JP5925998B2 - Magnetic resonance imaging apparatus and program - Google Patents

Description

  The present invention relates to a magnetic resonance imaging apparatus and a program for imaging a subject.

  In recent years, a technique for automatically setting a slice position and imaging a subject is known from the viewpoint of reducing the burden on an operator (see Patent Document 1).

JP 2010-264148 A

However, in the method of Patent Document 1, the operator cannot confirm the slice position until the scan is performed after the slice position is automatically set. Therefore, the operator needs to determine whether or not the automatically set slice position is appropriate by looking at the image obtained by scanning. When the slice position is not appropriate, the operator has to manually reset the slice position and perform re-scanning, and there is a problem that it takes time for imaging.
Therefore, it is desired that the operator can easily confirm the slice position.

According to a first aspect of the present invention, a positioning scan for obtaining positioning image data used when determining a slice position and an image based on the slice position determined using the positioning image data are provided. Scanning means for executing a first main scan for acquiring data;
Slice position determining means for determining a slice position of the first main scan based on the positioning image data;
Display control means for displaying the slice position determined by the slice position determination means on a display unit;
Slice position correcting means for correcting the slice position displayed on the display unit in response to an operation by an operator;
A magnetic resonance imaging apparatus.

According to a second aspect of the present invention, a positioning scan for obtaining positioning image data used when determining a slice position and an image based on the slice position determined using the positioning image data are provided. A program of a magnetic resonance imaging apparatus that executes a main scan for acquiring data,
A slice position determination process for determining a slice position of the main scan based on the positioning image data;
Display control processing for displaying on the display unit the slice position determined by the slice position determination processing;
A slice position correction process for correcting the slice position displayed on the display unit in accordance with an operation of an operator;
Is a program for causing a computer to execute.

  Since the slice position determined based on the positioning image data is displayed on the display unit, the operator can easily confirm the slice position determined by the slice position determination means. Further, when the operator wants to correct the displayed slice position, the operator can correct the slice position, so that the slice position suitable for the main scan can be set.

1 is a schematic diagram of a magnetic resonance imaging apparatus according to a first embodiment of the present invention. It is explanatory drawing of the scan performed with a 1st form. 2 is a diagram showing a processing flow of the MRI apparatus 100. FIG. It is a figure which shows roughly the image data DS for positioning. It is a figure which shows a median surface. It is explanatory drawing of an example of the determination method of the slice position of a reference | standard slice. FIG. 6 is a diagram showing the position of a reference slice displayed on the display screen of the display unit 11. It is a figure which shows the display screen of the display part 11 after correcting the slice position of a reference | standard slice. It is a figure which shows an example of the slice set when this scan is performed. It is a figure which shows the flow in a 2nd form. It is a figure which shows another slice position. It is a diagram showing an n-number of slice positions P ₁ to P _n displayed on the display screen of the display unit 11. is a view showing a display screen of the display unit 11 after correction for n slices positions P ₁ to P _n. It is a figure which shows the MRI apparatus 200 of the 3rd form. It is a figure which shows the flow in a 3rd form. It is a figure which shows the reference point a0. It is a figure which shows roughly the axial cross section AX and the coronal cross section CO which pass the control | reference point a0. FIG. 6 is a diagram showing the position of a reference slice displayed on the display screen of the display unit 11. It is a figure which shows the display screen of the display part 11 immediately after correcting the slice position on the port 11a. Is a diagram showing the ports 11b and 11c of the slice position P _{a 'is} displayed after being corrected. It is explanatory drawing of the scan performed in a 4th form. It is a figure which shows the flow in a 4th form. It is a diagram showing a slice position _{Q a} and _{R a.} FIG. 6 is a diagram showing the position of a reference slice displayed on the display screen of the display unit 11. It is a figure which shows the display screen of the display part 11 after correcting a slice position. It is a figure which shows an example of the slice set when each of this scan MS1, MS2, and MS3 is performed.

  Hereinafter, although the form for inventing is demonstrated, this invention is not limited to the following forms.

(1) First Embodiment FIG. 1 is a schematic diagram of a magnetic resonance imaging apparatus according to a first embodiment of the present invention.

