JP2022016312A - Magnetic resonance imaging device and magnetic resonance imaging method - Google Patents

Abstract

To improve image quality.SOLUTION: A magnetic resonance imaging device is a magnetic resonance imaging device for imaging an examination part of a subject, and includes a collection unit, a correction unit, and an image generation unit. The collection unit continuously collects a navigation echo signal and an imaging signal from the examination part in a plurality of times of shots respectively. The correction unit calculates an amount of movement of the subject by using a plurality of k spaces generated on the basis of the navigation echo signal in the plurality of times of shots respectively, and corrects an imaging k space generated on the basis of the imaging signal in the plurality of times of shots. The image generation unit generates an image of the examination part by using the imaging k space after correction.SELECTED DRAWING: Figure 1

Description

The embodiments disclosed herein and in the drawings relate to a magnetic resonance imaging apparatus and a magnetic resonance imaging method.

Magnetic resonance imaging (MRI) requires minutes to tens of minutes for a single scan, so patient movement during a scan may appear in the image as motion artifacts. One way to suppress motion artifacts is to collect data at high speed. For example, there is a sequence using SSFP (Steady-State Free Precession). Also, one of the other methods of suppressing motion artifacts is motion correction.
Further, in a 3D FSE (Fast Spin Echo) system sequence, VFA (Variable Flip Angle) may be generally used for the purpose of reducing blurring, improving tissue contrast, and reducing SAR (Special Absorption Rate).

Japanese Patent Laid-Open No. 2014-161566 Public Relations

One of the problems to be solved by the embodiments of the disclosure of the present specification and the drawings is to improve the image quality. However, the problems to be solved by the embodiments disclosed in the present specification and the drawings are not limited to the above problems. The problem corresponding to each effect by each configuration shown in the embodiment described later can be positioned as another problem.

The magnetic resonance imaging device according to the embodiment is a magnetic resonance imaging device for imaging an inspection site of a subject, and includes a collection unit, a correction unit, and an image generation unit. The collecting unit continuously collects the navigation echo signal and the imaging signal from the inspection site in each of the plurality of shots. The correction unit calculates the amount of movement of the subject using the plurality of k-spaces generated based on the navigation echo signal in the plurality of shots, and based on the imaging signal in the plurality of shots. Correct the generated imaging k-space. The image generation unit generates an image of the inspection site using the corrected imaging k-space.

FIG. 1 is a diagram showing an example of the configuration of the magnetic resonance imaging apparatus according to the embodiment. FIG. 2 is a diagram showing an example of a pulse sequence of the magnetic resonance imaging apparatus according to the embodiment. FIG. 3 is a diagram showing an example of a method for constructing a spherical k-space in an embodiment. FIG. 4 is a diagram showing an example of a method for three-dimensionally imaging an inspection site of a subject. FIG. 5 is a diagram showing an example of a pulse sequence of a magnetic resonance imaging apparatus according to a prior art.

Hereinafter, embodiments of the magnetic resonance imaging apparatus and the magnetic resonance imaging method will be described in detail with reference to the drawings.

Hereinafter, the magnetic resonance imaging apparatus 1 of the present invention will be described with reference to FIGS. 1 to 4. FIG. 1 is a block diagram of the magnetic resonance imaging apparatus 1. Hereinafter, each configuration of the magnetic resonance imaging device 1 will be described. The static magnetic field magnet 10 generates a static magnetic field in the imaging space in which the subject is placed. For example, the static magnetic field magnet 10 is formed of a superconducting magnet, a permanent magnet, or the like.

The gradient magnetic field coil 20 generates a gradient magnetic field. For example, the gradient magnetic field coil has an X-axis, a Y-axis, and a Z-coil corresponding to the X-axis, the Y-axis, and the Z-axis, respectively, which are orthogonal to each other. The X coil, the Y coil, and the Z coil generate a gradient magnetic field along each axial direction by the current supplied from the gradient magnetic field power supply 30. Here, the Z axis is set along the magnetic flux of the static magnetic field generated by the static magnetic field magnet 10. Further, the X axis is set along the horizontal direction orthogonal to the Z axis. The Y-axis is set along a direction orthogonal to both the Z-axis and the X-axis.

The gradient magnetic field power supply 30 supplies a current to the gradient magnetic field coil 20. When the gradient magnetic field power supply 30 supplies a current to the gradient magnetic field coil 20, the gradient magnetic field coil 20 can generate a gradient magnetic field.

