JP2009300319A - Nuclear medical diagnostic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nuclear medical diagnostic device capable of nuclear medical diagnosis of both breasts of a subject without moving the subject. <P>SOLUTION: The nuclear medical diagnostic device includes a gantry 2 for supporting (disposing) a subject M and a PET detector 3 for detecting γ rays generated from the breasts of the subject M nipping the gantry 2. The gantry 2 is provided with two openings 2a and 2b to allow the γ rays generated from the subject M to reach the PET detector 3. The PET detector 3 is provided with a movement means movable in the vertical direction shown by an arrow and a movement means reciprocating between the openings. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a nuclear medicine diagnostic apparatus that obtains nuclear medicine data of a subject based on radiation generated from the subject to which a radiopharmaceutical is administered, and more particularly to a mammo technique for diagnosing the breast of a subject.

  As the above-described nuclear medicine diagnosis apparatus, that is, an ECT (Emission Computed Tomography) apparatus, a PET (Positron Emission Tomography) apparatus will be described as an example. The PET apparatus detects a plurality of gamma rays generated by annihilation of positrons, that is, positrons, and reconstructs a tomographic image of a subject only when the gamma rays are simultaneously detected by a plurality of detectors. It is configured.

  In this PET apparatus, after a radiopharmaceutical is administered to a subject, the process of drug accumulation in the target tissue is measured over time, whereby quantitative measurement of various biological functions is possible. Therefore, the tomographic image obtained by the PET apparatus has functional information.

By the way, in the mammogram PET apparatus applied to the mammogram for breast cancer detection, the body (breast) of the subject and the detector are brought close to each other. For example, the two detectors facing each other are configured to be able to contact and separate both breasts of the subject, or the detector divided into four is configured to surround the subject's breast and be capable of contacting and separating. A detector can be brought close to the breast of the specimen, and nuclear medicine diagnosis (imaging) can be performed with sufficient sensitivity (see, for example, Patent Document 1).
JP2007-232685 (pages 1-8, 10-12, FIGS. 1-5, 8-12)

  However, in the conventional mammo PET apparatus, the detector is fixed, and the subject must move in order to image both breasts of the subject. In addition, when the nuclear medicine diagnosis of both breasts of the subject is performed by one imaging as in Patent Document 1 described above, the sensitivity is lowered.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a nuclear medicine diagnostic apparatus capable of performing nuclear medicine diagnosis of both breasts without moving a subject.

In order to achieve such an object, the present invention has the following configuration.
That is, the invention described in claim 1 is a nuclear medicine diagnostic apparatus for mammo that obtains nuclear medicine data of a subject based on radiation generated from the subject to which a radiopharmaceutical is administered. A supporting means for supporting, and a detecting means for nuclear medicine for detecting radiation generated from the subject across the supporting means, and the supporting means is arranged so that the radiation reaches the detecting means for nuclear medicine. A plurality of openings are provided.

  [Operation / Effect] According to the first aspect of the present invention, there is provided a supporting means for supporting the subject and a nuclear medicine detecting means for detecting radiation generated from the subject across the supporting means. The support means is provided with a plurality of openings so that the radiation generated from the specimen reaches the nuclear medicine detection means. One breast is inserted into one of these openings, and the other breast is inserted into one of the remaining openings. By inserting in this way, nuclear medicine diagnosis of both breasts is possible without moving the subject.

  In the above-described invention, it is preferable that the detection means for nuclear medicine is provided with a reciprocating means for reciprocating between at least a plurality of openings along the supporting surface of the supporting means (the invention according to claim 2). After imaging one breast, move the nuclear medicine detection means to the opening where the other breast is inserted, and perform imaging to enable nuclear medicine diagnosis of both breasts without moving the subject. is there.

  Moreover, in these inventions described above, it is preferable to include a vertical movement means for moving the detection means for nuclear medicine in a direction perpendicular to the support surface of the support means (the invention according to claim 3). In particular, as in the invention described in claim 2, in the case where the detection means for nuclear medicine is provided with a reciprocating means for reciprocating between at least a plurality of openings along the support surface of the support means, If the detection means for nuclear medicine is moved along the support surface without moving the detection means for nuclear medicine, interference between the breast and the detection means for nuclear medicine occurs. Therefore, in order to prevent interference between the breast and the detection means for nuclear medicine, as in the invention described in claim 3, the nuclear medicine is provided with a vertical movement means for moving the detection means for nuclear medicine in the vertical direction. The detection means can be moved smoothly, and the nuclear medicine diagnosis of both breasts can be performed smoothly.

  Further, in these inventions described above, the nuclear medicine detection means is constituted by a plurality of detector groups, and the detector groups are divided into a plurality of parts in the direction of the support surface of the support means. It is preferable that these detector groups are configured to be able to contact and separate from each other along the support surface (the invention according to claim 4). The imaging state by the nuclear medicine detection means changes depending on the breast size of the subject. If a small breast is imaged after a large breast is imaged, there may be a gap between the breast and the nuclear medicine detection means, which may reduce the sensitivity. On the other hand, when imaging a large breast after imaging a small breast, the pressure from the contact with the detection means for nuclear medicine is excessive on the breast and the subject is physically and mentally painful. May be accompanied. Therefore, as in the invention described in claim 4, the nuclear medicine detection means is constituted by a plurality of detector groups, and these detector groups are constituted by being divided into a plurality of parts in the direction of the support surface. By configuring the detector groups so as to be able to contact and separate from each other along the support surface, it is possible to perform imaging by moving the detector groups freely according to the size of the breast of the subject. A decrease in sensitivity due to the change can be prevented, and the physical and mental pain of the subject due to the change in the size of the breast can be reduced.

  In such a configuration, the detector groups are arranged in a circle along the support surface, and the divided detector groups are configured to be able to contact and separate from each other along the support surface. You may combine as a medical detection means (invention of Claim 5). By arranging the detector group in a circle along the support surface, the detector group can be placed close to the breast uniformly, and imaging with a uniform sensitivity to the breast, and in turn, nuclear medicine diagnosis Can do.

  In these inventions described above, the support means is arranged so that the support surface is horizontal (the invention according to claim 6). Such an arrangement is useful when the subject is lying down, that is, in a prone posture. That is, when the subject is in a prone posture and the breast is turned downward, the support means for supporting the subject becomes horizontal. With this prone posture, nuclear medicine diagnosis of the breast is possible. In addition, it becomes easier to perform nuclear medicine diagnosis using the gravity of the breast due to the prone state.

  Even in such a horizontal arrangement, it is preferable that the detection means for nuclear medicine is provided with a reciprocating means for reciprocating between at least a plurality of openings along a horizontal plane that is a support surface of the support means. Invention). After imaging one breast, move the nuclear medicine detection means to the opening where the other breast is inserted, and perform imaging to enable nuclear medicine diagnosis of both breasts without moving the subject. is there.

  Even in such a horizontal arrangement, it is preferable to include a vertical movement means for moving the nuclear medicine detection means up and down in the vertical direction perpendicular to the horizontal plane that is the support surface of the support means (the invention according to claim 8). ). In particular, as in the invention according to claim 7, when the nuclear medicine detection means is provided with a reciprocating means for reciprocating between at least a plurality of openings along a horizontal plane that is a support surface of the support means, If the nuclear medicine detection means is moved along the horizontal direction as the support surface without moving the nuclear medicine detection means in the vertical direction that is vertical, interference between the breast and the nuclear medicine detection means occurs. Accordingly, in order to prevent interference between the breast and the detection means for nuclear medicine, as in the invention described in claim 8, a vertical movement means for moving the detection means for nuclear medicine up and down vertically is provided. Therefore, the detection means for nuclear medicine can be moved smoothly, and the nuclear medicine diagnosis of both breasts can be performed smoothly.

  Even in such a horizontal arrangement, the detection means for nuclear medicine is constituted by a plurality of detector groups, and these detector groups are divided into a plurality of parts in the direction of the horizontal plane that is the support surface of the support means. These detector groups are preferably constructed so as to be able to contact and separate from each other along a horizontal plane which is a support surface (the invention according to claim 9). The imaging state by the nuclear medicine detection means changes depending on the breast size of the subject. If a small breast is imaged after a large breast is imaged, there may be a gap between the breast and the nuclear medicine detection means, which may reduce the sensitivity. On the other hand, when imaging a large breast after imaging a small breast, the pressure from the contact with the detection means for nuclear medicine is excessive on the breast and the subject is physically and mentally painful. May be accompanied. Therefore, as in the ninth aspect of the invention, the nuclear medicine detection means is constituted by a plurality of detector groups, and these detector groups are divided into a plurality of parts in the direction of the horizontal plane as the support surface. By configuring these divided detector groups so as to be able to contact and separate from each other along a horizontal plane as a support surface, it is possible to perform imaging by moving the detector groups freely according to the size of the breast of the subject. It is possible to prevent a decrease in sensitivity due to a change in the size of the breast, and to reduce physical and mental pain of the subject due to a change in the size of the breast.

