JP2011104095A - Phantom for biopsies - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a phantom for biopsies, capable of accurately and easily specifying each target member even on a radiation image obtained by stereo photographing where the number of times of photographing is small. <P>SOLUTION: The phantom comprises a plurality of target members 66 each of which has a needle shape and a circular cross section crossing the axial direction and which are made of a material having the low transmittance of radiation. The target members 66 respectively comprise characteristic surface shape (annular grooves 86, 88, 90). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention provides an accuracy of the calculated three-dimensional position of a biopsy device that calculates a three-dimensional position of a biopsy site of the inspection object based on at least two radiographic images obtained by stereo imaging of the inspection object. It is related with the phantom for biopsies used in order to confirm.

  2. Description of the Related Art Conventionally, a biopsy device for sampling a biopsy site in a subject to be examined (for example, a lesion site in a subject's breast) and performing a precise examination for diagnosing a disease, etc. Has been developed. In this case, in order to reliably collect the tissue, the three-dimensional position of the biopsy site needs to be specified in advance.

  Therefore, the radiation imaging apparatus is used to irradiate the inspection object with radiation from radiation sources arranged at two different angles, and the radiation transmitted through the inspection object is detected by a radiation detector. Stereo imaging for acquiring a single radiographic image is performed, and the three-dimensional position of the biopsy site is calculated based on the two radiographic images.

  As a method of managing the calculation accuracy of the three-dimensional position of the biopsy site in a facility such as a hospital, a phantom having a known three-dimensional shape is photographed, and the three-dimensional position of the reference point based on the obtained radiographic image In general, it is regularly checked whether or not it falls within a preset error range.

  Thus, in order to confirm the calculation accuracy of the three-dimensional position (and to correct it if necessary), various phantoms having technical characteristics in the internal structure are disclosed.

  Patent Document 1 discloses a phantom in which spherical target members are spirally arranged with respect to the axial direction of a cylindrical structure (see FIG. 1 of Patent Document 1).

  Patent Document 2 discloses a phantom that includes a thin line-shaped target member provided in a direction perpendicular to the detection surface of the radiation detector (see FIG. 1 of Patent Document 2).

  Patent Document 3 discloses a phantom in which a wire-shaped or rod-shaped target member made of a substance having a high X-ray absorption coefficient is embedded in a cylindrical support material having a low X-ray absorption coefficient (Patent Document 3). FIG. 2).

JP 2001-149363 A JP 2009-150667 A JP 2000-201918 A

  By the way, the position accuracy check operation is not a one-time operation, and it is necessary to perform it repeatedly and continuously. For this reason, it is desirable to set a reference point in the phantom in advance, and then calculate the position based on the reference point to manage its position accuracy.

  Usually, a predetermined portion of the target member is set in advance as a reference point, and its three-dimensional position is automatically calculated by a radiographic imaging device or the like. Specifically, by performing various image processing on the radiographic image of the phantom obtained by stereo imaging, the target member and its predetermined location are recognized on the radiographic image, and the location is used as a reference point. It is calculated as a three-dimensional position.

  By adopting such a configuration, the three-dimensional position of the reference point can be calculated with high accuracy, while it is necessary to eliminate errors in automatic recognition of the target member by image processing.

  For example, when there is only one target member as in the phantom disclosed in Patent Document 3, the problem of erroneous recognition hardly occurs. However, in the case of having two or more target members, it is essential that one target member and another target member can be identified, in other words, all the captured target members can be specified.

  However, in the phantoms described in Patent Documents 1 and 2, since the shapes of a plurality of targets are the same, each target member cannot be easily specified in many cases.

  On the other hand, in an imaging apparatus such as CT or MRI, it is possible to acquire a radiation image from almost all directions and reconstruct a three-dimensional image, so that each target is based on the relative positional relationship between target members. The member can be specified.

  On the other hand, when the number of radiographic image capturing is small as in stereo imaging, the amount of image information that can be acquired as a three-dimensional image is small. Therefore, when the relative positional relationship between the target members in the phantom cannot be uniquely determined due to an insufficient amount of image information, each target member cannot be specified. As a result, erroneous recognition of the target member due to image processing may occur, and the three-dimensional position of the reference point may be calculated incorrectly.