The RF (Radio Frequency) coil 40 applies a high-frequency magnetic field to a subject arranged in an imaging space, and receives an NMR (Nuclear Magnetic Resonance) signal generated from the subject. The high frequency magnetic field is sometimes called an RF pulse. The RF coil 40 includes a whole-body RF coil 41 installed so as to surround the imaging space and a local RF coil 42 arranged close to the subject. The functions of the RF coil 40 can be broadly divided into transmission of a high frequency magnetic field and reception of an NMR signal. Either the whole body RF coil 41 or the local RF coil 42 may have both transmission and reception functions, or the whole body RF coil 41 and the local RF coil 42 may be used for transmission and reception. May be good. Further, a plurality of local RF coils 42 may be used at the same time. The local RF coil 42 may be provided so as to be different for each site of the subject.

The transmission circuit 50 outputs a high-frequency pulse signal corresponding to the Larmor frequency peculiar to the target nucleus placed in the static magnetic field to the RF coil 40.

The receiving circuit 60 generates magnetic resonance (MR) data based on the NMR signal received by the RF coil 40, and outputs the generated MR data to the processing circuit 100. The bed 70 includes a top plate 71 on which a subject is placed, and the top plate 71 can be moved in the vertical direction and the horizontal direction.

The input interface 80 receives various instructions and input operations of various information from the operator. Specifically, the input interface 80 is connected to the processing circuit 100, converts the input operation received from the operator into an electric signal, and outputs the input operation to the processing circuit 100. For example, the input interface 80 includes a trackball, a switch button, a mouse, a keyboard, a touch pad for performing an input operation by touching an operation surface, a touch screen in which a display screen and a touch pad are integrated, and a non-optical sensor. It is realized by a contact input circuit, a voice input circuit, and the like. In the present specification, the input interface 80 is not limited to the one including physical operation parts such as a mouse and a keyboard. For example, an example of the input interface 80 includes an electric signal processing circuit that receives an electric signal corresponding to an input operation from an external input device provided separately from the device and outputs the electric signal to a control circuit.

The display 81 displays various information and various images. Specifically, the display 81 is connected to the processing circuit 100, and converts various information and various image data sent from the processing circuit 100 into electrical signals for display and outputs the data. For example, the display 81 is realized by a liquid crystal monitor, an LED monitor, a touch panel, or the like.

The storage circuit 90 stores various data and various programs. Specifically, the storage circuit 90 is connected to the processing circuit 100 and stores various data and various programs input / output by each processing circuit. For example, the storage circuit 90 is realized by a semiconductor memory element such as a RAM (Random Access Memory) or a flash memory, a hard disk, an optical disk, or the like.

The processing circuit 100 has a bed control function 101. The bed control function 101 controls the operation of the bed 70 by outputting an electric signal for control to the bed 70. For example, the bed control function 101 receives an instruction to move the top plate 71 from the operator via the input interface 80, and moves the top plate 71 of the bed 70 so as to move the top plate 71 according to the received instruction. Operate the mechanism. For example, the bed control function 101 moves the top plate 71 on which the subject is placed to the imaging space when the subject is imaged.

The processing circuit 100 has a collection function 102. The collection function 102 collects MR data of a subject by executing various pulse sequences. Specifically, the collection function 102 executes various pulse sequences by driving the gradient magnetic field power supply 30, the transmission circuit 50, and the reception circuit 60 according to the sequence execution data output from the processing circuit 100. Here, the sequence execution data is data representing a pulse sequence, the timing at which the gradient magnetic field power supply 30 supplies a current to the gradient magnetic field coil 20, the strength of the supplied current, and the transmission circuit 50 a high frequency pulse signal to the RF coil 40. This is information that defines the timing at which the magnetic resonance signal is supplied, the strength of the high-frequency pulse to be supplied, the timing at which the receiving circuit 60 samples the magnetic resonance signal, and the like. The sequence execution data is stored in the storage circuit 90 in advance, or is generated by receiving the input of the operator in the input interface 80. Further, the operator may edit the sequence execution data stored in the storage circuit 90 in advance. Then, the collection function 102 receives the MR data output from the reception circuit 60 as a result of executing the pulse sequence, and stores it in the storage circuit 90. At this time, the MR data stored in the storage circuit 90 is stored as k-space data. For example, when performing two-dimensional imaging, a phase-encoded gradient magnetic field is applied to the slice plane selected by the slice selection gradient magnetic field. The k-space data of the phase-encoded amount according to the applied gradient magnetic field is read out using the readout gradient magnetic field. The lead-out gradient magnetic field is also called a frequency-encoded gradient magnetic field. For example, in the case of three-dimensional imaging, a slice-encoded gradient magnetic field and a phase-encoded gradient magnetic field are applied, and k-space data of an encoding amount according to the applied gradient magnetic field is read out using the lead-out gradient magnetic field. The slice-selective gradient magnetic field, phase-encoded gradient magnetic field, lead-out gradient magnetic field, and slice-encoded gradient magnetic field described above are formed by the gradient magnetic field generated by one or more of the above-mentioned X coil, Y coil, and Z coil, respectively. Will be done.

