JP2008206959A - Magnetic resonance imaging apparatus and method of setting slice area - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily set a slice area in each scan in the case of performing scanning a plurality of times while moving a couch in a magnetic resonance imaging apparatus. <P>SOLUTION: A slice-area setting unit 17 arranges an observation point indicating a portion to be included in the slice area on a positioning image displayed on a display unit 12, receives specification of a scanning condition including the number of movements of the couch and the size of the slice area, and arranges the slice area including the observation point for each position to which the couch is to be moved, on the basis of the observation point and the scanning condition. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a magnetic resonance imaging apparatus and a slice region setting method.

  Conventionally, as a method for setting a slice region in a magnetic resonance imaging apparatus, a tomographic image of a subject is taken in advance as a positioning image, and an operator performs a slice region on the positioning image displayed on the console. There is a method of setting a slice area in the main photographing by arranging the positions (for example, refer to Patent Document 1 or 2).

  By the way, a magnetic resonance imaging apparatus excites hydrogen nuclei in a subject by irradiating a subject placed in a static magnetic field with an RF (Radio Frequency) wave, and a magnetic resonance signal emitted by this excitation. The image is reconstructed from the above, but the magnetic field uniformity is deteriorated at a position away from the center of the static magnetic field, and the captured image may be deteriorated.

  For this reason, when it is necessary to perform imaging over a wide range, the imaging is performed in a plurality of times while moving the top plate in the body axis direction of the subject. In this case, the slice area must be set for each movement of the top board. When the slice area is set using the positioning image described above, a rectangular parallelepiped shape indicating the slice area with respect to the positioning image. (Hereinafter referred to as “volume”) is arranged in accordance with the position of the top board to be moved. Here, when arranging the volume, the operator arranges the volume while adjusting the position and the inclination so that the region of interest fits inside the volume according to the region and posture of the subject.

JP 2003-290171 A JP 2003-290172 A

  However, for example, when angiography (angiography) of the lower limb is performed, there is a problem that the volume setting operation described above becomes very complicated. The lower limb angio needs to be photographed over a wide area, so it is necessary to shoot in multiple times. However, the lower limbs cannot be stretched completely in a straight line, and the blood vessels inside the lower limbs run in a three-dimensional direction. This is because it is difficult to arrange the volume so that the blood vessels of the region of interest completely fit.

  The present invention has been made to solve the above-described problems caused by the prior art, and a magnetic resonance imaging apparatus and a slice area that can easily set a slice area when imaging is performed in a plurality of times. An object is to provide a setting method.

  In order to solve the above-described problems and achieve the object, a magnetic resonance imaging apparatus according to an embodiment of the present invention displays a gazing point indicating a location to be included in a slice region on a display device based on an instruction from an operator. A gazing point arrangement unit arranged on the positioning image, an imaging condition reception unit that receives from the operator designation of imaging conditions including the number of movements and the size of the slice area during imaging of the top plate on which the subject is placed, and the note The position at which the top is moved in the slice area including the gazing point arranged by the gazing point arrangement unit based on the gazing point arranged by the viewpoint arrangement unit and the imaging condition received by the imaging condition reception unit Based on the slice region setting unit set for each and the slice region set by the slice region setting unit, the top plate is moved a plurality of times And a photographing unit for photographing the subject separately.

  A magnetic resonance imaging apparatus according to another aspect of the present invention includes a feature information acquisition unit that acquires feature information indicating an anatomical feature of a subject from a positioning image of the subject, and the feature information acquisition unit. Based on the acquired feature information, an imaging condition determination unit that determines imaging conditions including the number of movements and the size of the slice area during imaging of the top plate on which the subject is placed, and the imaging condition determination unit determine A slice region setting unit that sets a slice region for each position where the top plate is moved based on the imaging conditions, and the top plate is moved based on the slice region set by the slice region setting unit. And an imaging unit for imaging the subject in a plurality of times.

  Further, in the slice region setting method according to another aspect of the present invention, a gaze point indicating a location to be included in the slice region is arranged on the positioning image displayed on the display device based on an instruction from the operator, and the subject is Specification of imaging conditions including the number of movements and the size of the slice area during imaging of the top board to be placed is received from the operator, and based on the gazing point arranged on the positioning image and the imaging conditions received from the operator Then, a slice region including the gazing point is set for each position where the top plate is moved, and based on the set slice region, the subject is imaged in multiple steps while moving the top plate. Including.

  In addition, the slice region setting method according to another aspect of the present invention acquires feature information indicating an anatomical feature of the subject from a positioning image of the subject, and based on the acquired feature information, the subject The imaging conditions including the number of movements and the size of the slice area during imaging of the top plate on which the specimen is placed are determined, and a slice area is set for each position where the top board is moved based on the determined imaging conditions. And imaging the subject in a plurality of times while moving the top plate based on the set slice area.

  According to the present invention, there is an effect that a slice region can be easily set when shooting is performed in a plurality of times.

  Exemplary embodiments of a magnetic resonance imaging apparatus and a slice region setting method according to the present invention will be described below in detail with reference to the accompanying drawings. In the present embodiment, a case where a sagittal image and a coronal image are used as positioning images and a slice region of a coronal image is set as a slice region in actual photographing will be described.

