JP5468434B2 - Magnetic resonance imaging system - Google Patents

Description

  The present invention relates to a magnetic resonance imaging apparatus.

  A magnetic resonance imaging (MRI) apparatus is an apparatus that images a subject using a magnetic resonance phenomenon. Specifically, the MRI apparatus magnetically excites a nuclear spin of a subject placed in a static magnetic field with an RF (Radio Frequency) magnetic field having a Larmor frequency. Then, after applying a gradient magnetic field to the subject at a predetermined timing, the MRI apparatus detects an MR signal generated with the excitation of the nuclear spin, and reconstructs an image from the detected MR signal.

  In imaging by such an MRI apparatus, a positioning image (also referred to as a parent image) is usually captured before main imaging for imaging a diagnostic image. The positioning image here is an image used for setting an imaging position in the main imaging. When the MRI apparatus captures a positioning image, the MRI apparatus receives an operation for setting a region of interest (ROI) on the positioning image from the operator. In the main imaging, the MRI apparatus captures an image at a position where the ROI is set as a diagnostic image (see, for example, Patent Document 1).

JP 2005-118461 A

  However, in the conventional MRI apparatus, as described below, there are cases where the position intended by the operator is not correctly imaged.

  For example, in an MRI apparatus, it is known that an image at a position far from the center of the magnetic field is distorted due to the influence of various magnetic field inhomogeneities. The non-uniformity of various magnetic fields here is caused by a decrease in the linearity of the gradient magnetic field and the uniformity of the static magnetic field and the RF magnetic field. Therefore, for example, when an image of a wide range in the body axis direction of the subject is set as a positioning image, such as imaging of the spine, distortion may occur at a position away from the image center on the positioning image. . Furthermore, when the ROI is set at a position where there is distortion on the positioning image, the position of the actually captured image may be different from the position intended by the operator.

  The present invention has been made in view of the above, and provides a magnetic resonance imaging apparatus capable of correctly imaging a position intended by an operator even when an ROI is set on a positioning image having distortion. For the purpose.

  In order to solve the above-described problems and achieve the object, the present invention according to claim 1 is directed to an MRI apparatus, a setting unit that sets a plurality of regions of interest on a positioning image obtained by imaging a subject, Dividing means for dividing the plurality of regions of interest into a plurality of regions of interest with a region of interest falling within a distortion tolerance range that is a range allowing distortion due to non-uniformity, and the plurality of regions of interest group An image of a position in which a region of interest included in the region of interest group is set after combining the representative position and the position of the center of the magnetic field for each of the plurality of region of interest groups, and calculating means for calculating each representative position. And an imaging control means for controlling the imaging of the image.

  According to the first aspect of the present invention, even when the ROI is set on a distorted positioning image, there is an effect that the position intended by the operator can be captured correctly.

FIG. 1 is a diagram illustrating an overall configuration of the MRI apparatus according to the present embodiment. FIG. 2 is a functional block diagram illustrating a detailed configuration of the MRI apparatus according to the present embodiment. FIG. 3 is a flowchart illustrating the operation procedure of the MRI apparatus according to the present embodiment. FIG. 4 is a diagram (1) for explaining the flow of imaging by the MRI apparatus according to the present embodiment. FIG. 5 is a diagram (2) for explaining the flow of imaging by the MRI apparatus according to the present embodiment. FIG. 6 is a diagram (3) for explaining the flow of imaging by the MRI apparatus according to the present embodiment. FIG. 7 is a diagram (4) for explaining the flow of imaging by the MRI apparatus according to the present embodiment. FIG. 8 is a diagram (5) for explaining the flow of imaging by the MRI apparatus according to the present embodiment. FIG. 9 is a diagram (6) for explaining the flow of imaging by the MRI apparatus according to the present embodiment. FIG. 10 is a diagram (7) for explaining the flow of imaging by the MRI apparatus according to the present embodiment. FIG. 11 is a diagram (8) for explaining the flow of imaging by the MRI apparatus according to the present embodiment. FIG. 12 is a diagram (9) for explaining the flow of imaging by the MRI apparatus according to the present embodiment.

  Embodiments of an MRI apparatus according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by the Example shown below.

