JP5361113B2 - MRI image stitching method and apparatus, and MRI apparatus - Google Patents

Description

  The present invention relates to an MRI image stitching method and apparatus for stitching together MR images at a plurality of slice positions acquired by imaging a wide area for each part of a subject such as a patient (hereinafter referred to as stitching). In addition, the present invention relates to an MRI apparatus.

The MRI apparatus detects an MR signal when magnetic resonance is caused in a subject such as a patient, and after detecting and amplifying the MR signal, the MR signal is digitally converted, and the MR image is regenerated by performing two-dimensional / three-dimensional Fourier transform. Configure. In the MRI apparatus, each part of the subject is imaged in a wide area. For example, the head is imaged in a wide area as each part of the subject, and then the chest is imaged in a wide area by moving the imaging area. In each imaging of each part such as the head and chest, a plurality of MR images for each slice position are acquired.
When a plurality of MR images are acquired in this way, these MR images are displayed on a display screen of a monitor, and any MR image is stitched. In this stitching, a plurality of MR images are displayed on the monitor display screen, each MR image to be stitched is selected while visually confirmed by an operator, each stitched MR image is created, and the monitor display screen is displayed. It is displayed above.

  As described above, since the stitching is performed by the operator's visual observation, it is difficult to stitch each MR image without changing the position where each part of the subject is joined. For this reason, the stitched image of each MR image between each part of the subject cannot be displayed on the monitor display screen and smoothly read.

In addition, since each MR image must be stitched to create a stitched image, the capacity of the disk used to create the stitched image is used more than during normal processing. For this reason, the free space of the disk is reduced, and the so-called disk capacity is being pressed.
JP 2005-270213 A

  An object of the present invention is to provide an MRI image stitching method, an apparatus thereof, and an MRI apparatus capable of easily stitching each MR image and smoothly interpreting the stitched image.

The MRI image stitching method according to the first aspect of the present invention acquires a plurality of MR images at a plurality of slice positions at a plurality of different bed positions for a subject, and a plurality of different bed positions. in stitching method MRI images the MR image stitching of, MRI images of each bed position in the slice plane direction of the plurality of MRI images obtained, it is determined whether it is possible stitching, slice plane direction A mark that can be displayed is attached to each MRI image that can be stitched at each bed position that is substantially continuous .

The MRI image stitching apparatus according to the second aspect of the present invention acquires a plurality of MR images at a plurality of slice positions at a plurality of different bed positions for a subject, and a plurality of different bed positions. in the MR image stitching apparatus MRI image stitching, stitching determination section MRI image of each bed position in the slice plane direction of the plurality of MRI images obtained to determine whether it is possible stitching And a label adding unit that attaches a displayable label to each stitchable MRI image of each bed position that is substantially continuous in the slice plane direction as a result of the determination by the stitching determination unit.

  An MRI apparatus according to a third aspect of the present invention includes the above-described MRI image stitching apparatus.

  According to the present invention, it is possible to provide an MRI image stitching method, an apparatus thereof, and an MRI apparatus capable of easily stitching each MR image and smoothly interpreting the stitched image.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a block diagram of an MRI apparatus provided with an MRI image stitching apparatus. It has a magnetic field generating casing 1 and a bed 2. A subject 3 such as a patient is placed on the bed 2. The magnetic field generating casing 1 has, for example, a superconducting magnet and a gradient magnetic field coil, generates a static magnetic field by the superconducting magnet, and generates a gradient magnetic field by the gradient magnetic field coil. The magnetic field unit 4 generates and operates a static magnetic field and a gradient magnetic field from the superconducting magnet and the gradient magnetic field coil, respectively.
The MRI main body 1 is provided with an RF coil. The transmission / reception unit 5 applies a high frequency signal to the RF coil, generates a high frequency magnetic field from the RF coil, and applies it to the subject 3. The transmission / reception unit 5 detects a weak resonance signal when a high frequency magnetic field is applied to the subject 3 via the RF coil, and outputs it as an MR signal.

The control system 6 is configured by a computer. The control system 6 has a main control unit 7 composed of a CPU or the like. The main control unit 7 includes a magnetic field / signal control unit 8, an MR signal processing unit 9, a reconstruction unit 10, a stitching determination unit 11, a tagging unit 12, a stitching execution unit 13, and a communication unit. 14 and the operation command are issued respectively. In addition, a storage unit 15, a display unit 16, and an operation unit 17 are connected to the main control unit 7.
The magnetic field / signal control unit 8 controls the operation of the magnetic field unit 4 to generate a static magnetic field and a gradient magnetic field in the magnetic field generating casing 1, and generates a high frequency magnetic field from the RF coil by the transmission / reception unit 5. A weak resonance signal when a high frequency magnetic field is applied to the specimen 3 is detected by the RF coil.