  In addition, depending on the three-dimensional shape of the target member, the pattern of the target member projected on the radiographic image may change greatly as the angle of stereo shooting changes. Such a phenomenon may cause erroneous recognition of the target member by image processing.

  The present invention has been made in consideration of such problems, and can be used for biopsy that can accurately and easily specify each target member even on a radiographic image obtained by stereo imaging with a small number of imaging. The purpose is to provide a phantom.

  The biopsy phantom according to the present invention is calculated by the biopsy device that calculates the three-dimensional position of the biopsy site of the inspection object based on at least two radiographic images obtained by stereo imaging of the inspection object. The present invention relates to a biopsy phantom used to confirm the accuracy of a three-dimensional position.

  The biopsy phantom has a plurality of target members made of a material having a needle shape and a cross-sectional shape that intersects in the axial direction thereof, and a low transmittance of radiation, and each of the target members has a unique surface. Has a shape.

  In this way, since each target member has a unique surface shape, each target member can be identified based on a pattern formed as a projected image of the surface shape on a radiographic image, and a stereo with a small number of imaging Even on a radiographic image obtained by imaging, each target member can be accurately and easily specified.

  The surface shapes are preferably different numbers of annular grooves. Thereby, on the radiographic image obtained by irradiating the radiation from the side surface of the target member, a constant pattern (preferably, a concave portion) is formed as the projection image of the annular groove regardless of the stereo shooting angle. That is, since it is sufficient to detect the number of recesses in the projected image of the target member and measure the number thereof, each target member can be identified more easily.

  Furthermore, each of the target members preferably has a sharp tip. Thereby, on the radiographic image obtained by irradiating radiation from the side surface side of the target member, a triangular pattern is formed as a projected image of the tip portion. That is, the tip portion functions as a reference point to be calculated, and the three-dimensional position of the reference point can be calculated more accurately.

  Furthermore, it is preferable that at least two of the target members are provided at the same height when the biopsy phantom is placed. Thereby, it becomes easy to grasp the positional relationship of each target member provided in the biopsy phantom.

  Furthermore, it is preferable that at least two of the target members are provided at positions where the sizes on the radiation image are the same when the biopsy phantom is placed. Thereby, the recognition rate of a target member can be improved by using the size of the pattern formed by each target member as a clue.

  Furthermore, it is preferable that the at least two target members are provided so as to face each other. Thereby, the separation distance of the front-end | tip part of the opposing target member becomes short, the physical contact to the front-end | tip part which has a sharp shape can be avoided in advance, and it becomes an operator's protection.

  Furthermore, it has a first frame and a second frame spaced apart from the first frame by a predetermined distance, and each of the target members is disposed in a space between the first frame and the second frame. Is preferred.

  Furthermore, it is preferable that the first frame or the second frame constitutes a positioning surface. As a result, the biopsy phantom can be installed at a fixed position, and the reliability of the three-dimensional position calculation can be improved.

  Furthermore, it is preferable that each target member can be freely arranged at at least two positions on the first frame or the second frame. Thereby, since the operator can select a desired target member and arrange | position in a desired position, the effect which contributes to the improvement of the recognition rate is acquired.

  Furthermore, it is preferable that the at least two positions are determined so that each target member is within a range in which the accuracy of the three-dimensional position is to be confirmed. Thereby, it is possible to appropriately manage the calculation accuracy at an arbitrary position within the range.

  Furthermore, it is preferable that both the first frame and the second frame can be placed as placement surfaces. Thereby, it is possible to turn the mounting surface upside down, and it is possible to substantially increase the position of the target member, that is, the choice of three-dimensional positions that can be confirmed.

  The biopsy phantom according to the present invention has a plurality of target members made of a material that is needle-shaped and has a circular cross-sectional shape intersecting in the axial direction thereof, and has low radiation transmittance, and each of the target members is Since each has a unique surface shape, each target member can be specified based on a pattern formed as a projection image of the surface shape on a radiographic image, and obtained by stereo shooting with a small number of shootings Even on a radiographic image, each target member can be specified accurately and easily.

