KR102232606B1 - Device and method for dynamic tagged magnet resonance imaging - Google Patents

Abstract

The present invention discloses a method of generating a magnetic resonance image using a magnetic resonance imaging device. The method of generating a magnetic resonance image comprises the steps of: periodically acquiring a magnetic resonance image signal emitted from an object by a magnetic resonance image device, acquiring under-sampled partial data in accordance with a preset lattice pattern in K-space at each acquisition time point, and acquiring the under-sampled partial data in a state in which the lattice pattern is moved by a preset distance along a specific axis after acquiring sampling data at a previous time point; estimating a position difference between overlapping images based on a correlation between aliasing images acquired from the partial data acquired at each time point; and restoring a magnetic resonance image by reflecting the estimated position difference, wherein the lattice pattern is formed not to perform sampling at lattice points adjacent to each other in a row direction, and not to perform the sampling at the lattice points adjacent to each other in a column direction.

Description

A magnetic resonance imaging apparatus and a magnetic resonance image generation method {DEVICE AND METHOD FOR DYNAMIC TAGGED MAGNET RESONANCE IMAGING}

The present invention relates to a magnetic resonance imaging apparatus and a method of generating a magnetic resonance image, and more particularly, to a method and apparatus for restoring a magnetic resonance image capable of minimizing the influence of breathing movements.

In general, a device that processes magnetic resonance imaging (MRI) is a device that acquires a tomographic image of a specific area of a patient by using a resonance phenomenon caused by the supply of electromagnetic wave energy. There is no exposure and a tomographic image can be obtained relatively easily. For example, MRI devices are widely used for accurate disease diagnosis because they show bones as well as disks, joints, nerve ligaments, and the like from a desired angle in three dimensions.

However, since the scan time for acquiring the magnetic resonance image is long, there is a problem in that image quality is degraded in the case of chest and abdominal MRI in which the breathing movement of the patient affects.

In order to solve this problem, in the case of 2D MRI, a method of performing a scan while the patient holds his breath or repeating the scan when movement occurs is used. However, in the case of ultra-high resolution or three-dimensional MRI, the total scan time is as long as at least 30 seconds, so data cannot but be obtained during free breathing. In this case, a method is needed to minimize the effect of breathing movements.

The most commonly used breathing movement processing method is the so-called breathing navigator method, which shortly obtains a signal to determine the location of the test organ (e.g., heart, lung, liver) immediately before obtaining the MRI image data. do. Based on this, the image data is obtained only in the case of a specific breathing state (eg, exhalation), and if not, the data at the same location is secured by omitting the acquisition of the image data. However, there is a disadvantage in that the data acquisition omission time is lengthened, and the total scan time until all the desired image data is acquired is very long.

As another application example of the breathing navigator method, there is a method of continuously obtaining data but performing active motion correction using the obtained location information. However, there is a disadvantage in that only one-dimensional position (in the up-down direction) can be grasped through the breathing navigator, and there is a difference between the navigator data acquisition time and the main image data acquisition time, so that the accuracy of motion correction may be degraded.

Accordingly, the present invention proposes a method of generating a magnetic resonance image capable of correcting breathing movements without using a breathing navigator.

Korean Patent Registration No. 10-2092908 (Name of invention: Magnetic resonance imaging device for respiration movement correction)

The present invention is to solve the problems of the prior art, and some embodiments of the present invention are magnetic resonance images capable of correcting breathing movements through a method of using undersampled data using a preset grid pattern. It is an object of the present invention to provide a method and apparatus for generating.

However, the technical problem to be achieved by the present embodiment is not limited to the technical problem as described above, and other technical problems may exist.