  In the following, the magnetic resonance imaging apparatus is referred to as an “MRI (Magnetic Resonance Imaging) apparatus”, the magnetic resonance signal is referred to as an “MR (Magnetic Resonance) signal”, and an image for positioning performed prior to the main imaging is “ This is called “positioning image”.

  First, the concept of the slice region setting method in the MRI apparatus according to the present embodiment will be described with reference to FIGS. Here, it is assumed that a sagittal image and a coronal image of the subject P to be imaged have already been captured and stored in the MRI apparatus.

  When setting a slice region in the MRI apparatus according to the present embodiment, the operator first instructs the MRI apparatus to display a positioning image of the subject P. Upon receiving this instruction, the MRI apparatus extracts the sagittal image and coronal image of the subject P from the stored images, and displays the extracted images on the console as shown in FIG. FIG. 4A shows a sagittal image of the lower limb of the subject P, and FIG. 4B shows a coronal image of the lower limb of the subject P. As shown in the figure, each image includes an image of the blood vessel B inside the lower limb.

Here, the MRI apparatus defines a predetermined number of points on the space projected on the sagittal image and the coronal image, and displays the defined points on each image as shown in FIG. These points are hereinafter referred to as “gaze points”. This figure shows the case where three gazing points are defined, and the gazing points A ₁ , A ₂ and A ₃ displayed on the sagittal image are respectively gazing points A ₁ displayed on the coronal image. , A ₂ and A ₃ are the same. Furthermore, as shown in the figure, the MRI apparatus displays a connecting line W that connects the gazing point and the gazing point on each image. This connecting line W is hereinafter referred to as a “wire frame”.

  The plurality of gazing points displayed on the sagittal image and the coronal image are used by the operator to specify points to be included in the slice area. The operator repositions the gazing point along the image of the blood vessel B included in each image by operating an input device such as a mouse or a trackball provided in the console. At this time, the operator moves or deletes the gazing point for each image, adds a new gazing point between two gazing points, or creates a new gazing point with one gazing point as a branch point. Can be added.

  The MRI apparatus changes the display of the gazing point in accordance with the above operation. When the gazing point displayed in the sagittal image is moved, the MRI apparatus is displayed in the coronal image so as to correspond to the movement. The same gaze point moves at the same time. Similarly, when the gazing point displayed on the coronal image is moved, the same gazing point displayed on the sagittal image is also moved. In addition, the MRI apparatus automatically changes the display of the wire frame W as shown in FIG.

  When the gazing point has been arranged, the operator designates imaging conditions for performing the main imaging for the MRI apparatus. Specifically, the operator designates the number of times of movement of the top board and the size of the volume representing the slice area. Here, the operator designates the length of three orthogonal sides of the rectangular parallelepiped representing the volume. The lengths of these three sides are called slice length, slice width, and slice thickness. Then, after designating all the imaging conditions, the operator instructs the MRI apparatus to set a slice area.

  Upon receiving this instruction, the MRI apparatus arranges a volume indicating a slice area on each image based on the gazing point arranged in the sagittal image and the coronal image and the designated imaging condition. FIG. 4 shows the arrangement of the volume V when the number of times of movement of the top plate is three. As shown in FIG. 4, the MRI apparatus arranges the volume V of the designated size in the body axis direction of the subject P by the same number as the number of times of movement of the designated top board.

  At this time, the MRI apparatus arranges each volume so that the most gazing points are included inside the volume V. If the gazing point variation is large, not all gazing points may fit within the volume of the volume specified by the operator.

  The operator confirms whether or not the slice area is appropriately set by confirming the state of the volume displayed in the sagittal image and the coronal image. Here, when the slice area is not set appropriately, the operator changes the arrangement of the gazing point or the imaging condition.

  The MRI apparatus dynamically changes the volume arrangement according to these operations. For example, in the example shown in FIG. 4, when the operator changes the number of times the top plate is moved to 4, the number of volumes is increased by one as shown in FIG. Rearrange to match.

  Then, the operator repeats the above operation until the volume is properly arranged, and then instructs the MRI apparatus to perform main imaging. When this instruction is received, the MRI apparatus sets a slice area based on the arrangement of the volume on the positioning image at that time and performs the main imaging.

  As described above, in the slice region setting method in the MRI apparatus according to the present embodiment, the MRI apparatus arranges the gazing point indicating the location to be included in the slice area on the positioning image based on the instruction from the operator, and further Accepts from the operator the specification of the shooting conditions including the number of plate movements and the size of the slice area, and arranges the slice area including the gazing point at each position where the top board is moved based on the gazing point and the shooting condition. Therefore, when the photographing is performed in a plurality of times by moving the top plate, the slice area in each photographing can be easily set.

  Next, the configuration of the MRI apparatus according to the present embodiment will be described. FIG. 6 is a functional block diagram illustrating the configuration of the MRI apparatus according to the present embodiment. As shown in the figure, this MRI apparatus includes a static magnetic field magnet 1, a gradient magnetic field coil 2, an RF coil 3, a static magnetic field power supply 4, a gradient magnetic field power supply 5, a transmitter 6, and a receiver 7. The sequence control device 8 and the computer 10 are configured.

