JP2010279516A - Mammographic stereotactic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mammographic stereotactic device which selects a radiation dose detector placed in an optimal position. <P>SOLUTION: A mammography apparatus 20 includes an imaging position information acquisition part 90 of a radiation source 30 and a breast 28 or an automatic exposure control (AEC) sensor 64 and a part 92 for acquiring position information of a radiation shielding member for acquiring radiation shielding position information on three-dimensional positions of a biopsy needle 52, a biopsy hand part, or a compression plate 38. A measurement position selecting part 80 includes a presumptive position excluding part 94 which determines whether a projection image generated on a detection surface of a solid-state detector 60 by a radiation shielding member constituting a part or all of the biopsy needle 52, the biopsy hand part, or the compression plate 38 overlaps a region corresponding to the position of the AEC sensor 64 on the detection surface or not based on the imaging position information and the radiation shielding member position information and excludes the position of the AEC sensor 64 determined to have the overlapped region out of the positions of a plurality of AEC sensors 64. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a mammography localization apparatus that collects a part of a tissue by inserting a biopsy needle into a biopsy site of a breast (mammo) that is an inspection object.

  In the medical field, a biopsy device has been developed for the purpose of performing a precise examination by collecting tissue at a lesion site for diagnosing a disease or the like.

  The system disclosed in Patent Literature 1 is configured to incorporate a biopsy device into a mammography device that acquires a radiographic image of a mammo of the subject, and positions the mammo between the imaging table and the compression plate, The stereo image information is obtained by photographing the mammo from two directions. Thereby, the position information of the biopsy site can be acquired based on the image information, the biopsy needle can be inserted into the biopsy site according to the position information, and a part of the tissue of the biopsy site can be collected.

  In addition, when a radiographic image is obtained using such a biopsy device (hereinafter referred to as a mammography localization device), it is necessary to ensure good radiographic image quality while minimizing the radiation dose of the subject. Therefore, in order to acquire appropriate radiological image information of the region of interest in the subject, it is necessary to set an exposure control condition so that a desired amount of radiation is exposed to the region of interest. Therefore, a radiographic imaging apparatus including an automatic exposure control (AEC) system that controls the radiation dose exposed from the radiation source based on the detection result of the radiation dose transmitted through the subject has been proposed. In particular, when a plurality of AEC sensors are arranged in the radiation detector and only the AEC sensor within the position range where the radiation passes through the subject is selectively used, a more suitable AEC can be realized.

  In the X-ray imaging apparatus disclosed in Patent Document 2, a touch panel is provided on the lower surface of the compression plate, and the position range where the breast is arranged is detected by monitoring the pressure applied to the touch panel. Only AEC sensors within are selected. Thereby, it is possible to automatically detect the size of the subject and select the AEC sensor arranged at the optimum position.

JP 10-201749 A JP-A-8-238237

  By the way, there are cases where stereo imaging of a subject's breast is performed while a biopsy needle, its holding member, a small size compression plate for spot imaging, and the like are arranged between a radiation source and a radiation detector. In this case, when the position of the AEC sensor within the position range where the radiation passes through the breast of the subject overlaps with the position where the shape of the metal part provided in the biopsy needle or the like is reflected in the radiation receiver, the AEC sensor Since the original radiation dose to be transmitted through the subject's breast cannot be detected properly, the AEC may not function sufficiently. Thus, in the above-described case, there is a possibility that a suitable AEC cannot be realized even by the apparatus according to Patent Document 2.

  The present invention has been made in order to solve the above-described problems. A biopsy needle, its holding member, a small size compression plate for spot photography, and the like are disposed between a radiation source and a radiation detector. Provided is a mammography localization apparatus that can select a radiation dose detector disposed at an optimal position even when performing stereo imaging of a breast of a specimen.

  A mammography localization apparatus according to claim 1 of the present invention includes an imaging unit that exposes radiation to a subject's breast and captures a radiographic image, a biopsy needle that is inserted into the breast of the subject, and In a mammography stereotaxic apparatus that has a biopsy needle holding unit that holds a biopsy needle, and that samples a portion of tissue by inserting the biopsy needle into a biopsy site of the breast of the subject, the imaging unit includes: A compression plate that compresses and holds the breast of the subject; a radiation source that is supported rotatably about a rotation axis; and that emits radiation to the breast of the subject; and the radiation that has passed through the breast of the subject A radiation detector that detects image information; a plurality of radiation dose information detectors that detect a dose of the radiation that has passed through the breast of the subject and obtains radiation dose information for exposure control; and the radiation dose information detection From multiple measurement locations A radiation dose measurement position selection unit that selects one or more radiation dose measurement positions; and a dose of the radiation detected at the at least one radiation dose measurement position selected by the radiation dose measurement position selection unit. A radiation source control unit that controls the radiation dose exposed from the radiation source, an imaging position information acquisition unit that acquires imaging position information regarding the positions of the radiation source and the radiation dose information detector, and the biopsy needle A radiation shielding member position information acquisition unit that acquires radiation shielding member position information related to a three-dimensional position of the biopsy needle holding unit or the compression plate, and the radiation dose measurement position selection unit includes the imaging position information and the Based on the radiation shielding member position information, the radiation shielding member constituting a part or all of the biopsy needle, the biopsy needle holding part, or the compression plate is used to release the radiation. Determining whether or not there is an overlap between the projection image related to the radiation exposure scheduled to be generated on the detection surface of the line detection unit and the region corresponding to the radiation measurement position on the detection surface And an estimated position excluding unit that excludes the radiation dose measuring positions determined to be overlapped among the plurality of measurement positions.

  A mammography localization apparatus according to a second aspect of the invention is the mammography localization apparatus according to the first aspect of the invention, wherein the radiation dose measurement position selection unit is configured to detect the radiation detected at the plurality of measurement positions. A measurement position exclusion unit that excludes a radiation dose measurement position whose detected dose value is equal to or less than a threshold value is provided.

  A mammography localization apparatus according to claim 3 is the mammography localization apparatus according to claim 1 or 2, wherein all the plurality of measurement positions are excluded based on the estimated position exclusion unit. A shooting stop instruction unit for stopping the shooting and a warning unit for warning that the shooting has been stopped by the shooting stop instruction unit.

  According to the present invention, the projection of the radiation shielding member constituting part or all of the biopsy needle or the like based on the imaging position information on the position of the radiation source or the like and the radiation shielding member position information on the three-dimensional position of the biopsy needle or the like. Since the radiation dose information detector determined to overlap the area corresponding to the position where the radiation dose information detector is disposed is excluded, the biopsy needle and its holding member are disposed between the radiation source and the radiation detector. Even when stereo imaging of the subject's breast is performed with a small-size compression plate for spot imaging, etc., the radiation dose information detector disposed at the optimum position can be selected.