As a technical means for achieving the above-described technical problem, the magnetic resonance imaging apparatus for generating a magnetic resonance image according to the first aspect of the present invention includes a memory storing a program for restoring a magnetic resonance image from an MR signal obtained from an object. ; And a processor that executes the program, wherein the processor periodically acquires a MR image signal emitted from the object by the MR imaging device as the program is executed, Acquires partial data under-sampled according to a pre-set grid pattern of space K, and after obtaining sampling data at a previous point in time, obtains under-sampled partial data while moving the grid pattern by a preset distance along a specific axis. And, based on the correlation between the aliasing images acquired from the partial data acquired at each viewpoint, the positional difference between the overlapping images is estimated, and the magnetic resonance image is restored by reflecting the estimated positional difference. . In this case, the grid pattern is formed so that sampling is not performed at grid points adjacent to each other in the row direction, and sampling is not performed at grid points adjacent to each other in the column direction.

In addition, the method of generating a magnetic resonance image using the magnetic resonance imaging apparatus according to the second aspect of the present invention includes periodically acquiring a magnetic resonance image signal emitted from an object by the magnetic resonance imaging device, Acquires partial data under-sampled according to a pre-set grid pattern of space K, and after obtaining sampling data at a previous point in time, obtains under-sampled partial data while moving the grid pattern by a preset distance along a specific axis. The step of doing; Estimating a position difference between the overlapping images based on the correlation between the aliasing images acquired from the partial data acquired at each viewpoint; And restoring a magnetic resonance image by reflecting the estimated position difference, wherein the grid pattern does not perform sampling at grid points adjacent to each other in a row direction, and does not perform sampling at grid points adjacent to each other in a column direction. It was formed so as not to be.

According to the above-described problem solving means of the present invention, the present invention can determine the location of the test organ using only magnetic resonance image data without using a breathing navigator. You can acquire an image of.

In particular, when the image data is sampled in a grid pattern, since the three-dimensional position of the test organ is determined by using the characteristic that motion correlation is preserved between the partial data, the position of the test organ can be identified without using a breathing navigator.

1 is a block diagram showing an overall magnetic resonance imaging apparatus according to an embodiment of the present invention.
2 is a diagram showing the configuration of a magnetic resonance imaging apparatus according to an embodiment of the present invention.
3 is a diagram for explaining a sampling and image restoration process in a K-space applied in the prior art.
4 is a diagram for explaining a sampling and image restoration process in a K-space according to the magnetic resonance imaging method according to an embodiment of the present invention.
5 is a flowchart illustrating a method of generating a magnetic resonance image according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part is said to be "connected" with another part, this includes not only "directly connected" but also "electrically connected" with another element interposed therebetween. . In addition, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless specifically stated to the contrary.

In the present specification, "MRI (Magnetic Resonance Imaging)" refers to a magnetic field and non-ionizing radiation (radio frequency) as an object in order to acquire an image based on a physical principle called Nuclear Magnetic Resonace (NMR). It means the device to be applied.

In addition, "image" or "image" means multi-dimensional data composed of discrete elements, and a plurality of pixels in a two-dimensional image and a plurality of voxels in a three-dimensional image It means that it is composed of.

In addition, the "object" is an object to be imaged by the magnetic resonance imaging apparatus, and may include a person, an animal, or a part thereof. In addition, the object may include various organs such as the heart, brain, or blood vessels, or various types of phantoms.

In addition, the "user" may be a medical expert, such as a doctor, a nurse, a medical imaging expert, or a device repair technician, but is not limited thereto.

In addition, the "pulse sequence (or pulse train)" refers to a signal that is repeatedly applied by a magnetic resonance imaging apparatus. The pulse sequence may include a repetition time (TR) or an echo time (Time to Echo, TE) as a time parameter of the RF pulse.

Hereinafter, embodiments of a magnetic resonance imaging apparatus will be described with reference to the accompanying drawings.

1 is a block diagram showing an overall magnetic resonance imaging apparatus according to an embodiment of the present invention.

The magnetic resonance imaging apparatus 1 may include an MRI scanner 10, a signal processing unit 20, a control unit 40, a monitoring unit 50, and an interface unit 30.