The processing circuit 100 has a correction function 103. The correction function 103 uses at least a part of the k-space data collected by the collection function 102 to make corrections for suppressing motion artifacts caused by the movement of the subject.

The processing circuit 100 has an image generation function 104. The image generation function 104 generates various images based on the k-space data collected by the collection function 102. For example, an MR image is generated by subjecting k-space data to a reconstruction process such as a Fourier transform. In the following, the imaging k-space in the Cartesian coordinate system will be described as an example, but the imaging k-space in another coordinate system can also be used. The image generation function 104 can also add image processing as post-processing to the reconstructed image.

The processing circuit 100 has a display control function 105. The display control function 105 outputs the image generated by the image generation function 104 to the display 81. It is also possible to acquire an image stored in the storage circuit 90 or an external storage and display it on the display 81.

Each of the processing circuits 100 described above is realized by a processor. In this case, the processing function of each processing circuit is stored in the storage circuit 90 in the form of a program that can be executed by a computer, for example. Then, each processing circuit realizes a processing function corresponding to each program by reading each program from the storage circuit 90 and executing the program. In other words, each processing circuit in the state where each program is read has each function shown in each processing circuit of FIG.

Further, although the description has been made here that each processing circuit is realized by a single processor, the embodiment is not limited to this, and a plurality of independent processors are combined to form each processing circuit, and each processor is programmed. Each processing function may be realized by executing. Further, the processing functions of each processing circuit may be appropriately distributed or integrated into a single processing circuit or a plurality of processing circuits. Further, in the example shown in FIG. 1, a single storage circuit 90 has been described as storing a program corresponding to each processing function, but a plurality of storage circuits are distributed and arranged, and the processing circuits are individually stored. The configuration may be such that the corresponding program is read from the circuit. The collection function, the correction function, the image generation function, and the display control function are examples of the collection unit, the correction unit, the image generation unit, and the display unit, respectively.

FIG. 2 is a diagram showing an example of a pulse sequence included in the sequence execution data executed by the collection function 102. FIG. 2 shows a 3D FLAIR (Three-Dimensional Fluid Attenuated Inversion Recovery) sequence.

In FIG. 2, RF represents a radio frequency (RF) pulse. PE indicates a gradient magnetic field pulse in the phase-encoded gradient direction, SE indicates a gradient magnetic field pulse in the slice-encoded gradient direction, RO indicates a gradient magnetic field pulse in the frequency-encoded gradient direction, and ADC receives an MR signal as an analog signal. Indicates the timing of digitization. In one shot, an inversion recovery (IR) pulse is first applied, then an excitation pulse EP is applied, and then the pulse application of the stabilization step S1 and the imaging step S2 is started. Here, "one shot" is intended to apply one excitation pulse EP. The IR pulse is applied, for example, for the purpose of suppressing a water signal.

For example, in general, the navigation echo signal N is not collected in the stabilization step S1. Further, even if the navigation echo signal N is collected, it is not used for image generation. On the other hand, the present invention uses the signal collected in the stabilization step S1 to correct the signal collected in the imaging step S2. That is, the processing circuit 100 collects the navigation echo signal N by the collection function 102 in the stabilization step S1 for stabilizing the subsequent imaging signal (imaging echo signal E).

In the stabilization step S1, for example, by applying gradient magnetic field pulses in three different gradient directions of PE, SE, and RO, a navigation echo signal N capable of constructing a spherical k-space sks shown in FIG. 3 described later is acquired and once. One spherical surface k-space data is constructed based on the navigation echo signal N acquired in the shot of. The navigation echo signal N includes a plurality of data points. In the stabilization step S1, for example, an RF pulse of VFA is used.