  Even in such a horizontal arrangement, in such a configuration, the detector groups are arranged in a circle along a horizontal plane that is a support surface, and these divided detector groups are contacted and separated from each other along the horizontal plane that is a support surface. It may be configured so that it can be combined again as one nuclear medicine detection means when approaching (the invention according to claim 10). By arranging the detector group in a circle along the horizontal plane that is the support surface, the detector group can be brought close to the breast uniformly, and imaging with uniform sensitivity to the breast, and in turn, nuclear medicine diagnosis It can be performed.

  Moreover, in these inventions described above, it is preferable to include pressure detection means for detecting the pressure from the detection means for nuclear medicine on the breast of the subject positioned at the opening (the invention according to claim 11). The more the nuclear medicine detection means is brought into contact with the breast, the higher the sensitivity is. However, on the other hand, the pressure from the contact from the nuclear medicine detection means is excessively applied to the breast, and the subject is physically and eventually mental. May be painful. Therefore, the subject is provided with pressure detecting means for detecting the pressure from the detecting means for nuclear medicine, and the breast is imaged at an appropriate pressure so that the pressure due to contact from the detecting means for nuclear medicine is excessively applied to the breast. Can reduce physical and mental distress.

  In these inventions described above, it is preferable that imaging means for imaging the breast of the subject positioned at the opening is provided (the invention according to claim 12). In addition to imaging by the detection means for nuclear medicine, an imaging means for imaging the breast of the subject can be provided, so that nuclear medicine diagnosis can be performed while grasping the imaging status of the breast by the imaging means. For example, when the imaging means is provided along the central axis of the detection means for nuclear medicine and the nipple is at the center of the breast, the nucleus is arranged so that the nipple at the center of the breast is positioned at the center of the imaging screen by the imaging means. Medical detection means are set (especially when the nuclear medicine detection means is reciprocated between at least a plurality of openings along the support surface of the support means as in the inventions of claims 2 and 7. The detection means for nuclear medicine is set by slightly moving along the support surface, or a plurality of divided detector groups as in the inventions according to claims 4, 5, 9, and 10 are arranged along the support surface. In the case of a configuration that allows contact / separation, the center group of the detection means for nuclear medicine is positioned at the center of the breast where the nipple is located. , Imaging with uniform sensitivity to the breast, and thus nuclear medicine diagnosis Door can be.

  In addition, in the case where such an imaging unit is provided, a deviation detecting unit that detects a deviation based on an imaging result of the imaging unit is provided, and the detection unit for nuclear medicine is moved in order to eliminate the deviation detected by the deviation detecting unit. It is more preferable to do this (the invention according to claim 13). Displacement detection means for detecting a displacement based on the imaging result of the imaging means, and by moving the detection means for nuclear medicine to eliminate the displacement detected by the displacement detection means, imaging with a more uniform sensitivity, and thus A nuclear medicine diagnosis can be performed. For example, in the case where an imaging unit is provided along the central axis of the above-described nuclear medicine detection unit and a subject whose nipple is offset from the center of the breast is imaged, the nipple is centered on the imaging screen by the imaging unit. Even if the detection means for nuclear medicine is set so that is located, a deviation occurs between the central axis of the detection means for nuclear medicine and the center of the breast. Therefore, a deviation detecting means for detecting the deviation is provided, and the nuclear medicine detecting means is moved in order to eliminate the deviation detected by the deviation detecting means, so that the central axis of the nuclear medicine detecting means is set to the center of the breast. Even when imaging a subject that is located and the nipple is deviated from the center of the breast, it is possible to perform imaging with uniform sensitivity to the breast, and thus nuclear medicine diagnosis.

  According to the nuclear medicine diagnostic apparatus according to the present invention, the nuclear medicine diagnosis apparatus includes the support means for supporting the subject, and the nuclear medicine detection means for detecting radiation generated from the subject across the support means. By providing a plurality of openings in the support means so that the radiation reaches the detection means for nuclear medicine, nuclear medicine diagnosis of both breasts can be performed without moving the subject.

Embodiment 1 of the present invention will be described below with reference to the drawings.
FIG. 1A is a partial side cross-sectional view of the mammo PET apparatus according to the first embodiment, FIG. 1B is a plan view thereof, and FIG. FIG. 3 is a partial front sectional view showing a series of imaging modes, and FIG. 3 is a block diagram of a mammo PET apparatus according to Example 1 including Examples 2 and 3 to be described later. In the first embodiment, including later-described embodiments 2 and 3, a mammo PET (Positron Emission Tomography) apparatus will be described as an example of a nuclear medicine diagnostic apparatus for mammons. In the front sectional view of FIG. 2, the column portion of the PET detector support portion and the pressure sensor are originally overlapped in the front-rear direction, but in order to clearly illustrate the positional relationship between the PET detector and the opening, The post portion of the PET detector support and the pressure sensor will be illustrated in the direction of 1.

  As shown in FIG. 1, the mammo PET apparatus 1 according to the first embodiment includes a gantry 2 on which a subject M in a prone posture is placed. The mounting surface of the gantry 2 is provided with two openings for inserting the breast in order to diagnose the breast below the mounting surface. The right opening for inserting the right breast is 2a, and the left opening for inserting the left breast is 2b. In the first embodiment, the gantry 2 is disposed so that the placement surface (that is, the support surface) is horizontal. The gantry 2 corresponds to the support means in this invention.

  In the gantry 2, a PET detector 3 that detects γ rays generated from the subject M, a PET detector support portion 4 that supports the PET detector 3, and a support portion of the PET detector support portion 4 ) In the vertical direction (see FIG. 3), a horizontal movement unit 6 (see FIG. 3) for reciprocating the PET detector support 4 along the horizontal plane, and a PET detector support. A pressure sensor 7 that detects pressure from the PET detector 3, and a CCD (Charge Coupled Device) that is provided on the PET detector support unit 4 along the central axis of the PET detector 3. A solid-state solid-state imaging device (hereinafter abbreviated as “CCD”) 8. The PET detector 3 corresponds to the detection means for nuclear medicine in the present invention, the vertical movement unit 5 corresponds to the vertical movement unit in the present invention, and the horizontal movement unit 6 corresponds to the reciprocating movement unit in the present invention. The pressure sensor 7 corresponds to the pressure detection means in the present invention, and the CCD type solid-state imaging device (CCD) 8 corresponds to the imaging means in the present invention.

  The PET detector 3 includes a plurality of γ-ray detector groups, and the γ-ray detector groups are arranged in a circle along the mounting surface (that is, the support surface) of the gantry 2 to form the PET detector 3. ing. In the first embodiment, the support surface is a horizontal plane, and as shown in FIG. 1B, the γ-ray detector group of the PET detector 3 is circularly arranged along the horizontal plane as the support surface. The gamma ray detector group of the PET detector 3 is installed so as to surround one of the breasts inserted into the openings 2a and 2b.

  The γ-ray detector group of the PET detector 3 includes a scintillator block, a light guide, and a photomultiplier tube (all not shown). The scintillator block is composed of a plurality of scintillators. The scintillator block converts the γ-rays generated from the subject M to which the radiopharmaceutical has been administered into light, the light guide guides the converted light, and the photomultiplier tube photoelectrically converts it into an electrical signal. To do.

  The PET detector support unit 4 (the support column part) moves in a direction perpendicular to the support surface. By moving in this way, the PET detector 3 supported by the PET detector support unit 4 is configured to move the PET detector 3 in a direction perpendicular to the rotation surface of the support surface. In the first embodiment, as described above, the support surface is a horizontal plane, and the vertical movement unit 5 is provided with a PET detector support unit 4 as indicated by arrows in FIGS. 2 (a) and 2 (c). Is moved up and down in the vertical direction perpendicular to the horizontal plane as the support surface. Therefore, the PET detector 3 is moved up and down in the vertical direction perpendicular to the horizontal plane.