  A magnetic resonance imaging apparatus (hereinafter referred to as “MRI apparatus”. MRI: Magnetic Resonance Imaging) 100 includes a magnet 2, a table 3, a receiving coil 4, and the like.

  The magnet 2 has a bore 21 in which the subject 12 is accommodated, a superconducting coil 22, a gradient coil 23, and an RF coil 24. The superconducting coil 22 applies a static magnetic field B0, the gradient coil 23 applies a gradient magnetic field, and the RF coil 24 transmits an RF pulse. In place of the superconducting coil 22, a permanent magnet may be used.

  The table 3 has a cradle 3a. The cradle 3a is configured to be able to move into the bore 21. The subject 12 is transported to the bore 21 by the cradle 3a.

  The reception coil 4 is attached to the head of the subject 12. The receiving coil 4 receives a magnetic resonance signal from the subject 12.

  The MRI apparatus 100 further includes a sequencer 5, a transmitter 6, a gradient magnetic field power supply 7, a receiver 8, a central processing unit 9, an operation unit 10, and a display unit 11.

  Under the control of the central processing unit 9, the sequencer 5 sends information for imaging the subject 12 to the transmitter 6 and the gradient magnetic field power supply 7.

  The transmitter 6 outputs a drive signal for driving the RF coil 24 based on the information sent from the sequencer 5.

  The gradient magnetic field power supply 7 outputs a drive signal for driving the gradient coil 23 based on the information sent from the sequencer 5.

  The receiver 8 performs signal processing on the magnetic resonance signal received by the receiving coil 4 and outputs data obtained by the signal processing to the central processing unit 9.

  The central processing unit 9 implements various operations of the MRI apparatus 100 such as transmitting necessary information to the sequencer 5 and the display unit 11 and reconstructing an image based on data received from the receiver 8. The operation of each unit of the MRI apparatus 100 is controlled. The central processing unit 9 is constituted by a computer, for example.

  The central processing unit 9 includes a slice position determining unit 91, a display control unit 92, a slice position correcting unit 93, and the like.

  The slice position determining unit 91 determines the slice position of the main scan based on the positioning image data.

  The display control unit 92 displays the slice position determined by the slice position determination unit 91 on the display unit.

  The slice position correcting means 93 corrects the slice position displayed on the display unit 11 in accordance with the operation of the operator.

  The central processing unit 9 is an example of the slice position determining unit 91, the display control unit 92, and the slice position correcting unit 93, and functions as these units by executing a predetermined program.

The operation unit 10 is operated by an operator and inputs various information to the central processing unit 9. The display unit 11 displays various information.
The MRI apparatus 100 is configured as described above.

FIG. 2 is an explanatory diagram of the scan executed in the first mode.
In the first mode, a positioning scan and a main scan are executed.

  The positioning scan is a scan for acquiring positioning image data. The positioning image data is data used when determining the slice position. The main scan is a scan for acquiring image data based on the slice position determined using the positioning image data.

FIG. 3 is a diagram showing a processing flow of the MRI apparatus 100.
In step ST1, a positioning scan for acquiring positioning image data is executed. In the first embodiment, an axial 3D scan is performed. FIG. 4 schematically shows the positioning image data DS obtained by the positioning scan in step ST1. After performing the positioning scan, the process proceeds to step ST2.

  In step ST2, the slice position determining means 91 (see FIG. 1) first obtains a median plane based on the positioning image data (see FIG. 5).

FIG. 5 is a diagram showing a median plane.
As a method for obtaining the median plane, a method of detecting a longitudinal cerebral fissure can be considered. Since the longitudinal cerebrum divides the brain into left and right, the median plane can be obtained by detecting the longitudinal cerebral fissure. A longitudinal cerebral fissure is likely to have a signal intensity lower than that of the white matter or gray matter of the brain. Therefore, the longitudinal cerebral fissure can be detected by searching for a position where the signal intensity becomes small. The median plane image data DM is schematically shown on the lower side of FIG. After obtaining the median plane, the process proceeds to step ST3.

  In step ST3, the slice position determination unit 91 determines the slice position of a reference slice that serves as a reference for a slice of a main scan described later based on the median plane image data DM (see FIG. 6).

