JP2010185701A - Apparatus for nuclear medicine diagnosis - Google Patents

Abstract

An object of the present invention is to provide a nuclear medicine diagnosis apparatus capable of improving the efficiency of nuclear medicine diagnosis while outputting and displaying a notable image.
A MIP image display area 9C continuously outputs and displays MIP images acquired by an MIP image acquisition unit 14, selects a predetermined frame based on an output result of the MIP image, and acquires it by a reconstruction unit 13 The axial image display area 9B outputs and displays the axial image of the selected axial image in the selected frame. As described above, if there is a noticeable observation in the MIP image continuously output and displayed in the MIP image display area 9C, a frame having the finding is selected based on the output result of the MIP image, and the observation is performed. Since the axial image display area 9B outputs and displays the axial image in the frame in which there is a defect, the efficiency of nuclear medicine diagnosis can be improved while outputting and displaying a notable image.
[Selection] Figure 4

Description

  The present invention relates to a 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, and more particularly to nuclear medicine by continuously scanning the subject. It is related with technology to collect data.

  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.

  Specifically, a radiopharmaceutical containing a positron emitting nuclide is administered into a subject, and a 511 KeV pair annihilation gamma ray released from the administered subject consists of a group of a number of detection elements (for example, scintillators). Detect with a detector. And if γ-rays are detected at the same time by two detectors within a certain period of time, they are counted as a pair of annihilation γ-rays, and the point of occurrence of pair annihilation is on the straight line of the detected detector pair Is identified. By accumulating such coincidence information and performing reconstruction processing, a positron emitting nuclide distribution image (ie, a tomographic image) is obtained.

  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 various biological functions can be quantitatively measured (see, for example, Patent Document 1). . Therefore, the tomographic image obtained by the PET apparatus has functional information.

  Conventionally, in a PET apparatus that covers a wide range such as the whole body of a subject, a radiopharmaceutical is scanned continuously with respect to the subject by moving the top plate on which the subject is placed at a constant speed. Collect data (projection data) based on γ-rays generated from a subject to which is administered. Diagnostic data such as projection data and tomographic image of the subject (for nuclear medicine) while collecting data during nuclear medicine diagnosis (examination) by sequentially reconstructing the collected data and obtaining tomographic images sequentially Data) can be obtained sequentially, and a confirmation image can be provided to the operator at any time. While collecting diagnostic data, the diagnostic data can be confirmed in advance by looking at images that are sequentially output and displayed on the monitor.

JP 2007-155432 A

  However, since it is necessary for the operator to continuously watch the image to be output and displayed, it is difficult to perform other operations in parallel. In addition, when there is diagnostic data to be observed with attention, it is sequentially displayed and the output display of the image is updated. Conversely, when there is diagnostic data to be observed with attention, if an image based on the diagnostic data is output and displayed, the output display of the image to be obtained thereafter stops. Therefore, the efficiency of nuclear medicine diagnosis (examination) decreases.

  This invention is made in view of such a situation, and it aims at providing the nuclear medicine diagnostic apparatus which can improve the efficiency of nuclear medicine diagnosis, outputting and displaying the image which should be noted. .

In order to achieve such an object, the present invention has the following configuration.
That is, the invention according to claim 1 is a nuclear medicine diagnostic apparatus for obtaining nuclear medicine data of a subject based on radiation generated from the subject administered with a radiopharmaceutical, wherein the subject is based on the radiation. A transmission image acquisition means for acquiring a transmission image of a specimen, a tomographic image acquisition means for acquiring a tomographic image of the subject based on the radiation, and the transmission image acquired by the transmission image acquisition means are continuously output. Transmission image output display means for displaying, frame selection means for selecting a predetermined frame based on the output result of the transmission image, and the tomographic image acquired by the tomographic image acquisition means are selected by the frame selection means. And a tomographic image output display means for outputting and displaying the tomographic image in a frame.

  [Operation / Effect] According to the invention described in claim 1, the tomographic image acquisition means acquires the tomographic image of the subject and also acquires the transmission image based on the radiation generated from the subject to which the radiopharmaceutical is administered. The means acquires a transmission image of the subject. The transmission image output display means continuously outputs and displays the transmission image acquired by the transmission image acquisition means. On the other hand, as a standard for confirming whether there is an image to be noticed, a transmission image continuously output and displayed by the transmission image output display means is used. The transmission image is suitable as a standard for confirming whether there is an image to be noticed, and the frame selection means selects a predetermined frame based on the output result of the transmission image. Then, with respect to the tomographic image acquired by the tomographic image acquiring means, the tomographic image output display means outputs and displays the tomographic image at the frame selected by the frame selecting means. As described above, if there is a remarkable observation in the transmission image continuously output and displayed by the transmission image output display means, the frame having the observation is selected based on the output result of the transmission image, and the observation is performed. Since the tomographic image output display means outputs and displays the tomographic image in the frame where there is a defect, the transmission image output display means can continuously output and display the transmission image while displaying the tomographic image to be noted. it can. As a result, the efficiency of nuclear medicine diagnosis can be improved while outputting and displaying a noticeable image without stopping the output display of the transmission image.