In the imaging step S2, as shown in FIG. 2, the imaging echo signal E was acquired by applying a gradient magnetic field pulse different from the gradient magnetic field pulse applied in the stabilization step S1, and was acquired in one shot. One imaging k-spatial data is constructed based on the imaging echo signal E. The imaging echo signal E includes a plurality of data points.

As shown in FIG. 2, in one shot, the stabilization step S1 and the imaging step S2 are continuous. That is, the imaging echo signal E is immediately acquired after the navigation echo signal N is acquired. That is, the processing circuit 100 continuously collects the navigation echo signal and the imaging signal from the inspection site in each of the plurality of shots by the collection function 102.

Hereinafter, correction of the imaging k-space data by the correction function 103 will be described with reference to FIGS. 3 and 4.

FIG. 3 is a diagram showing a method of constructing a spherical k-space sks of an example of the present invention, and FIG. 4 is a diagram showing a method of three-dimensionally imaging an inspection site of a subject of the present invention.

As shown in FIG. 3, when inspecting the inspection site of the subject, the data of the inspection site is usually collected by a plurality of shots. FIG. 3 shows n shots, that is, shots 1 to n.

Acquire multiple navigation echo signals for each shot. For example, shot 1 is a plurality of navigation echo signals of a first signal nav1, a second signal nav2, a third signal nav3, a fourth signal nav4, a fifth signal nav5, .... include. Each navigation echo signal contains a plurality of data points and corresponds to each point in the spherical k-space sks. Further, although an example of acquiring the first signal nav1 to the mth signal navm (a natural number in which m is 6 or more) is given, the plurality of acquired navigation echo signals is not particularly limited and may be less than six. ..

In shot 1, when constructing a spherical k-space sks using a plurality of navigation echo signals, one point in the first signal nav1, one point in the second signal nav2, one point in the third signal nav3, and the fourth. One point in the signal nav4, one point in the fifth signal nav5, ... one point in the mth signal navm, another point in the first signal nav1, another point in the second signal nav2, the third signal. Another point on the nav3, another point on the fourth signal nav4, another point on the fifth signal nav5, ... another point on the mth signal navm, and so on. By arranging them in a spiral shape, one spherical k-space sks is constructed. That is, the spherical k-space sks are constructed so that the points in each navigation echo signal are arranged alternately. Similarly, in shots 2 to n, one spherical k-space sks is constructed in the same manner as in shot 1.

That is, the processing circuit 100 collects a plurality of navigation echo signals for each shot by the collection function 102, and the plurality of navigation echo signals are each composed of a plurality of data points. Further, the spherical k-space generated based on these navigation echo signals is constructed so that the data points in the plurality of navigation echo signals are arranged alternately.

Normally, there is a few seconds of free time between each shot, but considering that the test site of the subject may have moved after the free time, for two adjacent shots , Correct the imaging k-space portion (not shown) constructed with two adjacent shots, based on the amount of movement between each constructed spherical k-space sks. That is, the processing circuit 100 calculates the amount of movement of the subject using the plurality of spherical k-spaces generated based on the navigation echo signals in the plurality of shots by the correction function 103, and in the plurality of shots. The imaging k-space generated based on the imaging signal is corrected.

As an example, when the plurality of shots include the first shot and the second shot, the processing circuit 100 is constructed by the correction function 103 in the second shot with respect to the spherical k-space constructed in the first shot. The imaging k-space constructed in the second shot is corrected based on the amount of movement of the spherical k-space.

In imaging, the case where shot 1 and shot 2 are present will be described as an example. In shot 1, a first spherical k space is constructed using a plurality of navigation echo signals N (including the first signal nav1 to the mth signal navm), and a plurality of imaging echo signals E (signals E1, E2, E3, E4, (Including E5, ...) Is used to construct the first imaging k space portion, and similarly, in shot 2, a plurality of navigation echo signals N are used to construct a second spherical surface k space, and a plurality of imaging echo signals E are used. Is used to construct the second imaging k-space portion. The correction function 103 calculates the movement of the second spherical surface k-space with respect to the first spherical surface k-space based on the navigation echo signal N. The movement involves rotation and translation between two spherical k-spaces. As a method for calculating the rotation angle and the amount of translation between the two spherical k-spaces, the prior art may be used, and details will not be described here.