FIG. 6 is an explanatory diagram of an example of a method for determining the slice position of the reference slice.
FIG. 6A schematically shows median plane image data DM obtained based on the positioning image data DS. In the first embodiment, the positioning image data DS is data acquired by axial 3D scanning, and therefore has an axial format. However, since the median plane image data DM is sagittal cross-section data, the median plane image data DM cannot be obtained if the positioning image data DS remains in the axial format. Therefore, the positioning image data DS is reformatted into a sagittal format so that data on the median plane can be obtained. By reformatting, the median plane image data DM can be obtained from the positioning image data DS.

  Next, the slice position of the reference slice is determined based on the median plane image data DM.

The slice position determining means 91 has template data DT used for determining the slice position of the reference slice (see FIG. 6B). The template data DT represents standard median plane image data. The standard median plane data is data created by acquiring median plane data from a plurality of subjects and averaging these median plane data. Further, the template data DT, a slice position P _a across the head is shown. In the first embodiment, the slice positions P _a is across the feature points of the corpus callosum of the template data DT, is set. Point a1 slice positions P _a represents the position of the feature point of the front side of the corpus callosum, the point a2 represents the position of the feature point on the rear end side of the corpus callosum.

The slice position determining unit 91 performs matching between the median plane image data DM and the template data DT (see FIG. 6C), and the deviation between the median plane image data DM and the template data DT is minimized. the slice positions P _a, the slice position of the reference slice in the image data DM in the median plane. In FIG. 6 (d), shows the slice position P _a of the positioned reference slice on the image data in the median plane. After determining the slice position P _a reference slice, before proceeding to a step ST4.

  In step ST4, in order to confirm the slice position of the reference slice, the operator operates the operation unit 10 to display the slice position of the reference slice on the display unit 11 (see FIG. 7).

FIG. 7 is a diagram illustrating the position of the reference slice displayed on the display screen of the display unit 11.
From the operation unit 10, an instruction for confirming the slice position P _a reference slice is input, the display control unit 92 (see FIG. 1) causes the display unit 11 to display the slice position P _a reference slice . On the display unit 11 includes an image data DM in the median plane, the slice position P _a reference slice that is set to the median plane is displayed. When the slice position _{P a} is displayed, the process proceeds to step ST5.

In step ST5, the operator, with reference to the slice position P _a reference slice displayed on the display unit 11, determines whether to correct the slice position P _a of the reference slice. If the operator determines to correct the slice position of the reference slice, the process proceeds to step ST6. If the operator determines not to correct the slice position of the reference slice, the process proceeds to step ST7.

In step ST6, the operator operates the operation unit 10, instruction inputs a for correcting the slice position P _a reference slice (see Figure 8).

  FIG. 8 is a diagram illustrating a display screen of the display unit 11 after correcting the slice position of the reference slice.

When a command for correcting the slice position of the reference slice is input from the operation unit 10, the slice position correcting means 93 (see FIG. 1), according to the command input from the operation unit 10, the slice position P of the reference slice. to fix _a. In FIG. 8, the slice position Pa before correction is indicated by _a broken line, and the slice position Pa after correction is indicated by _a symbol “P _a ′”. If the slice position of the reference slice is corrected, the process proceeds to step ST7.

In step ST7, the main scan is executed.
FIG. 9 is a diagram illustrating an example of a slice set when the main scan is executed.
The slice position determining unit 91 determines another slice position based on the slice position P _a ′ of the corrected reference slice. In the first embodiment, it is assumed that the number of slices is n. Therefore, the slice position determining unit 91 determines other slice positions so that the total of the slice positions is n. In the first embodiment, the slice position determining unit 91 determines other slice positions P _{1 to} P _a-1 below the corrected slice position P _a ′, and sets the corrected slice position P _a ′. On the upper side, other slice positions P _{a + 1 to} P _n are determined. Therefore, n slice positions P _{1 to} P _n are determined at the head. Note that the slice interval is ΔS. Conditions such as the number of slices and the interval between slices are values input by the operator before the main scan is executed. However, it may be set in advance as a default value. Slice positions _P 1 to P _n need not be displayed on the display unit 11, so that the operator can confirm all the slice positions _P 1 to P _n before the scan, the slice position _P 1 to P _n You may display on the display part 11. FIG.