The static magnetic field magnet 1 is a magnet formed in a cylindrical shape, and generates a static magnetic field H ₀ in the space inside the cylinder where the subject P is arranged by the current supplied from the static magnetic field power supply 4. The gradient magnetic field coils 2 are three pairs of coils disposed inside the static magnetic field magnet 1, and three directions of x, y, and z are placed inside the static magnetic field magnet 1 by current supplied from the gradient magnetic field power supply 5. A gradient magnetic field is generated along

  The RF coil 3 is a coil disposed in the opening of the static magnetic field magnet 1 so as to face the subject P, and irradiates the subject P with an RF wave transmitted from the transmitter 6, and is excited. To receive the MR signal emitted from the hydrogen nucleus of the subject P. The static magnetic field power source 4 is a power source that supplies current to the static magnetic field magnet 1, and the gradient magnetic field power source 5 is a power source that supplies current to the gradient magnetic field coil 2 based on an instruction from the sequence control device 8.

  The transmitter 6 is a device that transmits an RF wave to the RF coil 3 based on an instruction from the sequence control device 8, and the receiver 7 detects the MR signal received by the RF coil 3, and the MR signal To generate raw data. Note that, when the receiver 7 generates raw data from the MR signal, the receiver 7 transmits the generated raw data to the sequence control device 8.

  The sequence control device 8 is a device that performs imaging of the subject P by driving the gradient magnetic field power supply 5, the transmitter 6, and the receiver 7 based on sequence information transmitted from the computer 10. Here, the sequence information refers to the strength of the power supplied from the gradient magnetic field power supply 5 to the gradient magnetic field coil 2 and the timing of supplying the power, the strength of the RF signal transmitted from the transmitter 6 to the RF coil 3, and the RF signal. This is information defining a procedure for performing imaging such as timing and timing at which the receiver 7 detects an MR signal.

  When the raw data is transmitted from the transmitter 6 as a result of imaging the subject P, the sequence control device 8 transfers the raw data to the computer 10.

  Next, the configuration of software executed by the computer 10 shown in FIG. 6 will be described. FIG. 7 is a functional block diagram showing a configuration of software executed by the computer 10 shown in FIG.

  This software controls the MRI apparatus based on an instruction from the operator and reconstructs an image from the raw data transmitted from the sequence control apparatus 8. As shown in FIG. As function units, the input unit 11, the display unit 12, the sequence control device interface unit 13, the storage unit 14, the image reconstruction unit 15, the control unit 16, and the slice region setting unit 17 are provided.

  The input unit 11 is a means for inputting various types of information, and is realized by a pointing device such as a mouse and a trackball, a keyboard, and the like. This input unit 11 cooperates with a display unit 12 to be described later, and accepts an instruction regarding shooting, shooting conditions, and the like from an operator.

  For example, the input unit 11 displays an imaged image, a gaze point display instruction, a gaze point change instruction, a slice area setting instruction, a shooting condition change instruction, and a shooting execution instruction illustrated in FIG. Are received from the operator. When receiving an instruction to set a slice area, the input unit 11 simultaneously determines the number of times the tabletop is moved and the volume size (slice length, slice width, and slice thickness) indicating the slice area. Let it be specified as

  The display unit 12 is a display device that displays various types of information, and is realized by a CRT (Cathode Ray Tube) display, a liquid crystal display, or the like. For example, the display unit 12 displays an image reconstructed by an image reconstructing unit 15 described later, a GUI (Graphical User Interface) for receiving a photographing instruction or photographing condition from the operator, and the like.

  The sequence control device interface unit 13 is a processing unit that controls transmission / reception of information exchanged between the computer 10 and the sequence control device 8. For example, the sequence control device interface unit 13 drives the gradient magnetic field power supply 5, the transmitter 6, and the receiver 7. Sequence information for control is transmitted to the sequence controller 8, and raw data obtained by digitizing the MR signal is received from the sequence controller 8.

  The storage unit 14 is a unit that stores data and programs necessary for various processes performed by the computer 10, and is reconstructed by, for example, raw data transmitted from the sequence control device 8 or an image reconstruction unit 15 described later. Stored images and the like are stored.

  The image reconstruction unit 15 is a processing unit that reconstructs an image from the raw data transmitted from the sequence control device 8. Specifically, the image reconstruction unit 15 reads raw data stored in the storage unit 14 based on an instruction from the control unit 16 to be described later, and performs a predetermined process such as Fourier transform processing on the read raw data. By performing image reconstruction processing, a three-dimensional image (such as a sagittal image, a coronal image, or an axial image) is reconstructed. When the image reconstruction unit 15 reconstructs a three-dimensional image, the image reconstruction unit 15 stores the reconstructed image in the storage unit 14.

  The control unit 16 is a processing unit that performs various processes for controlling imaging by the MRI apparatus based on instructions from the operator. Of the various processes performed by the control unit 16, only those particularly related to the present invention will be described here.