The MRI scanner 10 forms a magnetic field and generates a resonance phenomenon for an atomic nucleus, and a magnetic resonance image is captured while an object is located inside the MRI scanner 10. The MRI scanner 10 includes a main magnet 12, a gradient coil 14, an RF coil 16, and the like, through which a static magnetic field and a gradient magnetic field are formed, and an RF signal is irradiated toward the object.

The main magnet 12, the gradient coil 14 and the RF coil 16 are disposed in the MRI scanner 10 according to a preset direction. An object is positioned on a table that can be inserted into the cylinder along the horizontal axis of the cylinder, and the object can be positioned inside the bore of the MRI scanner 10 according to the movement of the table.

The main magnet 12 generates a static magnetic field that aligns the directions of magnetic dipole moments of atomic nuclei included in the object in a predetermined direction.

The gradient coil 14 includes an X coil, a Y coil, and a Z coil that generate gradient magnetic fields in the X-axis, Y-axis and Z-axis directions that are orthogonal to each other. The gradient coil 14 induces different resonant frequencies for each part of the object to obtain location information of each part of the object.

The RF coil 16 may irradiate an RF signal to an object and receive a magnetic resonance image signal emitted from the object. The RF coil 16 may output an RF signal having the same frequency as the frequency of the precession toward an atomic nucleus performing the precession, and then receive a magnetic resonance image signal emitted from the object.

For example, in order to transition the atomic nucleus from a low energy state to a high energy state, the RF coil 16 generates an RF signal having a frequency corresponding to the atomic nucleus and applies it to the object. Thereafter, when the RF coil 16 stops transmitting the RF signal, the atomic nucleus to which the electromagnetic wave was applied transitions from a high energy state to a low energy state, and radiates an electromagnetic wave having a Lamore frequency, and the RF coil 16 It receives the corresponding electromagnetic wave signal.

The RF coil 16 includes a transmitting RF coil for transmitting an RF signal having a radio frequency corresponding to the type of an atomic nucleus and a receiving RF coil for receiving an electromagnetic wave radiated from the atomic nucleus.

In addition, the RF coil 16 may be fixed to the MRI scanner 10 or may be detachable. The detachable RF coil 16 may be implemented in a form such as a head RF coil, a chest RF coil, a leg RF coil, a neck RF coil, a shoulder RF coil, a wrist RF coil, and an ankle RF coil, which can be coupled to a part of an object. I can.

The MRI scanner 10 may provide various types of information to a user or an object through a display, and may include a display 18 disposed outside and a display (not shown) disposed inside.

The signal processing unit 20 may control a gradient magnetic field formed inside the MRI scanner 10 according to a predetermined MR pulse sequence (ie, a pulse train), and may control transmission and reception of an RF signal and a magnetic resonance image signal.

The signal processing unit 20 may include a gradient magnetic field amplifying unit 22, a switching unit 24, an RF transmitting unit 26, and an RF receiving unit 28.

The gradient amplifier 22 drives the gradient coil 14 included in the MRI scanner 10, and transmits a pulse signal generating a gradient magnetic field under the control of the gradient magnetic field controller 44 to the gradient coil 14. ). By controlling the pulse signal supplied to the gradient coil 14 from the gradient magnetic field amplifying unit 22, gradient magnetic fields in the X-axis, Y-axis, and Z-axis directions can be synthesized.

The RF transmitter 26 drives the RF coil 16 by supplying an RF pulse to the RF coil 16. The RF receiver 28 receives the MR image signal transmitted after the RF coil 16 receives it.

The switching unit 24 may control a transmission/reception direction of an RF signal and a magnetic resonance image signal. For example, during the transmission operation, the RF signal is irradiated to the object through the RF coil 16, and during the reception operation, the MR image signal from the object is received through the RF coil 16. The switching operation 24 is controlled by a control signal from the RF control unit 46.

The interface unit 30 may command pulse sequence information to the control unit 40 according to a user's manipulation, and at the same time transmit a command to control the operation of the entire MRI system. The interface unit 30 may include an image processing unit 36, an output unit 34, and an input unit 32 for processing a magnetic resonance image signal received from the RF receiving unit 28.