  In this specification, a transmission image is defined as including a MIP image described later in addition to projection data obtained by coincidence counting. Accordingly, in the above-described invention, the transmission image is a maximum value projection method (MIP: Maximum Intensity Projection) in which a maximum value pixel is extracted from pixel values of a plurality of pixels along the radiation projection direction to create a projection image. ) May be an image (MIP image) obtained by (the invention according to claim 2). Since the MIP image obtained by this maximum value projection method (hereinafter abbreviated as “MIP”) is a transmission image in which information on the projection direction (depth direction) is added, the presence or absence of notable findings is confirmed. However, MIP images are optimal. Of course, the transmission image that is the target of continuous output display by the transmission image output display means is not limited to the MIP image obtained by the MIP described above. The above-described projection data (the invention described in claim 3) may be used, and a plurality of pixels along the projection direction such as a minimum value projection method (Min IP) or a cumulative addition average method may be used. It may be an image obtained by a method of creating a projection image by performing arithmetic processing on pixel values.

  In these inventions described above, when a frame is not selected by the frame selection means, the tomographic image output display means continuously outputs and displays the tomographic image, and when the frame is selected by the frame selection means, the tomographic image is displayed. The output display means preferably stops the continuous output display of the tomographic image and outputs and displays the tomographic image in the frame selected by the frame selecting means (the invention according to claim 4). In this way, not only the transmission image output display means but also the tomographic image output display means performs continuous output display, so that when there is no noticeable observation, that is, when no frame is selected, continuous tomographic image is displayed. Therefore, not only a transmission image but also a tomographic image can be provided to the operator as needed. Then, when there is a notable finding, that is, when a frame is selected, the continuous output display of the tomographic image is stopped, and the tomographic image at the selected frame is output and displayed. When there is a noticeable tomographic image, the tomographic image as well as the transmitted image can be provided to the operator as needed when there is no notable finding.

  In the invention described in claim 4 described above, it is more preferable to configure as follows. That is, the transmission image output display means and the tomographic image output display means are configured so as to share one screen, and the tomographic image output display means outputs and displays the tomographic image in a predetermined area of the above-described screen and outputs the transmission image. More preferably, the display means outputs and displays the transmission image in another area of the screen (the invention according to claim 5). With this configuration, it is possible to output and display both the tomographic image and the transmission image on one screen, and it is possible to pay attention to only one screen. Of course, it is not always necessary to share one screen as in the invention described in claim 5, and the transmission image output display means and the tomographic image output display means may be configured on separate screens (in claim 6). Described invention).

  Further, as in the fourth aspect of the present invention, when no frame is selected by the frame selection means, the tomographic image output display means does not necessarily need to continuously output and display the tomographic images. When no frame is selected by the frame selection means, the tomographic image output display means does not output and display the tomographic image, but only when a frame is selected by the frame selection means, the tomographic image output display means The tomographic image at the frame selected in (1) may be output and displayed (the invention according to claim 7).

  According to the nuclear medicine diagnostic apparatus of the present invention, the transmission image output display means continuously outputs and displays the transmission image acquired by the transmission image acquisition means, and selects a predetermined frame based on the output result of the transmission image. The means selects and the tomographic image output display means outputs and displays the tomographic image in the frame selected by the frame selecting means for the tomographic image acquired by the tomographic image acquiring means. As described above, if there is a remarkable observation in the transmission image continuously output and displayed by the transmission image output display means, the frame having the observation is selected based on the output result of the transmission image, and the observation is performed. Since the tomographic image output display means outputs and displays the tomographic image in the frame in which there was a defect, it is possible to improve the efficiency of nuclear medicine diagnosis while outputting and displaying the image to be noted.

1 is a side view and a block diagram of a PET (Positron Emission Tomography) apparatus according to an embodiment. It is a schematic diagram of each pixel used for description of the maximum value projection method (MIP). It is the figure which showed an example of the output display mode by the monitor of an output part. (A), (b) is the schematic diagram which showed the flow of the data in the case of pressing down a mode switching button.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a side view and a block diagram of a PET (Positron Emission Tomography) apparatus according to an embodiment. In this embodiment, a PET apparatus will be described as an example of a nuclear medicine diagnosis apparatus.

