JP2017056092A - Device and method for magnetic resonance imaging - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an MRI device processing method in which, in an odd-numbered additional imaging, a degradation in image quality caused by a T2 attenuation or the like can be reduced at an equivalent level with the even-numbered case without degrading SNR.SOLUTION: In odd-numbered times of imaging 2N+1 (N is counted from zero), 2N data having the same number of even-numbered times and odd-numbered times are added to generate additional data of even-numbered times. Next, self-inversion data M120 is generated in which a complex conjugate is inverted from surplus imaging data Mi119 that cannot form an even-odd pair, and the data is added to surplus imaging data 119 to obtain self-inversion addition data. Lastly, by adding even-numbered addition data to the self-inversion addition data, a degradation in image quality caused by a T2 attenuation or the like can be reduced in an odd-numbered additional imaging at an equivalent level with the case of an even-numbered imaging without degrading SNR.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a magnetic resonance imaging apparatus, and more particularly to a processing technique for reducing image quality degradation caused by a step between echoes.

  A high-speed spin echo (hereinafter FSE) sequence, which is one imaging method in a magnetic resonance imaging (hereinafter referred to as MRI) system, is used to irradiate multiple echo signals by irradiating refocus RF pulses at regular intervals after irradiating one excitation RF pulse. It is a high-speed sequence that can be collected continuously. The disadvantage of this sequence is that the intensity of the nuclear magnetic resonance (hereinafter referred to as NMR) signal collected for each refocusing RF pulse is attenuated by the T2 value of the radiographed tissue.

  Therefore, it is known that a Lorentzian point spread function (hereinafter referred to as PSF) is superimposed on the image space, resulting in blurring and ring-down artifacts.

  As a countermeasure against this, even in the even addition shooting, the echo arrangement in the k-space is inverted in the time direction in the even shooting and the signal addition with the odd data is added to cancel the influence of T2 attenuation etc. A method of reducing the thickness has been reported (see Patent Document 1).

JP 11-318847 A

  In the above prior art, even number of additions are premised, and in the case of multiple additions of odd numbers such as 3, 5 etc., even-odd pairs cannot be created, so there is a problem that a sufficient effect cannot be obtained. is there.

  In response to this problem, the optimum weighting processing is performed for each data obtained by multiple-time addition shooting, and the insufficient MR signal is amplified and then added to reduce the image quality degradation caused by T2 attenuation, etc. However, in this method, since the noise signal is also amplified by the weighting process, there is a problem that the SNR deteriorates.

  An object of the present invention is to solve the above-described problems and provide an MRI apparatus and a processing method capable of reducing image quality degradation without deteriorating SNR even in odd-number addition imaging.

  In order to achieve the above object, in the present invention, an MRI apparatus including a control unit that controls measurement of an echo signal in accordance with a pulse sequence, wherein the control unit performs imaging in even-numbered imaging and odd-numbered imaging. Provided is an MRI apparatus that performs processing for reversing the echo filling order of data into the k space and processing for adding data obtained by inverting the complex conjugate to surplus imaging data that cannot form an even-odd pair during addition imaging.

  In order to achieve the above object, according to the present invention, there is provided a processing method of an MRI apparatus including a control unit that controls measurement of an echo signal according to a pulse sequence. Processing method of the MRI apparatus that reverses the echo filling order of the imaging data into the k-space and adds the self-inversion data in which the complex conjugate is inverted to the surplus imaging data that cannot form an even-odd pair at the time of addition imaging I will provide a.

  According to the MRI apparatus of the present invention, not only the even number of times but also the odd number of times of addition photographing can obtain the same image quality deterioration reduction effect as the even number of times addition photographing without deterioration of the SNR.