When the slice positions P _{1 to} P _n are determined, the main scan is executed and the flow ends. In step ST5, if it is determined that the operator does not correct the slice position _{P a,} skips step ST6, the process proceeds to step ST7. In this case, the slice position determining means 91, based on the slice position P _a, determines the other slice location, the scan is performed.

In the first embodiment, the slice positions P _a reference slice slice position determining means 91 has determined is displayed on the display unit 11. Therefore, the operator by viewing the display unit 11, a slice position P _a reference slice can be easily confirmed. The operator, when he wants to modify the slice positions of the reference slice, the operation unit 10, by inputting an instruction to modify the slice position P _a reference slice, a slice of the reference slice position P _a Can be easily corrected. Therefore, the main scan can be executed at the optimum slice position.

(2) Second Embodiment Since the hardware configuration of the MRI apparatus of the second embodiment is the same as that of the first embodiment, the description of the hardware configuration of the MRI apparatus is omitted, and the difference from the first embodiment. Is mainly explained.

FIG. 10 is a diagram showing a flow in the second embodiment.
Steps ST1 to ST3 are the same as those in the first embodiment, and a description thereof will be omitted. After determining the slice position _{P a} reference slice at step ST3, the process proceeds to step ST31.

In step ST31, the slice position determining unit 91 determines another slice position (see FIG. 11) based on the slice position P _a (see FIG. 6) of the reference slice determined in step ST3.

FIG. 11 is a diagram illustrating other slice positions.
In the second embodiment, it is assumed that the number of slices is n. Therefore, the slice position determining unit 91 determines other slice positions so that the total of the slice positions is n. In the second embodiment, the slice positions determination means 91, the lower side of the slice position P _a, determines the other slice positions P ₁ to P _a-1, on the upper side of the slice position P _a, the other slice position P _{a + 1 to Pn} are determined. Therefore, n slice positions P _{1 to} P _n are determined at the head. Note that the slice interval is ΔS. Conditions such as the number of slices and the interval between slices are values input by the operator before the main scan is executed. However, it may be set in advance as a default value. After n slice positions P _{1 to} P _n are determined, the process proceeds to step ST4.

In step ST4, the operator, in order to confirm the n-number of slice positions _P 1 to P _n, by operating the operation unit 10 to display the n-number of slice positions _P 1 to P _n on the display unit 11 (FIG. 12).

FIG. 12 is a diagram illustrating n slice positions P _{1 to} P _n displayed on the display screen of the display unit 11.

When a command for confirming _n slice positions P _{1 to} P _n is input from the operation unit 10, the display control unit 92 (see FIG. 1) displays n slice positions P _{1 on the} display unit 11. ~ _Pn is displayed. The display unit 11 displays median plane image data DM and n slice positions P _{1 to} P _n set on the median plane. When n slice positions P _{1 to} P _n are displayed, the process proceeds to step ST5.

In step ST5, the operator determines whether or not to correct the _n slice positions P _{1 to} P _n while referring to the _n slice positions P _{1 to} P _n displayed on the display unit 11. If the operator determines to correct the slice position, the process proceeds to step ST6. If the operator determines not to correct the slice position, the process proceeds to step ST7.

For example, when the operator wants to shift the _n slice positions P _{1 to} P _n slightly downward, the process proceeds to step ST6.

In step ST6, the operator operates the operation unit 10 and inputs a command for correcting the _n slice positions P _{1 to} P _n (see FIG. 13).

FIG. 13 is a diagram showing a display screen of the display unit 11 after correcting _n slice positions P _{1 to} P _n .

When a command for correcting the _n slice positions P _{1 to} P _n is input from the operation unit 10, the slice position correction unit 93 (see FIG. 1) performs n according to the command input from the operation unit 10. The slice positions P _{1 to} P _n are corrected. In FIG. 13, the slice position before correction is indicated by a broken line (reference sign “P _{1 to} P _n ”), and the slice position after correction is indicated by a solid line (reference sign “P _{11 to} P _n1 ”). When the slice position is corrected, the process proceeds to step ST7.

