Magnetic resonance imaging apparatus and magnetic resonance imaging method

Abstract

The present invention provides a magnetic resonance imaging device and a magnetic resonance imaging method. The magnetic resonance imaging device is used to image an examination part of a subject, and comprises: an acquisition unit, which continuously acquires navigation echo signals and imaging echo signals from the examination part in multiple excitations; a correction unit, which uses multiple spherical k-spaces generated based on the navigation echo signals in the multiple excitations to calculate the movement amount of the subject and correct the imaging k-space generated based on the imaging signals in the multiple excitations; and an image generation unit, which uses the corrected imaging k-space to generate an image of the examination part.

Description

Technical Field

[0001] The present invention relates to a magnetic resonance imaging apparatus and a magnetic resonance imaging method capable of performing motion correction. Background Art

[0002] In magnetic resonance imaging (MRI), a single scan takes several minutes to several tens of minutes, so the movement of the patient during the scan may appear as motion artifacts in the image. One method for suppressing motion artifacts is high-speed data acquisition. For example, there is a sequence that utilizes SSFP (Steady-State Free Precession). Another method for suppressing motion artifacts is motion correction.

[0003] In magnetic resonance imaging, differences in the intensities of a plurality of echo signals used to obtain MR (Magnetic Resonance) images may deteriorate the contrast of MR images. Therefore, in order to stabilize the intensity of the echo signals, for example, VFA (Variable Flip Angle) may be used. Summary of the invention

[0004] The present invention provides a magnetic resonance imaging apparatus and a magnetic resonance imaging method capable of accurately correcting the movement of a subject without increasing the scanning time.

[0005] The magnetic resonance imaging apparatus of the present invention is used to image an examination part of a subject, and comprises: an acquisition unit, which continuously acquires navigation echo signals and imaging echo signals from the examination part in multiple excitations; a correction unit, which uses multiple spherical k-spaces generated based on the navigation echo signals in the multiple excitations to calculate the movement amount of the subject and correct the imaging k-space generated based on the imaging signals in the multiple excitations; and an image generation unit, which generates an image of the examination part using the corrected imaging k-space.

[0006] The magnetic resonance imaging method of the present invention is used to image the examination part of the subject, and continuously collects navigation echo signals and imaging echo signals from the above-mentioned examination part in multiple excitations. In the above-mentioned multiple excitations, multiple spherical k-spaces generated based on the above-mentioned navigation echo signals are used to calculate the movement amount of the above-mentioned subject, and the imaging k-space generated based on the above-mentioned imaging signal in the above-mentioned multiple excitations is corrected, and the image of the above-mentioned examination part is generated using the corrected imaging k-space.

[0007] Effects of the Invention

[0008] According to the magnetic resonance imaging apparatus and the magnetic resonance imaging method of the present invention, it is possible to accurately correct the movement of the subject without increasing the scanning time during magnetic resonance imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a structural block diagram of the magnetic resonance imaging device of the present invention.

[0010] Figure 2 FIG. 1 is a diagram showing an example of a pulse sequence of a magnetic resonance imaging apparatus.

[0011] Figure 3 FIG. 1 is a diagram showing a method of constructing a spherical k-space according to an example of the present invention.

[0012] Figure 4 It is a diagram showing a method of performing three-dimensional imaging of an examination part of a subject according to the present invention.

[0013] Figure 5 is a diagram of a pulse sequence of a magnetic resonance imaging apparatus in the prior art. DETAILED DESCRIPTION

[0014] Below, based on Figure 1 to Figure 4 The magnetic resonance imaging apparatus 1 of the present invention will be described.

[0015] Figure 1 1 is a block diagram of the structure of the magnetic resonance imaging apparatus 1. Hereinafter, each structure of the magnetic resonance imaging apparatus 1 will be described. The static magnetic field magnet 10 generates a static magnetic field in the imaging space where the subject is arranged. For example, the static magnetic field magnet 10 is formed of a superconducting magnet or a permanent magnet.