It is a perspective explanatory view of the mammography device of this embodiment. It is principal part explanatory drawing which shows the internal structure of the imaging stand in the mammography apparatus shown in FIG. FIG. 3 is a partially omitted perspective view showing an internal configuration of the photographing stand shown in FIG. 2. FIG. 2 is a block diagram of a photographing unit constituting the mammography apparatus shown in FIG. 1. It is a drive control circuit block diagram of the biopsy hand part which comprises the mammography apparatus shown in FIG. It is an operation | movement flowchart of the mammography apparatus of this embodiment. It is a flowchart which shows the process of a measurement position selection part. It is a flowchart of a presumed position exclusion step. 9A and 9B are diagrams illustrating specific examples of the shooting position information according to the mammography apparatus of the present embodiment. It is a figure which shows the specific example of the radiation shielding member position information which concerns on the mammography apparatus of this embodiment. It is a Y-axis direction sectional view (XZ top view) of a projection image of a radiation shielding member formed by radiation exposure. FIG. 12A is a front view of the breast 28 from the front imaging position when performing stereo imaging. FIG. 12B is a schematic diagram of a radiographic image that can be formed by the stereo imaging shown in FIG. 12A. It is explanatory drawing of the stereo imaging | photography which concerns on the mammography apparatus of this embodiment. It is a figure which shows an example of the warning part which concerns on the mammography apparatus of this embodiment.

  FIG. 1 is a configuration diagram of a mammography apparatus 20 of the present embodiment of the mammography localization apparatus according to the present invention.

  The mammography apparatus 20 includes a base 22 that is installed in an upright state, an arm member 26 that is fixed to a rotating shaft 24 that is disposed at a substantially central portion of the base 22, and a breast 28 (examination object) of a subject 27. 2, the radiation source 30 (FIG. 4) that exposes the radiation Xray to the object, FIG. 2), the radiation source storage portion 32 fixed to one end of the arm member 26, and the radiation Xray transmitted through the breast 28. A solid-state detector 60 (radiation detector, FIGS. 2 and 3) to be detected is housed, and an imaging table 36 fixed to the other end of the arm member 26 and a breast 28 pressed against the imaging table 36 and held. And a biopsy hand portion 40 that is attached to the compression plate 38 and collects a necessary tissue from a biopsy site of the breast 28. The base 22 displays imaging information such as the imaging region and imaging direction of the subject 27, ID information of the subject 27, and the like, and a display operation unit 42 that can set such information as necessary. Arranged.

  The arm member 26 connecting the radiation source storage unit 32 and the imaging table 36 is configured to be adjustable about the imaging direction of the subject 27 with respect to the breast 28 by rotating about the rotation shaft 24. The radiation source storage unit 32 is connected to the arm member 26 via a hinge unit 35 and is configured to be rotatable independently of the imaging table 36 in the direction of the arrow θ. The compression plate 38 is disposed between the radiation source storage unit 32 and the imaging table 36 while being connected to the arm member 26, and is configured to be displaceable in the arrow Z direction.

  The compression plate 38 is formed with an opening 44 for tissue collection using the biopsy hand unit 40. The biopsy hand unit 40 includes a post 46 fixed to the compression plate 38, a first arm 48 that is pivotally supported at one end of the post 46 and rotatable along the surface of the compression plate 38, and the first arm 48. One end is pivotally supported by the end, and a second arm 50 that is rotatable along the surface of the compression plate 38 is provided. A biopsy needle 52 that can move in the arrow Z direction is attached to the other end of the second arm 50. As shown in FIG. 2, the biopsy needle 52 includes a collection unit 56 that sucks and collects the tissue of the biopsy site 54 of the breast 28. The collection unit 56 of the biopsy needle 52 moves the first arm 48 and the second arm 50 of the biopsy hand unit 40 in the XY plane along the surface of the compression plate 38 and moves the biopsy needle 52 in the arrow Z direction. By moving it, it can be placed near the biopsy site 54.

  FIG. 2 is a main part explanatory view showing an internal configuration of the imaging stand 36 in the mammography apparatus 20, and shows a state in which a breast 28 that is an imaging region of the subject 27 is arranged between the imaging stand 36 and the compression plate 38. Reference numeral 29 indicates the chest wall of the subject 27.

  A solid-state detector 60 that accumulates radiation image information captured based on the radiation Xray emitted from the radiation source 30 built in the radiation source storage unit 32 and outputs the radiation image information as an electrical signal inside the imaging table 36. In order to read the radiation image information accumulated and recorded in the solid state detector 60, a reading light source unit 62 that irradiates the solid state detector 60 with reading light is housed. Furthermore, in order to determine the radiation Xray exposure control conditions, a plurality of radiation dose information detectors (hereinafter referred to as “radiation Xray”) that detect the radiation dose of the radiation Xray that has passed through the breast 28 and the solid detector 60 are provided inside the imaging table 36. In order to remove unnecessary charges accumulated in the solid state detector 60, an erasing light source unit 66 that irradiates the solid state detector 60 with erasing light is housed.

  The solid state detector 60 is a direct conversion type and optical readout type radiation solid state detector. The solid state detector 60 accumulates radiation image information based on the radiation Xray transmitted through the breast 28 as an electrostatic latent image, and reads from the reading light source unit 62. By scanning with light, a current corresponding to the electrostatic latent image is generated.

  For example, the solid state detector 60 having a structure disclosed in Japanese Patent Application Laid-Open No. 2004-154409 can be used. Specifically, the solid state detector 60 is formed on a glass substrate and transmits a radiation Xray. The recording photoconductive layer that generates a charge when exposed to radiation Xray and the latent image polar charge charged in the first conductive layer act as an insulator while being opposite to the latent image polar charge. A charge transport layer that acts as a substantially conductive material for the polar transport polar charge, a read photoconductive layer that exhibits electrical conductivity when irradiated with read light, and a second that transmits radiation Xray. A conductive layer is sequentially stacked. A power storage unit is formed at the interface between the recording photoconductive layer and the charge transport layer.

  The first conductive layer and the second conductive layer each constitute an electrode. The electrode of the first conductive layer is a two-dimensional flat plate electrode, and the electrode of the second conductive layer is a plurality of lines having a predetermined pixel pitch for detecting recorded radiographic image information as an image signal. Configured as an electrode. The arrangement direction of the linear electrodes corresponds to the main scanning direction, and the extending direction of the linear electrodes corresponds to the sub scanning direction.

  The reading light source unit 62 includes, for example, a line light source configured by arranging a plurality of LED chips in a line, and an optical system that linearly irradiates the reading light output from the line light source onto the solid state detector 60, The line light source in which the LED chips are arranged in a direction orthogonal to the extending direction of the linear electrode which is the second conductive layer of the solid state detector 60 is moved in the extending direction of the linear electrode (arrow C direction in FIG. 3). By doing so, the entire surface of the solid state detector 60 is exposed and scanned.