  In the first embodiment, as the vertical movement unit 5, for example, a motor, a drive shaft, a pinion, a rack, a guide rail (all not shown) are provided, and the pinion is rotated via the drive shaft by driving the motor. The rack fitted to the pinion is moved up and down along the guide rail as the pinion rotates, and the PET detector support unit 4 is moved up and down electrically as the guide rail moves up and down. When manually moving the PET detector support 4, a gas spring mechanism is employed, a ball screw is used instead of the rack described above, and a gas spring mechanism is used instead of the motor described above. Thus, the PET detector support 4 is moved up and down along the ball screw.

  On the other hand, as described above, the PET detector support unit 4 moves in the vertical direction (vertical direction in FIGS. 1 and 2) with respect to the support surface (horizontal plane in FIGS. 1 and 2) and along the support surface. Moving. By moving in this way, for the PET detector 3 supported by the PET detector support section 4, the PET detector 3 is moved along the support surface between the two openings 2a and 2b in the gantry 2. It is configured to reciprocate. In the first embodiment, as described above, the support surface is a horizontal plane, and the horizontal moving unit 6 is the support surface of the PET detector support unit 4 as indicated by the arrow in FIG. Reciprocate along a horizontal plane. Therefore, the PET detector 3 is configured to reciprocate at least two openings 2a and 2b along the horizontal plane.

  In the first embodiment, as the horizontal moving part 6, for example, a motor and a rail (both not shown) are provided. The above-described rail (not shown) is laid along the floor just below the two openings 2a and 2b, and a wheel or the like is disposed at the bottom of the base portion of the PET detector support 4 so that By being configured to move, the PET detector support 4 is reciprocated along the horizontal plane. The PET detector support 4 may be electrically reciprocated by the motor described above, or the PET detector support 4 may be moved manually.

  The pressure sensor 7 detects the pressure of the PET detector 3 from the breast when the breast of the subject M positioned at the openings 2 a and 2 b comes into contact with the PET detector 3. The pressure sensor 7 is composed of a piezoelectric element (piezo) typified by quartz or the like. By detecting the pressure of the PET detector 3 from the breast, the pressure on the breast due to contact from the PET detector 3 can also be detected. In order to detect the pressures on the left and right breasts, respectively, it is preferable to provide pressure sensors 7 on both struts of the PET detector support 4 as shown in FIG.

  The CCD 8 images the breast of the subject M positioned at the openings 2a and 2b. As shown in FIG. 1A, the CCD 8 is provided along the central axis of the PET detector 3 by providing the CCD 8 at the center of the base portion of the PET detector support 4.

  Next, a block diagram of the mammo PET apparatus 1 will be described. As shown in FIG. 3, the mammo PET apparatus 1 includes a console 10 in addition to the gantry 2 described above. The gantry 2 includes a drive control unit 20 and a PET data collection unit 30 in addition to the above-described PET detector 3, PET detector support unit 4, vertical movement unit 5, horizontal movement unit 6, pressure sensor 7, and CCD 8. Yes. The console 10 includes a data collection unit 11, an image reconstruction unit 12, an input unit 13, an output unit 14, and an imaging control unit 15.

  The drive control unit 20 controls driving parts (for example, motors) of the vertical movement unit 5 and the horizontal movement unit 6, and controls the position detection sensor (not shown), the pressure sensor 7, and the CCD 8 provided on the PET detector support unit 4. If the movement end timing is received based on this, a braking command is output to the drive part described above, or a data collection command is output to the imaging control unit 15. The drive control unit 20 and the imaging control unit 15 are configured by a central processing unit (CPU) and the like. Note that the position detection sensor may be a non-contact type sensor represented by a photo sensor or the like, or a contact type sensor represented by a micro switch or the like.

  The PET data collection unit 30 collects PET data (nuclear medicine data) based on the γ rays detected by the PET detector 3. The PET data collection unit 30 has a function of a coincidence counting circuit (not shown). The PET data collected by the PET data collection unit 30 is sent to the data collection unit 11.

  The data collection unit 11 performs various processes on the PET data collected by the PET data collection unit 30. In the case where an external radiation source (not shown) is provided and absorption correction is performed, transmission data (absorption correction data) obtained from the external radiation source is applied to the PET data by the data collection unit 11 so that the PET data Absorption correction may be performed. The data collection unit 11 sends the PET data to the image reconstruction unit 12 as projection data. The image reconstruction unit 12 reconstructs the projection data from the data collection unit 11 and generates a tomographic image.

  The input unit 13 sends data and commands input by the operator to the imaging control unit 15. The input unit 13 includes a pointing device represented by a mouse, a keyboard, a joystick, a trackball, a touch panel, and the like. The output unit 14 includes a display unit represented by a monitor, a printer, and the like.

  The imaging control unit 15 performs overall control of each part constituting the mammo PET apparatus 1 according to the first embodiment. Specifically, the imaging control unit 15 causes the vertical movement unit 5 and the horizontal movement unit 6 to be driven via the drive control unit 20. When the drive control unit 20 receives the movement end timing based on the position detection sensor (not shown), the pressure sensor 7 and the CCD 8 provided on the PET detector support unit 4, the data collection output from the drive control unit 20 is collected. The imaging control unit 15 receives the command and outputs a command for collecting each data to the PET data collecting unit 30 and the data collecting unit 11 and outputs a command for reconstructing the projection data to the image reconstruction unit 12. . The data collected by the PET data collection unit 30 and the data collection unit 11 and the tomographic image reconstructed by the image reconstruction unit 12 are sent to the output unit 14 via the imaging control unit 15 and output. When the output unit 14 is a display unit, output is displayed. When the output unit 14 is a printer, output printing is performed.

  The γ-rays generated from the subject M to which the radiopharmaceutical is administered are converted into light by the scintillator block of the corresponding γ-ray detector in the γ-ray detector group of the PET detector 3, and the converted light is converted into γ The photomultiplier tube of the line detector performs photoelectric conversion and outputs an electrical signal. The electrical signal is sent to the PET data collection unit 30 as image information (pixel value).

  Specifically, when a radiopharmaceutical is administered to the subject M, two γ rays are generated due to the disappearance of the positron of the positron emission type RI. The PET data collection unit 30 checks the position of the scintillator block of the γ-ray detector and the incident timing of the γ-ray, and when the γ-rays are simultaneously incident on the two scintillator blocks that are opposed to each other across the subject M. Only when the simultaneous counting is performed, the sent image information is determined as appropriate data. When γ rays are incident only on one scintillator block, the PET data collection unit 30 treats the image information sent at that time as noise instead of γ rays generated by the disappearance of the positron, and treats it as noise. Dismiss.

  The image information sent to the PET data collection unit 30 is sent to the data collection unit 11 as projection data (PET data). When absorption correction is performed with an external source (not shown), transmission data (absorption correction data) obtained from the external source is sent to the data collection unit 11.

  The data collection unit 11 performs various types of processing (for example, absorption correction) on the PET data, and sends the processed data to the image reconstruction unit 12. The image reconstruction unit 12 reconstructs the projection data that has been sent in, thereby generating a tomographic image. Generate.

  Next, an imaging mode in a series of diagnosis (imaging) will be described with reference to FIG. FIG. 2A shows an imaging mode when the PET detector support and the PET detector supported by the PET detector move downward after imaging of the right breast. FIG. 2B shows the PET detector support. FIG. 2C shows an imaging mode when the PET detector support unit and the PET detector supported by the PET detector support unit move upward. FIG. 2D shows an imaging mode when the left breast is imaged.

  A radiopharmaceutical is administered to the subject M to make a prone posture, and the right breast is inserted into the right opening 2a, and the left breast is inserted into the left opening 2b. On the other hand, the operator inputs imaging conditions to the input unit 13 (see FIG. 3) of the console 10 (see FIG. 3), and sends the input imaging conditions to the imaging control unit 15 (see FIG. 3). Based on the input imaging conditions, the imaging control unit 15 sends a data collection command to the PET data collection unit 30 (see FIG. 3) and the data collection unit 11 (see FIG. 3). Drive commands such as installation are output to the drive control unit 20 (see FIG. 3).

  First, diagnosis with the mammo PET apparatus 1 is performed in the mode shown in FIG. The imaging control unit 15 causes the vertical movement unit 5 and the horizontal movement unit 6 (see FIG. 3) to be driven via the drive control unit 20. Specifically, if the γ-ray detector group of the PET detector 3 has not advanced to a position surrounding the right breast inserted into the right opening 2a, the vertical movement unit 5 and the PET detector support unit 4 and The vertical movement of the PET detector 3 supported by the PET detector 3 is moved up and down, and the horizontal movement unit 6 reciprocates the PET detector support unit 4 and the PET detector 3 supported thereby along the horizontal plane. Control by 20 makes a diagnosis so as to surround the right breast inserted into the right opening 2a in the manner shown in FIG. When the drive control unit 20 receives the movement end timing based on the position detection sensor (not shown), the pressure sensor 7 and the CCD 8 provided on the PET detector support unit 4, the data collection output from the drive control unit 20 is collected. The imaging control unit 15 receives the command. The setting of the PET detector 3 based on the pressure sensor 7 and the CCD 8 will be described later together with the left breast.