  As shown in FIG. 1, the PET apparatus according to the present embodiment includes a top plate 1 on which a subject M is placed. The top plate 1 is configured to move up and down and translate along the body axis Z of the subject M. With this configuration, the subject M placed on the top 1 is scanned from the head to the abdomen and foot sequentially through the opening 2a of the gantry 2, which will be described later. Diagnostic data such as projection data and tomographic images are obtained. In this embodiment, diagnostic data such as an MIP image is also obtained. This diagnostic data corresponds to nuclear medicine data in the present invention.

  In addition to the top plate 1, the PET apparatus according to the present embodiment includes a gantry 2 having an opening 2a, a plurality of scintillator blocks (not shown) and a plurality of photomultipliers (not shown) arranged close to each other. ). The γ-ray detector 3 is arranged in a ring shape so as to surround the body axis Z of the subject M, and is embedded in the gantry 2. The photomultiplier is disposed outside the scintillator block. As a specific arrangement of the scintillator blocks, for example, two scintillator blocks are arranged in a direction parallel to the body axis Z of the subject M, and many scintillator blocks are arranged around the body axis Z of the subject M. Can be mentioned. The γ-ray detector 3 collects emission data to be described later.

  In addition, a point line source 4 and a γ-ray detector 5 for collecting absorption correction data (also referred to as “transmission data”) to be described later are provided. The γ-ray detector 5 for absorption correction data is composed of a scintillator block (not shown) and a photomultiplier (not shown) in the same manner as the γ-ray detector 3 for collecting emission data. The dotted line source 4 is a radiation source for irradiating a radioactive drug to be administered to the subject M, that is, a radiation of the same kind as the radioisotope (RI) (in this embodiment, γ rays), and is disposed outside the subject M. Has been. The dotted line source 4 is embedded in the gantry 2. The dotted line source 4 rotates around the body axis Z of the subject M.

  In addition, the PET apparatus according to the present embodiment includes a table driving unit 6, a controller 7, an input unit 8, an output unit 9, a projection data deriving unit 10, an absorption correction data deriving unit 11, and an absorption correcting unit 12. Unit 13, MIP image acquisition unit 14, and memory unit 15. The top plate driving unit 6 is a mechanism for driving the top plate 1 so as to perform the above-described movement, and is configured by a motor or the like not shown.

  The controller 7 comprehensively controls each part constituting the PET apparatus according to the present embodiment. The controller 7 includes a central processing unit (CPU).

  The input unit 8 sends data and commands input by the operator to the controller 7. The input unit 8 includes a pointing device represented by a mouse, a keyboard, a joystick, a trackball, a touch panel, and the like. The output unit 9 includes a display unit represented by a monitor, a printer, and the like.

  In the present embodiment, as shown in FIG. 3, the monitor 9A of the output unit 9 includes an axial image display area 9B for outputting and displaying an axial image of the tomographic image, and an MIP image display area 9C for outputting and displaying the MIP image. An image display slider 8A for selecting a frame, a display window adjustment slider 8B for adjusting the luminance of the monitor 9A corresponding to the pixel value, and a mode switching button 8C for switching to either a monitor mode or a display mode to be described later. , MIP switching button 8D for switching whether to display the MIP image from the front or the side, and stop button 8E for stopping the output display. The image display slider 8A, the display window adjustment slider 8B, the mode switching button 8C, the MIP switching button 8D, and the stop button 8E also have the function of the input unit 8. The monitor 9A will be described later with reference to FIG.

  The memory unit 15 is configured by a storage medium represented by ROM (Read-only Memory), RAM (Random-Access Memory), and the like. In this embodiment, the diagnostic data processed by the projection data deriving unit 10, the reconstruction unit 13, and the MIP image acquiring unit 14 and the absorption correction data obtained by the absorption correction data deriving unit 11 are written and stored in the RAM. Read from RAM as needed. The ROM stores in advance a program for performing various nuclear medicine diagnoses, and the controller 7 executes the program to perform nuclear medicine diagnosis according to the program. In the present embodiment, the memory unit 15 includes a tomographic image memory unit 15A for writing and storing a predetermined number of frames of tomographic images, and an MIP image memory unit 15B for writing and storing a predetermined number of frames of MIP images. Yes.

  The projection data derivation unit 10, the absorption correction data derivation unit 11, the absorption correction unit 12, the reconstruction unit 13, and the MIP image acquisition unit 14 are stored in a ROM of a storage medium represented by the memory unit 15 described above, for example. This is realized by the controller 7 executing a program or a command input by a pointing device represented by the input unit 8 or the like.