The image processing unit 36 may generate MR image data for an object by processing the MR image signal received from the RF receiver 28.

The image processing unit 36 applies various signal processing such as amplification, frequency conversion, phase detection, low frequency amplification, filtering, and the like to the MR image signal received by the RF receiver 28.

The image processing unit 36 may, for example, arrange digital data in a k-space, perform 2D or 3D Fourier transform, and reconstruct the data into image data.

In addition, various signal processing applied by the image processing unit 36 to the magnetic resonance image signal may be performed in parallel. For example, signal processing may be applied in parallel to a plurality of MR image signals received by a multi-channel RF coil to reconstruct a plurality of MR image signals into image data.

The output unit 34 may output image data or reconstructed image data generated by the image processing unit 36 to a user. In addition, the output unit 34 may output information necessary for a user to manipulate the MRI system, such as a user interface (UI), user information, or object information. The output unit 34 may include a speaker, a printer, or various image display means.

Through the input unit 32, the user may input object information, parameter information, scan conditions, pulse sequences, information on image synthesis or difference calculation, and the like. The input unit 32 may include a keyboard, a mouse, a trackball, a voice recognition unit, a gesture recognition unit, a touch screen, and the like, and may include various input devices within a range apparent to those skilled in the art.

The control unit 40 includes a sequence control unit 42 that controls a sequence of signals formed inside the MRI scanner 10, and a scanner control unit 48 that controls the MRI scanner 10 and devices installed in the MRI scanner 10. It may include.

The sequence control unit 42 includes a gradient magnetic field control unit 44 that controls the gradient magnetic field amplification unit 22, and an RF control unit 46 that controls the RF transmission unit 26, the RF receiving unit 28, and the switching unit 24. Includes. The sequence control unit 42 may control the gradient magnetic field amplification unit 22, the RF transmission unit 26, the RF reception unit 28 and the switching unit 24 according to the pulse sequence received from the interface unit 30. The pulse sequence includes all information necessary to control the gradient magnetic field amplifying unit 22, the RF transmitting unit 26, the RF receiving unit 28, and the switching unit 24, and applied to the gradient coil 14, for example. It may include information on the strength of the pulse signal, application time, application timing, and the like.

The monitoring unit 50 monitors or controls the MRI scanner 10 or devices mounted on the MRI scanner 10. The monitoring unit 50 may include a system monitoring unit 52, an object monitoring unit 54, a table control unit 56, and a display control unit 58.

The system monitoring unit 52 includes a state of a static magnetic field, a state of a gradient magnetic field, a state of an RF signal, a state of an RF coil, a state of a table, a state of a device measuring body information of an object, a power supply state, a state of a heat exchanger, You can monitor and control the condition of the compressor.

The object monitoring unit 54 monitors the state of the object, and measures the motion or position of the object, a respiration meter to measure the respiration of the object, an ECG meter to measure the electrocardiogram of the object, or the body temperature of the object. It may include a body temperature measuring device.

The table controller 56 controls movement of a table on which an object is located. The table control unit 56 may control the movement of the table in synchronization with a sequence control signal output from the sequence control unit 42. For example, in moving imaging of an object, the table control unit 56 can move the table according to sequence control, and thereby, the object is at a larger FOV than the field of view (FOV) of the MRI scanner. You can shoot.

The display control unit 58 turns on/off the display located outside and inside the MRI scanner 10 or controls a screen to be output on the display. In addition, when a speaker is located inside or outside the MRI scanner 10, the display controller 58 may control the speaker to be turned on/off or a sound to be output through the speaker.

The MRI scanner 10, the RF coil 16, the signal processing unit 20, the monitoring unit 50, the control unit 40, and the interface unit 30 may be connected to each other wirelessly or wired. It may further include a device (not shown) for synchronizing the clock (clock).