  First, the overall configuration of the MRI apparatus according to the present embodiment will be described. FIG. 1 is a diagram illustrating an overall configuration of an MRI apparatus 100 according to the present embodiment. As shown in FIG. 1, this MRI apparatus 100 includes a static magnetic field magnet 1, a gradient magnetic field coil 2, a gradient magnetic field power source 3, a bed 4, a bed control unit 5, a transmission RF coil 6, a transmission unit 7, a reception RF coil 8, A receiving unit 9, a sequence control unit 10, and a computer system 20 are provided.

  The static magnetic field magnet 1 is a magnet formed in a hollow cylindrical shape, and generates a uniform static magnetic field in an internal space. As the static magnetic field magnet 1, for example, a permanent magnet, a superconducting magnet or the like is used.

  The gradient magnetic field coil 2 is a coil formed in a hollow cylindrical shape, and is disposed inside the static magnetic field magnet 1. The gradient magnetic field coil 2 is formed by combining three coils corresponding to the X, Y, and Z axes orthogonal to each other, and these three coils are individually supplied with current from a gradient magnetic field power source 3 to be described later. In response, a gradient magnetic field whose magnetic field strength changes along the X, Y, and Z axes is generated. The Z-axis direction is the same direction as the static magnetic field. The gradient magnetic field power supply 3 supplies a current to the gradient magnetic field coil 2.

  Here, the gradient magnetic fields of the X, Y, and Z axes generated by the gradient magnetic field coil 2 correspond to, for example, the slice selection gradient magnetic field Gs, the phase encoding gradient magnetic field Ge, and the readout gradient magnetic field Gr, respectively. The slice selection gradient magnetic field Gs is used to arbitrarily determine an imaging section. The phase encoding gradient magnetic field Ge is used to change the phase of the magnetic resonance signal in accordance with the spatial position. The readout gradient magnetic field Gr is used for changing the frequency of the magnetic resonance signal in accordance with the spatial position.

  The couch 4 includes a couchtop 4a on which the subject P is placed. Under the control of a couch controller 5 described later, the couchtop 4a is placed in the cavity of the gradient magnetic field coil 2 with the subject P placed thereon. Insert into (imaging port). Usually, the bed 4 is installed such that the longitudinal direction is parallel to the central axis of the static magnetic field magnet 1. The couch controller 5 is a device that controls the couch 4 under the control of the controller 26, and drives the couch 4 to move the couchtop 4a in the longitudinal direction and the vertical direction.

  The transmission RF coil 6 is arranged inside the gradient magnetic field coil 2 and receives a high frequency pulse from the transmission unit 7 to generate a high frequency magnetic field. The transmission unit 7 transmits a high-frequency pulse corresponding to the Larmor frequency to the transmission RF coil 6.

  The reception RF coil 8 is disposed inside the gradient coil 2 and receives a magnetic resonance signal radiated from the subject P due to the influence of the high-frequency magnetic field. When receiving the magnetic resonance signal, the reception RF coil 8 outputs the magnetic resonance signal to the receiving unit 9.

  The receiving unit 9 generates k-space data based on the magnetic resonance signal output from the receiving RF coil 8. Specifically, the receiving unit 9 generates k-space data by digitally converting the magnetic resonance signal output from the reception RF coil 8. The k-space data includes PE (Phase Encode) direction, RO (Read Out) direction, SE (Slice Encode) direction by the above-described slice selection gradient magnetic field Gs, phase encoding gradient magnetic field Ge, and readout gradient magnetic field Gr. Information on the spatial frequency of the direction is associated. When the k-space data is generated, the receiving unit 9 transmits the k-space data to the sequence control unit 10.

  The sequence control unit 10 executes various imaging sequences by driving the gradient magnetic field power source 3, the transmission unit 7, and the reception unit 9 based on the sequence information transmitted from the computer system 20. Here, the sequence information refers to the strength of the power supplied from the gradient magnetic field power supply 3 to the gradient magnetic field coil 2 and the timing of supplying the power, the strength of the RF signal transmitted from the transmitter 7 to the transmission RF coil 6 and the RF signal. Information defining the procedure for executing the imaging sequence, such as the timing at which the receiving unit 9 detects the magnetic resonance signal.

  The sequence control unit 10 drives the gradient magnetic field power source 3, the transmission unit 7, and the reception unit 9 to execute the imaging sequence. As a result, when the k-space data is transmitted from the reception unit 9, the sequence control unit 10 calculates the k-space data. Transfer to system 20.