At step ST7, on the basis of the slice position _P 11 _{to P n1} after modification, the scan is performed, the flow is terminated. In step ST5, when the operator determines not to correct the slice positions P _{1 to} P _n , the process skips step ST6 and proceeds to step ST7. In this case, the main scan is executed based on the uncorrected slice positions P _{1 to} P _n .

In the second mode, the slice positions P _{1 to} P _n determined by the slice position determining unit 91 are displayed on the display unit 11. Therefore, the operator can easily confirm the slice positions P _{1 to} P _n by looking at the display unit 11. Further, when the operator wants to correct the slice positions P _{1 to} P _n , the operator inputs an instruction for correcting the slice positions P _{1 to} P _n from the operation unit 10, whereby the slice positions P ₁ to P _n are inputted. P _n can be easily corrected. Therefore, the main scan can be executed at the optimum slice position.

In the above description, the operator corrects all _n slice positions P _{1 to} P _n . However, the operator does not need to correct all of the _n slice positions P _{1 to} P _n , and may correct only a part of the slice positions as necessary.

(3) Third Embodiment FIG. 14 is a diagram showing an MRI apparatus 200 according to a third embodiment.

  Since the MRI apparatus 200 is the same as the first embodiment except for the central processing apparatus 9, the following mainly describes the central processing apparatus 9.

  The central processing unit 9 includes a reference point determination unit 94 in addition to the slice position determination unit 91 to the slice position correction unit 93. The reference point determination means 94 determines a reference point that serves as a mark when determining an axial section and a coronal section that cross the median plane. The central processing unit 9 is an example of the reference point determination unit 94, and functions as these units by executing a predetermined program.

Next, the operation of the MRI apparatus 200 will be described.
FIG. 15 is a diagram showing a flow in the third embodiment.

Steps ST1 to ST3 are the same as those in the first embodiment, and a description thereof will be omitted. After determining the slice position _{P a} reference slice at step ST3 (see FIG. 6), the process proceeds to step ST32.

In step ST32, the reference point determining means, on the slice position _{P a,} determines a reference point a0 (see FIG. 16).

FIG. 16 is a diagram illustrating the reference point a0.
The reference point a0 is a point that becomes a mark when an axial section and a coronal section (see FIG. 17) described later are obtained. In the third embodiment, the reference point a0 is an intermediate point between the points a1 and a2, but the reference point a0 may be positioned at a position shifted from the intermediate point. After the reference point a0 is determined, the process proceeds to step S33.

  In step S33, an axial section and a coronal section passing through the reference point a0 are obtained. FIG. 17 schematically shows an axial section AX and a coronal section CO passing through the reference point a0. After obtaining the axial section AX and the coronal section CO, the process proceeds to step S4.

  In step ST4, in order to confirm the slice position of the reference slice, the operator operates the operation unit 10 to display the slice position of the reference slice on the display unit 11 (see FIG. 18).

FIG. 18 is a diagram illustrating the position of the reference slice displayed on the display screen of the display unit 11.
From the operation unit 10, an instruction for confirming the slice position P _a reference slice is input, the display control unit 92 (see FIG. 14) causes the display unit 11 to display the slice position P _a reference slice . The display unit 11 shows three ports 11a, 11b, and 11c.

The port 11a, a image data of the median plane, the slice position P _a reference slice in the median plane is displayed.

The port 11b, a image data axial section AX passing through the reference point a0, the slice position P _a reference slice in axial section AX is displayed.

The port 11c, and the image data of the coronal cross section CO passing through the reference point a0, the slice position P _a reference slices in the coronal cross-sectional CO is displayed.
When the slice position _{P a} is displayed, the process proceeds to step ST5.

In step ST5, the operator, with reference to the slice position P _a reference slice displayed on the display unit 11, determines whether to correct the slice position P _a of the reference slice. If the operator determines to correct the slice position of the reference slice, the process proceeds to step ST6. If the operator determines not to correct the slice position of the reference slice, the process proceeds to step ST7.

In step ST6, the operator operates the operation unit 10 to input an instruction to modify a slice position P _a of the reference slice.