The MR signal processing unit 9 receives the MR signal output from the RF coil, and digitally converts the MR signal after detecting and amplifying the MR signal.
The reconstruction unit 10 receives the digital MR signal output from the MR signal processing unit 9 and reconstructs an MR image by performing two-dimensional / three-dimensional Fourier transform on the digital MR signal. As shown in FIG. 2, the MR image is scanned by scanning each part of the subject 3 in order to capture a corona image of the subject 3, for example. As an example of the scan, the first scan is performed on the head of the subject 3, the second scan is performed on the throat / neck, and the third scan is performed on the chest. Scanning the feet below the chest is omitted. In these scans, for example, a plurality of slice MR images in the slice direction A are acquired. The number of slices increases or decreases according to the thickness of the subject 3. The MR image is not limited to the Koruna image, but may be a sagittal image or an axial image. FIG. 3 shows each slice MR image of a Koruna image acquired at a plurality of scans. Each slice MR image S1-1 to S1-n is the first scan, each slice MR image S2-1 to S2-n is the second scan, and each slice MR image S3-1 to S3-m is the third scan. Eyes.

  The types of scans collected by the slice MR images S1-1 to S1-n,..., S3-m include field echo method (FE), spin echo method (SE), fast spin echo method (FSE), There is FASE etc. which further speeded up the high speed spin echo method. Therefore, the slice MR images S1-1 to S1-n,..., S3-m are classified according to each scan type such as FE, SE, FSE, FASE, etc., and stored in the storage unit 15 as a database. Good.

  The stitching determination unit 11 includes, for example, the slice MR images S1-1 to S1-n,..., S3-m of each scan shown in FIG. It is determined whether or not stitching is possible. The stitching determination unit 11 determines each slice MR image S1-1 to S1-n,..., S3- based on the position information in the spatial coordinate system of each slice MR image S1-1 to S1-n,. It is determined whether or not m can be stitched between the head, throat / neck, and chest of the subject 3. That is, the stitching determination unit 11 recognizes the magnetic field center generated in the magnetic field generating casing 1 in the spatial coordinate system. Accordingly, the stitching determination unit 11 determines whether each slice MR image S1-1 to S1-n,..., S3-m can be stitched based on the position information of the magnetic field center and the position information of the bed 2. Can be determined. Specifically, the stitching determination unit 11 performs vector data indicating each slice plane direction of each slice MR image S1-1 to S1-n,..., S3-m, for example, vector data W for the first scan shown in FIG. , And the slice MR images S1-1 to S1- based on the vector data of the slice MR images S1-1 to S1-n,..., S3-m, the position information of the magnetic field center, and the position information of the bed 2. It is determined whether n,..., S3-m can be stitched.

As a result of the determination by the stitching determination unit 11, the label addition unit 12 adds a label to each MRI image that can be stitched. For example, the label addition unit 12 may select each slice MRI image having the same slice position among the slice MR images S1-1 to S1-n,..., S3-m, for example, each slice MR image S1-3 on the magnetic field center. , S2-3, subjecting the labeled respectively S3-3, e.g. the marks _{M 1, M 2, M 3} . These marks M ₁ , M ₂ , and M ₃ are attached to portions other than the image portion of the subject ₃ in, for example, the slice MR images S1-3, S2-3, and S3-3.
The stitching execution unit 13 stitches the slice MR images S1-3, S2-3, and S3-3 to which the marks M ₁ , M ₂ , and M ₃ have been added by the label addition unit 12.