1 is a perspective view of a mammography apparatus in which a biopsy phantom according to the present embodiment is used. It is a perspective view of the phantom for biopsies which concerns on this Embodiment. FIG. 3 is a right side view of the biopsy phantom shown in FIG. 2. FIG. 3 is a side view of a target member attached to the biopsy phantom shown in FIG. 2. FIG. 2 is a partially omitted side view showing a state in which a biopsy phantom according to the present embodiment is arranged on a photographing table of the mammography apparatus shown in FIG. 1. 6A and 6B are schematic views showing partial regions of radiographic images obtained by the first and second stereo imaging. 7A to 7E are side views of the target member according to the first modification of the present embodiment. It is a perspective view of the phantom for biopsies which concerns on the 2nd modification of this Embodiment.

  A preferred embodiment of the biopsy phantom according to the present invention will be described with reference to FIGS. 2 to 4 in relation to the mammography apparatus shown in FIG.

  FIG. 1 is a perspective view of a mammography apparatus 12 in which a biopsy phantom 10 according to the present embodiment is used.

  The mammography apparatus 12 basically includes a base 14 installed in an upright state, and an arm member 18 fixed to a tip end of a turning shaft 16 disposed substantially at the center of the base 14. A radiation source (not shown) that irradiates a mammo as an inspection object of the subject (subject) 20 is accommodated, and the radiation source accommodating portion 22 fixed to one end of the arm member 18 is transmitted through the mammo. A solid-state detector (radiation detector) (not shown) that detects radiation is accommodated, and an imaging table 24 fixed to the other end of the arm member 18, and a compression plate 26 that compresses and holds the mammon against the imaging table 24. And a biopsy hand portion 28 that is attached to the compression plate 26 and collects a necessary tissue from a biopsy site of a mammo.

  The base 14 is provided with a display operation unit 30 that displays imaging conditions such as an imaging region of the subject 20, ID information of the subject 20, and the like, and can set such information as necessary. The

  The arm member 18 that couples the radiation source housing unit 22 and the imaging table 24 is configured so that the direction of the subject 20 relative to the mammo can be adjusted by turning about the turning axis 16. Moreover, the radiation source accommodating part 22 is connected to the arm member 18 via the hinge part 32, and is configured to be able to turn independently of the imaging table 24 in the arrow θ direction.

  The arm member 18 is provided with a groove 34 along the arrow Z direction on the side (front side) in the arrow X direction facing the subject 20, while the subject 20 is located on both sides in the arrow Y direction. A grip portion 36 is provided for each to hold. The compression plate 26 is disposed between the radiation source storage unit 22 and the imaging table 24 by inserting a base end portion of the compression plate 26 into the groove 34 and fitting with a mounting unit (not shown). By displacing along the groove portion 34 in the arrow Z direction, it can be displaced in the arrow Z direction integrally with the mounting portion.

  Further, an opening 38 for tissue collection using the biopsy hand unit 28 is provided on the subject 20 side of the compression plate 26. The biopsy hand portion 28 includes a post 40 fixed to the compression plate 26, a first arm 42 having one end pivotally supported on the post 40, and capable of turning along the surface of the compression plate 26, and the first arm 42. One end is pivotally supported on the end, and a second arm 44 that can pivot along the surface of the compression plate 26 is provided. A biopsy needle 46 that can move in the arrow Z direction is attached to the other end of the second arm 44.

  Next, the configuration of the biopsy phantom 10 according to the present embodiment will be described in detail with reference to FIGS.

  2 is a perspective view of the biopsy phantom 10 according to the present embodiment, FIG. 3 is a right side view of the biopsy phantom 10 shown in FIG. 2, and FIG. 4 is a target member attached to the biopsy phantom 10. It is a side view of (it mentions later).

  As shown in FIG. 2, the biopsy phantom 10 includes a horizontally long rectangular flat first frame 50, a horizontally long rectangular flat second frame 52, and a first frame 50 and a second frame 52 in parallel. It is basically composed of four columnar columns 54 connected so as to be separated from each other.

  The first frame 50, the second frame 52, and the support column 54 are made of a material that is lightweight, has impact resistance, and has high radiation transmittance. As the material, for example, a plastic material / polymer resin such as acrylic resin or polycarbonate is used.