  The γ-ray detector of the PET detector 3 detects γ-rays generated from the subject M to which the radiopharmaceutical is administered, and the imaging control unit 15 outputs a data collection command to the PET data collection unit 30. The PET data collection unit 30 collects the γ-ray count value, the γ-ray incident position, and the γ-ray generation position simultaneously counted by the γ-ray detector of the PET detector 3 as image information. Then, the image information regarding the right breast sent to the PET data collection unit 30 is sent to the data collection unit 11 as projection data (PET data).

  Next, as shown by the arrow in FIG. 2A from the imaging mode shown in FIG. 2A, the vertical movement unit 5 moves the PET detector support unit 4 and the PET detector 3 supported thereby downward. The drive control unit 20 controls as described above. When the PET detector 3 is moved to a position where interference with the breast does not occur as shown in FIG. 2B, the horizontal moving unit 6 supports the PET detector as shown by an arrow in FIG. The drive control unit 20 controls the unit 4 and the PET detector 3 supported by the unit 4 to move horizontally toward the left breast. Based on a position detection sensor (not shown) provided on the PET detector support unit 4 and the CCD 8, the drive control unit 20 receives the timing of the end of the horizontal movement. That is, after the PET detector 3 is horizontally moved to a position just below the left breast as shown in FIG. Receive.

  Next, as shown by the arrow in FIG. 2C from the imaging mode shown in FIG. 2C, the vertical movement unit 5 moves the PET detector support unit 4 and the PET detector 3 supported thereby upward. The drive control unit 20 controls as described above. When the drive control unit 20 receives the timing of the end of the upward movement based on the position detection sensor (not shown), the pressure sensor 7 and the CCD 8 provided on the PET detector support unit 4 (that is, the position detection sensor (not shown) After the PET detector 3 is moved to a position surrounding the left breast as shown in FIG. 2 (d) based on the pressure sensor 7 and the CCD 8, the drive control unit 20 receives the timing of the end of the upward movement) The imaging control unit 15 receives a data collection command output from the control unit 20.

  As in the case of the right breast, the γ-ray detector of the PET detector 3 detects γ-rays generated from the subject M to which the radiopharmaceutical is administered, and the imaging control unit 15 issues a data collection command. The PET data collection unit 30 outputs to the PET data collection unit 30 as image information the γ-ray count value, the γ-ray incidence position, and the γ-ray generation position simultaneously counted by the γ-ray detector of the PET detector 3. 30 collect. Then, the image information relating to the left breast sent to the PET data collection unit 30 is sent to the data collection unit 11 as projection data (PET data).

  When the diagnosis of the right breast and the left breast is completed, the imaging control unit 15 outputs a data collection command to the data collection unit 11, and the data collection unit 11 performs various processes on the PET data. The image reconstruction unit 12 (see FIG. 3) sends the projection data, and the image reconstruction unit 12 reconstructs the tomographic image. Then, the generated tomographic image is sent to the output unit 14 (see FIG. 3) via the imaging control unit 15 and output. Note that the projection data collected by the PET data collection unit 30 may be sent to the output unit 14 via the imaging control unit 15 and output as necessary.

  By the way, fine adjustment (setting) in the horizontal direction of the PET detector 3 based on the pressure sensor 7 and the CCD 8 will be described with reference to FIGS. FIG. 4 is a diagram showing an output mode by CCD when the nipple is at the center of the breast, and FIG. 5 is by CCD when there is no nipple at the center of the breast and the nipple is deviated from the center of the breast. It is a figure which shows an output mode. First, a case where the nipple is at the center of the breast will be described.

  The imaging result from the CCD 8 provided along the central axis of the PET detector 3 is output (output displayed) to the output unit 14 (in this case, a monitor). If the fine adjustment is not completed in the horizontal direction, the nipple N with respect to the center O of the monitor (imaging screen) coincident with the central axis of the PET detector 3 as shown in FIG. At the same time, the breast M ′ is shifted and output. Therefore, as shown in FIG. 4B, the PET detector support unit 4 and the PET detector supported by the PET detector support 4 so that the nipple N at the center of the breast M ′ is positioned at the center O of the monitor (imaging screen). Move 3 horizontally to make fine adjustments.

  At this time, it is more preferable to perform fine adjustment based on not only the imaging result from the CCD 8 but also the pressure result from the pressure sensor 7. The pressure applied to the breast is obtained in advance so as not to cause physical distress, and fine adjustment is performed by horizontally moving the PET detector support 4 and the PET detector 3 supported by the pressure so as not to exceed the pressure. When the pressure is exceeded, it is recognized that the pressure is excessively applied to the breast, and the horizontal movement of the PET detector support 4 and the PET detector 3 supported by the PET detector is stopped.

  Next, a case where there is no nipple at the center of the breast and the nipple is offset from the center of the breast will be described. As shown in FIG. 5A, even if the nipple N is positioned at the center O of the monitor (imaging screen), the whole breast M ′ is displaced from the center O of the monitor (imaging screen), and PET detection is performed. Deviation occurs between the central axis of the vessel 3 and the center N ′ of the breast M ′. In view of this, the function of the deviation detection unit for detecting the deviation is provided in, for example, the imaging control unit 15 or independently of the imaging control unit 15. In the case where the imaging control unit 15 has the function of the detection unit, the imaging control unit 15 corresponds to the deviation detection means in this invention.

  Specifically, a plurality of markers are attached around the breast. These markers are output (output displayed) to the output unit 14 (in this case, a monitor) together with the breast. As shown in FIG. 5A, a plurality of markers m attached around the breast are output to the monitor (imaging screen) together with the breast M ′. The imaging control unit 15 obtains the center N ′ of the breast M ′ from the plurality of markers m output to the monitor (imaging screen). Then, as shown in FIG. 5A, the center N ′ of the breast M ′ is shifted from the center O of the monitor (imaging screen) together with the whole breast M ′, but the center O of the breast N ′ and the center O of the breast M ′ are located. The imaging control unit 15 can obtain a deviation from N ′, that is, a deviation that occurs between the central axis of the PET detector 3 and the center N ′ of the breast M ′. In order to eliminate the deviation detected by the imaging controller 15, fine adjustment is performed by horizontally moving the PET detector support unit 4 and the PET detector 3 supported by the PET detector support unit 4 as shown in FIG. 5B. Even when there is no nipple at the center of the breast and the nipple is offset from the center of the breast, it is more preferable to perform fine adjustment based on the pressure result from the pressure sensor 7 as well as the imaging result from the CCD 8.

  According to the mammo PET apparatus 1 according to the first embodiment having the above-described configuration, the gantry 2 that supports (places) the subject M and the subject M (the breast) that is sandwiched between the gantry 2 are generated. a plurality of (two in the first embodiment) openings 2a and 2b in the gantry 2 so that the γ-rays generated from the subject M reach the PET detector 3. Is provided. One breast is inserted into one of the openings 2a and 2b, and the other breast is inserted into one of the remaining openings 2a and 2b. By inserting in this way, nuclear medicine diagnosis of both breasts is possible without moving the subject M.

  In the first embodiment, preferably, the PET detector 3 is reciprocated between at least a plurality of (two in the first embodiment) openings 2 a and 2 b along the support surface (mounting surface) of the gantry 2. A horizontal moving part 6 is provided. After imaging one breast (right breast in the first embodiment), the PET detector 3 is moved to the opening 2b into which the other breast (left breast in the first embodiment) is inserted, and imaging is performed. By doing so, it is possible to perform nuclear medicine diagnosis of both breasts without moving the subject M.

  In the first embodiment, the vertical movement unit 5 that moves the PET detector 3 in a direction perpendicular to the support surface (mounting surface) of the gantry 2 is preferably provided. In particular, as described above, when the PET detector 3 is provided with the horizontal moving portion 6 that reciprocally moves between the plurality of openings 2a and 2b along the support surface of the gantry 2, the PET detector in the vertical direction. If the PET detector 3 is moved along the support surface without moving the 3, interference between the breast and the PET detector 3 occurs. Therefore, in order to prevent interference between the breast and the PET detector 3, the PET detector 3 is smoothly moved by providing the vertical movement unit 5 that moves the PET detector 3 in the vertical direction as described above. It is possible to carry out the nuclear medicine diagnosis of both breasts smoothly.