  The γ-rays generated from the subject M to which the radiopharmaceutical is administered are converted into light by the scintillator block of the γ-ray detector 3, and the converted light is photoelectrically converted by the photomultiplier of the γ-ray detector 3. Output to electrical signal. The electric signal is sent to the projection data deriving unit 10 as image information (pixel).

  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 projection data deriving unit 10 checks the position of the scintillator block and the incident timing of the γ-ray, and is sent only when the γ-ray is simultaneously incident on two scintillator blocks that are opposed to each other across the subject M. The image information is determined as appropriate data. When γ rays are incident only on one scintillator block, the projection data deriving unit 10 treats the image information sent at that time as noise instead of γ rays generated by annihilation of the positron. Dismiss.

  The image information sent to the projection data deriving unit 10 is sent to the absorption correction unit 12 as projection data (also referred to as “emission data”). Absorption correction data (transmission data) sent from the absorption correction data derivation unit 11 to the absorption correction unit 12 is applied to the projection data sent to the absorption correction unit 12 to absorb γ rays in the body of the subject M. The projection data is corrected in consideration of the above.

  The point source 4 emits γ rays toward the subject M while rotating around the body axis Z of the subject M, and the irradiated γ rays are used as a scintillator block of the γ ray detector 5 for absorption correction data. (Not shown) converts it into light, and the converted light is photoelectrically converted by a photomultiplier (not shown) of the γ-ray detector 5 and output to an electrical signal. The electric signal is sent to the absorption correction data deriving unit 11 as image information (pixel).

  Absorption correction data is obtained based on the image information sent to the absorption correction data deriving unit 11. The absorption correction data deriving unit 11 obtains distribution data of the γ-ray absorption coefficient as absorption correction data. The derived absorption correction data is sent to the absorption correction unit 12 described above.

  The corrected projection data is sent to the reconstruction unit 13 and also sent to the MIP image acquisition unit 14. The reconstruction unit 13 reconstructs the projection data to obtain a tomographic image taking into account the absorption of γ rays in the body of the subject M. Thus, by providing the absorption correction unit 12 and the reconstruction unit 13, the projection data is corrected based on the absorption correction data and the tomographic image is corrected. The corrected tomographic image is sent to the output unit 9 and the tomographic image memory unit 15 A of the memory unit 15 via the controller 7. In this embodiment, an axial image will be described as an example of a tomographic image. An axial image is an image obtained for each tomographic plane (slice plane) orthogonal to the body axis Z of the subject M. The tomographic image is not limited to an axial image, but a coronal image obtained for each horizontal plane parallel to the top plate 1, a sagittal image obtained for each vertical plane, or an image obtained for each cross section from an oblique direction. It may be. The reconstruction unit 13 corresponds to the tomographic image acquisition means in this invention.

  An MIP image is obtained based on the corrected projection data sent to the MIP image acquisition unit 14. A specific MIP image acquisition method will be described with reference to FIG. FIG. 2 is a schematic diagram of each pixel for explaining the maximum value projection method (MIP). A maximum value pixel is extracted from pixel values of a plurality of pixels along the projection direction (depth direction) of the γ-ray to create an MIP image (projection image). As shown in FIG. 2, when the maximum value in each projection direction is illustrated by hatching with hatching, a pixel having the maximum value indicated by the hatching is extracted, and the extracted pixel is used as a pixel on the projection plane. Therefore, an image having information in the depth direction is obtained. Returning to the description of FIG. 1, the MIP image acquired by the MIP image acquisition unit 14 is sent to the output unit 9 and the MIP image memory unit 15 </ b> B of the memory unit 15 via the controller 7. The MIP image acquisition unit 14 corresponds to the transmission image acquisition means in this invention.

  Next, output display of tomographic images (axial images) and MIP images will be described with reference to FIGS. FIG. 3 is a diagram illustrating an example of an output display mode by the monitor of the output unit, and FIG. 4 is a schematic diagram illustrating a data flow when the mode switching button is pressed. As shown in FIG. 3, the monitor 9A includes the axial image display area 9B, the MIP image display area 9C, the image display slider 8A, the display window adjustment slider 8B, the mode switching button 8C, and the MIP switching button 8D. It consists of a stop button 8E. The image display slider 8A, the display window adjustment slider 8B, the mode switching button 8C, the MIP switching button 8D, and the stop button 8E also have a touch panel function as a function of the input unit 8, and the operator can use these sliders and buttons. Etc. can be input by touching on the monitor 9A. Of course, these sliders and buttons do not have a touch panel function, and the input unit 8 composed of a pointing device other than the touch panel can be dragged by moving the pointer to these sliders, or the pointer can be moved to these buttons. You may comprise so that it may click.