  For example, when receiving an instruction to display a captured image via the input unit 11, the control unit 16 takes out the instructed image from the images stored in the storage unit 14, and displays the display unit. 12 is displayed. In addition, when the control part 16 receives the instruction | indication which displays the image image | photographed in multiple times, it displays on the display part 12, after connecting the divided | segmented image.

  When the control unit 16 receives an instruction to display a gazing point, an instruction to change a gazing point, an instruction to set a slice area, or an instruction to change an imaging condition via the input unit 11, Based on this, the slice area setting unit 17 is instructed to display the gazing point, change the gazing point, set the slice area, or change the imaging condition.

  When the setting information for setting the slice area is transmitted from the slice area setting unit 17 as a result of instructing the setting of the slice area, the control unit 16 stores the setting information in the internal memory. This setting information includes information indicating the size, position, and inclination of the slice area necessary for generating sequence information.

  In addition, when the control unit 16 receives a shooting execution instruction via the input unit 11, the control unit 16 generates sequence information based on the setting information stored in the internal memory at that time, and generates the generated sequence information. Then, the data is transmitted to the sequence control device 8 via the sequence control device interface unit 13.

  Here, the control unit 16 transmits the sequence information to the sequence control device 8, whereby the subject P is imaged in the sequence control device 8. When the raw data is transferred from the sequence control device 8 as a result of photographing based on the sequence information, the control unit 16 causes the storage unit 14 to store the transferred raw data. Thereafter, the control unit 16 instructs the image reconstruction unit 15 to reconstruct an image from the raw data stored in the storage unit 14.

  The slice region setting unit 17 is a processing unit that sets a slice region in the actual photographing using the positioning image. The positioning image used here is displayed on the display unit 12 by the control unit 16 based on an instruction from the operator prior to setting the slice area. As this positioning image, an image obtained by connecting images that are captured in multiple times by moving the top plate may be used.

  Specifically, the slice area setting unit 17, when instructed by the control unit 16 to display the gazing point, is a predetermined portion of the sagittal image and the coronal image displayed on the display unit 12 as a positioning image. A predetermined number of gazing points are displayed on the screen.

  For example, when an image obtained by connecting images shot in multiple times by moving the top board is used as a positioning image, the control unit 16 places a note at a position located at the center of the image before connection. Display the viewpoint.

  Then, the slice region setting unit 17 displays a wire frame connecting the displayed gazing points after displaying the gazing point (see FIG. 2).

  In addition, when the control unit 16 instructs the slice region setting unit 17 to change the gazing point, the slice region setting unit 17 displays the sagittal image displayed on the display unit 12 and the sagittal image displayed on the display unit 12 according to the operation performed by the operator. Change the point of interest on the coronal image.

  Specifically, when the operator performs an operation of moving the gazing point, the slice area setting unit 17 moves the gazing point in a sagittal image and a coronal image according to the operation, When an operation to add a new gazing point was performed between gazing points, a new gazing point was added to each image according to the operation, and an operation to delete the gazing point was performed. In such a case, the gaze point is deleted from each image according to the operation, and when an operation for adding a new gaze point with one gaze point as a branch point is performed, Add a new point of interest to each image.

  Then, the slice area setting unit 17 changes the display of the gazing point according to the above operation, but when the gazing point displayed on the sagittal image is changed, the slicing area setting unit 17 displays the gazing point on the coronal image accordingly. The same point of interest that moves is also moved at the same time. Similarly, when the gazing point displayed on the coronal image is changed, the same gazing point displayed on the sagittal image is also changed accordingly.

  As described above, when the slice region setting unit 17 arranges the gazing point on the sagittal image and the coronal image that are the positioning images, and changes the arrangement of the gazing point arranged on any one of the images, Since the arrangement of the gazing point on the image is also changed, it is possible to adjust the arrangement of the gazing point while visually recognizing from two directions, and the operator arranges the gazing point easily and accurately. be able to.

  When the gazing point is changed, the slice region setting unit 17 also changes the arrangement of the wire frames in accordance with the changed gazing point (see FIG. 3).

  Here, when the arrangement of the gazing point is changed, the slice region setting unit 17 dynamically changes the display of the wire frame based on the changed arrangement of the gazing point. When the gazing point is placed, the wire frame is displayed along the blood vessel. Accordingly, it is possible to easily visually recognize a shift between the gazing point and the blood vessel, and the operator can accurately place the gazing point on the blood vessel.

  In addition, when the control unit 16 instructs the slice area setting unit 17 to set the slice area, the imaging conditions (the number of times the tabletop is moved, the size of the volume of the slice area) specified at the same time as the instruction are given. The volume indicating the slice area is arranged on the basis of the slice length, slice width, and slice thickness showing the image and the gazing point arranged on the positioning image at that time.

  Specifically, the slice area setting unit 17 first sets the space displayed in the sagittal image and the coronal image, which are positioning images, in the moving direction of the top plate by the same number as the number of times the specified top plate has moved. For each of the divided spaces, an approximate plane that approximates the distribution of the gazing point is defined based on the gazing point included in each space using, for example, the least square method.

