that the upper body of the subject is brought into close contact with the front cover 26 and the breast of the subject as the imaging target portion is inserted into the opening 20. Therefore, the grip portions 22a, 22b, 22c, and 22d on the CT imaging side do not protrude from the gantry 30 so as not to disturb the subject in close contact with the front cover 26. The grip portions 22a, 22b, 22c, and 22d on the CT imaging side are formed in a concave shape.

  The mammography side does not bring the upper body of the subject into close contact with the front cover 26. It is necessary to insert the subject's breast between the compression plate 14 protruding from the gantry 30 and the radiation detection unit 12 and sandwich it. Further, it is necessary to support the body of the subject while the breast of the subject is compressed. Therefore, the grip part 70 on the mammography side is projected with respect to the gantry 30. The grip part 70 on the mammography side is formed in a convex shape.

  As described above, the first side gantry 30 of the mammography apparatus 100 of the present invention is provided with the first gripping portion 70 to be gripped by the subject, and the second side gantry 30 opposite to the first side. Is provided with a second grip 22 having a shape different from that of the first grip 70. The first gripping portion 70 is formed in a convex shape with respect to the gantry 30, and the second gripping portion 22 is formed in a concave shape with respect to the gantry 30.

  Therefore, a subject who performs mammography and a subject who performs CT imaging appropriately hold the first grip 70 and the second grip 22 so that the subject has a posture suitable for imaging. Can take. Both mammography and CT imaging can be performed with the patient's breast properly held.

10 (10a, 10b) Radiation generation unit 12 (12a, 12b) Radiation detection unit 14 Compression plate 20 Aperture 22a, 22b, 22c, 22d CT imaging side gripping part 26 Front cover 30 Gantry 30a Fixed frame 30b Long cylindrical part 34 Breast Holding part 40 Support leg part 42 Long cylindrical part 46 Base part 48 Notch part 50 Operation part 70 Gripping part on the mammography side 300 Separating part

Claims (19)

A gantry having a radiation generation unit for generating radiation and a radiation detection unit for detecting radiation emitted from the radiation generation unit, and rotating the radiation generation unit and the radiation detection unit facing each other A mammography device capable of
The gantry includes an opening for inserting a breast of the subject, and a breast holding unit that holds the breast of the subject inserted from the opening, and the breast of the subject and the breast holding unit A mammography apparatus, wherein a separating unit for separating the breast of the subject and the breast holding unit is installed between the breasts.   An image processing unit that reconstructs projection data output from the radiation detection unit to acquire volume data, and the image processing unit includes volume data of a subject's breast and a volume other than the breast for the volume data The mammography apparatus according to claim 1, wherein the mammography apparatus is separated into data.   The mammography apparatus according to claim 2, wherein the image processing unit separates into volume data of a subject's breast, a breast holding unit, and a separation unit based on a pixel value of the volume data.   The mammography apparatus according to claim 2, wherein the image processing unit generates a three-dimensional image by rendering the volume data from which the volume data other than the breast is deleted.   The said image processing part produces | generates a three-dimensional image by rendering the volume data of the subject's breast from which the volume data other than the subject's breast has been deleted. Mammography device.   The mammography apparatus according to claim 2, wherein the image processing unit does not delete volume data other than the breast when generating a two-dimensional image by cutting out one cross section from the volume data.   The mammography apparatus according to claim 1, wherein the separation unit has a property different from that of the breast holding unit.   The mammography apparatus according to claim 1, wherein the separation unit is detachable from the breast holding unit.   2. The gantry is provided with a front cover that protects a subject from the radiation generation unit that rotates during CT imaging and the radiation detection unit, and the front cover has an opening. The mammography apparatus described in 1.   The mammography apparatus according to claim 9, wherein the front cover includes a shielding member that shields radiation.   The mammography apparatus according to claim 9, wherein the front cover is a translucent member.   The mammography apparatus according to claim 9, wherein the breast holding unit is formed along a periphery of the opening.   The mammography apparatus according to claim 1, wherein the breast holding unit is a transparent member and a member that transmits radiation.   The mammography apparatus according to claim 1, wherein the breast holding portion is hollow and curved in accordance with the shape of the breast of the subject.   The mammography apparatus according to claim 1, wherein a part of the breast holding portion is open.   The mammography apparatus according to claim 1, wherein the breast holding portion is detachable from the front cover. A radiation generation unit that generates radiation and a radiation detection unit that detects radiation emitted from the radiation generation unit can be rotated in a state in which the radiation generation unit and the radiation detection unit face each other. A photographing device,
An opening for inserting the subject site of the subject, and a holding portion for holding the subject site of the subject inserted from the opening, between the subject site and the holding portion of the subject, An imaging apparatus, comprising: a separation unit that separates a target region of a subject and a holding unit. Generating means for generating volume data from projection data detected by the radiation detection unit in a state where the radiation generation unit and the radiation detection unit are rotated;
Separating means for separating the volume data into volume data of the subject's target part and volume data other than the target part,
An image processing apparatus including a generating unit that generates a three-dimensional image by rendering volume data of a subject region of a subject from which volume data other than the subject region of the subject has been deleted. Generating volume data from projection data detected by the radiation detection unit while rotating the radiation generation unit and the radiation detection unit;
Separating the volume data into volume data of the subject's target part and volume data other than the target part;
An image processing method comprising: generating a three-dimensional image by rendering volume data of a subject region of a subject from which volume data other than the subject region of the subject has been deleted.

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