  By the way, in this specification, a mode for continuously outputting and displaying sequentially processed images while performing data processing is defined as “monitor mode”, and a mode for outputting and displaying an image in an arbitrary frame is defined as “mode”. It is defined as “display mode”. In this display mode, continuous output display of images (that is, image display update) is stopped, and an image in an arbitrary frame is output and displayed. In this embodiment, the output display of the MIP image always operates in the monitor mode, the output display of the axial image normally operates in the monitor mode, and the frame is selected by the image display slider 8B and the mode switching button 8C. Axial image output display operates in the display mode.

  An axial image display area 9B for outputting and displaying an axial image as a tomographic image is provided in the left area of the monitor 9A, and an MIP image display area 9C for outputting and displaying the MIP image is provided in a right area different from the left area of the monitor 9A. The MIP image display area 9C always operates in the monitor mode described above, and continuously outputs and displays MIP images. The axial image display area 9B normally operates in the above-described monitor mode, and continuously outputs and displays an axial image. When a frame is selected by the image display slider 8A and the mode switching button 8C, the axial image display area 9B operates in the above-described display mode, and outputs and displays an axial image in the selected frame. The cursor C displayed in the MIP image display area 9C represents the display position (slice position) of the axial image, and the cursor C moves with respect to the MIP image as the scan of the subject M progresses. Therefore, it is possible to confirm how much scanning has progressed at the position of the cursor C. The axial image display area 9B corresponds to the tomographic image output display means in this invention, and the MIP image display area 9C corresponds to the transmission image output display means in this invention.

  The image display slider 8A is configured to select an arbitrary frame from a predetermined number of frames stored in the tomographic image memory unit 15A and the MIP image memory unit 15B. For example, when the image display slider 8A is slid to the right, the later frame in time is selected, and when it is slid to the left, the earlier frame is selected. On the other hand, the mode switching button 8C switches to either the monitor mode or the display mode. If the MIP image has a noticeable observation when operating in the monitor mode, the mode is switched to the display mode by pressing the mode switching button 8C, and is output and displayed in the MIP image display area 9C at the timing of the pressing. Corresponding to the MIP image in the latest frame, the latest frame is selected. Note that an arbitrary frame may be selected by placing the pointer on the cursor C and dragging. Thus, the axial image display area 9B outputs and displays the axial image at the frame selected by the image display slider 8A and the mode switching button 8C. The image display slider 8A and the mode switching button 8C correspond to the frame selection means in this invention.

  The display window adjustment slider 8B adjusts the luminance of the monitor 9A corresponding to the pixel value of the axial image or the MIP image, and outputs and displays the axial image or the MIP image display region 9C that is output and displayed in the axial image display region 9B. Make it easier to see the MIP images being viewed. For example, in the display window adjusting slider 8B, when the slider is slid rightward, the luminance is increased overall, and when it is slid leftward, the luminance is decreased overall. The MIP switching button 8D switches whether to display the MIP image from the front or from the side. As described with reference to FIG. 2, the projection data of the MIP image differs depending on the data reference direction (projection direction). By operating this button, the projection data from two directions can be confirmed by switching the direction of the MIP image. can do. For example, when the MIP switch button 8D is pressed once and the LED in the right window in the MIP switch button 8D is lit, the MIP image is output and displayed from the front, and the MIP switch button 8D is pressed once to switch the MIP switch button. When the LED in the right window in 8D is turned off, the MIP image is output and displayed from the side. The stop button 8E forcibly stops the output display of the axial image and the MIP image.

  A data flow when the mode switching button 8C is pressed will be described. When operating in the monitor mode, as shown in FIG. 4A, the axial image acquired by the reconstruction unit 13 is processed through the controller 7 (see FIG. 1, not shown in FIG. 4). The image is temporarily sent to the image memory unit 15A, where it is stored. The tomographic image memory unit 15A stores axial images for a finite number of frames. In FIG. 4, n frames of axial images are sequentially written in the order of 1 frame,... K frame,... N frame (1.ltoreq.k.ltoreq.n). The axial image in the old frame is discarded, and the axial image in the latest frame is newly written as an axial image in n frames. Then, the axial image at the latest frame n is read from the tomographic image memory unit 15A, and the axial image display area 9B of the monitor 9A of the output unit 9 is sent via the controller 7 (see FIG. 1, not shown in FIG. 4). Outputs and displays an axial image at the latest frame n. In the tomographic image memory unit 15A, since the axial image at the latest frame n is sequentially updated for each writing / reading, the axial image display area 9B continuously outputs the axial image at the latest frame n in the monitor mode. indicate. The axial image at the latest frame n is shown by hatching in FIG.