  Subsequently, the slice area setting unit 17 defines a volume (a rectangular parallelepiped) having three sides each of which the specified slice length, slice width, and slice thickness intersect at right angles so that the most gazing point is included in the volume. In addition, the position and the inclination are calculated so that the angle is parallel to the approximate plane described above.

  Then, the slice area setting unit 17 arranges a volume for each divided space based on the calculated position and inclination. At this time, if the slice length of the volume designated by the operator is larger than the interval when the space is divided, the volumes are arranged so as to overlap at the boundary of the space (see FIG. 4). ).

  In addition, when the slice area setting unit 17 is instructed by the control unit 16 to change the gazing point or the imaging condition after the volume is arranged, the control unit 16 responds to each instruction by sagittal. Change the position of the point of interest and the wire frame on the image and coronal image. Further, the slice area setting unit 17 recalculates the position and inclination of the volume based on the changed arrangement of the gazing point, and reallocates the volume based on the most calculated position and inclination (see FIG. 5). reference).

  As described above, when the arrangement of the gazing point is changed by the operator, the slice area setting unit 17 rearranges the volume based on the changed arrangement of the gazing point. However, the arrangement of the gazing point can be changed, and the operator can set the slice area efficiently.

  In addition, when the imaging condition is changed by the operator, the slice area setting unit 17 rearranges the volume based on the changed imaging condition, so the top plate is moved while checking the volume state. The number of times and the size of the volume can be changed, and the operator can set the slice area efficiently.

  Each time the volume is rearranged, the slice area setting unit 17 transmits setting information including the size, position, and inclination of the volume to the control unit 16.

  The processing by the slice area setting unit 17 has been described above. For example, the slice area setting unit 17 sets two slice planes (a slice length and a slice width for each gazing point included in the volume when the volume is arranged. The gazing point closest to the slice plane is specified by calculating the shortest distance to the plane of the rectangular parallelepiped and the distance from the specified gazing point to the slice plane exceeds a predetermined threshold value. In this case, the slice thickness of the volume may be decreased until the distance and the threshold value are matched.

  In general, as the slice thickness increases, the time required for shooting increases. Thus, the time required for shooting is required by setting the volume size so that the slice thickness is as thin as possible. It can be shortened to the minimum time.

  On the other hand, when there is a large variation in the arrangement of gazing points, depending on the size of the volume designated by the operator, it may not be possible to fit all the gazing points in the volume. In this case, for the gazing point that does not fit in the volume, the slice area setting unit 17 notifies the operator that there is a gazing point that does not enter the slice area, for example, by changing the display color or blinking. You may make it do. As a result, it is possible to prompt the operator to review the size of the volume and the photographing conditions.

  Next, the flow of slice area setting by the computer 10 will be described. 8 and 9 are flowcharts showing the flow of slice area setting by the computer 10. As shown in FIG. 8, when the computer 10 is instructed to display a positioning image by the operator, the control unit 16 displays a sagittal image and a coronal image of the designated subject P on the display unit 12. (Step S101).

  Subsequently, when the operator instructs to display the gazing point, the slice region setting unit 17 displays the gazing point on the sagittal image and the coronal image displayed on the display unit 12 (step S102). Further, a wire frame connecting the displayed gazing points is displayed (step S103).

  Thereafter, when the operator instructs to move the gazing point (Yes in step S104), the slice region setting unit 17 moves the gazing point on the sagittal image and the coronal image in accordance with the instruction ( Step S105).

  When the operator instructs to add a gazing point (step S106, Yes), the slice region setting unit 17 responds to the instruction by the two slice areas displayed on the sagittal image and the coronal image. A new gazing point is added between gazing points (step S107).

  When the operator instructs to delete the gazing point (step S108, Yes), the slice area setting unit 17 selects the gazing point displayed in the sagittal image and the coronal image in response to the instruction. Delete (step S109).

  Further, when the operator instructs to branch the gazing point (step S110, Yes), based on the instruction, the slice area setting unit 17 displays one gazing point displayed on the sagittal image and the coronal image. A new gazing point is added so as to branch from the viewpoint (step S111).

  Subsequently, as shown in FIG. 9, when the number of movements of the top board is received from the operator as a photographing condition (step S112, Yes), and when the volume size indicating the slice area is received (step S113). , Yes), the slice area setting unit 17 calculates the position and inclination of the volume based on the gazing point and the photographing condition (step S114), and the sagittal image displayed on the display unit 12 based on the calculated position and inclination. And a volume is arrange | positioned on a coronal image (step S115).

  The computer 10 repeats the processes of steps S104 to S115 until the operator completes the operation related to the setting of the slice area. When the setting of the slice area is completed, the process is terminated (Yes in step S116).

  In this way, when the slice region setting unit 17 changes the arrangement of the gazing point based on an instruction from the operator and changes the arrangement of the gazing point, the slice area setting unit 17 changes the volume based on the changed arrangement of the gazing point. Since the rearrangement is performed, it is possible to change the arrangement of the gazing point while confirming the volume state, and the operator can set the slice area efficiently.