[0016] The gradient magnetic field coil 20 generates a gradient magnetic field. For example, the gradient magnetic field coil has an X-coil, a Y-coil, and a Z-coil corresponding to the mutually orthogonal X-axis, Y-axis, and Z-axis, respectively. The X-coil, the Y-coil, and the Z-coil generate a gradient magnetic field along the directions of the axes by means of 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. Moreover, the X-axis is set along the horizontal direction orthogonal to the Z-axis. The Y-axis is set along the direction orthogonal to both the Z-axis and the X-axis.

[0017] The gradient magnetic field power supply 30 supplies current to the gradient magnetic field coil 20. The gradient magnetic field power supply 30 supplies current to the gradient magnetic field coil 20, so that the gradient magnetic field coil 20 can generate a gradient magnetic field.

[0018] The RF (Radio Frequency) coil 40 applies a high-frequency magnetic field to the subject arranged in the imaging space, and receives NMR (Nuclear Magnetic Resonance) signals generated from the subject. The high-frequency magnetic field is sometimes also called an RF pulse. The RF coil 40 includes a whole-body RF coil 41 arranged to surround the imaging space and a local RF coil 42 arranged close to the subject. The functions of the RF coil 40 are roughly divided into the transmission of high-frequency magnetic fields and the reception of NMR signals. Either the whole-body RF coil 41 or the local RF coil 42 may have both the transmission and reception functions, or both the whole-body RF coil 41 and the local RF coil 42 may be used for transmission and reception. In addition, a plurality of local RF coils 42 may be used simultaneously. The local RF coil 42 may also be set to be different according to the part of the subject.

[0019] The transmission circuit 50 outputs a high-frequency pulse signal corresponding to the Larmor frequency inherent to the target atomic nuclei placed in the static magnetic field to the RF coil 40 .

[0020] 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 .

[0021] 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.

[0022] The input interface 80 receives input operations of various instructions and various information from the operator. Specifically, the input interface 80 is connected to the processing circuit 100, and converts the input operation received from the operator into an electrical signal and outputs it to the processing circuit 100. For example, the input interface 80 is implemented by a trackball, a switch button, a mouse, a keyboard, a touchpad for performing input operations by touching the operation surface, a touch screen integrating a display screen and a touchpad, a non-contact input circuit using an optical sensor, and a sound input circuit. In addition, in this specification, the input interface 80 is not limited to components including physical operating components such as a mouse and a keyboard. For example, a processing circuit for receiving an electrical signal corresponding to an input operation from an external input device that is separate from the device and outputting the electrical signal to a control circuit is also included in the example of the input interface 80.

[0023] The display 81 displays various information and various images. Specifically, the display 81 is connected to the processing circuit 100, and converts the various information and various image data sent from the processing circuit 100 into display electrical signals for output. For example, the display 81 is implemented by a liquid crystal monitor, an LED monitor, a touch panel, etc.

[0024] 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 and output by each processing circuit. For example, the storage circuit 90 is implemented by a semiconductor storage element such as RAM (Random Access Memory), a flash memory, or a hard disk, an optical disk, etc.

[0025] 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 electrical 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 operates a moving mechanism of the top plate 71 of the bed 70 according to the received instruction to move the top plate 71. For example, when photographing a subject, the bed control function 101 moves the top plate 71 on which the subject is placed toward the photographing space.

[0026] The processing circuit 100 has an acquisition function 102. The acquisition function 102 acquires MR data of the subject by executing various pulse sequences. Specifically, the acquisition function 102 drives the gradient magnetic field power supply 30, the transmission circuit 50, and the receiving circuit 60 according to the sequence execution data output from the processing circuit 100, thereby executing various pulse sequences. Here, the sequence execution data is data indicating the pulse sequence, and is information that specifies the timing at which the gradient magnetic field power supply 30 supplies current to the gradient magnetic field coil 20 and the intensity of the supplied current, the timing at which the transmission circuit 50 supplies a high-frequency pulse signal to the RF coil 40 and the intensity of the supplied high-frequency pulse, the timing at which the receiving circuit 60 samples the magnetic resonance signal, and the like. The sequence execution data is pre-stored in the storage circuit 90 or generated by receiving an input from an operator in the input interface 80. In addition, the operator can also edit the sequence execution data pre-stored in the storage circuit 90. In addition, the acquisition function 102 receives the MR data output from the receiving 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, in the case of two-dimensional imaging, a phase encoding gradient magnetic field is applied to the surface of the slice selected by the slice selection gradient magnetic field. The k-space data according to the phase encoding amount of the applied gradient magnetic field is read out using a readout gradient magnetic field. The readout gradient magnetic field is also called a frequency encoding gradient magnetic field. For example, in the case of three-dimensional imaging, a slice encoding gradient magnetic field and a phase encoding gradient magnetic field are applied, and the k-space data according to the encoding amount of the applied gradient magnetic field is read out using the readout gradient magnetic field. The slice selection gradient magnetic field, phase encoding gradient magnetic field, readout gradient magnetic field, and slice encoding gradient magnetic field described above are formed by the gradient magnetic field generated by one or more coils of the X coil, Y coil, and Z coil described above.