  On one side of the first frame 50, a large hole 56 having a substantially trapezoidal shape with an upper base longer than a lower base and rounded corners is provided. On the other side of the first frame 50, a substantially trapezoidal large hole 57 obtained by inverting the shape of the large hole 56 up and down is provided. The large holes 56 and 57 are provided in a positional relationship in which the hypotenuses of the trapezoid are opposed to each other and are point-symmetric with respect to the center position of the first frame 50.

  The first frame 50 is provided with five fitting holes 58, all of which are small circular holes having substantially the same diameter. Hereinafter, alphabet letters a to e are added after the reference numeral 58 in order to identify individual fitting holes.

  One fitting hole 58 a is provided on the upper left side of the large hole 56. Further, between the large hole 56 and the large hole 57, three fitting holes 58b to 58d are provided in order from the bottom to the top. Further, one fitting hole 58 e is provided at the lower right of the large hole 57.

  A needle-like target member 60 is detachably fitted in the fitting hole 58. Hereinafter, alphabet letters a to e are added after the reference numeral 60 in order to specify individual target members.

  The target members 60a to 60e fitted in the fitting holes 58a to 58e are formed of a material having low radiation transmittance. For example, tungsten, platinum, aluminum alloy, iron, nickel, chromium alloy or the like is used.

  On the other hand, the second frame 52 has substantially the same shape as the first frame 50. Specifically, large holes 62 and 63 having the same shape are provided in the second frame 52 at positions facing the large holes 56 and 57 of the first frame 50, respectively. The second frame 52 is provided with fitting holes 64a to 64e having the same shape at positions substantially opposite to the fitting holes 58a to 58e of the first frame 50, respectively. Furthermore, target members 66a to 66e are detachably fitted into the fitting holes 64a to 64e, respectively.

  The four corners of the first frame 50 are integrally fixed to one end of the four columns 54 by bolts 68, respectively. Similarly, the four corners of the second frame 52 are integrally fixed to the other ends of the four columns 54 by bolts 70, respectively.

  The second frame 52 is provided with a contact portion 72 extending in the short direction (downward portion). The two struts 54 below the biopsy phantom 10 and the abutment portion 72 intersect at an approximately right angle in the extending direction.

  As shown in FIG. 3, the front ends of the target members 60 a to 60 e attached to the first frame 50 are directed to the second frame 52. In addition, in order from the bottom, the target members 60b (60e), 60c, and 60d (60a) are arranged at substantially equal intervals in the height direction.

  Similarly, the front ends of the target members 66 a to 66 e attached to the second frame 52 are directed to the first frame 50. In addition, in order from the bottom, the target members 66b (66e), 66c, and 66d (66a) are arranged at substantially equal intervals in the height direction.

  The target members 60a, 60c and 60e are disposed at positions where the central axes thereof coincide with the central axes of the target members 66a, 66c and 66e. On the other hand, the target members 60b and 60d are disposed at positions whose center axes are deviated by a certain amount in the longitudinal direction of the first frame 50 with respect to the center axes of the target members 66b and 66d (see FIG. 2).

  As shown in FIG. 4, the target member 66b is composed of a main body portion 80, a tip portion 82, and a fitting portion 84, which are integrally formed.

  The main body portion 80 has a cylindrical shape, and one annular groove 86 is provided on the distal end portion 82 side. The tip 82 is conical and is coaxially sharpened. The fitting portion 84 has a columnar shape and is provided with a slightly smaller cross-sectional diameter than the coaxial main body portion 80. The target member 66 b is fitted into the fitting hole 64 of the second frame 52 through the fitting portion 84.

  The distal end portion 82 and the fitting portion 84 of the target member 66c have the same shape as the target member 66b. However, the difference is that an annular groove 88 having the same shape as the annular groove 86 is further provided on the distal end portion 82 side of the main body 80, that is, the two annular grooves 86 and 88 are provided.

  The tip portion 82 and the fitting portion 84 of the target member 66d have the same shape as the target member 66b. However, the difference is that annular grooves 88 and 90 having the same shape as the annular groove 86 are further provided on the distal end portion 82 side of the main body 80, that is, three annular grooves 86, 88 and 90 are provided.

  The biopsy phantom 10 according to the present embodiment is basically configured as described above. Next, its operation and effect will be described with reference to FIGS.