When a command for correcting the slice position of the reference slice is input from the operation unit 10, the slice position correcting means 93 (see FIG. 14) reads the slice position P of the reference slice according to the command input from the operation unit 10. to fix _a. Specifically, as described below, the slice position P _a is corrected.

The operator determines a port to be used for correcting the slice position from among the three ports 11a to 11c while referring to the display screen of the display unit 11 (see FIG. 18). Here, the operator, as a port for correcting the slice position P _a, and decide to use the port 11a. In this case, the operator, on the port 11a, to correct the slice position _{P a} (see FIG. 19).

  FIG. 19 is a diagram showing a display screen of the display unit 11 immediately after correcting the slice position on the port 11a.

In the port 11a, the slice position before correction is indicated by _a broken line (symbol “P _a ”), and the slice position after correction is indicated by a solid line (symbol “P _a ′”). When the slice position of the reference slice is corrected on the port 11a, the corrected slice position P _a ′ is also displayed on the other ports 11b and 11c according to the correction position (see FIG. 20).

FIG. 20 is a diagram illustrating the ports 11b and 11c on which the slice position P _a ′ after correction is displayed.

The port 11b shows image data of the axial section AX ′. The axial cross section AX ′ is a plane that crosses the reference point a0 of the slice position P _a ′ after correction.

In the port 11c, image data of the coronal section CO ′ is shown. The coronal section CO ′ is a plane that crosses the reference point a0 of the slice position P _a ′ after correction.

On the display screen of the display unit 11, the corrected slice position P _a ′ is shown on the median plane, the axial section, and the coronal section. Therefore, the operator can confirm the corrected slice position P _a ′ by using three different cross sections, so that the corrected slice position P _a ′ can be visually recognized more accurately.

When the operator wishes to adjust the slice position P _a ′ after the correction _a little, the operator may recorrect the slice position in the same procedure as described above. In the above description, the slice position is corrected at the port 11a, but may be corrected at a port different from the port 11a. For example, when the operator corrects the slice position on the port 11b, the corrected slice position is also displayed on the other ports 11a and 11c according to the correction position on the port 11b. Therefore, the operator can visually recognize the corrected slice position more accurately.
If the slice position of the reference slice is corrected, the process proceeds to step ST7.

In step ST7, as in the first embodiment, another slice position is determined based on the slice position P _a ′ of the corrected reference slice, and the main scan is executed. When the main scan is executed, the flow ends.

  In the third mode, the slice position is also displayed on the image data of a cross section (axial cross section, coronal cross section) crossing the median plane. Therefore, the operator can visually recognize the slice position before correction and the slice position after correction more accurately. In the third embodiment, an axial section and a coronal section are displayed as a section crossing the median plane, but only one of the axial section and the coronal section may be displayed, or an oblique section may be displayed. You may make it display.

(4) Fourth Embodiment In describing the fourth embodiment, differences from the first embodiment will be mainly described.

FIG. 21 is an explanatory diagram of a scan executed in the fourth mode.
In the fourth embodiment, the positioning scan and the main scans MS1, MS2, and MS3 are executed.

  The positioning scan is a scan for acquiring positioning image data. The positioning image data is data used when determining the slice positions of the main scans MS1, MS2, and MS3. The main scans MS1, MS2, and MS3 are scans for acquiring image data based on the slice position determined using the positioning image data.

FIG. 22 is a diagram showing a flow in the fourth embodiment.
Steps ST and ST2 are the same as those in the first embodiment, and a description thereof will be omitted. After obtaining the median plane in step ST2, the process proceeds to step ST3.

At step ST3, the slice positions determination means 91 (see FIG. 1) determines the slice position P _a reference slice as a slice of a reference of the main scan MS1. Slice position P _a is determined in the first embodiment and the same method (see FIG. 6). After determining the slice position _{P a,} the process proceeds to step ST34.

In step ST34, the slice position determining means 91 determines the slice position Q _a reference slice as a slice of a reference of the main scan MS2, the reference slice as a slice of a reference of the main scan MS3 and slice position R _a ( (See FIG. 23).