  Similarly, when operating in the monitor mode, as shown in FIG. 4A, the MIP image acquired by the MIP image acquisition unit 14 is transferred to the controller 7 (see FIG. 1, not shown in FIG. 4). Then, the data is temporarily sent to the MIP image memory unit 15B and stored. Similar to the tomographic image memory unit 15A, the MIP image memory unit 15B stores MIP images for a finite number of frames (the same number of n as the tomographic image memory unit 15A). In FIG. 4, n frames of MIP images are sequentially written in the order of 1 frame,... K frame,... N frame (1.ltoreq.k.ltoreq.n). The MIP image in the old frame is discarded, and the MIP image in the MIP image frame n in the latest frame is newly written. The latest frame n is newly written as an MIP image in n frames. Then, the MIP image at the latest frame n is read from the MIP image memory unit 15B, and the MIP image display area 9C of the monitor 9A of the output unit 9 is read via the controller 7 (see FIG. 1, not shown in FIG. 4). Outputs and displays the MIP image at the latest frame n. In the MIP image memory unit 15B, the MIP image in the latest frame n is sequentially updated every time it is written and read. Therefore, in the monitor mode, the MIP image display area 9C continuously outputs the MIP image in the latest frame n. indicate. Similarly, the MIP image at the latest frame n is shown by hatching in FIG. 4A.

  When the mode switching button 8C is pressed while operating in the monitor mode, the MIP image display area 9C of the monitor 9A continues to operate in the monitor mode, but the axial image display area 9B of the monitor 9A operates in the display mode. At this time, as shown in FIG. 4B, even in the display mode, data is written to the tomographic image memory unit 15A and the MIP image memory unit 15B in the same manner as in the monitor mode of FIG. Is called. That is, the axial image acquired by the reconstruction unit 13 is written in the tomographic image memory unit 15A in the order of 1 frame,... K frame,... N frame (1 ≦ k ≦ n) and acquired by the MIP image acquisition unit 14. The MIP image is written in the MIP image memory unit 15B in the order of 1 frame,... K frame,... N frame (1 ≦ k ≦ n). The axial image and the MIP image in the latest frame n are illustrated by lattice (check) hatching in FIG.

  Since the MIP image continues to operate in the monitor mode, the MIP image display area 9C of the monitor 9A continuously outputs and displays the MIP image in the latest frame n as in FIG. The cursor C displayed in the MIP image display area 9C also moves as the subject M progresses. On the other hand, since the axial image is switched to the display mode by the mode switching button 8C, the frame at the switching timing is selected. That is, the latest frame is selected at the timing of pressing the mode switching button 8C. At the pressing timing selected by the mode switching button 8C, the axial image (axial image shown by hatching in FIG. 4) in the latest frame is output and displayed in the axial image display area 9B, and the subsequent frames are displayed. The display update of the image is stopped without continuously outputting and displaying the axial image.

  In FIG. 4, the mode switching button 8C is pressed, and the latest frame is selected at the timing of pressing, but any frame (a frame between 1 ≦ k ≦ n in the case of FIG. 4) is selected by the image display slider 8A. ) Is selected, the latest frame at the timing of pressing the mode switching button 8C is the target of selection, but an arbitrary frame is the target of selection, except for the flow of data. Is the same. That is, the axial image acquired by the reconstruction unit 13 is written in the tomographic image memory unit 15A in the order of 1 frame,... K frame,... N frame (1 ≦ k ≦ n) and acquired by the MIP image acquisition unit 14. The MIP image is written in the MIP image memory unit 15B in the order of 1 frame,... K frame,... N frame (1 ≦ k ≦ n). For the MIP image, the MIP image display area 9C continuously outputs and displays the MIP image at the latest frame n, and for the axial image, the axial image at an arbitrary frame selected by the mode switching button 8C is displayed. The display area 9B outputs and displays, and the image display update is stopped without continuously outputting and displaying the axial images in the subsequent frames. When an arbitrary frame is selected by the image display slider 8A, after all the continuous output display for the axial image and the MIP image is completed, the arbitrary frame is selected by the image display slider 8A. It is also possible to output and display the selected axial image again.

  It is also possible to select an arbitrary frame with the image display slider 8A while the mode switching button 8C is pressed to switch to the display mode. Further, after the output display of the axial image in the selected frame, if necessary, the mode switching button 8C is pressed again to return to the monitor mode, and the axial image in the frames after the selected frame is returned. Can be output and displayed continuously.