  As shown in FIG. 3, the erasing light source 66 is configured by arranging a large number of LED chips 68 on the panel 70 that emit and extinguish light in a short time and have very little afterglow. The panel 70 is stored in the imaging stand 36 in a state of being arranged in parallel with the solid state detector 60.

  As shown in FIGS. 2 and 3, a plurality of AEC sensors 64 (16 in the case of this embodiment) are arranged on the sensor substrate 72 and formed on the panel 70 constituting the erasing light source unit 66. The direction of the solid detector 60 is directed from the hole 73. Each AEC sensor 64 is arranged in a state surrounded by a rectangular cylindrical member (not shown) extending from the hole 73 toward the AEC sensor 64 side along the radiation Xray direction from the radiation source 30. Is done.

  Such an AEC sensor 64 is arranged on the sensor substrate 72 so as to correspond to the breast 28 in a state where the breast 28 is positioned and fixed on the imaging table 36 (see FIG. 3).

  FIG. 4 is a block diagram of the photographing unit constituting the mammography apparatus 20.

  The control circuit of the mammography apparatus 20 is housed in the radiation source housing unit 32, and can be set by inputting the radiation condition control unit 76 that controls the radiation source 30 that emits the radiation Xray by operating the exposure switch 74 and the imaging conditions. A display operation unit 42, a drive control unit 78 that drives and controls the position and rotation angle of the radiation source 30, the position of the imaging table 36, and the like based on the imaging conditions that are input and set, and a plurality of AEC sensors (radiation dose information detection Unit) a measurement position selection unit (radiation dose measurement position selection unit) that selects at least one AEC sensor (radiation dose information detector) 64 suitable for use in AEC based on the radiation dose of radiation Xray detected by 64 ) 80 and the radiation X from the radiation source 30 based on the radiation dose per unit time of the radiation Xray detected by the AEC sensor 64 To calculate an appropriate exposure time ay, and a exposure time calculator 82 supplies the radiation source controller 76 as exposure control condition.

  Further, the control circuit of the mammography apparatus 20 displays a radiation image forming unit 84 that forms a radiation image based on the radiation image information (image information) detected by the solid state detector (radiation detection unit) 60 and the radiation image. And a display unit 86. As described above, the solid state detector 60 functions as a radiation image generation unit that detects radiation exposed from the radiation source 30 and generates a radiation image. The display unit 86 displays position information indicating the mammary gland position estimated by the measurement position selection unit 80, for example, an image representing the AEC sensor 64 superimposed on the radiation image.

  Further, the control circuit of the mammography apparatus 20 has a weighting coefficient adding unit 88 that multiplies each detection value (radiation dose information) from each AEC sensor 64 by a weighting coefficient, and imaging position information (radiation) supplied from the display operation unit 42. Including the position and rotation angle of the source 30, the position of the imaging stand 36, etc., and the same as the information supplied to the drive control unit 78.) And is supplied from the display operation unit 42. Radiation shielding member position information (information for determining the three-dimensional positions of the biopsy needle 52, the biopsy hand unit 40 and the compression plate 38. Specifically, the first arm 48 or the second arm 50 of the biopsy hand unit 40 Radiation shielding member position information acquisition including the rotation angle, the position of the imaging table 36 or the compression plate 38, etc., which is the same as the information supplied to the drive control unit 78). And a 92.

  Here, the radiation shielding member refers to a member such as a metal having a relatively low radiation transmittance as compared with the subject 27.

  Further, the measurement position selection unit 80 is based on the imaging position information supplied from the imaging position information acquisition unit 90 and the imaging position information supplied from the radiation shielding member position information acquisition unit 92, and the biopsy needle 52, the biopsy hand unit (Biopsy needle holder) 40 or a projection image when radiation Xray is exposed from the radiation source 30 to be generated on the solid detector 60 by a radiation shielding member constituting a part or all of the compression plate 38; A determination is made as to whether or not an overlap with an area corresponding to the position of each AEC sensor 64 occurs, and an estimated position exclusion unit 94 that excludes a radiation dose measurement position determined to cause an overlap of the areas; A measurement position excluding unit 96 that excludes the AEC sensor 64 whose detection value of the AEC sensor 64 is equal to or less than the threshold value, and is used for AEC among the plurality of AEC sensors 64. It includes a position selecting portion 98 that selects at least one or more AEC sensor 64, a.

  Further, the control circuit of the mammography apparatus 20 includes a shooting stop instruction unit 99 that stops shooting when it is determined that all the plurality of measurement positions are excluded based on the estimated position exclusion unit 94, and a shooting stop instruction. A warning unit 100 that warns that the shooting is stopped by the unit.

  As described above, the mammography apparatus 20 according to the present embodiment is based on the radiation dose detected by the AEC sensor 64 serving as the radiation dose information detection unit, and the AEC sensor disposed at the optimum position by the measurement position selection unit 80. 64 and an AEC (automatic exposure control) system in which the radiation source controller 76 controls the radiation source 30.

  FIG. 5 is a drive control circuit block diagram of the biopsy hand unit 40 constituting the mammography apparatus 20.

  The mammography apparatus 20 includes an imaging condition setting unit 102 for setting imaging conditions such as a tube current, a tube voltage, a type of target and filter set in the radiation source 30, an exposure dose of radiation X, an exposure time, and the like. A radiation source control unit 76 that drives and controls the radiation source 30 according to imaging conditions, a biopsy needle drive control unit 104 that moves the biopsy needle 52 to a predetermined position via a biopsy hand unit (biopsy needle holding unit) 40, and a compression plate 38 A compression plate drive control unit 106 that moves the sensor in the arrow Z direction, a detector control unit 108 that controls the solid state detector 60 that detects the radiation Xray transmitted through the breast 28 and converts it into image information, and the solid state detector 60. An image information storage unit 110 that stores the converted image information, and a CAD (Computer Aide) that automatically detects the biopsy site 54 by processing the image information. It comprises a Diagnosis) processor 112, a display unit 86 for displaying a radiation image of the breast 28 including autodiscovered biopsy region 54.

  The mammography apparatus 20 also includes a biopsy site selection unit 114 that selects a biopsy site 54 from a radiographic image displayed on the display unit 86 using a pointing device such as a mouse, and a selected raw image for the acquired image information. The biopsy site position information calculation unit 116 that calculates the position information of the test site 54 and the necessary movement amount of the breast 28 with respect to the movable range of the biopsy needle 52 or the movement amount of the biopsy needle 52 with respect to the biopsy site 54 are calculated. And a movement amount calculation unit 118.

  The mammography apparatus 20 of the present embodiment is basically configured as described above. Next, the workflow and apparatus operation will be described with reference to the flowchart shown in FIG.