1 is a block diagram showing an overall configuration of an MRI apparatus according to Embodiment 1. FIG. FIG. 3 is a sequence diagram illustrating an example of FSE according to the first embodiment. The figure which showed the example of the signal attenuation | damping and PSF in NEX1 imaging | photography based on Example 1. FIG. The figure which showed the example of the signal attenuation | damping and PSF in NEX2 imaging | photography based on Example 1. FIG. The figure which showed the example of the signal attenuation | damping at the time of adding the imaging | photography data of NEX1 and NEX2 based on Example 1. FIG. The figure which showed the example of the signal attenuation | damping at the time of adding the imaging | photography data of NEX1, NEX2, and NEX3 based on Example 1. FIG. FIG. 6 is a diagram illustrating an example of excess shooting data at the time of odd-number addition shooting according to the first embodiment. FIG. 6 is a diagram for explaining cancellation of signal fluctuation due to T2 attenuation or the like based on surplus shooting data and self-inversion data according to the first embodiment. The figure which showed the flowchart of the example of preparation of the self inversion addition data based on Example 1. FIG. FIG. 3 is a flowchart illustrating an example of phase correction according to the first embodiment. The figure which showed the signal attenuation | damping of the self inversion addition data based on Example 1. FIG. The figure which showed the signal attenuation | damping of NEX1 + NEX2 + self-inversion addition data based on Example 1. FIG. The figure for demonstrating inconsistency at the time of creating self-inversion data when k space is asymmetrical based on Example 2. FIG. The figure for demonstrating inconsistency cancellation by combined use, such as a half estimation process, based on Example 2. FIG. FIG. 10 is a diagram for explaining an application example to Parallel Imaging according to the third embodiment.

  Hereinafter, preferred embodiments of the MRI apparatus of the present invention will be described in detail with reference to the accompanying drawings. In all the drawings for explaining the embodiments of the invention, those having the same function are given the same reference numerals, and their repeated explanation is omitted.

  Example 1 is an MRI apparatus including a control unit that controls measurement of an echo signal according to a pulse sequence, and the control unit fills echoes into k-space of imaging data in even-numbered and odd-numbered imaging in addition imaging. It is the Example of the MRI apparatus which performs the process which reverses the order, the process which adds the data which reversed the complex conjugate to the excess imaging | photography data which cannot make an even-odd pair at the time of addition imaging | photography, and its processing method.

First, an MRI apparatus commonly used in all the embodiments will be described with reference to FIG.
FIG. 1 is a block diagram showing the overall configuration of an embodiment of an MRI apparatus. This MRI apparatus uses a NMR phenomenon to obtain a tomographic image of a subject 101. As shown in FIG. 1, a static magnetic field generating magnet 102, a gradient magnetic field coil 103, a gradient magnetic field power supply 109, and an RF transmission coil 104 and an RF transmitter 110, an RF receiver coil 105 and a signal processor 107, a measurement controller 111, an overall controller 112, a display unit 108, an operation unit 118, and a top plate on which the subject 101 is mounted. And a bed 106 to be taken in and out of the static magnetic field generating magnet 102. In this specification, the measurement control unit 111 and the overall control unit 112 are collectively referred to as a control unit.

  The static magnetic field generating magnet 102 generates a uniform static magnetic field in the direction perpendicular to the body axis of the subject 101 in the vertical magnetic field method and in the body axis direction in the horizontal magnetic field method. A permanent magnet type, normal conducting type or superconducting type static magnetic field generating source is arranged around the.

  The gradient magnetic field coil 103 is a coil wound in the three-axis directions of X, Y, and Z that are the real space coordinate system (stationary coordinate system) of the MRI apparatus, and each gradient magnetic field coil is a gradient magnetic field that drives it. A current is supplied to the power source 109. Specifically, the gradient magnetic field power supply 109 of each gradient coil is driven according to a command from the measurement control unit 111 described later, and supplies a current to each gradient coil. Thereby, gradient magnetic fields Gx, Gy, and Gz are generated in the three-axis directions of X, Y, and Z. The gradient magnetic field coil 103 and the gradient magnetic field power supply 109 are included in the gradient magnetic field generator.