The magnetic resonance imaging apparatus 1 according to an embodiment of the present invention has a characteristic in the configuration of the image processing unit 36. In this case, the magnetic resonance imaging device 1 may be implemented as a magnetic resonance imaging device 100 in the form of a separate computing device, as shown in FIG. 2, and the memory 110 and the processor 120 mounted in the computing device ) May be used to perform a magnetic resonance image restoration operation, which will be described later.

In this case, a program for restoring a magnetic resonance image is stored in the memory 110. The memory 110 collectively refers to a nonvolatile storage device that continuously maintains stored information even when power is not supplied, and a volatile storage device that requires power to maintain stored information.

The processor 120 instructs an imaging pulse train to the signal processing unit 20 of FIG. 1 according to execution of a program stored in the memory 110 and receives a magnetic resonance signal from the signal processing unit 20. Hereinafter, it will be described in detail with reference to FIGS. 3 to 5.

2 is a diagram illustrating a configuration of a magnetic resonance imaging apparatus according to an embodiment of the present invention.

Depending on the embodiment, the magnetic resonance imaging apparatus 100 may be any image processing device capable of reconstructing a magnetic resonance image by using a magnetic resonance signal obtained by photographing a magnetic resonance image. In addition, the magnetic resonance imaging apparatus 100 may be a magnetic computing device capable of controlling acquisition of a magnetic resonance signal in magnetic resonance imaging.

Referring to FIG. 2, the magnetic resonance imaging apparatus 100 according to the embodiment may include a memory 110 and a processor 120.

Specifically, the magnetic resonance imaging apparatus 100 may be included in the MRI system 1 described with reference to FIG. 1. In this case, each of the processors 120 of the magnetic resonance imaging apparatus 100 corresponds to the controller 40 illustrated in FIG. 1.

The memory 110 stores various programs and various information. The memory 110 may store a program for applying a pulse sequence to an object and reconstructing a magnetic resonance image using an MR signal obtained in correspondence with the pulse sequence.

The processor 120 controls the overall operation of the magnetic resonance imaging apparatus 100. For example, by executing a program stored in the memory 110, the processor 120 forms a static magnetic field and a gradient magnetic field inside the scanner 10, and transmits a control signal for applying an RF signal to the object. To pass.

In addition, the processor 120 may restore the MR image by receiving the MR signal emitted from the object from the scanner 10 by executing a program stored in the memory 110.

3 is a diagram for explaining a sampling and image restoration process in a K-space applied in the prior art.

The magnetic resonance imaging apparatus acquires data from a Fourier transform domain (so-called k-space) of a desired image, and expresses it in the form of an Nx * Ny * Nz three-dimensional matrix in a 3D kx-ky-kz space. One line of data can be acquired in k-space for a time of 5-10 ms, called TR (repetition time), which corresponds to one-dimensional kx data for specific ky and kz values. As shown in FIG. 3, full sampling is always performed in the kx direction, and data is obtained while changing values of ky and kz to fill the ky-kz plane. Thereafter, an inverse Fourier transform is applied to the obtained 3D k-space matrix data, thereby obtaining a desired 3D MR image.

4 is a diagram for explaining a sampling and image restoration process in a K-space according to a magnetic resonance imaging method according to an embodiment of the present invention.

As shown, the magnetic resonance image signal is obtained in synchronization with the diastole phase in which the heart movement is the least in every cardiac cycle, but as shown, under the pre-set lattice pattern. Acquire sampled partial data (segmented acquisition data). In this case, information on the diastolic phase of the cardiac cycle may be obtained based on electrocardiogram information collected through an ECG pad attached to the patient's chest. As shown in (a) of FIG. 4, ECG information is acquired in a graph form, and data is acquired after a predetermined time has elapsed (approximately 600 ms) after the peak occurrence point.

Each circle shown in the figure represents all the data sample positions necessary to obtain an image without aliasing, and the black circle represents the location where sampling is performed, and the white circle represents the location where sampling is not performed. will be.