  First, before performing a biopsy using the mammography apparatus 12, the operator uses the biopsy phantom 10 to check the calculation accuracy of the three-dimensional position obtained by radiography. This confirmation is performed immediately after activation of the mammography apparatus 12 or at regular intervals such as each week or month in accordance with a predetermined management rule.

  FIG. 5 is a partially omitted side view showing a state in which the biopsy phantom 10 according to the present embodiment is arranged on the imaging table 24 of the mammography apparatus 12 shown in FIG. For convenience of explanation, the compression plate 26 and the biopsy hand unit 28 provided in the mammography apparatus 12 are omitted.

  The operator holds the biopsy phantom 10 and photographs the two columns 54 below the biopsy phantom 10 while maintaining the positional relationship in which the first frame 50 is directed to the arm member 18 (see FIG. 1). It is placed in contact with the upper surface of the table 24. Thereafter, the biopsy phantom 10 is slid in the back side direction of the imaging table 24, and one surface of the contact portion 72 is brought into contact with the long side surface of the imaging table 24.

  As described above, since the second frame 52 forms a positioning surface in the X direction, the biopsy phantom 10 can be installed at a fixed position, and the reliability of the three-dimensional position calculation can be improved. . Note that the contact portion 72 may be provided not only on the second frame 52 but also on the first frame 50, and a positioning member may be provided on the side surface side (Y direction).

  In addition, since the target members 60 and 66 provided on the first frame 50 and the second frame 52 are provided so as to face each other, the distance between them is shortened, and the physical movement to the tip portion 82 having a sharp shape is performed. Contact can be avoided in advance, thus protecting the operator.

  Furthermore, since the target members 60a, 60d, 66a, and 66d are provided at the same height when the biopsy phantom 10 is placed, it is easy to grasp the positional relationship between them.

  Next, radiation 92 (see FIG. 5) is applied to the biopsy phantom 10 to perform stereo imaging. For example, the first stereo angle is θ = −15 ° (see FIG. 1), and the second stereo angle is θ = + 15 °.

  6A and 6B are schematic views showing a partial region R (see FIG. 5) of a radiographic image obtained by stereo imaging. For convenience of explanation, the radiation image 100 shown in FIG. 6A and FIG. 6B represents only its outline, and the shade of the region is omitted. In the radiographic image, a portion where the image is black (high density) is a region where the detection amount by a radiation detector (not shown) is large, and a portion where the image is white (low density) is a region where the detection amount is small.

  FIG. 6A shows a radiation image 100 obtained by the first stereo imaging. The radiation image 100 includes a blank region 102 obtained by passing the radiation 92 through the biopsy phantom 10 as it is, an image region 104 obtained by transmitting the radiation 92 through the second frame 52, and the radiation 92 being the target member 66b. , 66c and 66d, and image regions 106b, 106c and 106d obtained through transmission.

  In the actual radiographic image, the radiation 92 is detected without being absorbed by the biopsy phantom 10, and therefore the image density of the element missing region 102 is high. On the other hand, since the radiation 92 is partially absorbed by the biopsy phantom 10, the image areas 104 and 106a to 106d have a low image density.

  A two-dimensional position corresponding to a reference point inside the biopsy phantom 10 is detected using the radiographic image 100 thus obtained. For example, it is assumed that a reference point is set at the distal end portion 82 (see FIG. 4) of the target member 66c. As described below, the two-dimensional position of the reference point can be measured using a known image processing technique, for example, a pattern matching method.

  First, the image area 104 extending in the Y direction is extracted, and rectangular patterns (image areas 106b to 106d) extending in the X direction from the image area 104 are extracted. Next, concave portions (image regions 108b to 108d) extending in the Y direction are detected for each of the image regions 106b to 106d, and the number thereof is measured. As a result, the image region 106b having one recess is specified as the target member 66c. Finally, a triangular pattern that is a projection image of the tip 82 (see FIG. 4) is extracted from the extracted image region 106b, and the vertex of the triangle is set as the first measurement position 110.

  Thus, since the number of the annular grooves 86, 88, 90 included in each target member 66 is different from each other, the target member 66 can be identified more easily. Since the surface shape is a groove, the density (contour) of the target member 66 on the radiation image 100 becomes clear, and the patterns of the image regions 106b to 106d are easily recognized.