FIG. 23 is a diagram illustrating slice positions Q _a and R _a .
Slice position Q _a, similar to the slice position P _a, represents the slice position of the cross section perpendicular to the median plane. However, the slice position Q _a is passed through a midpoint m of the slice position P points _a a1 and a2, and so as to be perpendicular to the slice position P _a, are determined. It may be determined so as to pass through a position shifted from the intermediate point m.

Slice position R _a represents a slice position of the median plane of the same cross-section. The slice position R _a is determined so as to pass through the intermediate point m and to be perpendicular to the slice positions P _a and Q _a .

After determining the slice positions Q _a and R _a , the process proceeds to step ST4.
In step ST4, the operator, the slice position _P a, in order to confirm the _{Q a,} and _{R a,} by operating the operation unit 10 to display the slice position _P a, the _{Q a,} and _{R a} on the display unit 11 (See FIG. 24).

FIG. 24 is a diagram illustrating the position of the reference slice displayed on the display screen of the display unit 11.
When a command for confirming the slice position of the reference slice is input from the operation unit 10, the display control unit 92 (see FIG. 1) displays the slice position P _a , Q _a , and the reference slice on the display unit 11. _Ra is displayed. The display unit 11 shows three ports 11a, 11b, and 11c.

The port 11a displays median plane image data and slice positions P _a , Q _a , and R _{a on} the median plane.

The port 11b displays image data of an axial section passing through the intermediate point m and slice positions P _a , Q _a , and R _a in the axial section.

In the port 11c, image data of a coronal section passing through the intermediate point m and slice positions P _a , Q _a , and R _a in the coronal section are displayed.
When the slice positions P _a , Q _a , and R _a are displayed, the process proceeds to step ST5.

In step ST5, the operator, slice position is displayed on the display unit 11 _P a, with reference to the _{Q a,} and _{R a,} determines whether to correct the slice position _P a, _{Q a,} and _{R a} . Operator, the slice position _P a, if it is determined that modifying at least one of the slice position of the _{Q a,} and _{R a,} the process proceeds to step ST6, all slice positions _P a, modify the _{Q a,} and _{R a} If it is determined not to proceed, the process proceeds to step ST7.

In step ST6, the operator operates the operation unit 10 to input a command for correcting at least one of the slice positions P _a , Q _a , and R _a (see FIG. 25).

FIG. 25 is a diagram illustrating the display screen of the display unit 11 after correcting the slice position.
When a command for correcting the slice position of the reference slice is input from the operation unit 10, the slice position correcting means 93 (see FIG. 1) determines the slice position of the reference slice according to the command input from the operation unit 10. Correct it. In Figure 25, the slice position P _a and Q _a are not corrected, an example of a case where the corrected slice position R _a is shown, slice position R _a after modification, by the symbol "R _{a ''} It is shown. In FIG. 24, the port 11b has a slice position R _a (dashed line) before correction so that the difference between the slice position R _a before correction and the slice position R _a ′ after correction can be easily recognized. It is shown. When the slice position is corrected, the process proceeds to step ST7.

In step ST7, the main scans MS1, MS2, and MS3 are executed in order.
FIG. 26 is a diagram illustrating an example of slices set when each of the main scans MS1, MS2, and MS3 is executed.

Slice positions determination means 91 (see FIG. 1), for the scan MS1 is (upper see FIG. 26), based on the slice position P _a, determines the other slice position. Also, the main scan MS2 is (middle see FIG. 26), based on the slice position Q _a, determines the other slice position, the main scan MS3 is (refer to the bottom of FIG. 26), the slice position of the corrected R Based on _a ', another slice position is determined.

  According to the slice position shown in FIG. 26, the main scans MS1, MS2, and MS3 are sequentially executed, and the flow ends.

In the fourth embodiment, since the slice positions P _a , Q _a , and R _a determined by the slice position determination unit 91 can be visually recognized, the slice positions P _a , Q _a , and R _a are optimal. It is possible to easily determine whether or not it is a position. Further, when the operator wishes to correct the slice position P _a , Q _a , or R _a , the operator inputs a command for correcting the slice position P _a , Q _a , or R _a from the operation unit 10. Thus, the slice positions P _a , Q _a , and R _a can be easily corrected. Therefore, even when a plurality of main scans are executed, each main scan can be executed at an optimum slice position.