The correction function 103 corrects the second imaging k-space portion based on the amount of movement of the second spherical surface k-space with respect to the first spherical surface k-space, that is, the rotation angle and the translation amount, and the corrected second imaging k-space. Generate a part. After that, the image generation function 104 reconstructs the image of the detection site of the subject using the imaging k-space including the corrected second imaging k-space portion and the reference first imaging k-space portion.

In the two shots, the amount of movement between the spherical k-spaces is the amount of movement of the test site of the subject, and the amount of movement is used to correct the imaging k-space portion constructed in the imaging step adjacent to the stabilization step. However, since the movement amount can be recognized as the movement amount of the inspection site of the subject in the imaging stage, accurate correction can be performed for the imaging k-space portion.

Even if the inspection site of the subject moves, the amount of movement of the second imaging k-space portion is corrected, so that motion artifacts are suppressed from occurring in the reconstructed image.

In the above, the case where the imaging includes two shots of shot 1 and shot 2 and the imagery k-space portion is corrected by using the two adjacent shots has been described, but the present invention is not limited to this. For example, three or more shots may be included in the imaging, and non-adjacent shots can be used to correct the imaging k-space portion. For example, correction can be made between shot 1 and shot 3, between shot 1 and shot 4, between shot 2 and shot 5, and the like. That is, the imaging k-space portion constructed in the rear shot is corrected based on the amount of movement of the spherical k-space constructed in the rear shot with respect to the spherical k-space. In this way, the imaging k-space portion constructed in the rear shot is corrected so as not to move as compared with the imaging k-space portion constructed in the front shot.

Further, since the test site of the subject is a rigid body, the movement amount (translation amount and rotation angle) of a certain site in the test site of the subject can be regarded as the movement amount of the entire test site. That is, the amount of movement calculated by the processing circuit 100 includes the rotation angle and the amount of translation between the spherical k-spaces. It should be noted that the shot used as a reference in the correction of the movement amount does not necessarily have to be a shot acquired earlier in chronological order, and it is also possible to use a shot acquired later in chronological order as a reference.

Hereinafter, a method of three-dimensionally imaging the inspection site of the subject will be described with reference to FIG. In step S11, the collection function 102 collects a plurality of shots of data such that the navigation echo signal N is collected in the stabilization step S1 and the imaging echo signal E is collected in the imaging step S2 according to the sequence execution data. The plurality of shots include at least shot 1 and shot 2. In Shot 1, the first navigation echo signal and the first imaging echo signal are collected. In shot 2, the second navigation echo signal and the second imaging echo signal are collected. Here, the data collected in Shot 1 is used as a reference, and the data collected in Shot 2 is targeted for correction.

In step S12, the correction function 103 calculates a correction value due to the movement of the subject between shots based on the first navigation echo signal and the second navigation echo signal. In step S13, the correction function 103 corrects the second imaging k-space data obtained in shot 2 by using the correction value calculated in step S12. The correction process may include a gridding process. That is, the processing circuit 100 may perform gridding processing on the corrected imaging k-space by the correction function 103.

In step S14, the image generation function 104 constructs complete k-space data using the first imaging k-space data and the corrected second imaging k-space data, and for the complete k-space data, the image generation function 104 MR images are generated by performing processing such as Fourier transform. That is, the processing circuit 100 generates an image of the inspection site using the corrected imaging k-space by the image generation function 104.

According to at least one embodiment described above, it is possible to improve the accuracy of motion correction.

As a comparative example with the invention according to the present embodiment, a PROMO (Prospective motion correction) sequence, which is a motion correction technique, will be described. PROMO collects data along three mutually perpendicular planes, a coronal plane, a sagittal plane, and an axial plane, prior to the imaging sequence ET, as shown in FIG. The data collection section before this imaging sequence ET is called the navigator segment NS, and the movement of the subject is estimated based on the data collected in the navigator segment NS, and the imaging sequence ET is corrected based on the estimation result to make a motion artifact. Suppress. Here, when FLAIR imaging and PROMO are used together, an IR pulse is applied between the navigator segment NS and the imaging stage, so the correction value acquired by the navigator segment NS may not be suitable for correction in the imaging stage. be. That is, since a time difference occurs between the navigator segment NS and the imaging stage, it is not possible to accurately correct the movement of the subject that occurs between the navigator segment NS and the imaging stage. Further, since the motion correction requires the support of a scanner having a hardware feedback loop, it is also restricted in terms of hardware.