  The computer system 20 performs overall control of the MRI apparatus 100. For example, the computer system 20 performs data collection, image reconstruction, and the like by driving the above-described units. The computer system 20 includes an interface unit 21, an image reconstruction unit 22, a storage unit 23, an input unit 24, a display unit 25, and a control unit 26.

  The interface unit 21 controls input / output of various signals exchanged with the sequence control unit 10. For example, the interface unit 21 transmits sequence information to the sequence control unit 10 and receives k-space data from the sequence control unit 10. Upon receiving the k-space data, the interface unit 21 stores each k-space data in the storage unit 23 for each subject P.

  The image reconstruction unit 22 performs post-processing, that is, reconstruction processing such as Fourier transform, on the k-space data stored in the storage unit 23, thereby obtaining spectrum data or images of desired nuclear spins in the subject P. Generate data.

  The storage unit 23 stores the k-space data received by the interface unit 21 and the spectrum data and image data generated by the image reconstruction unit 22 for each subject P.

  The input unit 24 receives various instructions and information input from the operator. As the input unit 24, a pointing device such as a mouse or a trackball, a selection device such as a mode change switch, or an input device such as a keyboard can be used as appropriate.

  The display unit 25 displays various types of information such as spectrum data or image data under the control of the control unit 26. As the display unit 25, a display device such as a liquid crystal display can be used.

  The control unit 26 includes a CPU, a memory, and the like (not shown) and performs overall control of the MRI apparatus 100. For example, the control unit 26 generates sequence information based on the imaging condition input from the operator via the input unit 24 and transmits the sequence information to the sequence control unit 10, thereby imaging the sequence control unit 10. Run the sequence. Further, when k-space data is sent from the sequence control unit 10, the control unit 26 controls the image reconstruction unit 22 to reconstruct an image from the k-space data.

  The overall configuration of the MRI apparatus 100 according to the present embodiment has been described above. With such a configuration, the MRI apparatus 100 sets a plurality of ROIs (regions of interest) on the positioning image obtained by imaging the subject P. After that, the MR apparatus 100 divides a plurality of ROIs into a plurality of ROI groups by dividing ROIs that fall within a distortion tolerance range that is a tolerance range of distortion due to magnetic field inhomogeneity into one ROI group (region of interest group), The representative position of each ROI group is calculated. The MRI apparatus 100 performs control so as to capture an image of the position where the ROI included in the ROI group is set after the representative position and the position of the magnetic field center are matched for each of the plurality of ROIs. Here, the allowable strain range is a range that is uniquely determined for each apparatus according to the spatial arrangement and strength of the static magnetic field magnet, the gradient magnetic field, and the RF magnetic field.

  That is, in this embodiment, when a plurality of ROIs are set on the positioning image, the MRI apparatus 100 divides each ROI into a plurality of ROI groups so as to be within the allowable distortion range, and represents each ROI group. Imaging is performed a plurality of times while adjusting the position to the magnetic field center. In this way, by performing imaging in a plurality of times while aligning the representative position of the ROI group with the center of the magnetic field, an ROI image set outside the allowable distortion range is imaged within the allowable distortion range at the first positioning. Become so. Therefore, according to the present embodiment, even when the ROI is set on a positioning image having distortion, the position intended by the operator can be captured correctly.

  Below, this MRI apparatus 100 is demonstrated in detail. FIG. 2 is a functional block diagram illustrating a detailed configuration of the MRI apparatus 100 according to the present embodiment. FIG. 2 shows the bed control unit 5, the sequence control unit 10, and the computer system 20 among the units of the MRI apparatus 100 shown in FIG. Here, the functions related to the storage unit 23 and the control unit 26 included in the computer system 20 will be mainly described.

  As illustrated in FIG. 2, the storage unit 23 includes an image storage unit 23a. The image storage unit 23 a stores the image data generated by the image reconstruction unit 22.

  The control unit 26 includes an ROI setting unit 26a, an additional imaging determination unit 26b, an ROI group division unit 26c, a representative position calculation unit 26d, an imaging control unit 26e, an image display control unit 26f, and an imaging information display control unit 26g. .

  The ROI setting unit 26a sets a plurality of ROIs on the positioning image obtained by imaging the subject P. For example, the ROI setting unit 26 a receives an operation for designating the ROI on the positioning image displayed on the display unit 25 via the input unit 24. The ROI setting unit 26a generates information indicating the position and size of the ROI designated by the operator, attaches the generated information to the positioning image, and stores the information in the image storage unit 23a.