  When imaging a two-dimensional slice plane, a slice gradient magnetic field pulse (Gs) is applied in a direction orthogonal to the slice plane (imaging cross section) to set a slice plane for the subject 101, orthogonal to the slice plane and orthogonal to each other. Phase encoding gradient magnetic field pulse (Gp) and frequency encoding (reading) gradient magnetic field pulse (Gf) are applied in the remaining two directions, and position information in each direction is encoded in the nuclear magnetic resonance signal (echo signal). The

  The RF transmission coil 104 is a coil that irradiates the subject 101 with an RF pulse, and is connected to the RF transmission unit 110 and supplied with a high-frequency pulse current. As a result, an NMR phenomenon is induced in the spins of atoms constituting the living tissue of the subject 101. Specifically, the RF transmission unit 110 is driven in accordance with a command from the measurement control unit 111 (to be described later), amplitude-modulates and amplifies the high-frequency pulse, and then the RF transmission unit 104 is placed near the subject 101 after being amplified. By supplying, the subject 101 is irradiated with the RF pulse. The RF transmission coil 104 and the RF transmission unit 110 constitute an RF pulse generation unit.

  The RF receiving coil 105 is a coil that receives an echo signal emitted by the NMR phenomenon of spin that constitutes the living tissue of the subject 101, and is connected to the signal processing unit 107 so that the received echo signal is sent to the signal processing unit 107. Sent.

  The signal processing unit 107 performs detection processing of the echo signal received by the RF receiving coil 105. Specifically, in accordance with a command from the measurement control unit 111 described later, the signal processing unit 107 amplifies the received echo signal and divides it into two orthogonal signals by quadrature detection, For example, 128, 256, 512, etc.) are sampled, and each sampling signal is A / D converted into a digital quantity. Accordingly, the echo signal is obtained as echo data that is time-series digital data including a predetermined number of sampling data. Then, the signal processing unit 107 performs various processes on the echo data, and sends the processed echo data to the measurement control unit 111.

  The measurement control unit 111 mainly transmits various commands for collecting echo data necessary for reconstruction of the tomographic image of the subject 101 to the gradient magnetic field power source 109, the RF transmission unit 110, and the signal processing unit 107. And a control unit for controlling them. Specifically, the measurement control unit 111 operates under the control of the overall control unit 112 described later, and the gradient magnetic field power source 109, the RF transmission unit 110, and the signal processing unit 107 are controlled based on control data of a predetermined pulse sequence. Control to repeatedly perform the irradiation of the RF pulse and the application of the gradient magnetic field pulse to the subject 101 and the detection of the echo signal from the subject 101 to reconstruct an image of the imaging region of the subject 101 Control the collection of required echo data. In the repetition, the application amount of the phase encoding gradient magnetic field is changed in the case of two-dimensional imaging, and the application amount of the slice encoding gradient magnetic field is further changed in the case of three-dimensional imaging. Values such as 128, 256, and 512 are normally selected as the number of phase encodings, and values such as 16, 32, and 64 are normally selected as the number of slice encodings. With these controls, echo data from the signal processing unit 107 is output to the overall control unit 112.

  The overall control unit 112 controls the measurement control unit 111 and controls various data processing and display and storage of processing results, and includes an arithmetic processing unit (CPU) 114, a memory 113, and a magnetic disk. And the like, and a network IF 116 that interfaces with an external network. Further, an external storage unit 117 such as an optical disk may be connected to the overall control unit 112.

  Specifically, when the measurement control unit 111 collects echo data by executing an imaging sequence and the echo data is input from the measurement control unit 111, the arithmetic processing unit 114 converts the encoded information applied to the echo data. Based on this, the data is stored in an area corresponding to the k space in the memory 113. Hereinafter, the statement that the echo data is arranged in the k space means that the echo data is stored in an area corresponding to the k space in the memory 113. A group of echo data stored in an area corresponding to the k space in the memory 113 is also referred to as k space data.

  Then, the arithmetic processing unit 114 performs processing such as signal processing or image reconstruction by Fourier transform on the k-space data, and displays the resulting image of the subject 101 on the display unit 108 described later, It is recorded in the internal storage unit 115 or the external storage unit 117, or transferred to an external device via the network IF 116.

  The display unit 108 displays the reconstructed image of the subject 101. The operation unit 118 includes a trackball, a mouse, a keyboard, and the like for inputting various control information of the MRI apparatus and control information of processing performed by the overall control unit 112. The operation unit 118 is disposed close to the display unit 108, and an operator interactively controls various processes of the MRI apparatus via the operation unit 118 while looking at the display unit 108.