  In the first embodiment, the gantry 2 is arranged so that the support surface is horizontal. Such an arrangement is useful when the subject M is in a prone posture. That is, when the subject M is in a prone posture and the breast is directed downward, the support surface of the gantry 2 that supports the subject M becomes horizontal. With this prone posture, nuclear medicine diagnosis of the breast is possible. In addition, it becomes easier to perform nuclear medicine diagnosis using the gravity of the breast due to the prone state.

  Even in such a horizontal arrangement, preferably, the PET detector 3 is provided with a horizontal moving section 6 that reciprocates between at least the plurality of openings 2 a and 2 b along a horizontal plane that is a support surface of the gantry 2. After imaging one breast, by moving the PET detector 3 to the opening 2b in which the other breast is inserted and performing imaging, nuclear medicine diagnosis of both breasts is possible without moving the subject M It is.

  Even in such a horizontal arrangement, a vertical movement unit 5 is preferably provided that moves the PET detector 3 up and down in the vertical direction perpendicular to the horizontal plane that is the support surface of the gantry 2. In particular, as described above, in the case where the PET detector 3 is provided with the horizontal moving unit 6 that reciprocates between the plurality of openings 2a and 2b along the horizontal plane that is the support surface of the gantry 2, the PET detector 3 is vertical. If the PET detector 3 is moved along the horizontal direction as the support surface without moving the PET detector 3 in the vertical direction, interference between the breast and the PET detector 3 occurs. Therefore, in order to prevent interference between the breast and the PET detector 3, as described above, the PET detector 3 is provided with the up-and-down moving unit 5 that moves the PET detector 3 up and down in the vertical direction that is vertical. It can move smoothly, and the nuclear medicine diagnosis of both breasts can be performed smoothly.

  In the first embodiment, a pressure sensor 7 for detecting the pressure from the PET detector 3 on the breast of the subject M positioned at the openings 2a and 2b is preferably provided. The more the PET detector 3 is brought into contact with the breast, the higher the sensitivity is. On the other hand, the pressure from the PET detector 3 is excessively applied to the breast, so that the subject M is physically and eventually mental. May be painful. Therefore, the pressure sensor 7 for detecting the pressure from the PET detector 3 is provided, and the breast M is imaged at an appropriate pressure, so that the pressure of the subject M caused by the contact from the PET detector 3 is excessively applied to the breast. Physical and mental pain can be reduced.

  In the first embodiment, a CCD solid-state imaging device (CCD) 8 that images the breast of the subject M positioned at the openings 2a and 2b is preferably provided. In addition to imaging by the PET detector 3, by providing the CCD 8 that images the breast of the subject M, nuclear medicine diagnosis can be performed while grasping the imaging status of the breast by the CCD 8. For example, as described above, when the CCD 8 is provided at the center of the base portion of the PET detector support section 4 (that is, along the central axis of the PET detector 3) and the nipple is at the center of the breast, the monitor by the CCD 8 is used. The PET detector 3 is set so that the nipple N at the center of the breast M ′ is positioned at the center O of the (imaging screen). In particular, as described above, when the PET detector 3 is reciprocated between at least the plurality of openings 2a and 2b along the support surface of the gantry 2, the PET detector 3 is moved slightly along the support surface. Set (with fine adjustment). By setting in this way, the central axis of the PET detector 3 is positioned at the center of the breast M ′ where the nipple N is located, and imaging with a uniform sensitivity to the breast, and thus nuclear medicine diagnosis can be performed.

  Further, when such a CCD 8 is provided, preferably, the imaging control unit 15 has a function of a deviation detection unit that detects a deviation based on the imaging result of the CCD 8, and the deviation detected by the imaging control unit 15 is detected. The PET detector 3 is moved to eliminate it. The imaging control unit 15 has a function of a deviation detection unit that detects deviation based on the imaging result of the CCD 8, and the PET detector 3 is moved to eliminate the deviation detected by the imaging control unit 15. Imaging with uniform sensitivity, and thus nuclear medicine diagnosis can be performed. For example, when the CCD 8 is provided along the central axis of the PET detector 3 described above and the subject M whose nipple is biased from the center of the breast is imaged, the center O of the monitor (imaging screen) by the CCD 8 is used. Even if the PET detector 3 is set so that the nipple N is positioned, a deviation occurs between the central axis of the PET detector 3 and the center N ′ of the breast M ′. Therefore, the imaging control unit 15 has a function of a deviation detection unit for detecting the deviation, and the PET detector 3 is moved by moving the PET detector 3 to eliminate the deviation detected by the imaging control unit 15. Even when imaging the subject M whose center axis is located at the center N ′ of the breast M ′ and the nipple N is biased from the center N ′ of the breast M ′, the imaging is performed with uniform sensitivity to the breast, and thus nuclear medicine diagnosis. It can be carried out.

Next, Embodiment 2 of the present invention will be described with reference to the drawings.
6 to 9 are plan views of the mammo PET apparatus according to the second embodiment and are a diagram illustrating a series of imaging modes. The portions common to the above-described first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the first embodiment described above, the plurality of γ-ray detector groups constituting the PET detector 3 are moved together, whereas in the second embodiment, the γ-ray detector groups are connected to the gantry 2. The γ-ray detectors are arranged in a circle along the horizontal plane as the support surface, and the γ-ray detector groups are divided into a plurality (two in this embodiment) in the horizontal plane direction. As shown by the arrows in FIG. 6 (c), these divided γ-ray detector groups are configured to be able to contact and separate from each other along the horizontal plane. Further, when approaching, they are combined as one PET detector 3 again. In the second embodiment, the following will be described by taking two as an example of the number of divisions. However, the number of divisions is not limited to two, and may be three or more. One divided γ-ray detector group is 3A, and the other γ-ray detector group is 3B.

  Thus, by dividing the γ-ray detector groups 3A and 3B into two, the relative positions and orientations of the γ-ray detector groups 3A and 3B always change. That is, the relative position and orientation of the breast and the γ-ray detector groups 3A and 3B also change according to the size (size) of the breast of the subject M. Thereby, the amount of γ-rays detected by the γ-ray detector groups 3A and 3B is increased, and the γ-ray detection sensitivity of the γ-ray detector groups 3A and 3B is improved. Therefore, in the second embodiment, imaging proceeds while the positions and orientations of the γ-ray detector groups 3A and 3B with respect to the mechanical origin of the apparatus are changed.

  Next, a reconstruction algorithm when the position / orientation of the γ-ray detector groups 3A and 3B with respect to the mechanical origin of the apparatus changes will be described with reference to FIGS. FIG. 10 is a schematic diagram showing the positional relationship between the two γ-ray detector groups 3A and 3B and the image reconstruction area. FIG. 11 shows the coordinate system of the two γ-ray detector groups 3A and 3B and the image reconstruction area. It is a graph to show.

  As shown in FIGS. 10 and 11, each γ-ray detector group 3A, 3B is an assembly of minute γ-ray detection elements a, b, and between the γ-ray detector groups 3A, 3B, An image reconstruction area S having a center coordinate OC defined by a vector VC starting from the mechanical origin OM is set. Vectors VA and VB from the mechanical origin OM of the apparatus to the center coordinates OA and OB of the respective γ-ray detector groups 3A and 3B are the values of the γ-ray detector groups 3A and 3B detected by a position sensor (not shown). It is obtained based on the position data and the rotation angle data of each γ-ray detector group 3A, 3B detected by an angle sensor (not shown).

  Accordingly, when a phenomenon occurs in which γ rays emitted from the subject M are simultaneously counted (hereinafter abbreviated as “event” as appropriate), a γ ray detecting element a that simultaneously detects γ rays from the mechanical origin OM of the apparatus. , B, the vectors uA and uB are also obtained according to the following equations (1) and (2).

uA = VA + WA (1)
uB = VB + WB (2)
On the other hand, when a phenomenon (event) in which γ rays emitted from the subject m are simultaneously counted occurs, address pair data of the γ ray detection elements a and b that detect γ rays, and γ that detects γ rays. Address pair data of vectors uA and uB for the line detection elements a and b are collected and stored as list mode type data for each event. On the other hand, a straight line LOR (Line of Response) connecting γ-ray detection elements a and b that simultaneously detect γ-rays is obtained for each event from address pair data of vectors uA and uB collected and stored as list mode type data. The positron emitting species is above the straight line LOR.