  Further, each target member 60, 66 has a sharply shaped tip 82, and by setting this as a reference point in advance, the three-dimensional position of the reference point on the radiation image 100 can be calculated more accurately. Can do.

  FIG. 6B represents the radiation image 112 obtained by the second stereo imaging. Similarly to the case of the radiation image 100, the second measurement position 114 corresponding to the tip portion 82 of the target member 66c is acquired.

  After acquiring the first measurement position 110 and the second measurement position 114, the coordinates (X, Y, Z) of the three-dimensional position corresponding to the reference point can be calculated by the principle of triangulation. In this calculation, known values such as the address of the measurement position on the radiographic image, the pixel size of the radiographic image, the stereo imaging angle, and the SID are used.

  It is determined whether or not the three-dimensional position calculated in this way falls within an error range allowed for the ideal value.

  In addition, it is preferable that the target members 60 and 66 exist in the range which should confirm the precision of the three-dimensional position of a reference point. For example, it is possible to cover all the application ranges in the constancy tests described in IEC 60601-2-45: 2001 defined by the IEC (International Electrotechnical Commission) standard. Therefore, the arrangement positions of the fitting holes 58 and 64 and the shapes of the target members 60 and 66 can be appropriately provided.

  Further, the biopsy phantom 10 may be brought into contact with the short side surface of the imaging table 24, and a range different from the case of the long side surface (see FIG. 5) can be confirmed.

  Further, the contact portion 72 may be provided above the first frame 50. In such a case, the position of the target members 60 and 66, that is, the choice of three-dimensional positions that can be confirmed can be substantially increased by turning the mounting surface upside down.

  Furthermore, since each target member 60 and 66 is detachable with respect to each fitting hole 58 and 64 of the same diameter, it is preferable because an operator can set appropriately according to the management mode.

  As described above, the biopsy phantom 10 according to the present invention is provided with a plurality of target members 66 made of a material having a needle shape, a circular cross-sectional shape with respect to the axial direction, and a low transmittance of radiation 92, Since the target member 66 has a unique surface shape (annular grooves 86, 88, and 90), each target member 66 can be specified based on the pattern formed on the radiation image 100, and the number of times of imaging is small. Even on the radiographic image 100 obtained by stereo imaging, each target member 66 can be specified accurately and easily.

  By the way, as a shape for specifying each target member 66, it is not restricted to attaching the annular grooves 86, 88, 90 to the main-body part 80 as shown in this Embodiment (FIG. 4), Various shapes are mentioned. Can be used. Hereinafter, the target member 66 according to a first modification of the present embodiment will be described with reference to FIGS. 7A to 7E.

  As shown in FIG. 7A, the main body 120 may be provided with an annular convex portion 122. The distal end portion 124 has a circular shape with the same diameter as the main body portion 120. In such a case, the target member 66 can be specified according to the number of rectangular projections on the radiographic image.

  As shown in FIG. 7B, the main body 126 may be provided with a leopard-shaped recess 128. The recess 128 is formed by continuously changing the circular diameter of the cross section with respect to the axial direction from the main body 126 to the distal end 124. In such a case, the target member 66 can be specified according to the number of curves (dents) having a gentle gradient on the radiographic image.

  As shown in FIG. 7C, the main body 130 may be provided with a protruding convex portion 132. The convex portion 132 is formed by continuously changing the circular diameter of the cross section with respect to the axial direction from the main body portion 130 to the distal end portion 124. In such a case, each target member 66 can be specified according to the number of curves (protrusions) having a gentle gradient on the radiographic image.

  As shown in FIG. 7D, the shape of the main body portion 134 may be a so-called barrel shape in which the circular diameter of the cross section in the axial direction continuously changes over the distal end portion 124. Further, the main body portion 134 of each target member 66 may have a different curvature or diameter size. In such a case, the target member 66 can be specified in accordance with the slope or line width of the curve on the radiographic image.

  As shown in FIG. 7E, the shape of the main body 136 may be a hexagonal prism instead of a cylindrical shape. If it does so, the cross-sectional shape of the front-end | tip part 138 is a regular hexagon. The polygon is not limited to a hexagonal prism, but may be an arbitrary polygon. However, a polygon or a circle with more corners is more preferable so that the appearance of a pattern on a radiographic image does not depend on the angle of stereo imaging.