FIG. 2 shows an example of a pulse sequence of the FSE (Fast Spin Echo) method for acquiring a plurality of echo signals, which is executed under the control of the control unit of the MRI apparatus of the present embodiment.
In this figure, RF, Gs, Gp, Gr, A / D, and Signal are RF pulse application, slice selection gradient magnetic field pulse application, phase encoding gradient magnetic field pulse application, frequency encoding gradient magnetic field pulse application, and analog, respectively. Represents an axis indicating digital conversion and echo signal acquisition. Further, here, as an example, an FSE sequence for acquiring the echo signal 220 group by A / D conversion 219 for each of a plurality of inverted RF pulses 213 for one 90 ° excitation RF pulse 208 is shown.

  In the FSE sequence, first, a slice selection gradient magnetic field pulse 209 is applied together with a 90 ° excitation RF pulse 208 that applies a high-frequency magnetic field to spins in the imaging plane, and then the phase dispersion caused by the slice selection gradient magnetic field 209 is converged. A focus gradient magnetic field pulse 210 is applied. Thereafter, a 180 ° inversion RF pulse 213 for inverting the spin in the slice plane is repeatedly applied. As described above, the 180 ° inverted RF pulse 213 is repeatedly applied a plurality of times in order to acquire the echo signal 220 group in each DA period 219 for one 90 ° excitation RF pulse 208. Each time the 180 ° inversion RF pulse 213 is applied, a slice encode gradient magnetic field pulse 216, a phase encode gradient magnetic field pulse 217, and a frequency encode gradient magnetic field pulse 218 for selecting a slice are periodically applied. In the figure, 211 indicates a frequency dephase gradient magnetic field, and 221 and 222 indicate rewind gradient magnetic fields.

  This FSE sequence is a sequence in which a plurality of echo data is measured after excitation by one RF pulse and the echo data is arranged in one k space. The measured echo data is arranged and filled in the k space in the same order as the measured echo order for each echo number. The radionuclide to be imaged by the MRI apparatus is a hydrogen nucleus (proton) that is a main constituent material of the subject as widely used clinically. By imaging information on the spatial distribution of proton density and the spatial distribution of relaxation time in the excited state, the form or function of the human head, abdomen, limbs, etc. is imaged two-dimensionally or three-dimensionally.

  Next, the PSF that is convolved on the image by T2 attenuation or the like in the FSE sequence or the like in the MRI apparatus of the present embodiment will be described with reference to the drawings.

  In the upper and lower sections of Fig. 3, the first shooting data NEX (Number of Excitation) of the Echo array that fills the k space in ascending order for Echo Numbers 129 to 394 and descending order for Echo Numbers 1 to 64 and 395 to 512. 1 shows time domain signal attenuation and image domain PSF, respectively. The second imaging data NEX2 is as shown in FIG. 4 because the echo arrangement is inverted in the time direction. NEX1 shooting data and NEX2 shooting data are reversed in the time direction in the time domain, and there is no difference in the PSF of the image domain. FIG. 5 shows the result of adding both, that is, adding even numbers, as a solid line. As shown in the upper part of the figure, the signal change in the time domain becomes gradual, and as shown in the lower part of the figure, the PSF of the image domain also shows an improvement that the line width is reduced.

  Here, FIG. 6 shows the result of PSF or the like when the same addition processing is performed when the number of additions is an odd number 3. As shown in the figure, the signal attenuation after the addition processing is larger than that in the case of the even number addition, and the PSF of the image domain after the addition has a wide line width. As mentioned earlier, for this measure, in the case of odd-numbered addition shooting, it is possible to weight the even-numbered images and add them after combining the intensity with the odd-numbered shooting data. It is done. As a result, the change in signal attenuation can be suppressed even when shooting an odd number of times to the same level as when adding an even number of times, so image quality deterioration can be reduced. However, the noise component also rises due to the weighting process, so the SNR deteriorates.

