JP2004097606A - Rf coil and magnetic resonance imaging device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an RF (radio frequency) coil which is constituted by using a fused array coil of multiple channels, and can stably receive a magnetic resonance signal excited on a subject in every face direction, and a magnetic resonance imaging device using the RF coil. <P>SOLUTION: Four single loop coil elements 101 to 104 are built up into a cylindrical shape, and four single loop coil elements 105 to 108 are built up into a cylindrical shape in the same manner, and the two cylindrical shapes are arranged in the major axis direction, and this RF coil of 8 channels is formed. In the single loop coil, a pair is formed with a pair of adjacent coil elements, and the ground for respective pairs of the coils are commonalized. Also, two adjacent coils are overlapped with each other, and an area of the overlapped part is equal and is formed, e.g., to become approximate 10% of the coil loop area. Thus, a mutual inductance between adjacent coil elements roughly becomes 0. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an RF (Radio frequency) coil and a magnetic resonance imaging apparatus that performs imaging using the RF coil, in particular, an RF coil using a single-loop coil element formed in a cylindrical shape, and using such an RF coil. The present invention relates to a magnetic resonance imaging apparatus.
[0002]
[Prior art]
The magnetic resonance imaging apparatus performs RF excitation of spin (spin) in a living tissue of a subject to be imaged and receives a magnetic resonance signal in which the excited spin is generated. Based on the received signal, the biological tissue of the subject is detected. Visualize the interior.
[0003]
A phased array coil that receives a magnetic resonance signal includes, for example, a single-loop coil element that is formed in a substantially cylindrical shape. These coil elements are approximately the same size, are formed in a loop along the surface of the cylinder, and are assembled so as to form a cylindrical shape as a whole.
[0004]
Two of the four coil elements are arranged in pairs and face each other with the center axis of the cylinder interposed therebetween. In addition, adjacent portions overlap each other so that mutual inductance between adjacent coils is zero, thereby suppressing signal interference between the coils.
The RF coil configured as described above is called a phased array coil when each channel (coil) independently receives an RF signal.
[0005]
When performing imaging, a living body tissue of a subject, for example, a portion of a human head, abdomen, or a knee (hereinafter, referred to as a subject for convenience) is placed in the internal space of a cylinder composed of phased array coils of four channels. By storing and feeding an RF signal to each RF coil in accordance with a predetermined protocol, spins are excited in the living tissue of the subject housed in the internal space of the cylinder, and the magnetic resonance signal generated thereby is, for example, , Spin echo or gradient echo in a two-dimensional space by a receiving RF coil. The living tissue in the subject can be stereoscopically imaged by predetermined signal processing according to the collected echo signals.
[0006]
In the above-described conventional RF coil and the magnetic resonance imaging apparatus using the same, it is possible to generate a high-frequency magnetic field in the internal space of the cylinder by supplying an RF signal to the transmission RF coil according to a predetermined protocol. By supplying power as a pair of a pair of RF coils arranged to face each other, a magnetic field can be generated in a direction perpendicular to the long axis of the cylinder. Also, by appropriately controlling the phase of the RF signal supplied to each set of coils, the phase of the generated magnetic field can be controlled.
[0007]
[Patent Document 1]
JP-A-11-318851 [Patent Document 2]
Japanese Patent Application Laid-Open No. 2000-185021
[Problems to be solved by the invention]
Meanwhile, in the above-described conventional RF coil and the magnetic resonance imaging apparatus using the same, when a parallel imaging technique called SENSE (Sensitivity encoding) is used by a 4-channel RF coil arranged to face each other, a cylindrical shape is used. The magnetic resonance signal can be received as a phase direction only in a direction perpendicular to the long axis of the cylinder in the internal space of the coil formed in the above, and the magnetic resonance signal cannot be received in the other direction as the phase direction.
[0009]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide an RF coil configured using a single-loop coil element and applicable to the SENSE method regardless of which direction is selected as a phase direction. To provide a magnetic resonance imaging apparatus using the RF coil.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the RF coil of the present invention is configured such that a cylindrical shape including four single-loop coil elements that form a substantially cylindrical shape is a set, and two sets of the cylindrical coils are arranged in a longitudinal direction of the cylindrical shape. In the coils of each set, the adjacent single-loop coil elements form two pairs, and the two single-loop coil elements in each pair are commonly grounded.