  According to the PET apparatus according to the present embodiment having the above-described configuration, the reconstruction unit 13 uses the tomographic image of the subject M (this embodiment) based on the γ rays generated from the subject M to which the radiopharmaceutical is administered. Then, the MIP image acquisition unit 14 acquires a transmission image of the subject M (MIP image in this embodiment). Then, the MIP image acquired by the MIP image acquisition unit 14 is continuously output and displayed in the MIP image display area 9C of the monitor 9A. On the other hand, MIP images that are continuously output and displayed in the MIP image display area 9C are used as a guideline for confirming whether there is an image to be noted. A transmission image typified by an MIP image or the like is suitable as a standard for confirming whether or not there is an image of interest, and based on the output result of the MIP image, a predetermined frame is displayed as an image display slider 8A or a mode. The switch button 8C is selected. For the axial image acquired by the reconstruction unit 13, the axial image display area 9B of the monitor 9A outputs and displays the axial image at the frame selected by the image display slider 8A or the mode switching button 8C. As described above, if there is a noticeable observation in the MIP image continuously output and displayed in the MIP image display area 9C, a frame having the finding is selected based on the output result of the MIP image, and the observation is performed. Since the axial image display area 9B outputs and displays the axial image in the frame in which there is an error, the MIP image display area 9C can also continuously output and display the MIP image while displaying the remarkable axial image. it can. As a result, the efficiency of nuclear medicine diagnosis can be improved while outputting and displaying a noticeable image without stopping the output display of a transmission image represented by an MIP image or the like.

  In this embodiment, the transmission image is an image obtained by a maximum value projection method (MIP) in which a maximum value pixel is extracted from pixel values of a plurality of pixels along the radiation projection direction to create a projection image (MIP). MIP image). Since the MIP image obtained by this MIP is a transmission image in which information on the projection direction (depth direction) is added, the MIP image is optimal for confirming the presence or absence of notable findings.

  In this embodiment, when the frame is not selected by the image display slider 8A or the mode switching button 8C (that is, in the monitor mode), the axial image display area 9B continuously outputs and displays the axial image, and displays the image. When the frame is selected by the slider 8A or the mode switching button 8C (that is, in the display mode), the axial image display area 9B stops the continuous output display of the axial image, and the image display slider 8A and the mode The axial image in the frame selected by the switching button 8C is preferably output and displayed. In this way, not only the MIP image display area 9C but also the axial image display area 9B performs continuous output display, so that when there is no noticeable observation, that is, when no frame is selected, the axial image is continuously displayed. Therefore, not only a transmission image typified by an MIP image but also a tomographic image typified by an axial image can be provided to the operator as needed. When there is a notable finding, that is, when a frame is selected, the continuous output display of the axial image is stopped, and the axial image at the selected frame is output and displayed. When there is a noticeable axial image, the operator is provided with a tomographic image typified by an axial image as well as a transmitted image typified by an MIP image or the like as needed. be able to.

  In this embodiment, preferably, the axial image display area 9B and the MIP image display area 9C are configured to share one screen (in this embodiment, the monitor 9A), and the axial image display area 9B is the monitor 9A described above. The axial image is output and displayed in a predetermined area (left area in FIG. 3), and the MIP image display area 9C outputs and displays the MIP image in another area (right area in FIG. 3) of the monitor 9A. With this configuration, the monitor 9A, which is a single screen, can output and display both a tomographic image typified by an axial image and a transmission image typified by an MIP image. Only 9A can be watched.

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

  (1) In the above-described embodiments, the PET apparatus has been described as an example of a nuclear medicine diagnostic apparatus. However, the present invention is a nuclear medicine diagnosis that obtains nuclear medicine data of a subject based on radiation other than γ rays. If it is an apparatus, it is applicable also to alpha rays and beta rays. Moreover, it is applicable also to PET-CT provided with a PET apparatus and an X-ray CT apparatus.

  (2) In the above-described embodiments, the PET apparatus has been described as an example. However, the present invention is a SPECT (Single Photon Emission CT) apparatus that reconstructs a tomographic image of a subject by detecting a single γ-ray. It can also be applied.

  (3) In the above-described embodiment, the transmission γ-ray detector 5 is a stationary type that detects γ-rays while still, but the γ-ray detector 5 rotates around the subject M while γ It may be a rotary type that detects a line.