[0027] The processing circuit 100 includes a correction function 103. The correction function 103 uses at least a part of the k-space data acquired by the acquisition function 102 to perform correction for suppressing motion artifacts caused by movement of the subject.

[0028] The processing circuit 100 has an image generation function 104. The image generation function 104 generates various images based on the k-space data acquired by the acquisition function 102. For example, an MR image is generated by performing reconstruction processing such as Fourier transform on the k-space data. The following description will be given using the imaging k-space in the Cartesian coordinate system as an example, but the imaging k-space in other coordinate systems can also be used. In addition, the image generation function 104 can also apply image processing to the reconstructed image as post-processing.

[0029] The processing circuit 100 includes a display control function 105. The display control function 105 outputs the image generated by the image generation function 104 to the display 81. Furthermore, the display control function 105 can acquire an image stored in the storage circuit 90 or an external memory and display it on the display 81.

[0030] The processing circuits 100 described above are each implemented by a processor. In this case, the processing functions of each processing circuit are 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 reads out each program from the storage circuit 90 and executes it to implement the processing function corresponding to each program. In other words, each processing circuit that reads out the state of each function has Figure 1 The functions shown in each processing circuit.

[0031] Moreover, here, it is explained that each processing circuit is implemented by a single processor, but the implementation is not limited to this. A plurality of independent processors may be combined to form each processing circuit, and each processor executes a program to implement each processing function. Moreover, the processing functions of each processing circuit may also be appropriately dispersed or concentrated in a single or multiple processing circuits. Figure 1 In the example shown, a single storage circuit 90 stores programs corresponding to respective processing functions. However, a plurality of storage circuits may be dispersedly arranged, and a processing circuit may read a corresponding program from each independent storage circuit.

[0032] Figure 2 This is a diagram showing an example of a pulse sequence included in the sequence execution data executed by the acquisition function 102 . Figure 2 A 3D FLAIR (Three-Dimensional Fluid Attenuated Inversion Recovery) sequence is shown in FIG.

[0033] exist Figure 2 In the figure, RF represents a radio frequency (RF) pulse, PE represents a gradient magnetic field pulse in the phase encoding gradient direction, SE represents a gradient magnetic field pulse in the slice encoding gradient direction, RO represents a gradient magnetic field pulse in the frequency encoding gradient direction, and ADC represents a timing for receiving an MR signal as an analog signal and digitizing it.

[0034] In one excitation, an inversion recovery (IR) pulse is applied first, followed by an excitation pulse EP, and then pulses are applied in the stabilization phase S1 and the imaging phase S2. Here, "one excitation" refers to the application of an excitation pulse EP. The IR pulse is applied, for example, to suppress water signals.

[0035] For example, in the stabilization phase S1, the navigator echo signal N is usually not collected. Moreover, even if the navigator echo signal N is collected, it is not used in image generation. In contrast, the present invention uses the signal collected in the stabilization phase S1 to correct the signal collected in the imaging phase S2.

[0036] In the stabilization stage S1, for example, by applying gradient magnetic field pulses in three different gradient directions of PE, SE, and RO, a gradient magnetic field pulse is obtained to construct the following Figure 3 The navigator echo signal N of the spherical k-space sks shown is used to construct a spherical k-space data according to the navigator echo signal N acquired in one excitation. The navigator echo signal N includes a plurality of data points. In addition, in the stabilization phase S1, for example, an RF pulse of a VFA is used.