  Further, the positions and the number of target members 66 that can be disposed are five fitting holes 58a to 58e, 64a in the first frame 50 and the second frame 52, respectively, as shown in the present embodiment (FIG. 2). It is not limited to providing -64e. Hereinafter, a biopsy phantom 10 according to a second modification of the present embodiment will be described with reference to FIG.

  On the first frame 50, a large number of fitting holes 58 are two-dimensionally arranged instead of the large holes 56 and 57. Similarly, a large number of fitting holes 64 are two-dimensionally arranged in the second frame 52 instead of the large holes 62 and 63.

  Each of the fitting holes 58 is a small circular hole having substantially the same diameter, and the target member 60 is detachably fitted thereto. Similarly, each of the fitting holes 64 is a small circular hole having substantially the same diameter, and the target member 66 is detachably fitted thereto.

  Since it comprises in this way, position adjustment of the target members 60 and 66 can be performed in the arbitrary positions on the 1st flame | frame 50 and the 2nd flame | frame 52. FIG. The operator can freely set a reference point in the biopsy phantom 10 in order to adapt to various characteristics of the mammography apparatus 12, facility management rules, and the like.

  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 summary of this invention.

  For example, in the present embodiment, the biopsy phantom 10 is used for confirming the accuracy of the three-dimensional position, but the present invention is not limited to this. For example, the position correction data is obtained based on the radiation images 100 and 112. You may get it.

  In the present embodiment, the diameters of the fitting holes 58 and 64 are all the same, but they may be combined so as to have two or more different diameters.

  Further, in the present embodiment, the lengths of the target members 60 and 66 are all the same, but they may be combined so as to have two or more different lengths.

DESCRIPTION OF SYMBOLS 10 ... Phantom for biopsies 12 ... Mammography apparatus 24 ... Imaging stand 50 ... 1st frame 52 ... 2nd frame 54 ... Support | pillar 58, 58a-58e, 64, 64a-64e ... Fitting hole 60, 60a-60e, 66, 66a ... 66e ... target member 72 ... contact part 80, 120, 126, 130, 134, 136 ... main body part 86, 88, 90 ... annular groove 100, 112 ... radiation image 110 ... first measurement position 114 ... second Measurement position

Claims (11)

In order to confirm the accuracy of the calculated three-dimensional position of the biopsy device that calculates the three-dimensional position of the biopsy site of the inspection object based on at least two radiographic images obtained by stereo imaging of the inspection object A biopsy phantom used for
It has a plurality of target members made of a material that is needle-shaped and has a circular cross-sectional shape that intersects in the axial direction, and that has a low radiation transmittance,
Each of the target members has a unique surface shape. A biopsy phantom characterized by the above. In the biopsy phantom according to claim 1,
The biopsy phantom characterized in that the surface shape is a different number of annular grooves. The biopsy phantom according to claim 1 or 2,
Each of the target members has a sharp tip portion. A biopsy phantom characterized by the above. In the phantom for biopsy of any one of Claims 1-3,
The biopsy phantom, wherein at least two of the target members are provided at the same height when the biopsy phantom is placed. In the phantom for biopsies of any one of Claims 1-4,
The biopsy phantom, wherein at least two of the target members are provided at the same size on the radiation image when the biopsy phantom is placed. In the phantom for biopsies of any one of Claims 1-5,
The biopsy phantom, wherein the at least two target members are provided so as to face each other. In the phantom for biopsy of any one of Claims 1-6,
A first frame and a second frame spaced apart from the first frame by a predetermined interval;
Each of the target members is disposed in a space between the first frame and the second frame. A biopsy phantom characterized by the above. In the phantom for biopsies of any one of Claims 1-7,
The biopsy phantom, wherein the first frame or the second frame constitutes a positioning surface. In the phantom for biopsy of any one of Claims 1-8,
Each of the target members can be freely arranged at at least two positions on the first frame or the second frame. In the phantom for biopsies of any one of Claims 1-9,
The biopsy phantom is characterized in that the at least two positions are determined so that each target member is within a range in which accuracy of the three-dimensional position is to be confirmed. In the phantom for biopsy of any one of Claims 1-10,
Both of the first frame and the second frame can be mounted as a mounting surface. A biopsy phantom characterized by the above-mentioned.

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