The vector uA is determined according to the position and orientation information of the γ-ray detector groups 3A and 3B stored as list mode type data and the following equation (3). Note that the position and orientation data of the γ-ray detector groups 3A and 3B may be stored as tag information only when there is a change.
uA = R _X , R _Y , R _Z , T, WA (3)
However, as shown below, R _X , R _Y , and R _Z are rotations of the γ-ray detector groups 3A and 3B around the X, Y, and Z axes orthogonal to each other with the mechanical origin OM of the apparatus as the origin. T is a position (that is, VA) in each direction of the X axis, Y axis, and Z axis. Further, the vector uB can be obtained in the same manner as the vector uA.

  In this way, when a straight line LOR (Line of Response) connecting γ-ray detection elements a and b that simultaneously detect γ-rays is obtained for each event, a successive approximation list mode reconstruction algorithm is applied [ For example, see J Reader et al 1998 Phys. Med Bial. 43 835-846 (non-patent literature). The image update formula of this list mode reconstruction algorithm is as shown in formula (4). The RI distribution image is obtained by repeating the updating formula (4).

Here, f ^k _j is the pixel value of the pixel j in the k-th iteration, a _ij is the probability that the γ-ray emitted from the pixel j is detected by LORi, M is the number of measured events, and I is the main imaging condition It is the number of all LORs in (detector plate arrangement). The update formula used in the image reconstruction algorithm applied to the embodiment is not limited to the formula (4).

Further, in the embodiment, the center coordinate OC of the image reconstruction area S is set to the middle point between the two γ-ray γ-ray detector groups 3A and 3B. Further, since the PET detector 3 bundled together only rotates around one axis of the vertical axis, β = 0 and γ = 0. As a result, R _Y , R in the equation (3) _Z is expressed by the following formula (5).

  Next, an imaging mode in a series of diagnosis (imaging) will be described with reference to FIGS. FIG. 6 shows an imaging mode when the PET detector support and the PET detector supported by the PET detector are moved away from each other with the downward movement after imaging of the right breast, and FIG. 7 shows the PET detector support and the PET detector support. FIG. 8 is an imaging mode when the supported PET detector moves horizontally, and FIG. 8 is an imaging mode when the PET detector support and the PET detector supported by the PET detector move upward and move closer, FIG. 9 shows an imaging mode when imaging the left breast after combining. 6 to 9, illustration of the subject M including the breast is omitted.

  In the same manner as in Example 1 described above, a radiopharmaceutical is administered to the subject M, and the right breast is inserted into the right opening 2a in a prone posture, and the left breast is inserted into the left opening 2b. Since the imaging conditions and drive commands input from the operator are the same as those in the first embodiment, the description thereof is omitted.

  First, diagnosis with the mammo PET apparatus 1 is performed in the manner shown in FIG. If the γ-ray detector group of the PET detector 3 has not advanced to a position surrounding the right breast inserted into the right opening 2a, the vertical movement unit 5 (see FIG. 3) is the PET detector support 4 The PET detector 3 supported thereby is moved up and down in the vertical direction, and the horizontal moving portion 6 (see FIG. 3) reciprocates the PET detector support portion 4 and the PET detector 3 supported thereby along the horizontal plane. By making the movement, the diagnosis is made so as to surround the right breast inserted into the right opening 2a in the manner shown in FIG. At this time, similarly to the left breast to be imaged later, the right breast may be approached while being divided into the γ-ray detector groups 3A and 3B, and diagnosis may be performed according to the size of the breast. Since the flow of the PET data obtained from the PET detector 3 is the same as that in the first embodiment, the description thereof is omitted.

  Next, from the imaging mode shown in FIG. 6, the vertical movement unit 5 moves the PET detector support unit 4 and the PET detector 3 supported by the vertical movement unit downward, and as shown by the arrows in FIG. 6 moves the γ-ray detector groups 3A and 3B of the PET detector 3 away from each other. When the respective γ-ray detector groups 3A and 3B are moved to positions where interference with the breast does not occur as shown in FIG. 7, the horizontal moving unit 6 supports the PET detector as shown by arrows in FIG. The unit 4 and the γ-ray detector groups 3A and 3B supported by the unit 4 are horizontally moved toward the left breast. Also in the second embodiment, as in the first embodiment described above, γ-ray detection is performed up to just below the left breast as shown in FIG. 8 based on the position detection sensor (not shown) and the CCD 8 (see FIG. 2). The horizontal movement ends after the instrument groups 3A and 3B are moved horizontally.

  Next, from the imaging mode illustrated in FIG. 8, the vertical movement unit 5 moves the PET detector support unit 4 and the γ-ray detector groups 3 </ b> A and 3 </ b> B supported by the PET detector support unit 4 upward, as indicated by the arrows in FIG. 8. The horizontal moving unit 6 moves the γ-ray detector groups 3A and 3B closer to each other. Based on a position detection sensor (not shown), a pressure sensor 7 (see FIG. 2), and a CCD 8 provided on the PET detector support unit 4, each γ-ray detector group 3A, 3B is moved to a position surrounding the breast. The γ-ray detector groups 3A and 3B are coupled close to each other (see FIG. 9). Then, the right breast is diagnosed. When the size of the breast is large, the γ-ray detector groups 3A and 3B do not necessarily have to be coupled, and the breast may be diagnosed with the γ-ray detector groups 3A and 3B being somewhat separated from each other. .

  The fine adjustment (setting) in the horizontal direction of the PET detector 3 based on the pressure sensor 7 and the CCD 8 is substantially the same as in the first embodiment described above, but in the first embodiment described above, a plurality of components constituting the PET detector 3 are included. However, in the second embodiment, the γ-ray detector groups 3A and 3B divided into two can move independently of each other. Therefore, fine adjustment may be performed by fixing one of the γ-ray detector groups 3A and 3B and moving only the other. Therefore, for example, either the pressure sensor 7 on the γ-ray detector group 3A side or the pressure sensor 7 on the γ-ray detector group 3B side is detected exceeding the pressure applied to the breast to the extent that no physical pain is involved. In this case, the horizontal movement of either one of the γ-ray detector groups 3A and 3B on the pressure sensor 7 side detected in excess is stopped, and the γ-ray detector on the pressure sensor 7 side not detected in excess is stopped. What is necessary is just to continue the horizontal movement of either group 3A, 3B.

  According to the mammo PET apparatus 1 according to the second embodiment having the above-described configuration, as in the first embodiment described above, the gantry 2 that supports (places) the subject M, and the object to be sandwiched between the gantry 2. A PET detector 3 for detecting γ-rays generated from the specimen M (the breast), and a plurality of gantry 2 (also in the second embodiment) so that the γ-rays generated from the subject M reach the PET detector 3. By providing the two openings 2a and 2b, nuclear medicine diagnosis of both breasts can be performed without moving the subject M.

  In the second embodiment, as in the first embodiment described above, preferably, at least a plurality of (two in the second embodiment) PET detectors 3 are provided along the support surface (mounting surface) of the gantry 2. A horizontal moving unit 6 that reciprocates between the units 2a and 2b is provided, and a vertical moving unit 5 that moves the PET detector 3 in a direction perpendicular to the support surface (mounting surface) of the gantry 2 is provided. Similar to the first embodiment described above, the PET detector 3 can be moved smoothly without causing interference between the breast and the PET detector 3, and the nuclear medicine diagnosis of both breasts can be performed smoothly. In the second embodiment, as in the first embodiment described above, the gantry 2 is disposed so that the support surface is horizontal, which is useful when the subject M is in a prone posture.

  Even in such a horizontal arrangement, the PET detector 3 is preferably reciprocated between at least the plurality of openings 2a and 2b along the horizontal plane that is the support surface of the gantry 2 as in the first embodiment. In addition to the horizontal moving part 6, the apparatus includes a vertical moving part 5 that moves the PET detector 3 up and down in the vertical direction perpendicular to the horizontal plane that is the support surface of the gantry 2. Similar to the first embodiment described above, the PET detector 3 can be moved smoothly without causing interference between the breast and the PET detector 3, and the nuclear medicine diagnosis of both breasts can be performed smoothly.