  As described above, in the present embodiment, the slice region setting unit 17 arranges a gazing point indicating a location to be included in the slice region on the positioning image displayed on the display unit 12 based on an instruction from the operator, Furthermore, the operator accepts an imaging condition specification including the number of times the top plate is moved and the size of the slice area from the operator, and based on the gazing point and the imaging condition, the position where the top board is moved in the slice area including the gazing point Therefore, when the photographing is performed in a plurality of times by moving the top board, the slice area in each photographing can be easily set.

  In the present embodiment, the operation and shooting conditions related to the arrangement of the gazing point are received from the operator, and the slice region is set for each movement of the top plate based on the gazing point and the shooting conditions. The method of setting the area is not limited to this. For example, feature information indicating an anatomical feature of a subject may be acquired from a pre-captured positioning image, and a slice region may be set based on the acquired feature information.

  In this case, for example, the slice region setting unit 17 extracts the length of the imaging region along the moving direction of the top board from the positioning image of the subject, and calculates the number of times the top board is moved from the extracted length. Thereafter, the slice region setting unit 17 extracts the contour of the imaging region from the positioning image, and the size of the slice region so that the imaging region is included at each position where the top board is moved from the extracted contour. Calculate the height and orientation. Then, the slice area setting unit 17 sets a slice area for each position where the top is moved, using the calculated number of movements, the size and direction of the slice area as imaging conditions.

  For example, when photographing a bone, the slice region setting unit 17 extracts a bone outline from the positioning image, and detects the length, thickness, orientation, and the like of the bone from the extracted outline. Then, the slice region setting unit 17 has a slice region having a size and an orientation that include the entire bone at each position where the top is moved based on the detected length, thickness, orientation, and the like. Set.

  In this way, the feature information indicating the anatomical features of the subject is acquired from the positioning image, and based on the acquired feature information, the imaging conditions including the number of times the top plate is moved and the size of the slice region at the time of imaging are obtained. By determining and setting the slice region for each position where the top is moved based on the determined imaging conditions, it becomes possible to automatically set the slice region based on the positioning image of the subject, The operator can set the slice area more easily.

  Here, the slice area setting unit 17 accepts information related to the number of times of movement of the top board and the size of the slice area from the operator, determines the imaging condition based on the received information, and sets the slice area. It may be set.

  Alternatively, the slice area setting unit 17 arranges a gazing point indicating a location to be included in the slice area on the positioning image based on the feature information acquired from the positioning image, and based on the arranged gazing point and imaging conditions, You may set the slice area | region containing a gazing point for every position to which a top plate is moved. In this case, the slice region setting unit 17 sets a gazing point according to the shape and size of the imaging region based on information indicating anatomical features acquired from the positioning image.

  For example, when photographing the inside of the thigh, the slice region setting unit 17 extracts the contour of the thigh from the positioning image, and detects the length, thickness, orientation, and the like of the thigh from the extracted contour. To do. Thereafter, the slice area setting unit 17 divides the thigh to be imaged into a predetermined number of parts based on the detected length, and places the gazing point at the center of each part. And the slice area | region setting part 17 sets the slice area | region which includes a gaze point in each position for every position to which a top plate is moved.

  In the present embodiment, as shown in FIG. 4, the case where the volumes V are arranged side by side only in the body axis direction of the subject P has been described. For example, when the left and right lower limbs are displayed in the positioning image In the case where a plurality of parts are displayed in the positioning image, such as when the volume V is arranged on each of the left and right sides, a slice region is individually set for each part according to the branch of the wire frame. May be.

  In this embodiment, the case where a sagittal image and a coronal image are used as positioning images has been described. However, the present invention is not limited to this, and other images taken from different viewpoints including an axial image and the like are used. Even when a plurality of images are used as positioning images, the same can be applied.

  That is, the slice area setting unit 17 arranges the gazing point on a plurality of positioning images photographed from different viewpoints, and arranges the gazing point arranged on any one of the plurality of positioning images. When it is changed, the arrangement of the gazing points arranged on the other positioning images is also changed in conjunction. Thereby, it becomes possible to adjust the arrangement of the gazing point while visually recognizing from a plurality of directions, and the operator can arrange the gazing point easily and accurately.

  Further, in this embodiment, as the positioning image, an image obtained by connecting images shot in multiple times by moving the top plate may be used. However, the top plate at the time of shooting the positioning image is used. The number of times of movement and the number of times of movement of the top specified as the photographing condition for the main photographing do not necessarily match. Therefore, the positioning image is shot with as few moves as possible so that the image quality does not hinder the gaze point arrangement. In this shooting, the number of moves is increased to obtain a good image quality. This makes it possible to perform shooting efficiently.

  Moreover, when connecting the image divided | segmented into several and using it as a positioning image, a connection location does not necessarily need to overlap a connection location. Therefore, when shooting the positioning image in multiple times, it is possible to reduce the number of times the top plate is moved by shooting only the part necessary for placing the gazing point. The time required for shooting can be reduced. As a result, the total time taken for imaging can be reduced, and the burden on the patient as the subject can be reduced.