[0037] In the imaging stage S2, as Figure 2 As shown, by applying a gradient magnetic field pulse different from the gradient magnetic field pulse applied in the stabilization phase S1, an imaging echo signal E is obtained, and an imaging k-space data is constructed according to the imaging echo signal E obtained in one excitation. The imaging echo signal E contains multiple data points.

[0038] like Figure 2 As shown, in one excitation, the stabilization phase S1 is continuous with the imaging phase S2 , that is, the imaging echo signal E is acquired immediately after the navigator echo signal N is acquired.

[0039] Below, based on Figure 3 as well as Figure 4 The correction of the imaging k-space data performed by the correction function 103 will be described.

[0040] Figure 3 is a diagram showing a method of constructing a spherical k-space sks according to an example of the present invention, Figure 4 It is a diagram showing a method of performing three-dimensional imaging of an examination part of a subject according to the present invention.

[0041] like Figure 3 As shown, when an examination region of a subject is examined, data of the examination region is usually acquired through multiple excitations. Figure 3 , n excitations are shown, namely, from excitation 1 to excitation n.

[0042] In each excitation, multiple navigation echo signals are acquired respectively. For example, excitation 1 includes multiple navigation echo signals including the first signal nav1, the second signal nav2, the third signal nav3, the fourth signal nav4, the fifth signal nav5, ... the mth signal navm (m is a natural number greater than 6). Each navigation echo signal includes multiple data points corresponding to each point of the spherical k-space sks. Moreover, although an example of acquiring the first signal nav1 to the mth signal navm (m is a natural number greater than 6) is given, the multiple navigation echo signals acquired are not particularly limited and may be less than 6.

[0043] In the first shot, when a spherical k-space sks is constructed using a plurality of navigator echo signals, the points are arranged in a spiral shape on a sphere in the order of one point in the first signal nav1, one point in the second signal nav2, one point in the third signal nav3, one point in the fourth 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, another point in the third signal nav3, another point in the fourth signal nav4, another point in the fifth signal nav5, ... another point in the mth signal navm, ..., thereby constructing a spherical k-space sks. That is, the spherical k-space sks is constructed in a manner in which the points in the respective navigator echo signals are arranged alternately.

[0044] Likewise, in each of the shots 2 to n, a spherical k-space sks is constructed in the same manner as in the shot 1.

[0045] Usually, there is an interval of several seconds between each excitation. Considering that the examination part of the subject may move during this interval, the imaging k-space part (not shown) constructed in the two adjacent excitations is corrected according to the movement amount between the respectively constructed spherical k-spaces sks.

[0046] In imaging, the case where there are excitation 1 and excitation 2 is used as an example for explanation. In excitation 1, a first spherical k-space is constructed using multiple navigation echo signals N (including the first signal nav1 to the mth signal navm), and a first imaging k-space portion is constructed using multiple imaging echo signals E (including signals E1, E2, E3, E4, E5, ...). Similarly, in excitation 2, a second spherical k-space is constructed using multiple navigation echo signals N, and a second imaging k-space portion is constructed using multiple imaging echo signals E.

[0047] The correction function 103 calculates the movement of the second spherical k-space relative to the first spherical k-space based on the navigator echo signal N. The movement includes the rotation and translation between the two spherical k-spaces. The calculation method of the rotation angle and the translation amount between the two spherical k-spaces can use the existing technology and will not be repeated here.

[0048] The correction function 103 corrects the second imaging k-space portion according to the movement of the second spherical k-space relative to the first spherical k-space, that is, the rotation angle and the translation amount, to generate a corrected second imaging k-space portion, and then the image generation function 104 uses the imaging k-space composed of the corrected second imaging k-space portion and the first imaging k-space portion as a reference to reconstruct the image of the detection part of the subject.

[0049] In the two excitations, the movement amount between the spherical k-space is the movement amount of the examination part of the subject, and the movement amount is used to correct the imaging k-space part constructed in the imaging stage adjacent to the stabilization stage. The movement amount can be identified as the movement amount of the examination part of the subject in the imaging stage, so the imaging k-space part can be accurately corrected.