In the fourth embodiment, slice positions P _a , Q _a , and R _a are displayed in step ST4 (see FIG. 24). However, as in the second embodiment, other slice positions may also be displayed (see FIG. 12) so that not only the slice positions P _a , Q _a , and R _a but also other slice positions can be corrected. .

2 Magnet 3 Table 3a Cradle 4 Receiving coil 5 Sequencer 6 Transmitter 7 Gradient magnetic field power supply 8 Receiver 9 Central processing unit 10 Operation unit 11 Display unit 12 Subject 21 Bore 22 Superconducting coil 23 Gradient coil 24 RF coil 91 Slice position determination Means 92 Display control means 93 Slice position correction means 94 Reference point determination means 100, 200 MRI apparatus

Claims (9)

A magnetic resonance imaging apparatus for acquiring image data of a subject,
First scan for acquiring first image data used when determining a slice position, and acquiring second image data based on the slice position determined using the first image data Scanning means for executing a second scan for performing,
Based on the first image data, image data of the first cross section of the subject is obtained, and based on the image data of the first cross section, a slice of a reference slice serving as a reference for the slice of the second scan Slice position determining means for determining the position;
Display control means for displaying a slice position of the reference slice on a display unit;
Slice position correcting means for correcting the slice position of the reference slice displayed on the display unit in accordance with an operation by an operator;
Have
The display control means includes
The display unit displays the image data of the first cross section, and displays the slice position of the reference slice on the image data of the first cross section.
The display control means further includes
The display unit displays image data of a second cross section obtained using a reference point determined based on a slice position of the reference slice, and the reference slice is displayed on the image data of the second cross section. Display the slice position of
The slice position determining means includes
A magnetic resonance imaging apparatus that determines another slice position in the second scan based on the slice position of the reference slice corrected by the slice position correcting means.   The magnetic resonance imaging apparatus according to claim 1, wherein the display control unit causes the display unit to display the other slice position in the second scan. The image data of the first cross section is image data of the median plane, the magnetic resonance imaging apparatus according to claim 1 or 2. The magnetic resonance imaging apparatus according to claim 3 , wherein the image data of the second section is image data of an axial section or image data of a coronal section. The scanning unit performs a third scan for acquiring third image data based on a slice position determined using the first image data;
The slice position determining means determines a slice position of another reference slice serving as a reference of the slice of the third scan based on the first image data;
The display control means displays the slice position of the other reference slice on the display unit,
The slice position correcting means, in response to operation of the operator to correct the slice position of the other reference slice displayed on the display unit, a magnetic resonance according to any one of claims 1 to 4 apparatus. The slice position determining means includes
The magnetic resonance imaging apparatus according to claim 5 , wherein another slice position in the third scan is determined based on a slice position of the other reference slice corrected by the slice position correcting unit. The magnetic resonance imaging according to claim 5 , wherein the display unit displays a slice position of the other reference slice on the image data of the first cross section or the image data of the second cross section. apparatus. Having a reference point determining means for determining the reference point, a magnetic resonance imaging apparatus according to any one of claims 1 to 7. A magnetic resonance imaging apparatus for acquiring image data of a subject , wherein a first scan for acquiring first image data used for determining a slice position and the first image data are used. A program of a magnetic resonance imaging apparatus that executes a second scan for acquiring second image data based on the slice position determined in the above,
Based on the first image data, image data of the first cross section of the subject is obtained, and based on the image data of the first cross section, a slice of a reference slice serving as a reference for the slice of the second scan A slice position determination process for determining the position;
Display control processing for displaying the slice position of the reference slice on a display unit;
A slice position correction process for correcting the slice position of the reference slice displayed on the display unit in accordance with an operation of the operator;
Is a program for causing a computer to execute
The display control process includes:
The display unit displays the image data of the first cross section, and displays the slice position of the reference slice on the image data of the first cross section.
The display control process further includes
The display unit displays image data of a second cross section obtained using a reference point determined based on a slice position of the reference slice, and the reference slice is displayed on the image data of the second cross section. Display the slice position of
The slice position determination process includes:
A program for determining another slice position in the second scan based on a slice position of the reference slice corrected by the slice position correction process.

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