[Step S1]
First, an engineer uses the imaging condition setting unit 102 to analyze subject information relating to the age, sex, body type, subject identification number, etc. of the subject 27, radiographic image information imaging conditions, imaging method, and biopsy hand unit 40. Processing conditions such as a movement restriction amount when the movement is restricted and the length of the biopsy needle 52 are set. These processing conditions can be confirmed by displaying them on the display operation unit 42 of the mammography apparatus 20.

  Among the processing conditions set by the imaging condition setting unit 102, imaging conditions such as the tube current of the radiation source 30, the tube voltage, the exposure dose of the radiation X, and the exposure time are set in the radiation source control unit 76. Of the processing conditions, geometric imaging conditions such as SID and stereo angle are supplied to the drive controller 78 to perform a predetermined drive operation.

  Further, information related to the movement limit amount of the biopsy hand unit 40 and the length of the biopsy needle 52 is set in the biopsy needle drive control unit 104.

[Step S2]
Next, the engineer positions the breast 28 of the subject 27 in accordance with the designated imaging method. In this embodiment, the engineer performs setting for scout shooting. Scout imaging is imaging performed by setting the optical axis of the radiation Xray to be in the normal direction with respect to the imaging table 36 without rotating the radiation source storage unit 32.

  As shown in FIG. 1, when photographing the breast 28, the arm member 26 is rotated by a predetermined angle around the rotation axis 24 (hereinafter, this angle is referred to as “stereo angle”) and set to a predetermined angular position. To do. Further, the right breast 28 of the subject 27 is positioned with respect to the mammography apparatus 20. In this case, after placing the right breast 28 on the mounting surface of the imaging table 36, the compression plate 38 is pushed down to hold the breast 28 between the imaging table 36 and the compression plate 38 (see FIG. 2). That is, with the outer side (right arm side) of the right breast 28 in contact with the imaging table 36, the compression plate 38 is pressed and held from the inner side (left breast 28 side).

[Step S3]
Next, the engineer sets an exposure control condition in the mammary gland region, which is a region of interest, by setting the radiation dose of the radiation Xray to be exposed to the breast 28 small (hereinafter referred to as “pre-exposure”). I do. When the engineer presses the exposure switch 74, the radiation Xray is exposed to the breast 28, and then the exposure control condition is automatically held in a memory (not shown). Thus, the engineer can make settings necessary for a suitable AEC without being aware of the internal processing of the mammography apparatus 20.

  Hereinafter, the operation of the mammography apparatus 20 corresponding to step S3 will be described.

  The AEC sensor 64 detects the radiation amount of the radiation Xray that has passed through the compression plate 38, the breast 28, and the solid detector 60, and supplies it to the measurement position selection unit 80. The measurement position selection unit 80 calculates the radiation dose per unit time from the radiation dose of the radiation Xray detected every predetermined sampling time by the AEC sensor 64, and based on the radiation dose, the AEC sensor 64 in the vicinity of the breast gland position is calculated. select. That is, the measurement position selection unit 80 selects a sensor that detects the minimum radiation dose from the plurality of AEC sensors 64 arranged on the sensor substrate 72 and estimates the mammary gland position, thereby measuring a predetermined radiation dose. A position having the highest breast density as a position can be detected as a breast position (region of interest).

  The imaging position information input and set by the display operation unit 42 is supplied to the drive control unit 78, and drive control such as the position and rotation angle of the radiation source 30 and the position of the imaging table 36 is performed. On the other hand, the shooting position information is also supplied to the shooting position information acquisition unit 90 and then supplied to the measurement position selection unit 80.

  Further, the biopsy needle position information input and set by the display operation unit 42 is supplied to the drive control unit 78, and the drive control of the rotation angle of the first arm 48 and the second arm 50, the position of the compression plate 38, and the like is performed.

  Further, the biopsy needle position information is also supplied to the radiation shielding member position information acquisition unit 92 as radiation shielding member position information, and is then supplied to the measurement position selection unit 80.

  FIG. 7 is a flowchart showing the processing of the measurement position selection unit 80. The measurement position selection unit 80 selects a suitable measurement position from among the plurality of AEC sensors 64 according to this procedure. The measurement position selection method performed here includes three steps of an estimated position exclusion step S31, a measurement position exclusion step S32, and a position selection step S33.

  FIG. 8 is a flowchart of the presumed position excluding step S31 and shows the process of the presumed position excluding unit 94.

  First, imaging position information and radiation shielding member position information are input (S311). Here, the imaging position information refers to the position and rotation angle of the radiation source 30, the position of the imaging stand 36, and the like supplied from the imaging position information acquisition unit 90. The radiation shielding member position information is the rotation angle of the first arm 48 or the second arm 50 of the biopsy hand unit 40, the position of the compression plate 38, and the like supplied from the radiation shielding member position information acquisition unit 92.

  FIG. 9 is a diagram showing a specific example of shooting position information related to the mammography apparatus 20. FIG. 9A shows a plan view of the imaging stand 36. When the radiation source 30 is rotated around the rotation axis 24, the trajectory of the intersection point where the perpendicular line is drawn from the radiation source 30 to the plane of the imaging table 36 is taken as the X axis (Y = 0), and the scout imaging condition (stereo angle θ Is the origin O (0, 0, 0). At this time, if the coordinates where the AEC sensor 64 is disposed are (x, y, 0), x and y correspond to the shooting position information.

  9B is a Y-axis direction cross-sectional view (XZ plan view) of the positional relationship among the radiation source 30, the imaging stand 36, and the AEC sensor 64. The plane formed by the solid state detector 60 (or imaging table 36) is Z = 0, and the distance between the radiation source 30 and the solid state detector 60 (or imaging table 36) under the scout imaging condition (θ = 0 °) is D. To do. The radiation source 30 can be driven to draw a circular orbit with a radius R around an isocenter O ′ (0, 0, D−R), which is one point on the rotation shaft 24. Further, the AEC sensor 64 is installed at the position of coordinates (x, 0, z). At this time, θ, D, R, x, and z correspond to shooting position information.

  The photographing position information includes the stereo angle θ, the position (x, y, z) of the AEC sensor 64, the position of the isocenter O ′ (0, 0, DR), and the photographing stand 36 (or the solid state detector 60). Preferably, the detection surface is composed of four parameters of the position in the normal direction (Z = 0). However, even shooting conditions other than the four parameters can be used as parameters for determining the shooting position information as long as the four parameters can be uniquely derived. For example, in FIG. 9B, D (corresponding to the SID at the time of scout imaging) is used as a parameter for determining imaging position information, instead of the position in the normal direction of the detection surface related to the isocenter O ′ and the solid state detector 60. You can also.