[0050] Even if the examination site of the subject moves, the amount of movement of the second imaging k-space portion is corrected, thereby suppressing the occurrence of motion artifacts in the reconstructed image.

[0051] The above describes a case where two excitations, namely excitation 1 and excitation 2, are included in the imaging, and the imaging k-space portion is corrected using the two adjacent excitations, but it is not limited to this. For example, more than three excitations may be included in the imaging, and non-adjacent excitations may be used to correct the imaging k-space portion. For example, correction may be performed between excitation 1 and excitation 3, between excitation 1 and excitation 4, between excitation 2 and excitation 5, and so on. In other words, the imaging k-space portion constructed in the subsequent excitation is corrected according to the amount of movement of the spherical k-space constructed in the subsequent excitation relative to the spherical k-space. In this way, the imaging k-space portion constructed in the subsequent excitation is corrected to not move relative to the imaging k-space portion constructed in the previous excitation.

[0052] In addition, the inspection part of the subject is a rigid body, so the movement amount (translation amount and rotation angle) of a certain part of the inspection part of the subject can be regarded as the movement amount of the entire inspection part. In addition, the excitation used as a reference in the correction of the movement amount does not necessarily need to be the excitation obtained in the front of the time series, and the excitation obtained in the back of the time series can also be used as a reference.

[0053] Below, based on Figure 4 A method of performing three-dimensional imaging of an examination site of a subject will be described.

[0054] In step S11, the acquisition function 102 performs data acquisition of multiple excitations such as acquiring a navigator echo signal N in the stabilization phase S1 and acquiring an imaging echo signal E in the imaging phase S2 according to the sequence execution data. The multiple excitations include at least excitation 1 and excitation 2. In excitation 1, the first navigator echo signal and the first imaging echo signal are acquired. In excitation 2, the second navigator echo signal and the second imaging echo signal are acquired. Here, the data acquired in excitation 1 is used as a reference and the data acquired in excitation 2 is used as the object of correction.

[0055] In step S12 , the correction function 103 calculates a correction value due to the movement of the subject between excitations based on the first navigator echo signal and the second navigator echo signal.

[0056] In step S13, the correction function 103 uses the correction value calculated in step S12 to correct the second imaging k-space data obtained in shot 2. In addition, the correction process may include a gridding process.

[0057] 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 performs Fourier transform and other processing on the complete k-space data to generate an MR image.

[0058] According to at least one of the embodiments described above, it is possible to improve the accuracy of motion correction.

[0059] As a comparative example to be compared with the invention involved in this embodiment, a PROMO (Prospective motion correction) sequence as a motion correction technique will be described. In PROMO, Figure 5 As shown, before the imaging sequence ET, data is collected along three mutually perpendicular planes: the coronal plane, the sagittal plane, and the axial plane. The data collection interval before the imaging sequence ET is called the navigation segment NS. The movement of the subject is estimated based on the data collected in the navigation segment NS, and the imaging sequence ET is corrected based on the estimated result, thereby suppressing motion artifacts. Here, when FLAIR imaging and PROMO are used simultaneously, since the application of IR pulses is sandwiched between the navigation segment NS and the imaging stage, there is a situation where the correction value obtained in the navigation segment NS is not suitable for the correction of the imaging stage. In other words, since a time difference occurs between the navigation segment NS and the imaging stage, the movement of the subject generated between the navigation segment NS and the imaging stage cannot be accurately corrected. Moreover, in this motion correction, the support of a scanner with a hardware feedback loop is required, so it is also limited in hardware.

[0060] On the other hand, according to at least one of the embodiments described above, since the motion correction data is acquired by utilizing the interval of the stabilization phase, even when the IR pulse is used simultaneously, the timing of acquiring the motion correction data can be suppressed from being offset in time relative to the acquisition in the imaging phase, and the accuracy of the correction data can be improved. When the accuracy of the correction data is improved, the motion artifacts in the MR image can be further suppressed.

[0061] In addition, according to at least one embodiment described above, the above correction is performed automatically without the support of a scanner having a hardware feedback loop, and therefore, there is no need to add additional hardware.