  In the second embodiment, the PET detector 3 is composed of a plurality of γ-ray detector groups, and unlike the first embodiment described above, these γ-ray detector groups are arranged on the support surface of the gantry 2 (this embodiment). In Example 2, each of the γ-ray detector groups (γ-ray detector groups 3A and 3B in the present embodiment) is divided into a plurality (two in the second embodiment) in the direction of the horizontal plane. It is comprised so that it can mutually contact along a support surface (horizontal plane). The imaging state by the PET detector 3 changes according to the breast size of the subject M. When imaging of a small breast is performed after imaging of a large breast, there is a possibility that a gap may be formed between the breast and the PET detector 3 to reduce the sensitivity. On the other hand, when imaging of a large breast is performed after imaging of a small breast, the pressure from contact with the PET detector 3 is excessive on the breast, and the subject M is physically and mentally painful. May be accompanied. Therefore, as in the second embodiment, the γ-ray detector group is composed of a plurality of γ-ray detector groups in the direction of the support surface (horizontal plane) of the gantry 2, and these γ-ray detector groups are supported on the support surface (horizontal plane). The γ-ray detector group is divided into a plurality of parts in the direction of), and the divided γ-ray detector groups are configured so as to be able to contact and separate from each other along the support surface (horizontal plane). Thus, the γ-ray detector group can be moved freely to perform imaging, the sensitivity can be prevented from being lowered due to the change in the size of the breast, and the physical and mental of the subject M due to the change in the size of the breast Pain can be reduced.

  In such a configuration, the γ-ray detector groups are arranged in a circle along the support surface (horizontal plane in the second embodiment), and these divided γ-ray detector groups are in contact with each other along the support surface (horizontal plane). It is configured to be separable, and is combined as one PET detector 3 again when approaching. By arranging the γ-ray detector group in a circle along the support surface (horizontal plane), the γ-ray detector group can be uniformly brought close to the breast, and imaging with uniform sensitivity to the breast. As a result, nuclear medicine diagnosis can be performed.

  In the second embodiment, similarly to the first embodiment described above, the pressure sensor 7 for detecting the pressure from the PET detector 3 on the breast of the subject M positioned at the openings 2a and 2b is preferably provided. I have. A pressure sensor 7 that detects the pressure from the PET detector 3 is provided, and the breast is imaged at an appropriate pressure, so that the physical pressure of the subject M due to excessive pressure applied to the breast by the contact from the PET detector 3・ Reduced mental distress.

  In the second embodiment, similarly to the first embodiment described above, a CCD type solid-state imaging device (CCD) 8 that images the breast of the subject M positioned at the openings 2a and 2b is preferably provided. Therefore, the nuclear medicine diagnosis can be performed while grasping the imaging state of the breast by the CCD 8. For example, as in the first embodiment, when the CCD 8 is provided along the central axis of the PET detector 3 and the nipple is at the center of the breast, the breast M is located at the center O of the monitor (imaging screen) by the CCD 8. The PET detector 3 is set so that the nipple N at the center of 'is located. In particular, a plurality of (two in the second embodiment) γ-ray detector groups (γ-ray detector groups 3A and 3B in the second embodiment) divided as described above are arranged along the support surface (horizontal plane). In the case where the contact / separation is possible, the γ-ray detector group of the PET detector 3 is set by moving the contact / separation. By setting in this way, the center axis of the PET detector 3 is positioned at the center of the breast M ′ where the nipple N is located, as in the first embodiment, and imaging with a uniform sensitivity to the breast is performed. A nuclear medicine diagnosis can be performed. In the second embodiment described above, the function of a deviation detection unit that detects deviation based on the imaging result of the CCD 8 may be provided.

Next, Embodiment 3 of the present invention will be described with reference to the drawings.
12 to 15 are plan views of the mammo PET apparatus according to the third embodiment and are diagrams illustrating a series of imaging modes. The parts common to the first and second embodiments described above are denoted by the same reference numerals and the description thereof is omitted. In FIGS. 12 to 15, the illustration of the subject M including the breast is omitted as in FIGS. 6 to 9 in the second embodiment.

  In the first and second embodiments described above, the plurality of γ-ray detector groups constituting the PET detector 3 are arranged in a circle along the horizontal plane that is the support surface of the gantry 2. In Example 3, rectangular parallelepiped γ-ray detector groups 3A and 3B are arranged along a horizontal plane. As in the second embodiment described above, a plurality of γ-ray detector groups constituting the PET detector 3 are divided into a plurality (two in the third embodiment) in the horizontal plane direction. As shown by the arrows in FIG. 14, the divided γ-ray detector groups are configured to be able to contact and separate from each other along the horizontal plane. The γ-ray detector groups thus divided are the above-described rectangular parallelepiped γ-ray detector groups 3A and 3B. Further, unlike the second embodiment described above, the γ-ray detector groups 3A and 3B are in a divided state without being combined as one PET detector 3 when approaching. Also in the third embodiment, the number of divisions is not limited to two, and may be three or more.

  By dividing the gamma ray detector groups 3A and 3B into two, the relative position and orientation of the gamma ray detector groups 3A and 3B always change, but the gamma ray detector group 3A with respect to the mechanical origin of the apparatus. , 3B when the position / orientation changes, since it has already been described in the second embodiment, the description thereof will be omitted.

  Next, an imaging mode in a series of diagnosis (imaging) will be described with reference to FIGS. FIG. 12 shows an imaging mode when the PET detector support and the PET detector supported by the PET detector are moved away from each other with the downward movement after imaging of the right breast, and FIG. 13 shows the PET detector support and the PET detector support FIG. 14 is an imaging mode when the supported PET detector moves horizontally, and FIG. 14 is an imaging mode when the PET detector support part and the PET detector supported by the PET detector move up and move together, FIG. 15 shows an imaging mode when imaging the left breast.

  As in Examples 1 and 2 described above, a radiopharmaceutical is administered to the subject M, and the right breast is inserted into the right opening 2a in a prone posture, and the left breast is inserted into the left opening 2b. . In the second embodiment described above, the movement target is the semicircular γ-ray detector groups 3A and 3B, whereas in the third embodiment, the movement target is a rectangular parallelepiped γ-ray detector group 3A and 3B. It has only been replaced by. Therefore, in FIGS. 12-14, since it is the same as the movement of FIGS. 6-9, the description is abbreviate | omitted.

  However, in the second embodiment described above, the γ-ray detector groups 3A and 3B are coupled to be close to each other in FIG. 9, whereas in the third embodiment, as shown in FIG. In the sandwiched state, the γ-ray detector groups 3A and 3B are separated from each other, and the breast is diagnosed in that state.

  Since the fine adjustment (setting) in the horizontal direction of the PET detector 3 based on the pressure sensor 7 and the CCD 8 is also the same as in the first and second embodiments, the description thereof is omitted. Regarding the operation / effect of the mammo PET apparatus 1 according to the third embodiment having the above-described configuration, the same parts as the operation / effect of the mammo PET apparatus 1 according to the first and second embodiments are omitted.

  In the third embodiment, as in the second embodiment described above, these γ-ray detector groups are arranged in a plurality (two in the second embodiment) in the direction of the support surface of the gantry 2 (horizontal plane in the second embodiment). The divided γ-ray detector groups (in this embodiment, the γ-ray detector groups 3A and 3B) are configured to be able to contact and separate from each other along a support surface (horizontal plane). Similar to the second embodiment described above, imaging can be performed by freely moving the γ-ray detector group according to the breast size of the subject M, thereby preventing a decrease in sensitivity due to a change in the breast size. The physical and mental pain of the subject M due to the change in the size of the breast can be reduced.

  In the third embodiment, as described above, the rectangular parallelepiped γ-ray detector groups 3A and 3B are arranged along the horizontal plane, so that they are not combined as one PET detector 3 when approaching. The γ-ray detector groups 3A and 3B are in a divided state. Accordingly, the γ-ray detector groups 3A and 3B are separated with the breast sandwiched therebetween, and the breast is diagnosed in that state.

  The present invention is not limited to the above-described embodiment, and can be modified as follows.

  (1) In each of the above-described embodiments, the mammographic PET apparatus has been described as an example. However, the present invention detects a single gamma ray and reconstructs a tomographic image of the subject. It can also be applied to CT) devices.

  (2) In each of the above-described embodiments, the breast of the subject in the prone posture is diagnosed, but the breast may be diagnosed with the subject facing up, that is, in the supine posture.

  (3) In each of the above-described embodiments, the support means (gantry 2 in each embodiment) is disposed so that the subject is in a prone posture and the support surface is horizontal, but the present invention is not limited to such a support surface. Support means (gantry 2) may be arranged so that the subject is in a standing posture and the support surface is vertical. In this case, reciprocating means (each of which each of the nuclear medicine detecting means (PET detector 3 in each embodiment) is reciprocated up and down between at least a plurality of openings along a vertical surface which is a supporting surface of the supporting means. In the embodiment, the horizontal movement section 6), the vertical movement section (in each embodiment, the vertical movement section) moves the nuclear medicine detection means (PET detector 3) horizontally in a horizontal direction perpendicular to the vertical plane which is the support surface. 5). The same applies when the subject is placed in an oblique posture.