  FIG. 10 is a diagram showing a specific example of radiation shielding position information related to the mammography apparatus 20 (the coordinate definition of the XY cross-sectional view is the same as FIG. 9A). The post 46 is erected at a position separated by G in the Y-axis negative direction from the origin O of the XY cross-sectional view, and the shaft fulcrum between the post 46 and the first arm 48 is the imaging table 36 (or the solid state detector 60). ) Above the detection surface according to FIG. The length of the first arm 48 is L1, and the rotation angle of the first arm 48 (the angle formed by the first arm 48 and the Y axis) is φ1. Further, the length of the second arm 50 is L2, and the rotation angle of the second arm 50 (the angle formed by the second arm 50 and the Y axis) is φ2. At this time, the three-dimensional coordinates (reference coordinates) where the biopsy needle exists are expressed as (L1 × sin (φ1) + L2 × sin (φ2), L1 × cos (φ1) + L2 × cos (φ2) −G, H). be able to. Similarly, three-dimensional coordinates (reference coordinates) where the first arm 48 and the second arm 50 exist can also be calculated. At this time, G, H, L1, L2, φ1, and φ2 correspond to radiation shielding position information.

  Thus, the imaging position information and radiation shielding position information exemplified above are input (S311).

  Next, the radiation shielding member constituting part or all of the biopsy needle 52, the biopsy hand unit 40, or the compression plate 38 is divided into N division elements (N is a natural number), and each is defined (S312). Here, when the biopsy needle 52, the biopsy hand part 40, or the compression plate 38 has N radiation shielding members that are physically separated, each radiation shielding member is defined as each divided element (N pieces in total). Also good. Furthermore, when the biopsy needle 52, the biopsy hand unit 40, or the compression plate 38 has one radiation shielding member having a complicated shape, the radiation shielding member can be defined by being divided into a plurality of divided elements. In such a case, each divided element can be replaced with a simple shape such as a rectangular parallelepiped, a cylinder, or a sphere in order to simplify calculation of a projection image (described later) of the divided element. In addition, the three-dimensional position coordinates with respect to a reference point such as the center of gravity of each divided element and various sizes (three-dimensional coordinate notation, polar coordinate notation, etc.) of the divided elements are calculated in advance.

  Next, the counter is initialized (S313). Note that the counter is a counter for counting the number of division elements that overlap with the projection image related to the division element at the position of each AEC sensor 64.

  Next, the following operation is performed on the i (i = 1 to N) th division element. First, the projection image of the i-th division element is estimated (S314).

  FIG. 11 is a Y-axis direction sectional view (XZ plan view) of a projection image of a radiation shielding member (dividing element) formed by radiation exposure. Here, the definition of the XYZ coordinates is the same as in FIG. 9B. Due to the exposure of the radiation Xray from the radiation source 30, the projection image 124 of the dividing element 122 which is a part of the radiation shielding member included in the biopsy needle 52, the biopsy hand unit 40 or the compression plate 38 becomes the detection surface of the solid state detector 60. It is formed on the top (Z = 0). The dividing element 122 is a disk perpendicular to the Z axis, the center coordinates are (0, 0, d), and the radius of the circle is r. When the stereo angle of the radiation source 30 is θ = 0 °, the projection image 124 has a circular area on the XY plane with the origin O (0, 0, 0) as the center and a radius of r × D / (D−d). Formed. The projected image 124 when the stereo angle is θ (θ ≠ 0 °) has an elliptical area centered on the point (−d × R sin θ / (D−R cos θ−d), 0, 0) on the XY plane. It is formed.

  With such a geometric consideration, it is possible to estimate the projected image shape in the i-th segment.

  Next, it is determined whether or not the projection image of the i-th division element overlaps the area corresponding to the position of each AEC sensor 64 (S315). The position of the k-th (k = 1 to M) AEC sensor 64 out of the total number M of AEC sensors 64 is the projection image area (circular area or elliptical area in FIG. 11) related to the i-th division element. It is determined whether it is within the range. If the AEC sensor 64 is within the projected image area, 1 is added to the k-th counter (S316).

  When such an operation is performed from i = 1 to N, it is possible to calculate the number of division elements in which overlapping of regions in the k (k = 1 to M) th AEC sensor 64 occurs.

  Next, a determination is made as to whether or not there is an overlapping area for each AEC sensor 64 (S317). When the value of the k-th counter is 0, it is determined that the k-th AEC sensor 64 is used (not excluded) because there is no overlap with all the divided elements. When the value of the k-th counter is 1 to N, it is determined that the k-th AEC sensor 64 is not used (excluded) because there is an overlapping area with the projection image of one of the divided elements. Is done.

  As described above, the radiation shielding member that constitutes part or all of the biopsy needle 52, the biopsy hand unit 40, or the compression plate 38 when the estimated position exclusion step S31 is performed and the radiation Xray is exposed from the radiation source 30. The AEC sensor 64 determined that the projected image on the solid-state detector 60 according to the above overlaps with the area corresponding to the position of each AEC sensor 64 is estimated.

  Next, the measurement position exclusion step S32 will be outlined. In the presumed position exclusion step S31, when it is determined that m AEC sensors 64 out of M are excluded, the remaining (M−m) AEC sensors 64 are respectively detected and threshold values. Compare size. Here, the threshold value is set to a numerical value that can identify an apparent imaging abnormality at the time of mammography. Specifically, assuming imaging conditions that can actually be set in various imaging modes, values smaller than all the detection values detected by the AEC sensor 64 when the radiation Xray is exposed under the imaging conditions, It is preferable to set as a threshold value.

  Here, a state in which the radiation shielding member constituting a part or all of the biopsy needle 52, the biopsy hand unit 40, or the compression plate 38 is reflected in the radiation image will be described with reference to FIGS. 12A and 12B. FIG. 12A shows a front view of the breast 28 from the front imaging position when performing stereo imaging. The biopsy hand unit 40 is arranged as shown in FIG. 12A and emits the radiation Xray from the radiation source 30 located on the upper right side when viewed from the paper surface. It is assumed that a part of the biopsy needle 52 is configured by a radiation shielding member.

  FIG. 12B shows a schematic diagram of a radiographic image that can be formed by the stereo imaging shown in FIG. 12A. The radiation image Img, which is a monochrome multi-tone image formed by the radiation Xray transmitted through the opening 44, becomes darker as the radiation Xray detected by the solid state detector 60 increases, and the radiation decreases as the dose decreases. The image is drawn so as to be thin. In the radiation image Img, a breast image 28I of the breast 28 is formed by the difference in the transmitted dose of the radiation Xray. On the other hand, since the radiation shielding member hardly transmits the radiation Xray compared to the subject 27, the radiation shielding member of the biopsy needle 52 is formed as a reflected image 52I on the radiation image Img.

  At this time, since the AEC sensor 64a partially overlaps the reflected image 52I of the biopsy needle 52, it is expected that the AEC sensor 64a shows a significantly lower value than the detection value of the AEC sensor 64b. In such a case, in the measurement position exclusion step S22, the detection values of the AEC sensor 64a and the AEC sensor 64b are compared in magnitude with the threshold value, and the position of the AEC sensor 64b whose detection value will exceed the threshold value is not excluded, The position of the AEC sensor 64a whose detection value will be below the threshold is excluded.