  Therefore, in the configuration of the MRI apparatus of this embodiment, signal attenuation is improved by self-inverted data addition processing. Here, when the odd number addition shooting specified by the user interface such as the operation unit 118 is 2N + 1 (N is 0 counting), the even number addition data obtained by adding N even-odd pairs as shown in FIG. Can be divided into one surplus shooting data 119. Therefore, if the influence of signal attenuation can be canceled from the surplus shooting data 119, image quality deterioration can be reduced. For this reason, in the configuration of the present embodiment, as shown in FIG. 8, self-inversion data 120 for canceling the fluctuation of the signal that is the influence of T2 attenuation or the like is created from the excess imaging data 119 itself, Make a pair. That is, by adding the surplus shooting data 119 and the created self-inversion data 120 and then adding the even-numbered addition data, a good image quality deterioration reduction effect can be obtained even in odd-numbered shooting.

FIG. 9 shows a flowchart of a method for realizing addition imaging in the MRI apparatus of the present embodiment described above. First, self-inversion data M _FC (kx, ky) 120 is created by simulating data in which k spaces are filled in reverse order from surplus imaging data Mi (kx, ky) 119. The self-inversion data 120 is obtained by calculating a complex conjugate from the surplus photographing data 119 and inverting it up and down and left and right. Note that when the surplus imaging data 119 and the self-inversion data 120 are subjected to 2D Fourier transform, the absolute value images are the same but the phase is inverted due to the conjugate symmetry of the k space. This self-reversed data 120 can be thought of as the extra photographic data 119 filled in the k space in reverse order, so adding them together to obtain self-reversed summed data cancels the effects of T2 attenuation, etc. can do. Further, since the absolute value images have the same property, there is no deterioration in SNR even if they are added.

However, if it is added to the self-inversion data 120 due to a slight shift between the center of the k space in the surplus imaging data 119 and Echo Peak, the low frequency phase interferes and shading occurs. Therefore, phase correction 121, 122 is performed, the phase of the low frequency band is removed from each image, M_Cori (x, y), M_Cor _FCC (x, y) are added after addition, and self-inverted addition data M_out (x, y) 123 is obtained, and shading can be suppressed. FIG. 10 shows a specific example of the phase corrections 121 and 122. The phase corrections 121 and 122 have the same configuration, and input data and phase correction data are indicated by Min (kx, ky) and p ^* (x, y) Min (x, y), respectively. Here, p ^* (x, y) = exp (−iangle {M _Low (x, y)}).

  With the configuration of the present embodiment described above, self-inverted addition data 123 in which image quality deterioration due to T2 attenuation or the like is reduced can be created from surplus imaging data 119 itself.

  FIG. 11 shows the results of improving the effects of T2 attenuation, etc., on even-numbered addition data (NEX1 + NEX 2), surplus imaging data (NEX 1), and self-anti-addition data (NEX1 + self-inversion data) at the number of additions NEX 3. It is recognized that the signal change of the surplus photographing data becomes gentle in the self-inverted addition data as in the even-numbered addition data. As shown in Figure 12, by adding the even-numbered addition data (NEX1 + NEX2) obtained above and the self-inversion addition data (NEX3 + self-inversion data), an odd number such as (NEX1 + NEX2 + NEX3) Even in the case of multiple addition shooting 2N + 1, an effect of reducing image quality degradation due to T2 attenuation or the like can be obtained. Further, since the present invention does not include a process for raising noise, there is no deterioration in SNR. Although the description has been given assuming that the surplus shooting data is 2N + 1, any shooting data may be handled as the surplus shooting data as long as it is odd-numbered shooting data.

  In the description of the first embodiment, even when odd number addition shooting is UI-specified odd number addition shooting is 2N + 1 (N is 0), even when N = 0 single shooting, that is, NEX = 1 The self-inverted addition data calculation process of this embodiment can be used. In this case, there is no even-numbered addition data. That is, the shooting is an odd number of times of shooting, and the control unit performs processing of adding self-inversion data obtained by inverting the complex conjugate to the shooting data obtained in the first time. An effect can be obtained.

  In addition, it goes without saying that the self-inverted addition data calculation process of this embodiment can be used for every shooting data with respect to the UI-specified number of additions. In this case, after reducing the image quality deterioration due to T2 attenuation or the like for every shooting data, all the shooting data is added.