  (4) In each of the above-described embodiments, two openings, the right opening 2a and the left opening 2b, are provided, but the number is not limited to two, and a plurality of three or more openings may be provided. Then, from these openings, an opening for inserting the right breast and an opening for inserting the left breast may be selected.

  (5) In each of the above-described embodiments, the nuclear medicine detection means (PET detector 3 in each embodiment) reciprocates between a plurality of openings (openings 2a and 2b in each embodiment). However, each of the openings is provided with a nuclear medicine detection means (PET detector 3), and each of the nuclear medicine detection means moves only in the vicinity of the associated opening and does not move to the other openings. There may be.

  (6) In each of the above-described embodiments, pressure detection means (in each embodiment, the pressure sensor 7) is provided in order to reduce the physical and mental pain of the subject. If pain is not taken into consideration, it is not always necessary to provide pressure detection means (pressure sensor 7).

  (7) In each of the above-described embodiments, the imaging means (CCD type solid-state imaging device (CCD) 8 in each embodiment) is provided in order to grasp the imaging situation of the breast. However, the imaging situation of the breast is not considered. For example, the image pickup means (CCD 8) is not necessarily provided. Further, the image pickup means is not limited to the CCD 8 and may be any one that picks up a normal breast. For example, the imaging means may be a thermistor for imaging the temperature distribution of the breast.

  (8) In each of the above-described embodiments, in order to perform imaging with uniform sensitivity to the breast, and thus to perform nuclear medicine diagnosis, the shift detection means (imaging control unit 15 in each embodiment) is provided. If this is not taken into consideration, it is not always necessary to provide the displacement detection means (imaging control unit 15).

  (9) In each of the above-described embodiments, in order to perform imaging with uniform sensitivity to the breast, and thus to perform nuclear medicine diagnosis, along the central axis of the detection means for nuclear medicine (PET detector 3 in each embodiment). The imaging means (CCD type solid-state imaging device (CCD) 8 in each embodiment) is provided. However, if the imaging state of the breast is simply grasped, the center axis of the detection means for nuclear medicine (PET detector 3) is used. It is not necessary to provide the image pickup means (CCD8) along the line, and the image pickup means (CCD8) may be provided at another location.

(A) is a partial side sectional view of the mammo PET apparatus according to the first embodiment, and (b) is a plan view thereof. (A)-(d) is a partial front sectional view of the mammo PET apparatus according to the first embodiment, and shows a series of imaging modes. It is a block diagram of the mammo PET apparatus which concerns on each Example. (A), (b) is a figure which shows the output mode by CCD in case a nipple is in the center of a breast. (A), (b) is a figure which shows the output mode by CCD when there is no nipple at the center of a breast and the nipple is biased from the center of a breast. It is a top view of the mammo PET apparatus which concerns on Example 2, Comprising: It is an imaging aspect when a PET detector support part and the PET detector supported by it move away with a downward movement after imaging of the right breast. It is a top view of the mammo PET apparatus which concerns on Example 2, Comprising: It is an imaging aspect when a PET detector support part and the PET detector supported by it move horizontally. It is a top view of the mammo PET apparatus which concerns on Example 2, Comprising: It is an imaging aspect when a PET detector support part and the PET detector supported by it move close together with a raise movement. It is a top view of the mammo PET apparatus which concerns on Example 2, Comprising: It is an imaging aspect at the time of imaging of the left breast after a coupling | bonding. It is a schematic diagram which shows the arrangement | positioning relationship of both gamma-ray detector groups and an image reconstruction area | region. It is a graph which shows the coordinate system of both gamma ray detector groups and an image reconstruction area. It is a top view of the mammo PET apparatus which concerns on Example 3, Comprising: It is an imaging aspect when a PET detector support part and the PET detector supported by it move apart with a downward movement after imaging of the right breast. It is a top view of the mammo PET apparatus which concerns on Example 3, Comprising: It is an imaging aspect when a PET detector support part and the PET detector supported by it move horizontally. It is a top view of the mammo PET apparatus which concerns on Example 3, Comprising: It is an imaging aspect when a PET detector support part and the PET detector supported by it move close together with a raise movement. It is a top view of the mammo PET apparatus which concerns on Example 3, Comprising: It is an imaging aspect at the time of imaging of the left breast.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Mammo PET apparatus 2 ... Gantry 2a, 2b ... Opening part 3 ... PET detector 5 ... Vertical moving part 6 ... Horizontal moving part 7 ... Pressure sensor 8 ... CCD type solid-state image sensor (CCD)
15 ... Imaging control unit M ... Subject

Claims (13)

  A mammary nuclear medicine diagnostic apparatus for obtaining nuclear medicine data of a subject based on radiation generated from a subject to which a radiopharmaceutical is administered, the supporting means for supporting the subject, and the supporting means sandwiched between the supporting means And a nuclear medicine detection means for detecting radiation generated from the subject, and the support means is provided with a plurality of openings so that the radiation reaches the nuclear medicine detection means. Nuclear medicine diagnostic equipment.   2. The nuclear medicine diagnosis apparatus according to claim 1, further comprising a reciprocating means for reciprocally moving the nuclear medicine detecting means at least between the plurality of openings along a supporting surface of the supporting means. Nuclear medicine diagnostic equipment.   3. The nuclear medicine diagnosis apparatus according to claim 1, further comprising a vertical moving means for moving the detection means for nuclear medicine in a direction perpendicular to a support surface of the support means. apparatus.   The nuclear medicine diagnosis apparatus according to any one of claims 1 to 3, wherein the detection means for nuclear medicine is constituted by a plurality of detector groups, and these detector groups are arranged in a direction of a support surface of the support means. A nuclear medicine diagnostic apparatus comprising a plurality of divided detector groups and a configuration in which the divided detector groups are configured to be able to contact and separate from each other along a support surface.   5. The nuclear medicine diagnosis apparatus according to claim 4, wherein the detector groups are arranged in a circle along the support surface, and the divided detector groups are configured to be able to contact and separate from each other along the support surface. The nuclear medicine diagnosis apparatus is characterized by being combined again as one nuclear medicine detection means when approaching.   The nuclear medicine diagnosis apparatus according to any one of claims 1 to 5, wherein the support means is disposed so that a support surface is horizontal.   7. The nuclear medicine diagnosis apparatus according to claim 6, further comprising a reciprocating means for reciprocating the detecting means for nuclear medicine along at least a plurality of openings along a horizontal plane that is a supporting surface of the supporting means. Features nuclear medicine diagnostic equipment.   8. The nuclear medicine diagnosis apparatus according to claim 6, further comprising a vertical moving means for moving the detecting means for nuclear medicine up and down in a vertical direction perpendicular to a horizontal plane that is a support surface of the support means. A nuclear medicine diagnostic device.   The nuclear medicine diagnosis apparatus according to any one of claims 6 to 8, wherein the nuclear medicine detection means is composed of a plurality of detector groups, and these detector groups are horizontal surfaces that are support surfaces of the support means. A nuclear medicine diagnosis apparatus comprising: a plurality of divided detector groups in the direction of 1 to 5 and configured to be able to contact and separate from each other along the horizontal plane as a support surface.   10. The nuclear medicine diagnosis apparatus according to claim 9, wherein the detector groups are arranged in a circle along a horizontal plane that is the support surface, and the divided detector groups are arranged along a horizontal plane that is the support surface. A nuclear medicine diagnostic apparatus characterized in that it is configured to be able to contact and separate, and is combined again as one nuclear medicine detection means when approaching.   11. The nuclear medicine diagnosis apparatus according to claim 1, further comprising a pressure detection unit configured to detect a pressure from the nuclear medicine detection unit with respect to the breast of the subject positioned at the opening. That the nuclear medicine diagnostic equipment.   The nuclear medicine diagnosis apparatus according to any one of claims 1 to 11, further comprising an imaging unit that images the breast of the subject positioned at the opening.   13. The nuclear medicine diagnosis apparatus according to claim 12, further comprising: a deviation detecting unit that detects a deviation based on an imaging result of the imaging unit, and the nuclear medicine detecting unit to eliminate the deviation detected by the deviation detecting unit. A nuclear medicine diagnostic apparatus, characterized by moving

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