The communication unit 14 includes, for example, a radiology department information management system (RIS) that centrally manages medical devices such as the MRI apparatus, diagnostic X-ray system, and X-ray CT apparatus, and medical images of these medical apparatuses. The network is connected to a hospital information system (HOSpital Information System: HIS) that manages the entire hospital. The communication unit 14 can be stitched by the stitching determination unit 11 when the slice MR images S1-1 to S1-n,..., S3-m are transferred from the MRI apparatus to, for example, an RIS terminal apparatus. the determined e.g. each slice MR image and S1-3, S2-3, subjecting each example the marks _{M 1,} M 2, _{M 3} to S3-3.
The storage unit 15 stores various data such as the slice MR images S1-1 to S1-n,..., S3-m acquired by the reconstruction unit 10.
The display unit 16 includes, for example, a liquid crystal display.
The operation unit 17 includes, for example, a keyboard and a mouse. The operation unit 17 includes a key for instructing whether or not to perform stitching of each slice MR image S1-1 to S1-n,..., S3-m, for example. When the main control unit 7 determines that the operation instruction key is turned on, for example, stitching of each slice MR image S1-1 to S1-n,..., S3-m is performed, and the operation instruction key is turned off. If it is determined, for example, the stitching of each slice MR image S1-1 to S1-n,..., S3-m is not executed.
The determination of whether or not to execute stitching may be performed as follows. For example, when the subject 3 such as a patient in the RIS is received, the fact that the stitching is executed or not executed is registered. The main control unit 7 determines whether or not to perform stitching from the information of the subject 3 transmitted from the RIS via the network.

Next, an MRI image stitching operation in the MRI apparatus configured as described above will be described with reference to an MRI image stitching flowchart shown in FIG.
For example, in HIS, in step # 1, the subject 3 such as a patient is received and registered. At the time of reception, registration of execution or non-execution of stitching of each slice MR image is registered in the HIS. The patient information of the subject 3 registered by the HIS is sent to the RIS, for example, via the network, and sent to the MRI apparatus connected to the RIS.
Next, the main controller 7 of the present MRI apparatus receives patient information of the subject 3 in step # 2, and determines whether or not to execute stitching from the patient information of the subject 3. When the main control unit 7 determines that the operation instruction key is turned on, for example, the main control unit 7 causes the slice MR images S1-1 to S1-n,. If it is determined that the off operation is performed, for example, the stitching of the slice MR images S1-1 to S1-n,..., S3-m is not executed.

Next, in step # 3, the main control unit 7 issues operation commands to the magnetic field / signal control unit 8 and the MR signal processing unit 9, respectively, and takes an MR image. That is, the magnetic field / signal control unit 8 controls the operation of the magnetic field unit 4 to generate a static magnetic field and a gradient magnetic field in the magnetic field generating casing 1. In a state where the static magnetic field and the gradient magnetic field are generated in the magnetic field generating casing 1, the transmission / reception unit 5 generates a high frequency magnetic field from the RF coil and is weak when the high frequency magnetic field is applied to the subject 3. The resonance signal is detected by the RF coil. The MR signal processing unit 9 receives the MR signal output from the RF coil, and digitally converts the MR signal after detecting and amplifying the MR signal. For example, as shown in FIG. 2, the MR image is captured by performing the first scan on the head of the subject 3, the second scan on the throat / neck, and the third scan on the chest. Do eyes.
Next, in step # 4, the reconstruction unit 10 inputs the digital MR signal output from the MR signal processing unit 9, and performs 2-dimensional / 3-dimensional Fourier transform on the digital MR signal to reconstruct the MR image. Configure. Thus, for example, as shown in FIG. 3, each slice MR image S1-1 to S1-n of the first scan, each slice MR image S2-1 to S2-n of the second scan, and each of the third scan The slice MR images S3-1 to S3-m are reconstructed.
Next, the stitching determination unit 11 is shown in FIG. 3 based on the position information of the magnetic field center in the magnetic field generating casing 1 and the position information of the bed 2 in the spatial coordinate system recognized in advance in step # 5. It is determined whether each slice MR image S1-1 to S1-n,..., S3-m can be stitched between the head, throat / neck, and chest of the subject 3. For example, the stitching determination unit 11 stitches each slice MR image S1-3, S2-3, and S3-3 on the center of the magnetic field between the head, throat / neck, and chest portions of the subject 3, for example. Judge that it is possible. That is, the stitching determination unit 11 obtains each vector data indicating each slice plane direction of each slice MR image S1-3, S2-3, S3-3. Next, the stitching determination unit 11 determines each slice MR image S1 based on the vector data of each slice MR image S1-3, S2-3, S3-3, the position information of the magnetic field center, and the position information of the bed 2. −1 to S1-n,..., S3-m are substantially continuous in the same slice plane direction, these slice MR images S1-1 to S1-n,. to decide. Note that “substantially continuous” means that slices exist on substantially the same plane, but the slices are included on the substantially same plane even if the angles and positions of the slices are slightly different. Note that a predetermined range may be set in advance as a reference for determining whether slices are on substantially the same plane.