  According to the present embodiment described above, it is possible to reduce the image quality deterioration caused by T2 attenuation or the like even in odd number addition shooting without deterioration of SNR as in the case of even number shooting.

  Embodiment 2 is an embodiment of an MRI apparatus to which self-inverted addition data calculation processing is applied during half scan or partial echo imaging. That is, the imaging data of the MRI apparatus of the present embodiment is data obtained by half scan imaging or partial echo imaging, and the control unit adds self-inversion data obtained by inverting the complex conjugate to the imaging data. It is an Example of the MRI apparatus of the structure which performs a process.

  When performing half scan that only partially fills in phase encoding or partial echo imaging that partially samples echo during frequency encoding, the complex conjugate is inverted as it is because the captured data is arranged asymmetrically with respect to k-space. As shown in FIG. 13, inconsistency occurs at the filling location. In this case, by estimating the non-filling data by the Half estimation process and creating the photographic data that is symmetric in the k space, the above-described calculation process of the self-inverted addition data can be used. FIG. 14 shows an example in which the estimated surplus imaging data 125 is obtained by the half estimation with respect to the surplus imaging data 124 obtained by the half scan, and then self-inversion data 126 is created by inverting the complex conjugate vertically and horizontally. The half estimation process may be performed after the self-inversion data is created. Moreover, the algorithm of a half estimation process should just use the algorithm currently used normally.

  The third embodiment is an embodiment of an MRI apparatus that uses a calculation process of self-inverted addition data in the case of parallel imaging. That is, in the MRI apparatus of the present embodiment, the imaging data is data obtained by parallel imaging, and the control unit performs a process of adding self-inversion data obtained by inverting the complex conjugate to the imaging data. It is an Example of an MRI apparatus.

  In this embodiment, the self-inversion / addition process may be applied either before or after the expansion of data obtained by parallel imaging. FIG. 15 shows a schematic configuration when the self-inversion process is performed on the developed image of the present embodiment. Since the phase of the self-inverted addition data has been lost due to the above-described phase correction processing, depending on the Parallel Imaging algorithm, it is necessary to consider returning the phase correction to the original when applied before development. . That is, 2D FFT and various corrections are performed on each of the plurality of thinned-out data 126 obtained by Parallel Imaging, and the obtained data 127 is SENSE-developed to create a developed image 128, self-inversion processing is performed, and self-inversion is performed. Addition data 129 can be obtained. For Parallel Imaging, a commonly used algorithm may be used.

  Example 4 is an example in which self-inverted addition data calculation processing is used in 3D measurement. That is, in the present embodiment, the shooting data is data acquired by 3D measurement, and the control unit inverts the complex conjugate for each of the slice axis, phase axis, and frequency axis of the 3Dk space with respect to the excess shooting data. 2 is an example of an MRI apparatus configured to create self-reversing data. When performing 3D measurement, the complex conjugate of the obtained surplus imaging data is spatially inverted, and the inversion processing is performed for each of the slice axis, phase axis, and frequency axis in the 3Dk space including the slice axis. . Alternatively, the present invention may be applied to a 2D cross section composed of a slice axis and a phase axis, or a slice axis and a frequency axis.

  Embodiment 5 is an embodiment that uses self-inverted addition data calculation processing when adding after excluding shooting data that is severely deteriorated in image quality due to the influence of body movement or the like in multiple addition shooting of the trunk or the like. is there.

  In such multiple addition shooting, there is one surplus shooting data that cannot make even-odd pairs with the shooting data remaining after exclusion in the application that adds after excluding shooting data whose image quality is severely degraded due to the influence of body movement etc. There may be more. For example, when image quality deterioration is severe in all odd-numbered shooting data, removing them may leave only even-numbered shooting data, and it may not be possible to create even-odd pairs. In the present embodiment, a process of adding data obtained by inverting the complex conjugate to the surplus shooting data that cannot form an even-odd pair at the time of addition shooting is performed.