On the other hand, according to at least one embodiment described above, since the motion correction data is collected by utilizing the interval of the stabilization stage, the motion correction data is collected even when the IR pulse is used in combination. It is possible to prevent the timing of the pulse from being time-shifted with respect to the collection in the imaging stage, and improve the accuracy of the correction data. If the accuracy of the correction data is improved, motion artifacts in the MR image can be further suppressed.

Further, according to at least one embodiment described above, the correction is performed automatically, and a scanner having a hardware feedback loop is not required, so that it is not necessary to add extra hardware.

Then, according to at least one embodiment described above, when constructing the spherical k-space, the points in each navigation echo signal are constructed so as to be arranged alternately, so that between two shots. Even if the subject moves, the amount of movement can be corrected, so that accurate k-space data can be obtained. However, it is also possible to construct a spherical k-space using another construction method. For example, the spherical k-space is arranged so that a plurality of points in the first navigation echo signal, a plurality of points in the second navigation echo signal, and the like are arranged in order on the spherical surface. Can be built.

According to at least one embodiment described above, the image quality can be improved.

Although some embodiments have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other embodiments, and various omissions, replacements, changes, and combinations of embodiments can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope of the invention described in the claims and the equivalent scope thereof, as are included in the scope and gist of the invention.

100 Processing circuit 101 Bed control function 102 Collection function 103 Correction function 104 Image generation function 105 Display control function

Claims (14)

A magnetic resonance imaging device for imaging the inspection site of a subject.
A collection unit that continuously collects navigation echo signals and imaging signals from the inspection site in multiple shots, respectively.
The amount of movement of the subject is calculated using the plurality of k-spaces generated based on the navigation echo signal in the plurality of shots, and the imaging generated based on the imaging signal in the plurality of shots. A correction unit that corrects k-space,
A magnetic resonance imaging apparatus including an image generation unit that generates an image of the inspection site using the corrected imaging k-space. The plurality of shots includes a first shot and a second shot, and includes the first shot and the second shot.
The correction unit corrects the imaging k-space constructed in the second shot based on the amount of movement of the k-space constructed in the second shot with respect to the k-space constructed in the first shot. Item 1. The magnetic resonance imaging apparatus according to Item 1. The magnetic resonance imaging apparatus according to claim 1, wherein the correction unit further performs a gridding process on the corrected imaging k-space. The magnetic resonance imaging device according to claim 1, wherein the collecting unit collects the navigation echo signal in a stabilization step for stabilizing the subsequent imaging signal. The inspection site is rigid and
The magnetic resonance imaging apparatus according to claim 1, wherein the movement amount includes a rotation angle between spherical k-spaces and a translation amount. The collecting unit collects a plurality of navigation echo signals for each shot, and collects a plurality of navigation echo signals.
The plurality of navigation echo signals each consist of a plurality of data points.
The magnetic resonance imaging device according to claim 1, wherein the k-space is constructed so that data points in the plurality of navigation echo signals are arranged alternately. The magnetic resonance imaging apparatus according to claim 1, wherein the k-space is a spherical k-space. A magnetic resonance imaging method for imaging the test site of a subject.
Navi echo signals and imaging signals are continuously collected from the inspection site in each of multiple shots.
The amount of movement of the subject is calculated using the plurality of k-spaces generated based on the navigation echo signal in the plurality of shots, and the imaging generated based on the imaging signal in the plurality of shots. Correct the k-space and
A magnetic resonance imaging method for generating an image of the inspection site using the corrected imaging k-space. The plurality of shots includes a first shot and a second shot, and includes the first shot and the second shot.
The correction is claimed to correct the imaging k-space constructed in the second shot based on the amount of movement of the k-space constructed in the second shot with respect to the k-space constructed in the first shot. 8. The magnetic resonance imaging method according to 8. The magnetic resonance imaging method according to claim 8, wherein the correction further performs a gridding process on the corrected imaging k-space.
The magnetic resonance imaging method according to claim 8, wherein the collection is to collect the navigation echo signal in a stabilization step for stabilizing the subsequent imaging signal. The inspection site is rigid and
The magnetic resonance imaging method according to claim 8, wherein the movement amount includes a rotation angle between spherical k-spaces and a translation amount. The collection is to collect a plurality of navigation echo signals for each shot.
The plurality of navigation echo signals each consist of a plurality of data points.
The magnetic resonance imaging method according to claim 8, wherein the k-space is constructed so that data points in the plurality of navigation echo signals are arranged alternately. The magnetic resonance imaging method according to claim 8, wherein the k-space is a spherical k-space.

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