  As described above, since the degree of the influence of the biopsy hand unit 40 and the like (in FIG. 11B, the biopsy needle 52) is reflected in the radiographic image is intermediate, the measurement position exclusion by the estimated position exclusion step S31 occurs. Even in such a case, the position of the AEC sensor 64a can be excluded based on the actual measurement value in the measurement position exclusion step S32.

  As described above, the measurement position exclusion step S32 is executed, and the AEC sensor 64 whose detection value is equal to or less than the threshold value is excluded in terms of measurement.

  Finally, if a limit is imposed on the maximum number of AEC sensors that can be selected, a more suitable AEC sensor 64 can be obtained by further narrowing down the number of AEC sensors 64 selected in the position selection step S33. You can choose.

  As described above, the measurement position selection unit 80 selects at least one suitable measurement position from among the positions of the plurality of AEC sensors 64.

  By the way, the detection value of each AEC sensor 64 is not used as it is in the measurement exclusion step S32, but can be multiplied by a weighting coefficient according to the sensitivity characteristic of each AEC sensor, imaging position condition, breast positioning mode, and the like. .

  The weighting coefficient assigning unit 88 can supply a value obtained by multiplying the detection value of each AEC sensor 64 by a weighting coefficient that uniformly corrects sensor sensitivity variation and the like of each AEC sensor 64 to the measurement position selection unit 80. . In such a case, it is possible to select a suitable AEC sensor 64 that reduces the effects of differences in sensor sensitivity and shooting position information.

  Furthermore, the weighting coefficient assigning unit 88 can supply the measurement position selecting unit 80 with a value obtained by further multiplying the detection value of each AEC sensor 64 by a weighting coefficient that takes into account the change in stereo angle during stereo shooting. In such a case, it is possible to select a suitable AEC sensor 64 that eliminates the influence of the distortion of the relative relationship related to the distance between the radiation source 30 and each AEC sensor.

  Further, the weighting coefficient assigning unit 88 is installed on the AEC sensor 64 that is installed closer to the center than the peripheral part of the breast 28 and closer to the nipple side than the chest wall 29 side. It is also a preferred aspect that a value obtained by further multiplying the detection value of each AEC sensor 64 by the weighting coefficient set so that it can be preferentially selected at is supplied to the measurement position selector 80. In such a case, it is effectively prevented that the installation position of the AEC sensor 64 that overlaps the pectoral muscle that tends to have a larger radiation absorption coefficient than the mammary gland region is erroneously selected as the mammary gland location (region of interest).

  As described above, when the AEC sensor 64 estimated to be in the vicinity of the mammary gland position is selected by the measurement position selection unit 80, the exposure time calculation unit 82 performs the per unit time detected by the AEC sensor 64 at the mammary gland position. Based on the radiation dose, an exposure time for exposing the radiation dose necessary to obtain appropriate radiation image information of the mammary gland region of the breast 28 is calculated as an exposure control condition.

  In this way, by setting the radiation dose of the radiation Xray to be exposed to the breast 28 to be small by pre-exposure, it is possible to determine the exposure control condition in the mammary gland region that is the target region.

[Step S4]
Next, the engineer drives the radiation source 30 and performs stereo imaging of the breast 28. In this case, the radiation source storage unit 32 is moved around the hinge unit 35 (FIG. 1), and the radiation source 30 is disposed at the position A as shown in FIG. And taking a picture while being held by the compression plate 38. When the engineer presses the exposure switch 74, imaging is started, and after the radiation Xray is exposed based on the exposure time calculated by the exposure time calculation unit 82, a radiation image relating to the breast 28 is automatically formed. Is done. Similarly, as shown in FIG. 13, when the radiation source 30 is arranged at the B position and imaging is started, a radiation image relating to the breast 28 is automatically formed.

  Hereinafter, the operation of the mammography apparatus 20 corresponding to step S4 will be described.

  By arranging the radiation source 30 at the A position and the B position and exposing the radiation Xray, the radiation Xray transmitted through the breast 28 is detected as a radiation dose by the solid state detector 60 of the imaging table 36. The detector control unit 108 controls the solid state detector 60 to acquire radiation image information (image information) from the radiation dose of the breast 28 at the A position and the B position, and the radiation image information is stored in the radiation image forming unit. 84.

  On the other hand, the AEC sensor 64 detects the radiation dose of the radiation Xray transmitted through the compression plate 38, the breast 28 and the solid detector 60. The weighting coefficient assigning unit 88 assigns a weighting coefficient to the detected value and supplies the weighting coefficient to the measurement position selecting unit 80. The measurement position selection unit 80 calculates an exposure time for exposing a radiation dose necessary for obtaining appropriate radiographic image information of the mammary gland region of the breast 28 as an exposure control condition, and a radiation source control unit as necessary. 76 exposure times can be updated. The details of the method for calculating the exposure time after the detection value of the AEC sensor 64 is supplied to the measurement position selection unit 80 are the same as described above, and will be omitted.

  Further, the detection value of each AEC sensor 64 is supplied to the radiation image forming unit 84 and can be used as a parameter relating to image processing including CAD processing described later (step S5). Further, various pieces of photographing information such as detection values and exposure times of the respective AEC sensors 64 can be displayed together with images, or can be made into a database. Thereby, the engineer or the doctor can utilize the history of the exposure information of the patient stored in the database for subsequent diagnosis and treatment.

  Here, in order to effectively use the detection value of each AEC sensor 64, a weighting coefficient at the time of scout shooting is not used as it is, but a suitable weighting coefficient according to the geometric shooting conditions of each stereo shooting is used. It is desirable to use

[Step S5]
Next, the technician performs a necessary GUI operation using a mouse, a touch panel, or the like, so that the radiation image forming unit 84 performs CAD processing.

  As shown in FIG. 13, after imaging by rotating the radiation source 30 to the A position and the B position, these two pieces of radiation image information are temporarily stored in the image information storage unit 110 to create a stereo image. Are displayed on the display unit 86. The CAD processing unit 112 extracts an abnormal candidate site by performing quantitative image processing on the image information stored in the image information storage unit 110.

[Step S6]
Next, the engineer performs a necessary GUI operation using a mouse, a touch panel, or the like, thereby displaying an image on the display unit 86.

  The abnormal candidate part extracted by the CAD processing unit 112 is displayed on the display unit 86 together with the radiation image of the breast 28. It is preferable to display the radiation image of the breast 28, the marker indicating the abnormal candidate site extracted by the CAD process, and the image of the opening 44 of the compression plate 38 on the display unit 86.