  In this embodiment, the case where the ROI setting unit 26a sets the ROI based on the operation by the operator will be described. However, for example, the ROI setting unit 26a may automatically set the ROI based on the anatomical characteristics of the part to be imaged. For example, when the region to be imaged is a spine, the ROI setting unit 26a extracts a curve along the spine from the positioning image, and sets a predetermined number of ROIs so as to intersect the extracted curve vertically. Set.

  The additional imaging determination unit 26b determines whether all the ROIs set by the ROI setting unit 26a are within the allowable distortion range. In the present embodiment, the allowable distortion range is a range having a predetermined width in the moving direction of the top 4a on which the subject P is placed. Then, when all the ROIs are within the allowable distortion range, the additional imaging determination unit 26b instructs the imaging control unit 26e described later to execute the main imaging. On the other hand, when all the ROIs are not within the allowable distortion range, the ROI group dividing unit 26c described later is instructed to divide the ROI set on the positioning image.

  When the ROI group dividing unit 26c is instructed to divide the ROI from the additional imaging determination unit 26b, the ROI that falls within the allowable distortion range is set as one ROI group, and the plurality of ROIs set on the positioning image are set to the plurality of ROIs. Divide into ROI groups. Thereby, the plurality of ROIs set on the positioning image are divided so as to fall within the allowable distortion range.

  The representative position calculating unit 26d calculates the representative position of each of the plurality of ROI groups divided by the ROI group dividing unit 26c. Note that, when the representative position calculation unit 26d calculates the representative position of each ROI group, the representative position calculation unit 26d notifies the imaging control unit 26e described later of information regarding the calculated representative position. The information related to the representative position here is information indicating the coordinates of the representative position when the spatial position in the MRI apparatus 100 is expressed in the apparatus coordinate system, for example.

  In the present embodiment, a case where the representative position calculation unit 26d calculates the center position of the ROI group as a representative position will be described. However, the representative position of the ROI group is not limited to the center position. For example, when the uniformity of the magnetic field is not symmetrical about the center of the magnetic field, a position shifted by a predetermined amount from the center position may be set as the representative position.

  The imaging control unit 26e controls the sequence control unit 10 to perform imaging according to various imaging sequences. For example, the imaging control unit 26e causes the sequence control unit 10 to execute an imaging sequence for capturing a positioning image. Further, when instructed to execute the main imaging from the additional imaging determination unit 26b, the imaging control unit 26e controls the sequence control unit 10 to capture an image at a position where the ROI is set on the positioning image. .

  Further, for example, when the information regarding the representative position of each ROI group is notified from the representative position calculation unit 26d, the imaging control unit 26e, for each ROI group, the representative position and the magnetic field calculated by the representative position calculation unit 26d. After matching the center position, the sequence control unit 10 is controlled so as to capture an image of the ROI included in the ROI group. At this time, the imaging control unit 26e controls the bed control unit 5 based on the information on the representative position notified from the representative position calculation unit 26d to move the table 4a of the bed 4 so that each ROI group can be moved. Match the representative position with the center of the magnetic field.

  For example, when the imaging control unit 26e receives an operation for approving the position of the ROI superimposed on the additional positioning image by the image display control unit 26f described later, the image at the position where the ROI is set. The sequence control unit 10 is controlled so as to capture the image. Further, the imaging control unit 26e controls the sequence control unit 10 to capture an additional positioning image that is a new positioning image every time the representative position of the ROI group and the position of the magnetic field center are matched. And the imaging control part 26e attaches the information regarding the ROI of the ROI group corresponding to the additional positioning image to the captured additional positioning image.

  Also, depending on the type of MRI apparatus, when the positioning image is captured, various incidental information may be added to the captured positioning image. The supplementary information here is map data for parallel imaging, shimming data for fat suppression, center frequency data, and the like, for example. Therefore, the imaging control unit 26e may attach various types of supplementary information to the additional positioning image when the additional positioning image is captured.

  The image display control unit 26 f causes the display unit 25 to display various images generated by the image reconstruction unit 22. For example, the image display control unit 26 f causes the display unit 25 to display the positioning image generated by the image reconstruction unit 22. For example, when an additional positioning image is captured, the image display control unit 26f superimposes the ROI included in the ROI group and the additional positioning image corresponding to the ROI group for each of the plurality of ROI groups. It is displayed on the display unit 25.