  In the present embodiment, the case where one computer is used has been described. However, the functional units described above may be distributed and arranged in a plurality of computers.

  As described above, the magnetic resonance imaging apparatus and the slice region setting method according to the present invention are useful when setting a slice region using a pre-positioned positioning image, and in particular, by moving the top plate. Suitable for shooting multiple times.

It is a figure for demonstrating a positioning image. It is a figure for demonstrating the display of a gaze point and a wire frame. It is a figure for demonstrating the change of a gaze point and a wire frame. It is a figure for demonstrating the display of a volume. It is a figure for demonstrating the change of a volume. It is a functional block diagram which shows the structure of the MRI apparatus which concerns on a present Example. It is a functional block diagram which shows the structure of the software performed by the computer shown in FIG. It is a flowchart (1) which shows the flow of the slice area | region setting by a computer. It is a flowchart (2) which shows the flow of the slice area | region setting by a computer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Static magnetic field magnet 2 Gradient magnetic field coil 3 RF coil 4 Static magnetic field power supply 5 Gradient magnetic field power supply 6 Transmitter 7 Receiver 8 Sequence control apparatus 10 Computer 11 Input part 12 Display part 13 Sequence control apparatus interface part 14 Storage part 15 Image reconstruction Unit 16 Control unit 17 Slice area setting unit

Claims (25)