[0062] Moreover, according to at least one embodiment described above, when constructing the spherical k-space, the points in each navigator echo signal are arranged alternately. This construction method can facilitate the comparison of the spherical k-spaces constructed in two excitations and the calculation of the movement between the two spherical k-spaces. However, other construction methods can also be used to construct the spherical k-space, for example, the spherical k-space can be constructed by sequentially arranging multiple points in the first navigator echo signal, multiple points in the second navigator echo signal, etc. on a sphere.

[0063] As described above, although the above-mentioned embodiment of the present invention is described, the embodiment is shown as an example and is not intended to limit the scope of the invention. The embodiment can be implemented in various other ways, and various omissions, substitutions, and changes can be made without departing from the scope of the main purpose of the invention. The embodiment and its variations are included in the scope and main purpose of the invention, and are included in the invention recorded in the technical solution and the scope equivalent thereto.

Claims

1. A magnetic resonance imaging device for imaging an inspection part of a subject, characterized in that: have: An acquisition unit, which continuously acquires navigation echo signals and imaging echo signals from the examination site in multiple excitations; a correction unit that calculates the movement amount of the subject using a plurality of spherical k-spaces generated based on the navigator echo signals in the plurality of excitations, and corrects the imaging k-space generated based on the imaging signals in the plurality of excitations; and The image generating unit generates an image of the examination part using the corrected imaging k-space. The acquisition unit first applies an inversion recovery pulse in one excitation, then applies an excitation pulse, and then performs pulse application in a stabilization phase for stabilizing the subsequent imaging echo signal and an imaging phase for acquiring the imaging echo signal. The acquisition unit acquires the navigation echo signal in the stabilization phase. The acquisition unit acquires a plurality of navigation echo signals in each excitation. The above-mentioned multiple navigation echo signals are respectively composed of multiple data points. The spherical k-space is constructed in a manner in which the data points in the plurality of navigator echo signals are arranged alternately.

2. The magnetic resonance imaging apparatus according to claim 1, wherein: The multiple excitations include the first excitation and the second excitation. The correcting unit corrects the imaging k-space constructed in the second excitation based on an amount of movement of the spherical k-space constructed in the second excitation relative to the spherical k-space constructed in the first excitation.

3. The magnetic resonance imaging apparatus according to claim 1, wherein: The correction unit further performs gridding processing on the corrected imaging k-space.

4. The magnetic resonance imaging apparatus according to claim 1, wherein: The above inspection part is a rigid body. The above-mentioned movement amount includes the rotation angle and translation amount between spherical k-spaces.

5. A magnetic resonance imaging method for imaging an inspection part of a subject, characterized in that: In multiple excitations, navigation echo signals and imaging echo signals are continuously collected from the above-mentioned examination parts. In the multiple excitations, a plurality of spherical k-spaces generated based on the navigator echo signals are used to calculate the movement amount of the subject, and an imaging k-space generated based on the imaging signal in the multiple excitations is corrected. Use the corrected imaging k-space to generate an image of the above-mentioned examination site. The acquisition is performed by first applying an inversion recovery pulse, then applying an excitation pulse, and then performing pulse application in a stabilization phase for stabilizing the subsequent imaging echo signal and an imaging phase for acquiring the imaging echo signal. The acquisition is to acquire the navigation echo signal in the stabilization stage. The above acquisition is to collect multiple navigation echo signals in each excitation. The above-mentioned multiple navigation echo signals are respectively composed of multiple data points. The spherical k-space is constructed in a manner in which the data points in the plurality of navigator echo signals are arranged alternately.

6. The magnetic resonance imaging method according to claim 5, characterized in that: The multiple excitations include the first excitation and the second excitation. The correction is to correct the imaging k-space constructed in the second excitation according to the amount of movement of the spherical k-space constructed in the second excitation relative to the spherical k-space constructed in the first excitation.

7. The magnetic resonance imaging method according to claim 5, characterized in that: The correction mentioned above is to further perform gridding processing on the imaging k-space after the correction mentioned above.

8. The magnetic resonance imaging method according to claim 5, characterized in that: The above inspection part is a rigid body. The above-mentioned movement amount includes the rotation angle and translation amount between spherical k-spaces.

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