[Step S7]
Next, the engineer instructs the biopsy site 54 from the stereo image displayed on the display unit 86 using the biopsy site selection unit 114. The biopsy site selection unit 114 can be configured by a GUI such as a mouse or a touch panel.

  Thereafter, the operation of the mammography apparatus 20 corresponding to the following steps S8 to S10 is automatically performed based on the operation of the biopsy site exploitation start by the technician.

[Step S8]
Next, an operation for calculating biopsy site position information is performed (step S8). The biopsy site position information calculation unit 116 calculates the position information of the biopsy site 54 based on the biopsy site 54 instructed by the engineer and the two pieces of radiation image information stored in the image information storage unit 110. To do. This position information is three-dimensional position information of the biopsy site 54. The position information of the biopsy site 54 calculated by the biopsy site position information calculation unit 116 is supplied to the movement amount calculation unit 118.

  Thereafter, the movement amount calculation unit 118 calculates the movement amount by which the biopsy needle 52 is moved to the biopsy site 54 using the position information of the biopsy site 54. In this case, the amount of movement of the biopsy needle 52 is set in the biopsy needle drive control unit 104 as the amount of movement in the X direction and the amount of movement in the Y direction with reference to the coordinates of the center of the opening 44, for example. The movement amount of the biopsy needle 52 calculated by the movement amount calculation unit 118 is supplied to the biopsy needle drive control unit 104.

[Step S9]
Next, a biopsy needle moving operation is performed (step S9). The biopsy needle drive control unit 104 controls the biopsy needle 52 to move to a predetermined position according to the movement amount of the biopsy needle 52 supplied from the movement amount calculation unit 118. The biopsy hand unit 40 moves the first arm 48 and the second arm 50 in the XY plane according to the position information of the biopsy site 54 in the X direction and the Y direction, and moves the biopsy needle 52 above the biopsy site 54. Position to. Next, the biopsy needle 52 is moved in the Z direction, and an operation of inserting the biopsy needle 52 into the breast 28 through the opening 44 formed in the compression plate 38 is started.

  The position information of the biopsy needle 52 in the Z direction is sequentially calculated by the biopsy site position information calculation unit 116 and supplied to the biopsy needle drive control unit 104. The biopsy needle 52 is moved in the Z direction by the biopsy needle drive control unit 104 according to the position information of the biopsy needle 52 in the Z direction and the movement limit amount of the biopsy hand unit 40 that has been set, and the sampling unit 56 ( 2) is brought to the vicinity of the biopsy site 54. In this case, since the movement of the biopsy needle 52 in the XY plane is restricted, the biopsy needle 52 does not inadvertently move greatly in the X direction or the Y direction in the inserted state, and the breast 28 A situation in which tissue is damaged can be avoided.

[Step S10]
Finally, a biopsy site collection operation is performed (step S10). When the collection part 56 of the biopsy needle 52 reaches the vicinity of the biopsy site 54, suction processing by the biopsy needle 52 is started, and the biopsy site 54 is collected. Thereafter, by moving the biopsy needle 52 in the Z direction, the biopsy needle 52 is extracted from the breast 28, and the operation is completed.

[AEC sensor detection error processing]
The workflow and apparatus operation using the mammography apparatus 20 of the present embodiment have been described above. Next, an operation when a detection abnormality of the AEC sensor 64 occurs will be described.

  In the case of pre-exposure (S3) or stereo imaging (S4) shown in the flowchart of FIG. 6, when all the AEC sensors 64 are excluded by the estimated position exclusion unit 94, the measurement position selection unit 80 displays the AEC. The imaging stop instruction unit 99 is notified that a sensor detection abnormality has occurred.

  Receiving the notification, the imaging stop instruction unit 99 notifies the warning unit 100, the radiation source control unit 76, and the drive control unit 78 to that effect.

  After receiving the notification, the radiation source control unit 76 immediately stops the exposure operation when the radiation source 30 is performing the radiation exposure operation. Further, the radiation source control unit 76 locks the exposure lock from the state where the radiation source 30 is stopped. When the exposure lock is applied, the radiation Xray is prevented from being exposed from the radiation source 30 even if the exposure switch 74 is pressed.

  After receiving the notification, the warning unit 100 warns the technician that an AEC sensor detection abnormality has occurred. The warning may be in any form as long as it can directly appeal to the senses of the engineer regardless of tangible / intangible. For example, a warning sound by a buzzer or the like, a warning display by a screen display unit, or the like is preferable.

  FIG. 14 is a diagram illustrating an example of warning display by the warning unit 100 of the mammography apparatus 20 according to the present embodiment. In this embodiment, the warning unit 100 and the display operation unit 42 also serve as an image display function. After receiving the notification that the detection abnormality of the AEC sensor 64 has occurred, the warning unit 100 displays a message for alerting the technician as a window display image 1000. The engineer reads the message and confirms the work according to the confirmation items described in the window display image 1000. When the cause of the AEC sensor detection abnormality is identified by the engineer and the cause is resolved, the window display image 1000 disappears and the radiation source is displayed by pressing the [Continue Shooting] button 1002 on a GUI such as a touch panel. The exposure lock related to the control unit 76 is released. If the engineer cannot identify the cause of the AEC sensor detection abnormality, the mammography apparatus 20 automatically changes the AEC function from on to off by pressing the [AEC Cancel] button 1004, and then the engineer. Can continue shooting.

  As described above, the mammography apparatus 20 according to the above-described embodiment includes the imaging unit that exposes radiation to the breast 28 of the subject 27 and captures a radiographic image, and the biopsy needle that is inserted into the breast 28 of the subject 27. 52 and a biopsy hand unit 40 that holds the biopsy needle 52 are disposed. A mammography localization apparatus that inserts the biopsy needle 52 into the biopsy site 54 of the breast 28 of the subject 27 and collects a part of the tissue. The imaging unit exposes the radiation Xray to the compression plate 38 for compressing and holding the breast 28 of the subject 27 and the breast 28 of the subject 27 supported rotatably about the rotation axis (hinge portion 35). The radiation source 30 to be irradiated, the solid state detector 60 for detecting image information of the radiation Xray transmitted through the breast 28 of the subject 27, and the dose of the radiation Xray transmitted through the breast 28 of the subject 27 are detected to control the exposure. A plurality of AEC sensors 64 for acquiring radiation dose information for measurement, a measurement position selector 80 for selecting at least one radiation dose measurement position from a plurality of measurement positions where the AEC sensor 64 is disposed, and a measurement position selection A radiation source controller 76 for controlling the radiation dose exposed from the radiation source 30 based on the radiation Xray dose detected at the at least one radiation dose measurement position selected by the unit 80; And the imaging position information acquisition part 90 which acquires the imaging position information regarding the position of the AEC sensor 64, and the radiation shielding member position information acquisition part 92 which acquires the radiation shielding member position information regarding the three-dimensional positions of the biopsy needle 52 and the biopsy hand part 40 The measurement position selection unit 80 includes a biopsy needle 52 based on the imaging position information and the radiation shielding member position information. The projection image related to the radiation Xray exposure to be generated on the detection surface of the solid state detector 60 by the radiation shielding member constituting part or all of the biopsy hand unit 40 or the compression plate 38, and the position of the AEC sensor 64 It is determined whether or not there is overlap with the corresponding area on the detection surface, and the position of the AEC sensor 64 determined to be overlapped among the positions of the plurality of AEC sensors 64 is excluded. A configuration including the estimated position exclusion unit 94 is provided.