  When the image display control unit 26f receives an operation requesting reference display from the operator after an image at a position where the ROI is set is captured by the imaging control unit 26e, the image display control unit 26f The ROI image set in the image is displayed side by side on the display unit 25. At this time, when the image display control unit 26f receives an operation requesting reference display regarding the additional positioning image, the image display control unit 26f is included in the additional positioning image requested by the operator and the ROI group corresponding to the additional positioning image. The ROI images are displayed side by side on the display unit 25.

  The imaging information display control unit 26g causes the display unit 25 to display information related to various types of imaging such as imaging of the positioning image and main imaging. The information related to imaging referred to here is, for example, information indicating imaging conditions or execution status related to imaging scheduled to be executed or imaging being executed. For example, when the additional positioning image is captured by the imaging control unit 26e, the imaging information display control unit 26g displays a list of information regarding each imaging in response to a request from the operator. Alternatively, the imaging information display control unit 26g may display a list of information related to imaging scheduled from the beginning, and display information related to the additional positioning image as a tree in response to a request from the operator.

  Next, an operation procedure of the MRI apparatus 100 according to the present embodiment will be described with reference to FIGS. FIG. 3 is a flowchart illustrating the operation procedure of the MRI apparatus 100 according to the present embodiment. 4 to 12 are diagrams for explaining the flow of imaging by the MRI apparatus 100 according to the present embodiment.

  As illustrated in FIG. 3, in the MRI apparatus 100, when the imaging control unit 26e receives an instruction to start imaging of the positioning image from the operator (step S101, Yes), an imaging sequence for imaging the positioning image. Is executed by the sequence control unit 10 (step S102).

  Then, after the positioning image is generated by the image reconstruction unit 22, the image display control unit 26f displays the generated positioning image on the display unit 25 (step S103). For example, as shown in FIG. 4, the image display control unit 26 f causes the display unit 25 to display a sagittal image of the subject P as the positioning image 30.

  Subsequently, the ROI setting unit 26a sets a plurality of ROIs on the positioning image displayed on the display unit 25 (step S104). For example, the ROI setting unit 26a sets a plurality of ROIs 41 to 44 on the positioning image 30, as shown in FIG.

  Thereafter, when the operator gives an instruction to start actual imaging (step S105, Yes), the additional imaging determination unit 26b confirms that all ROIs set by the ROI setting unit 26a are within the allowable distortion range. It is determined whether or not (step S106). For example, as illustrated in FIG. 6, the additional imaging determination unit 26 b has all of the ROIs 41 to 44 set by the ROI setting unit 26 a within a distortion allowable range A having a predetermined width in the body axis direction of the subject P. It is determined whether or not it is accommodated.

  Here, when all the set ROIs are within the allowable distortion range (step S106, Yes), the imaging control unit 26e captures an image of the position where the ROI is set on the positioning image. The sequence control unit 10 is controlled (step S113).

  On the other hand, if all the set ROIs are not within the allowable distortion range (No in step S106), the ROI group dividing unit 26c determines that the ROIs that are within the allowable distortion range are set as one ROI group. A plurality of ROIs set on the image are divided into a plurality of ROI groups (step S107). For example, the ROI group dividing unit 26c sets the ROIs 41 and 42 as the ROI group 51 and the ROIs 43 and 44 as the ROI group 52 as shown in FIG.

  Subsequently, the representative position calculation unit 26d calculates the representative position of each of the plurality of ROI groups into which the ROI has been divided by the ROI group division unit 26c (step S108). For example, the representative position calculation unit 26d calculates the center position 61 of the ROI group 51 as the representative position of the ROI group 51, as shown in FIG. Further, the representative position calculation unit 26d calculates the center position 62 of the ROI group 52 as the representative position of the ROI group 52 as shown in FIG.

  Thereafter, the imaging control unit 26e captures an additional positioning image for each ROI group (step S109). At this time, the imaging control unit 26e controls the bed control unit 5 and the sequence control unit 10 to match the representative position calculated by the representative position calculation unit 26d with the position of the magnetic field center for each ROI group. An additional positioning image is taken. For example, as illustrated in FIG. 9A, the imaging control unit 26e captures an additional positioning image 71 when the center position 61 of the ROI group 51 is aligned with the magnetic field center. Further, as illustrated in FIG. 9B, the imaging control unit 26 e captures an additional positioning image 72 when the center position 62 of the ROI group 52 is aligned with the magnetic field center.