At this time, assuming that the size of k spatial data to be obtained is Ny*Nz, the grid pattern performs undersampling at constant integer multiple intervals in the row direction (ky direction), and in the column direction (kz direction), as shown. It is formed to perform undersampling at constant integer multiple intervals. At this time, the two integer values are independently determined, and may each have a minimum value of 2 to a maximum Ny/2 (ky direction) or Nz/2 (kz direction) value. In this case, Ny and Nz denote the number of samples to be acquired in the ky and kz directions, respectively.

For example, in the drawing, undersampling is performed at double intervals in the row direction (ky direction), and undersampling is performed at three times intervals in the column direction (kz direction). That is, the sampling is not performed at positions adjacent to each other in the row direction or the column direction, so that the sampling position and the non-sampling position appear alternately with each other. Accordingly, when Nx * Ny * Nz is 10 * 10 * 10, undersampling is performed at intervals of up to 5 times, but between the first sampling position and the second sampling position, the space occupied by the sampling position is 4 times as much. Make sure that no sampling is performed in the region.

Then, at the next point in time when sampling data is acquired, undersampling is performed while the grid pattern is moved by a predetermined distance along a specific axis (eg, ky axis or kz axis) to obtain data. For example, in the second view of the drawing, the grid pattern is moved by 1 along the ky axis compared to the first view, and the grid pattern is moved by 1 along the ky axis compared to the second view at the third view. . That is, since the grid pattern has already reached the last point at the second point in time, sampling is started at the first coordinate of the next line.

This process is repeatedly performed, and the three-dimensional position of the test organ is grasped by using the characteristic that the motion association is preserved between the partial data for each viewpoint acquired in this way.

That is, as shown in the figure, the location at which data is obtained varies as the grid pattern moves, but since the shape of the location at which data is obtained maintains the same grid pattern, each grid pattern is obtained through an inverse Fourier transform. It can be seen that the pattern of the aliased image is the same.

In this way, since the correlation of the linear motion is still preserved even between the superimposed images, based on the location of the test organ at the time of obtaining partial data at a specific time point, the relative of the test organ at the time of obtaining partial data at the rest of the time point. You can predict your location.

Various formulas can be used as a correlation metric for predicting a relative position, and cross correlation and least square error techniques can be used as representative examples.

Relative position prediction using cross-correlation can be expressed by Equation 1.

[Equation 1]

이때, I_ref(x, y, z) 는 임의의 기준시점에서의 3D 중첩영상, I(x-Δx, y-Δy, z-Δz) 는 움직임 보정이 필요한 나머지 시점에서의 3D 중첩영상을 x,y,z 축으로 각각 Δx, Δy, Δz 만큼 이동시킨 영상을 나타낸다.

At this time, I _ref (x, y, z) is the 3D superimposed image at an arbitrary reference point, and I(x-Δx, y-Δy, z-Δz) is the 3D superimposed image at the rest of the view points that require motion correction. Represents images moved by Δx, Δy, and Δz along the ,y,z axes, respectively.

The relative position prediction using the least squares error can be expressed by Equation 2.

[Equation 2]

로 계산된 k-공간 데이터를

라 할때, 보정후의 k-공간 데이터

를 수학식 3에 따라 계산한다.As above, after calculating the three-dimensional relative position, the corresponding motion correction can be corrected by applying a linear phase to the k-space data. That is, the relative position

K-spatial data calculated with

, K-space data after correction

Is calculated according to Equation 3.

[Equation 3]

5 is a flowchart illustrating a method of generating a magnetic resonance image according to an embodiment of the present invention.

First, partial data is obtained by performing under-sampling according to a grid pattern at the time of acquiring the first data (S510).

Next, at the second data acquisition point that arrives after the first data acquisition point, partial data is obtained by performing under-sampling according to the shifted grid pattern (S520).

After repeatedly performing the above steps, a position difference between the overlapping images is estimated based on the correlation between the overlapping images obtained from each partial data (S530). As described above, the position difference is estimated using the relative position prediction using the cross-correlation and the relative position prediction using the least squares error.

Then, the MR image is restored by correcting the estimated position difference (S540). That is, as in Equation 3 described above, spatial data obtained by correcting the position difference is secured to restore the magnetic resonance image.