  In this way, based on the imaging position information regarding the position of the radiation source and the like and the radiation shielding member regarding the three-dimensional position such as the biopsy needle, the radiation shielding member constituting a part or all of the biopsy needle, biopsy hand part or compression plate Since the projection image is configured to exclude the radiation dose information detector determined to overlap with the region corresponding to the position where the radiation dose information detector is disposed, the biopsy needle is disposed between the radiation source and the radiation detector. Even when performing stereo imaging of the subject's breast with its holding member, small-size compression plate for spot imaging, etc., the radiation dose information detector arranged at the optimum position should be selected Can do.

  In addition, the measurement position selection unit 80 includes a measurement position exclusion unit 96 that excludes the position of the AEC sensor 64 in which the detected value of the radiation Xray dose detected at the positions of the plurality of AEC sensors 64 is equal to or less than a threshold value. Therefore, the probability that a sensor suitable for AEC can be selected by the double check of measurement position exclusion is improved, and the accuracy of AEC can be further improved.

  Further, when it is determined that all of the plurality of measurement positions are excluded based on the estimated position exclusion unit 94, the imaging stop instruction unit 99 for stopping the imaging and the imaging stop by the imaging stop instruction unit 99 are stopped. Therefore, the engineer is alerted to the possibility of an AEC malfunction, and the reliability of the AEC can be improved.

  In addition, this invention is not limited to embodiment mentioned above, Of course, it can change freely in the range which does not deviate from the main point of this invention.

  For example, the weighting coefficient described in the above embodiment can be changed as appropriate according to the apparatus and method to which the present invention is applied, and the number of AEC sensors can be changed as a matter of course.

  Moreover, although the case where the solid state detector 60 was used was demonstrated in the said embodiment, it replaces with the solid state detector 60 and the radiographic image imaging comprised so that a storage fluorescent substance panel is detachable with respect to the imaging stand 36 is possible. An apparatus may be used.

  In the above-described embodiment, the so-called optical scanning method in which the electrostatic latent image accumulated in the solid state detector 60 is scanned with the reading light from the reading light source unit 62 to generate current has been described as an example. However, it may be configured such that the charge of the electrostatic latent image can be read by the TFT method without using the reading light source unit 62 as described above. Furthermore, a radiation solid detector capable of generating an image by directly converting without using the reading light source unit 62 as described above can be used.

  In the above-described embodiment, the solid state detector 60 that is an image sensor and the AEC sensor 64 that is a radiation dose information detector are illustrated and described as separate bodies. In this case, a part of the image sensor can be used as a radiation dose information detector. In this case, the radiation dose information detector can be replaced by an image sensor. In such a case, a radiographic image obtained by pre-irradiation performed before stereo imaging can be used. An appropriate region of interest can be derived by applying various image processing algorithms to the radiation image, and irradiation control of the radiation source 30 can be performed based on the number, position, and size of the region of interest. .

DESCRIPTION OF SYMBOLS 20 ... Mammography apparatus 22 ... Base 24 ... Rotating shaft 26 ... Arm member 27 ... Subject 28 ... Breast 29 ... Chest wall 30 ... Radiation source 32 ... Radiation source storage part 36 ... Imaging stand 38 ... Compression plate 42 ... Display operation part 60 ... Solid detectors 64, 64a, 64b ... AEC sensor 74 ... Exposure switch 76 ... Radiation source control part 78 ... Drive control part 80 ... Measurement position selection part 82 ... Exposure time calculation part 84 ... Radiation image forming part 86 ... Display Unit 88 ... Weighting coefficient assigning unit 90 ... Imaging position information unit 92 ... Radiation shielding member position information acquisition unit 94 ... Estimated position exclusion unit 96 ... Measurement position exclusion unit 98 ... Position selection unit 99 ... Imaging stop instruction unit 100 ... Warning Part 1000 ... Window display image

Claims (3)

An imaging unit that radiates radiation onto the breast of the subject and captures a radiographic image;
A biopsy needle that pierces the breast of the subject;
A biopsy needle holding part for holding the biopsy needle,
In a mammography stereotaxic apparatus that inserts the biopsy needle into a biopsy site of the subject's breast and collects a part of the tissue,
The photographing unit
A compression plate for compressing and holding the breast of the subject;
A radiation source that is rotatably supported about a rotation axis and that exposes radiation to the breast of the subject;
A radiation detector that detects image information of the radiation transmitted through the breast of the subject;
A plurality of radiation dose information detectors for detecting a dose of the radiation transmitted through the breast of the subject and acquiring radiation dose information for exposure control;
A radiation dose measurement position selector for selecting at least one radiation dose measurement position from a plurality of measurement positions where the radiation dose information detector is disposed;
A radiation source control unit that controls the radiation dose exposed from the radiation source based on the radiation dose detected at the at least one radiation dose measurement position selected by the radiation dose measurement position selection unit; ,
An imaging position information acquisition unit that acquires imaging position information related to the positions of the radiation source and the radiation dose information detector;
A radiation shielding member position information acquisition unit that acquires radiation shielding member position information related to a three-dimensional position of the biopsy needle, the biopsy needle holding unit, or the compression plate;
The radiation dose measurement position selection unit is configured by the radiation shielding member constituting a part or all of the biopsy needle, the biopsy needle holding unit, or the compression plate based on the imaging position information and the radiation shielding member position information. Determining whether or not there is an overlap between a projection image related to the radiation exposure scheduled to be generated on the detection surface of the radiation detection unit and a region corresponding to the radiation measurement position on the detection surface A mammography localization apparatus, further comprising: an estimated position exclusion unit that excludes radiation dose measurement positions determined to be overlapped among the plurality of measurement positions. The mammography localization apparatus according to claim 1, wherein
The radiation dose measurement position selection unit includes a measurement position exclusion unit that excludes a radiation dose measurement position in which a detection value of the radiation dose detected at the plurality of measurement positions is equal to or less than a threshold value. Stereotaxic device. The mammography localization apparatus according to claim 1 or 2,
An imaging stop instruction unit for stopping the imaging when it is determined that all the plurality of measurement positions are excluded based on the estimated position exclusion unit;
A mammography localization apparatus, comprising: a warning unit that warns that the imaging has been stopped by the imaging stop instruction unit.

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