  After the additional positioning image is captured, the image display control unit 26f superimposes the ROI included in the ROI group and the additional positioning image corresponding to the ROI group for each of the plurality of ROI groups. (Step S110). For example, the image display control unit 26f causes the display unit 25 to superimpose the ROIs 41 and 42 included in the ROI group 51 and the additional positioning image 71 as illustrated in FIG. Further, for example, as shown in FIG. 10B, the image display control unit 26f causes the display unit 25 to display the ROIs 43 and 44 included in the ROI group 52 and the additional positioning image 72 so as to overlap each other.

  Thereafter, until the imaging control unit 26e accepts an operation for approving the position of the ROI (No at Step S111), the ROI setting unit 26a changes the position of the ROI according to the operation by the operator (Step S112). ). When the imaging control unit 26e receives an operation for approving the position of the ROI superimposed on the additional positioning image from the operator (step S111, Yes), the representative position calculation unit 26d performs the operation for each ROI group. After the calculated representative position and the position of the magnetic field center are matched, the sequence control unit 10 is controlled to capture an image of the ROI included in the ROI group (step S113).

  Then, after the image at the position where the ROI is set is captured, when the image display control unit 26f receives an operation requesting the reference display regarding the additional positioning image from the operator (Yes in step S114), the addition is performed. The positioning image and the ROI image corresponding to the additional positioning image are displayed side by side on the display unit 25 (step S115). For example, as illustrated in FIG. 11, the image display control unit 26 f displays the additional positioning image 71 and the image 81 of the ROI 42 corresponding to the additional positioning image 71 side by side.

  Here, an example has been described in which the image display control unit 26f displays one positioning image when a reference display is requested by the operator. However, for example, the image display control unit 26f generates a combined positioning image obtained by combining a plurality of additional positioning images captured for each ROI group, and an image of the ROI corresponding to the generated combined positioning image and the plurality of additional positioning images. May be displayed side by side on the display unit 25.

  In this case, for example, the image display control unit 26f generates a combined positioning image by combining the additional positioning image 71 and the additional positioning image 72 as shown in FIG. Then, the image display control unit 26f cuts out the image 73 in the same range as the positioning image 30 shown in FIG. 4 from the generated combined positioning image, and causes the ROI 41 to 44 to be superimposed on the cut out image 73 and displayed on the display unit 25. .

  As described above, in this embodiment, the ROI setting unit 26a sets a plurality of ROIs on the positioning image obtained by imaging the subject P. Further, the ROI group dividing unit 26c divides a plurality of set ROIs into a plurality of ROI groups by setting ROIs that fall within a distortion allowable range, which is a range allowing distortion due to magnetic field inhomogeneity, as one ROI group. . Further, the representative position calculation unit 26d calculates the representative position of each of the plurality of ROI groups. Then, after the image pickup control unit 26e matches the representative position and the position of the magnetic field center for each of the plurality of ROI groups, the image pickup control unit 26e performs control so as to pick up an image of the position where the ROI included in the ROI group is set. In this way, by performing imaging in multiple times while aligning the representative position of the ROI group with the center of the magnetic field, all ROI images set outside the allowable distortion range in the initial positioning are within the allowable distortion range. An image is taken. Therefore, according to the present embodiment, even when the ROI is set on a positioning image having distortion, the position intended by the operator can be captured correctly.

  In this embodiment, the allowable distortion range is a range having a predetermined width in the moving direction of the bed 4 on which the subject P is placed. Then, the imaging control unit 26e moves the top plate 4a of the bed 4 to match the representative position of the ROI group with the position of the magnetic field center. Therefore, according to the present embodiment, even when the ROI is set on the positioning image that is distorted due to the non-uniformity of the magnetic field along the moving direction of the bed, the position intended by the operator is correctly imaged. be able to.

  In the present embodiment, the imaging control unit 26e captures an additional positioning image, which is a new positioning image, each time the representative position of the ROI group and the position of the magnetic field center are matched. Then, the image display control unit 26f causes the display unit 25 to display the ROI included in the ROI group on the additional positioning image corresponding to the ROI group for each of the plurality of ROI groups. Therefore, according to the present embodiment, the operator can easily confirm the positional relationship between the additional positioning image captured as a new positioning image and the region of interest set in the positioning image used in the initial positioning. Can do.