Next, the label adding unit 12 adds each label, for example, each mark M ₁ , to each slice MR image S1-3, S2-3, S3-3 determined to be stitchable by the stitching determination unit 11. M ₂ and M ₃ are added to portions other than the image portion of the subject 3.
Next, the stitching execution unit 13 stitches the slice MR images S1-3, S2-3, and S3-3 to which the marks M ₁ , M ₂ , and M ₃ have been added by the label addition unit 12. In FIG. 3, stitching lines T are attached so that the slice MR images S1-3, S2-3, and S3-3 to be stitched are visually easy to understand.
In addition, the stitching execution unit 13 determines that each slice MR image S1-3, which is determined to be stitchable, if each slice thickness is uniform when acquiring each slice MR image S3-1 to S3-m. For example, the slice MR images S1-2, S2-2, and S3-2 adjacent to S2-3 and S3-3, as well as the slice MR images S1-1, S2-1, and S3-1 can be stitched. Judge that there is.

Next, the main control unit 7 displays the slice MR images S1-3, S2-3, and S3-3 stitched by the stitching execution unit 13 on the screen of the display unit 16 in Step # 6. Further, the main control unit 7 can also display, for example, the slice MR images S1-2, S2-2, and S3-2, the slice MR images S1-1, S2-1, and S3-1 that can be stitched. On the screen.
However, the reading doctor reads each of the stitched slice MR images S1-3, S2-3, S3-3 on the screen of the display unit 16.

On the other hand, the communication unit 14 transfers the slice MR images S1-1 to S1-n,..., S3-m from the MRI apparatus to, for example, an RIS terminal apparatus. At this time, for example, each of the slice MR images S1-3, S2-3, and S3-3 determined that the stitching determination unit 11 can perform the stitching, for example, each of the marks M ₁ , M ₂ , subjecting the M _3.

As described above, according to the above-described embodiment, it is determined whether each slice MR image S1-1 to S1-n,..., S3-m acquired by each scan can be stitched. If possible, for example, each slice MR image S1-3, S2-3, S3-3 on the center of the magnetic field is provided with each label, for example, each of the marks M ₁ , M ₂ , M _3. The slice MR images S1-3, S2-3, and S3-3 between the head, throat / neck, and chest regions can be automatically and accurately stitched without changing the stitching positions. Thereby, for example, the slice MR images S1-3, S2-3, and S3-3 between the parts of the subject 3 such as the head, throat / neck, and chest are stitched on the display screen of the display unit 16. It can be displayed and interpreted smoothly.

Further, for example, the marks _{M 1,} M 2, each slice MR image marked with _{M 3} S1-3, S2-3, can be displayed side by side on the display screen of the display unit 16 to S3-3. For example, an interpreting doctor can operate the operation unit 17 while viewing each mark M ₁ , M ₂ , M ₃ of each slice MR image S1-3, S2-3, S3-3 displayed side by side on the display screen of the display unit 16. The slice MR images S1-3, S2-3, and S3-3 can be stitched manually. Furthermore, if the slice doctor recognizes that the slice thickness is uniform when acquiring the slice MR images S3-1 to S3-m, for example, the image interpretation doctor determines that each slice MR image is determined to be stitchable. For example, each slice MR image S1-2, S2-2, S3-2 adjacent to S1-3, S2-3, S3-3, and each slice MR image S1-1, S2-1, S3-1, etc. Stitching can be performed manually by operating the operation unit 17.

The storage unit 15 such as a disk is not used to create a stitching image, and the free space of the storage unit 15 can be increased.
The MR image is not limited to a corona image, and even if it is a sagittal image or an axial image, it is determined whether or not each slice MR image can be stitched. Marking, for example, each mark, can be stitched.

  Each slice MR image S1-1 to S1-n,..., S3-m is classified according to the type of scan, for example, FE, SE, FSE, FASE, etc., and stored in the storage unit 15 as a database. Each slice MR image S1-3, S2-3, S3-3, etc. stitched by type can also be managed.