Based on an instruction from the operator, a gazing point arrangement unit that arranges a gazing point indicating a location to be included in the slice area on the positioning image displayed on the display device;
An imaging condition receiving unit that receives from the operator the specification of imaging conditions including the number of movements and the size of the slice area during imaging of the top plate on which the subject is placed;
Based on the gazing point arranged by the gazing point arrangement unit and the imaging condition received by the imaging condition receiving unit, the top plate is moved in the slice area including the gazing point arranged by the gazing point arrangement unit. A slice area setting section to be set for each position,
Based on the slice region set by the slice region setting unit, an imaging unit that images the subject in multiple steps while moving the top plate;
A magnetic resonance imaging apparatus comprising: A gazing point changing unit that changes the arrangement of the gazing point arranged by the gazing point arrangement unit based on an instruction from the operator;
The slice area setting unit, when the arrangement of the gazing point is changed by the gazing point changing unit, resets the slice area based on the changed arrangement of the gazing point. 2. The magnetic resonance imaging apparatus according to 1. The gazing point arrangement unit arranges the gazing point on a plurality of positioning images taken from different viewpoints, respectively.
When the gaze point changing unit changes the arrangement of the gaze point arranged on any one of the plurality of positioning images, the gaze point changing unit also arranges the gaze points arranged on the other positioning images. The magnetic resonance imaging apparatus according to claim 2, wherein the magnetic resonance imaging apparatus is changed in conjunction with the magnetic resonance imaging apparatus.   The gaze point changing unit, when instructed to move the gaze point by the operator, moves the gaze point arranged by the gaze point arrangement unit based on the instruction. Item 3. The magnetic resonance imaging apparatus according to Item 2.   The gaze point changing unit, when instructed by the operator to delete the gaze point, deletes the gaze point arranged by the gaze point arrangement unit based on the instruction. Item 3. The magnetic resonance imaging apparatus according to Item 2.   When the operator is instructed to add the gazing point, the gazing point changing unit adds a gazing point in addition to the gazing point arranged by the gazing point arrangement unit based on the instruction. The magnetic resonance imaging apparatus according to claim 2. Based on an instruction from the operator, further includes a shooting condition changing unit that changes the shooting condition received by the shooting condition receiving unit,
3. The slice area setting unit according to claim 2, wherein when the imaging condition is changed by the imaging condition changing unit, the slice area setting unit resets the slice area based on the changed imaging condition. Magnetic resonance imaging equipment. Based on an instruction from the operator, further includes a shooting condition changing unit that changes the shooting condition received by the shooting condition receiving unit,
The slice area setting unit, when the imaging condition is changed by the imaging condition changing unit, resets the slice area based on the changed imaging condition. Magnetic resonance imaging equipment. When the gazing point is arranged by the gazing point arrangement unit, a linking line display unit that displays a linking line connecting the arranged gazing points on the positioning image;
A connection line changing unit that changes the display of the connection line based on the changed arrangement of the gaze point when the arrangement of the gaze point is changed by the gaze point change unit;
The magnetic resonance imaging apparatus according to claim 2, further comprising: When the gazing point is arranged by the gazing point arrangement unit, a linking line display unit that displays a linking line connecting the arranged gazing points on the positioning image;
A connection line changing unit that changes the display of the connection line based on the changed arrangement of the gaze point when the arrangement of the gaze point is changed by the gaze point change unit;
The magnetic resonance imaging apparatus according to claim 3, further comprising: A feature information acquisition unit that acquires feature information indicating an anatomical feature of the subject from the positioning image of the subject;
Based on the feature information acquired by the feature information acquisition unit, an imaging condition determination unit that determines imaging conditions including the number of movements and the size of the slice area at the time of imaging of the top plate on which the subject is placed,
A slice region setting unit that sets a slice region for each position to which the top plate is moved based on the photographing condition determined by the photographing condition determining unit;
Based on the slice region set by the slice region setting unit, an imaging unit that images the subject in multiple steps while moving the top plate;
A magnetic resonance imaging apparatus comprising: An imaging condition receiving unit that receives information related to the number of times the top plate has moved and the size of the slice area at the time of shooting from an operator;
The magnetic resonance imaging apparatus according to claim 11, wherein the imaging condition determination unit determines the imaging condition based on information received by the imaging condition reception unit. Based on the feature information acquired by the feature information acquisition unit, further comprising a gazing point arrangement unit that arranges a gazing point indicating a location to be included in the slice region on the positioning image displayed on the display device,
The slice area setting unit includes a gazing point arranged by the gazing point arrangement unit based on the gazing point arranged by the gazing point arrangement unit and the photographing condition determined by the photographing condition determination unit. The magnetic resonance imaging apparatus according to claim 11, wherein: is set for each position where the top plate is moved. Based on the feature information acquired by the feature information acquisition unit, further comprising a gazing point arrangement unit that arranges a gazing point indicating a location to be included in the slice region on the positioning image displayed on the display device,
The slice area setting unit includes a gazing point arranged by the gazing point arrangement unit based on the gazing point arranged by the gazing point arrangement unit and the photographing condition determined by the photographing condition determination unit. The magnetic resonance imaging apparatus according to claim 12, wherein: is set for each position where the top plate is moved. A gazing point changing unit that changes the arrangement of the gazing point arranged by the gazing point arrangement unit based on an instruction from the operator;
The slice area setting unit, when the arrangement of the gazing point is changed by the gazing point changing unit, resets the slice area based on the changed arrangement of the gazing point. 14. A magnetic resonance imaging apparatus according to 14. The gazing point arrangement unit arranges the gazing point on a plurality of positioning images taken from different viewpoints, respectively.
When the gaze point changing unit changes the arrangement of the gaze point arranged on any one of the plurality of positioning images, the gaze point changing unit also arranges the gaze points arranged on the other positioning images. The magnetic resonance imaging apparatus according to claim 15, wherein the magnetic resonance imaging apparatus is changed in conjunction with the magnetic resonance imaging apparatus.   The gaze point changing unit, when instructed to move the gaze point by the operator, moves the gaze point arranged by the gaze point arrangement unit based on the instruction. Item 16. The magnetic resonance imaging apparatus according to Item 15.   The gaze point changing unit, when instructed by the operator to delete the gaze point, deletes the gaze point arranged by the gaze point arrangement unit based on the instruction. Item 16. The magnetic resonance imaging apparatus according to Item 15.   When the operator is instructed to add the gazing point, the gazing point changing unit adds a gazing point in addition to the gazing point arranged by the gazing point arrangement unit based on the instruction. The magnetic resonance imaging apparatus according to claim 15. Based on an instruction from the operator, further includes a shooting condition changing unit that changes the shooting condition received by the shooting condition receiving unit,
16. The slice area setting unit according to claim 15, wherein when the imaging condition is changed by the imaging condition changing unit, the slice area setting unit resets the slice area based on the changed imaging condition. Magnetic resonance imaging equipment. Based on an instruction from the operator, further includes a shooting condition changing unit that changes the shooting condition received by the shooting condition receiving unit,
The slice area setting unit, when the imaging condition is changed by the imaging condition changing unit, resets the slice area based on the changed imaging condition. Magnetic resonance imaging equipment. When the gazing point is arranged by the gazing point arrangement unit, a linking line display unit that displays a linking line connecting the arranged gazing points on the positioning image;
A connection line changing unit that changes the display of the connection line based on the changed arrangement of the gaze point when the arrangement of the gaze point is changed by the gaze point change unit;
The magnetic resonance imaging apparatus according to claim 15, further comprising: When the gazing point is arranged by the gazing point arrangement unit, a linking line display unit that displays a linking line connecting the arranged gazing points on the positioning image;
A connection line changing unit that changes the display of the connection line based on the changed arrangement of the gaze point when the arrangement of the gaze point is changed by the gaze point change unit;
The magnetic resonance imaging apparatus according to claim 16, further comprising: Based on an instruction from the operator, a gazing point indicating a location to be included in the slice area is arranged on the positioning image displayed on the display device,
Accepting from the operator the specification of imaging conditions including the number of movements and the size of the slice area during imaging of the top plate on which the subject is placed,
Based on the gazing point arranged on the positioning image and the imaging conditions received from the operator, a slice area including the gazing point is set for each position where the top board is moved,
Based on the set slice area, image the subject in multiple steps while moving the top plate,
A slice area setting method. Obtaining feature information indicating the anatomical features of the subject from the subject positioning image,
Based on the acquired feature information, determine the imaging conditions including the number of movements and the size of the slice area when imaging the top plate on which the subject is placed,
Based on the determined shooting conditions, set a slice area for each position where the top plate is moved,
Based on the set slice area, image the subject in multiple steps while moving the top plate,
A slice area setting method.

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