  In this embodiment, when the operation for approving the position of the ROI superimposed on the additional positioning image is received from the operator, the imaging control unit 26e captures an image at the position where the ROI is set. Control. Therefore, according to the present embodiment, since the imaging is performed after the operator confirms the position of the ROI, the position intended by the operator can be imaged more accurately.

  In the present embodiment, the image display control unit 26f captures the additional positioning image and the ROI image included in the ROI group corresponding to the additional positioning image after the image at the position where the ROI is set is captured. Are displayed on the display unit 25 side by side. Therefore, according to the present embodiment, since the position of the captured image can be confirmed using the additional positioning image in which the ROI is set in a range with less distortion, the operator can determine the position of the captured image. It can be grasped more accurately.

  In the present embodiment, the image display control unit 26f generates a composite positioning image by combining a plurality of additional positioning images captured for each ROI group, and corresponds to the generated combined positioning image and the plurality of additional positioning images. The ROI images are displayed side by side on the display unit 25. Therefore, according to the present embodiment, the positions of a plurality of ROIs set in the initial positioning can be confirmed on one composite positioning image, so that the operator can easily grasp the position of the captured image. can do.

  In this embodiment, the imaging information display control unit 26g causes the display unit 25 to display information related to the imaging of the additional positioning image. Therefore, according to the present embodiment, even when imaging of the additional positioning image is added to the imaging originally planned, the operator can easily confirm information regarding the added imaging.

  In this embodiment, the representative position is the center position of the ROI group. Therefore, according to the present embodiment, when the uniformity of the magnetic field is symmetric about the magnetic field center, even when the ROI is set on the positioning image that is distorted due to the influence of the magnetic field inhomogeneity, The position intended by the operator can be captured correctly.

DESCRIPTION OF SYMBOLS 100 MRI apparatus 20 Computer system 26 Control part 26a ROI setting part 26b Additional imaging determination part 26c ROI group division | segmentation part 26d Representative position calculation part 26e Imaging control part 26f Image display control part 26g Imaging information display control part

Claims (8)

Setting means for setting a plurality of regions of interest on a positioning image obtained by imaging the subject;
A dividing unit that divides the plurality of regions of interest into a plurality of regions of interest with one region of interest as a region of interest that falls within a distortion tolerance range that is a range that allows distortion due to magnetic field non-uniformity;
Calculating means for calculating a representative position of each of the plurality of region of interest groups;
Imaging control means for controlling to capture an image of a position where a region of interest included in the region of interest is set after combining the representative position and the position of the center of the magnetic field for each of the plurality of regions of interest. A magnetic resonance imaging apparatus comprising: The strain allowable range is a range having a predetermined width in the moving direction of the bed on which the subject is placed,
The magnetic resonance imaging apparatus according to claim 1, wherein the imaging control unit adjusts the representative position and the position of the magnetic field center by moving the bed. The imaging control means captures an additional positioning image that is a new positioning image every time the representative position and the position of the magnetic field center are matched.
It further comprises image display control means for displaying the region of interest included in the region of interest group on the additional positioning image corresponding to the region of interest group and displaying it on the display unit for each of the plurality of region of interest groups. The magnetic resonance imaging apparatus according to claim 1 or 2.   The imaging control unit controls to capture an image of a position where the region of interest is set when an operation for approving the position of the region of interest superimposed on the additional positioning image is received from an operator. The magnetic resonance imaging apparatus according to claim 3.   The image display control unit arranges the additional positioning image and the image of the region of interest included in the region of interest corresponding to the additional positioning image after the image of the position where the region of interest is set is captured. The magnetic resonance imaging apparatus according to claim 3, wherein the magnetic resonance imaging apparatus is displayed on a display unit.   The image display control unit generates a combined positioning image obtained by combining a plurality of additional positioning images captured for each region of interest, and generates an image of the region of interest corresponding to the generated combined positioning image and the plurality of additional positioning images. The magnetic resonance imaging apparatus according to claim 5, wherein the two are displayed side by side on a display unit.   The magnetic resonance imaging apparatus according to claim 3, further comprising an information display control unit configured to display information related to the imaging of the additional positioning image on a display unit.   The magnetic resonance imaging apparatus according to claim 1, wherein the representative position is a center position of the region of interest group.

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