In addition, this invention is not limited to the said one Embodiment, You may deform | transform as follows.
In the above embodiment, as shown in FIG. 2, each part of the subject 3 is scanned in order to capture a corona image of the subject 3. As shown, the slice direction B in each scan may be inclined with respect to the slice direction A of the Koruna image. When each slice MR image is acquired in the inclined slice direction B in this way, the main control unit 7 recognizes each vector data Q in the slice direction of each slice MR image. Therefore, the main control unit 7 determines whether each slice MR image can be stitched based on the vector data Q in the slice direction of each slice MR image, the position information of the magnetic field center, and the position information of the bed 2. If it can be determined and stitched, a mark such as a mark can be attached.

  The MR image can be reconstructed into slice images having different cross sections such as an axial image, a color image, and a sagittal image. Therefore, if each slice image of one cross section is acquired, it is reconstructed into an axial image, a Koruna image, or a sagittal image to be another cross section, and whether or not stitching is possible in these axial images, Koruna images, or sagittal images. If the stitching is possible, for example, a mark such as a mark can be attached.

1 is a block diagram showing an MRI apparatus provided with an embodiment of an MRI image stitching apparatus according to the present invention. The schematic diagram which shows each site | part of the imaging of MR image in the same apparatus. The schematic diagram which shows each slice MR image acquired at each scan of the same apparatus. The MRI image stitching flowchart in the same apparatus. The schematic diagram which shows the modification of the scan which acquires the MRI image in the same apparatus.

Explanation of symbols

  1: magnetic field generating casing, 2: bed, 3: subject, 4: magnetic field unit, 5: transmission / reception unit, 6: control system, 7: main control unit, 8: magnetic field / signal control unit, 9: MR signal processing Unit: 10: reconstruction unit, 11: stitching determination unit, 12: tagging unit, 13: stitching execution unit, 14: communication unit, 15: storage unit, 16: display unit, 17: operation unit.

Claims (15)

In an MRI image stitching method for acquiring a plurality of MR images at a plurality of slice positions at a plurality of different bed positions for a subject and stitching the plurality of MR images at the plurality of different bed positions . ,
Of the plurality of acquired MRI images, it is determined whether or not the MRI images at the respective bed positions in the slice plane direction can be stitched, and the respective bed positions that are substantially continuous in the slice plane direction can be stitched. A stitching method for MRI images, characterized in that a displayable mark is attached to each MRI image. 2. The stitching method for MRI images according to claim 1, wherein the marker is attached to each MRI image in which the slice positions are substantially on the same plane . The stitching method for an MRI image according to claim 1, wherein each of the MRI images to which the mark is attached is stitched. The stitching method for an MRI image according to claim 1, wherein whether or not each MRI image can be stitched is determined based on positional information of a spatial coordinate system of the MRI image.   2. The stitching method for an MRI image according to claim 1, wherein the mark has a mark that permits stitching.   2. The method of stitching MRI images according to claim 1, wherein the stitching is performed by attaching the marker to each MRI image obtained by image reconstruction. 2. The stitching method for MRI images according to claim 1, wherein when the MRI image is transferred through at least a network to which an MRI apparatus is connected, the mark is attached to each MRI image. The stitching method for an MRI image according to claim 1, wherein the marker is attached to a portion other than the image portion of the subject in each MRI image. In an MRI image stitching apparatus that acquires a plurality of MR images at a plurality of slice positions at a plurality of different bed positions with respect to a subject and stitches the plurality of MR images at the plurality of different bed positions . ,
A stitching determination unit that determines whether the MRI images at the respective bed positions in the slice plane direction among the plurality of acquired MRI images can be stitched;
As a result of the determination by the stitching determination unit, a label addition unit that attaches a label that can be displayed on each MRI image that can be stitched at each bed position that is substantially continuous in the slice plane direction ;
A stitching apparatus for MRI images, comprising: 10. The MRI image stitching apparatus according to claim 9, wherein the marker adding unit adds the marker to each of the MRI images in which the slice positions are substantially on the same plane . A stitching execution unit for stitching each MRI image to which the mark is attached by the mark adding unit;
The MRI image stitching apparatus according to claim 9, comprising: The stitching determination unit according to claim 9, wherein the stitching determination unit determines whether or not each MRI image can be stitched based on position information of a spatial coordinate system of the MRI image. Device. 10. The stitching apparatus for MRI images according to claim 9, wherein the sign adding unit attaches a mark allowing stitching as the mark to each MRI image. 10. The MRI image stitching apparatus according to claim 9, wherein the label adding unit adds the label to a portion other than the image portion of the subject in each MRI image.   An MRI apparatus comprising the MRI image stitching apparatus according to any one of claims 9 to 14.

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