  As described above, in the present embodiment, the self-inverted addition data calculation process is used not only in the case of odd-number addition shooting but also in the case where an even-odd pair cannot be formed in this way. In the case of the present embodiment, it is assumed that one or more surplus shooting data exists in shooting data with little image quality degradation, and self-inversion data is created using the surplus shooting data, and each is added as an even-odd pair. . In other words, in the present embodiment, the surplus photographing data is self-inverted addition data using self-inverted data, respectively, so that addition processing is performed after image quality deterioration due to T2 attenuation or the like is reduced.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, in the description of the above embodiment, the FSE sequence of the MRI apparatus has been described as an example. However, the present invention is not limited to the FSE sequence, and image quality degradation caused by an echo interval or the like such as an EPI (Echo Planer Imaging) sequence occurs. The same can be applied to the sequence. Further, the above-described embodiments have been described in detail for better understanding of the present invention, and are not necessarily limited to those having all the configurations described above. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  Furthermore, each of the above-described configurations, functions, processing units, and the like has been described as an example of creating a program to be executed by a CPU that realizes part or all of them. Needless to say, it may be realized by hardware.

101 Subject
102 Static magnetic field generating magnet
103 gradient coil
104 RF transmitter coil
105 RF receiver coil
106 beds
107 Signal processor
108 Display
109 Gradient magnetic field power supply
110 RF transmitter
111 Measurement controller
112 Overall control unit
113 memory
114 Arithmetic processing unit (CPU)
115 Internal storage
116 Network IF
117 External storage
118 Control panel
119, 124 Surplus shooting data
120, 126 Self-reversing data
121, 122 Phase correction
123, 129 Self-inverted addition data
127 Thinned out data
128 Expanded image
208 90 ° excitation RF pulse
209, 214 Slice selective gradient magnetic field pulses
210, 215 Refocus gradient magnetic field pulse
211 Frequency dephase gradient magnetic field
212 Crusher gradient magnetic field pulse
213 180 ° inverted RF pulse
216 slice encoding gradient magnetic field pulses
217 Phase encoding gradient magnetic field pulse
218 Frequency encoding gradient magnetic field pulse
219 A / D period
220 Echo signal
221 and 222 Rewind gradient magnetic field pulse

Claims (7)

A magnetic resonance imaging (hereinafter referred to as MRI) apparatus comprising a control unit that controls measurement of echo signals according to a pulse sequence,
The controller is
Processing for reversing the echo filling order of the captured data into k-space for even and odd shots in additive shooting,
A process of adding self-inversion data obtained by inverting the complex conjugate to surplus shooting data that cannot form an even-odd pair at the time of addition shooting,
An MRI apparatus characterized by that. The MRI apparatus according to claim 1,
The additive shooting is 2N + 1 (N is an integer starting from 0) times, and
The controller is
2N + 1 (N is an integer starting from 0), the self-inversion data obtained by inverting the complex conjugate is added to the shooting data obtained at the second time,
An MRI apparatus characterized by that. The MRI apparatus according to claim 1,
The imaging data is data obtained by Half Scan imaging or partial echo imaging,
The controller is
A process of adding the self-inversion data obtained by inverting the complex conjugate to the imaging data is performed.
An MRI apparatus characterized by that. The MRI apparatus according to claim 1,
The imaging data is data obtained by parallel imaging,
The controller is
A process of adding the self-inversion data obtained by inverting the complex conjugate to the imaging data is performed.
An MRI apparatus characterized by that. The MRI apparatus according to claim 1,
It is data obtained by shooting the shooting data by 3D measurement,
The controller is
For the surplus imaging data, the complex conjugate is inverted for each of the slice axis, phase axis, and frequency axis of the 3Dk space to create the self-inversion data.
An MRI apparatus characterized by that. The MRI apparatus according to claim 1,
The surplus shooting data is the corresponding odd-numbered shooting data when the even-numbered shooting data is data with image quality degradation,
The control unit generates and adds the self-inversion data from the odd-numbered shooting data.
An MRI apparatus characterized by that. A processing method of an MRI apparatus including a control unit that controls measurement of an echo signal according to a pulse sequence,
The control unit reverses the order of filling the echoes into the k-space of the shooting data in the even-numbered shooting and the odd-numbered shooting in the additional shooting,
Add the self-inversion data that is the inversion of the complex conjugate to the surplus shooting data that cannot make even-odd pairs during addition shooting.
A processing method of an MRI apparatus characterized by the above.

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