Meanwhile, an embodiment of the present invention may be implemented in the form of a recording medium including instructions executable by a computer, such as a program module executed by a computer. Computer-readable media can be any available media that can be accessed by a computer, and includes both volatile and nonvolatile media, removable and non-removable media. Further, the computer-readable medium may include all computer storage media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data.

The above description of the present invention is for illustrative purposes only, and those of ordinary skill in the art to which the present invention pertains will be able to understand that other specific forms can be easily modified without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative and non-limiting in all respects. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as being distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the claims to be described later rather than the detailed description, and all changes or modified forms derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention. do.

1: MRI system
10: MRI scanner
20: signal processing unit
30: interface unit
40: control unit
50: monitoring unit
100: magnetic resonance imaging device
110: memory
120: processor

Claims (9)

In the magnetic resonance imaging apparatus for generating a magnetic resonance image,
A memory for storing a program for reconstructing a magnetic resonance image from an MR signal obtained from an object; And
Includes a processor (processor) that executes the program,
As the program is executed, the processor periodically acquires the MR image signal emitted from the object by the MR imaging apparatus, and the portion under-sampled according to a preset grid pattern of k-space for each acquisition time point After acquiring data and acquiring partial data under-sampled at a previous acquisition point among the acquisition points, under-sampled partial data is acquired while the grid pattern is moved by a predetermined distance along a specific axis. Based on the correlation between the aliasing images acquired from the partial data acquired at the time of acquisition, the position difference between the overlapping images is estimated, and the magnetic resonance image is restored by reflecting the estimated position difference,
Wherein the grid pattern is formed so as not to perform sampling at grid points adjacent to each other in a row direction and not to perform sampling at grid points adjacent to each other in a column direction. The method of claim 1,
Wherein the processor acquires the partial data for each diastolic phase of every cardiac cycle. The method of claim 1,
When the size of the k-space to which data is to be acquired is N*N (N is a natural number), the processor performs undersampling at integer multiple intervals in the row direction according to the lattice pattern, and undersampling at integer multiple intervals in the column direction. A magnetic resonance imaging apparatus that performs sampling, but performs undersampling at an integer multiple of N/2 from a minimum 2-fold interval. The method of claim 1,
Wherein the processor performs relative position prediction using cross correlation or relative position prediction using least square error in order to estimate a position difference between the superimposed images. In the method of generating a magnetic resonance image using a magnetic resonance imaging device,
Periodically acquiring the MR image signal emitted from the object by the MR imaging apparatus, obtaining partial data under-sampled according to a preset grid pattern of k-space for each acquisition time point, and obtaining an earlier one of the acquisition time points After acquiring the partial data under-sampled at the time point, acquiring under-sampled partial data while moving the grid pattern by a predetermined distance along a specific axis;
Estimating a position difference between the overlapping images based on the correlation between the aliasing images acquired from the partial data acquired at each acquisition time point; And
Including the step of restoring the magnetic resonance image by reflecting the estimated position difference,
The grid pattern is formed so as not to perform sampling at grid points adjacent to each other in a row direction and not to perform sampling at grid points adjacent to each other in a column direction. The method of claim 5,
The obtaining of the partial data includes obtaining the partial data at each diastolic phase of every cardiac cycle. The method of claim 5,
When the size of the k-space in which data can be acquired is N*N (N is a natural number), the step of acquiring the partial data performs undersampling at integer multiple intervals in the row direction according to the grid pattern, and In the direction of performing the undersampling at integer multiples of intervals, but performing undersampling at an integer multiple of N/2 from a minimum of 2 times intervals, MR image generation method. The method of claim 5,
The step of estimating the position difference between superimposed images obtained from the under-sampled k-spatial data is to perform relative position prediction using cross correlation or relative position prediction using least square error. Phosphorus, magnetic resonance image generation method. A computer-readable recording medium having a computer program recorded thereon for performing the method of any one of claims 5 to 8.

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