  (4) In the above-described embodiment, the PET apparatus includes the point source 4 (see FIG. 1), and the point source 4 emits the same γ rays as the radiopharmaceutical and transmits through the subject M, so Although the absorption correction data is obtained as a biomorphological image based on this, the absorption correction data may be obtained from CT or the like. Further, it is not always necessary to perform absorption correction. Therefore, a nuclear medicine diagnosis may be performed using a biological function image that is not subjected to absorption correction.

  (5) In the above-described embodiment, the MIP image is taken as an example of the transmission image. However, the transmission image that is a target of continuous output display by the transmission image output display means (the MIP image display area 9C in the embodiment). Is not limited to the MIP image obtained by the MIP described above. Projection data obtained by the projection data deriving unit 10 may be used, or arithmetic processing may be performed on pixel values of a plurality of pixels along the projection direction, such as a minimum value projection method (MIP) or a cumulative addition average method. May be an image obtained by a method of creating a projection image by applying the above.

  (6) In the embodiment described above, not only the transmission image output display means (MIP image display area 9C in the embodiment) but also the tomographic image output display means (axial image display area 9B in the embodiment) perform continuous output display. However, when the frame is not selected by the frame selection means (image display slider 8A or mode switching button 8C in the embodiment), the tomographic image output display means does not necessarily continuously display the tomographic image (axial image in the embodiment). There is no need to display the output. When no frame is selected by the frame selection means, the tomographic image output display means does not output and display the tomographic image, but only when a frame is selected by the frame selection means, the tomographic image output display means The tomographic image at the frame selected in (1) may be output and displayed.

  (7) In the embodiment described above, the transmission image output display means (MIP image display area 9C in the embodiment) and the tomographic image output display means (axial in the embodiment) so as to share one screen (monitor 9A in the embodiment). The tomographic image output display means outputs and displays the tomographic image in the predetermined area of the screen, and the transmission image output display means outputs and displays the transmission image in another area of the screen. The output display mode is not limited to this. The transmission image output display means and the tomographic image output display means may be configured on separate screens.

DESCRIPTION OF SYMBOLS 8A ... Image display slider 8C ... Mode switching button 9A ... Monitor 9B ... Axial image display area 9C ... MIP image display area 13 ... Reconstruction part 14 ... MIP image acquisition part M ... Subject

Claims (7)

  A nuclear medicine diagnostic apparatus for obtaining nuclear medicine data of a subject based on radiation generated from a subject to which a radiopharmaceutical has been administered, wherein the transmission image obtaining means obtains a transmission image of the subject based on the radiation. A tomographic image acquisition unit that acquires a tomographic image of the subject based on the radiation, a transmission image output display unit that continuously outputs and displays the transmission image acquired by the transmission image acquisition unit, and the transmission A frame selecting unit that selects a predetermined frame based on an output result of the image, and the tomographic image at the frame selected by the frame selecting unit is output and displayed for the tomographic image acquired by the tomographic image acquiring unit. A nuclear medicine diagnostic apparatus comprising a tomographic image output display means.   The nuclear medicine diagnosis apparatus according to claim 1, wherein the transmission image is a maximum value projection in which a maximum value pixel is extracted from pixel values of a plurality of pixels along the radiation projection direction to create a projection image. A nuclear medicine diagnostic apparatus characterized by being an image obtained by the method.   The nuclear medicine diagnosis apparatus according to claim 1, wherein the transmission image is projection data projected based on the radiation.   4. The nuclear medicine diagnosis apparatus according to claim 1, wherein when a frame is not selected by the frame selection unit, the tomographic image output display unit continuously outputs and displays the tomographic image. When the frame is selected by the frame selection means, the tomographic image output display means stops the continuous output display of the tomographic image, and the tomogram in the frame selected by the frame selection means A nuclear medicine diagnostic apparatus characterized in that an image is output and displayed.   5. The nuclear medicine diagnosis apparatus according to claim 4, wherein the transmission image output display unit and the tomographic image output display unit are configured to share one screen, and the tomographic image output display unit includes a predetermined area of the screen. The nuclear medicine diagnosis apparatus is characterized in that the tomographic image is output and displayed, and the transmission image output display means outputs and displays the transmission image in another area of the screen.   5. The nuclear medicine diagnosis apparatus according to claim 4, wherein the transmission image output display means and the tomographic image output display means are configured on separate screens.   In the nuclear medicine diagnosis apparatus according to any one of claims 1 to 3, when a frame is not selected by the frame selection unit, the tomographic image output display unit does not output and display the tomographic image, The nuclear medicine diagnosis apparatus, wherein the tomographic image output display means outputs and displays the tomographic image in the frame selected by the frame selection means only when a frame is selected by the frame selection means.

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