[0011]
Further, the magnetic resonance imaging apparatus of the present invention is a magnetic resonance imaging apparatus that generates an image of a subject based on a magnetic resonance signal received by applying a high-frequency magnetic field to a subject to be imaged under a static magnetic field and a gradient magnetic field. An imaging apparatus, comprising: an RF coil for receiving the magnetic resonance signal excited by the subject by the high-frequency magnetic field, wherein the RF coil has a cylindrical shape including four substantially single-cylindrical coil elements. As one set of coils, two sets of the cylindrical coils are arranged side by side in the longitudinal direction of the cylindrical shape, and in each set of coils, the adjacent single loop coil elements form a pair by two, The two single loop coil elements in each pair are commonly grounded.
[0012]
Further, in the present invention, preferably, in the single loop coil, adjacent coil elements are arranged so as to overlap with each other such that mutual inductance between two adjacent coils is substantially zero.
[0013]
Further, in the present invention, preferably, the two single loop coil elements adjacent in the long axis direction of the cylindrical shape are such that adjacent coil elements overlap with each other so that mutual inductance between the coil elements becomes substantially zero. Are located.
[0014]
Further, in the present invention, preferably, in the single loop coil element, two adjacent coil elements overlap each other, and the area of the overlapping portion is equal to the area of the overlapping portion between the other adjacent coil elements. Is formed.
[0015]
Further, in the present invention, preferably, the single loop coil element is formed such that two adjacent coil elements overlap each other, and the area of the overlapping portion is about 10% of the area of the entire coil element. Have been.
[0016]
Further, in the present invention, preferably, in the single loop coil element, the interval between two adjacent coil elements is formed to be equal to the interval between the other two adjacent coil elements.
[0017]
According to the present invention, an eight-channel cylindrical RF coil is configured by using two cylindrical coils each including four substantially single-loop coil elements and being arranged in the longitudinal direction of the cylinder. In each cylindrical coil, a pair is formed by two adjacent coil elements, and the ground of the two coil elements of each pair is shared. That is, the two coil elements in each pair are connected to a common ground potential line.
[0018]
Further, in the present invention, each single loop coil element is formed such that the mutual inductance between two adjacent coil elements is substantially zero.
[0019]
Further, two adjacent coil elements overlap each other, the area of the overlapping portion is formed equal to the area of the overlapping portion between other adjacent coil elements, and the area of the overlapping portion is, for example, a coil element. It is formed so as to be equal to about 10% of the entire area. Further, in the present invention, the interval between two adjacent coil elements is formed equal to the interval between the other two adjacent coil elements.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a magnetic resonance imaging apparatus of the present invention and an RF coil used therein will be described with reference to the drawings.
[0021]
FIG. 1 is a configuration diagram showing an embodiment of a magnetic resonance imaging (MRI: Magnetic Resonance Imaging) system employing a magnetic resonance imaging apparatus according to the present invention.
[0022]
As shown in FIG. 1, the MRI system 10 according to the present embodiment includes an MRI apparatus 20 disposed in a scan room (not shown) that forms a closed space that prevents leakage of radiated electromagnetic waves from a magnet and entry of disturbance electromagnetic waves. And an operator console 30 operated by an operator in an operation room provided adjacent to the scan room, for example, as a main component.
[0023]
Hereinafter, the MRI apparatus 20 and the operator console 30 will be described step by step.
[0024]
As shown in FIG. 1, the MRI apparatus 20 has a magnet system 21, an RF drive unit 22, a gradient drive unit 23, a data collection unit 24, a control unit 25, and a cradle 26.
[0025]
As shown in FIG. 1, the magnet system 21 has a substantially cylindrical internal space (bore) 211 in which a cradle 26 on which the subject 40 is placed via a cushion is transported (not shown). Department.
[0026]
In the magnet system 21, as shown in FIG. 1, a main magnetic field magnet unit 212, a gradient coil unit 213, and an RF coil unit 214 are arranged around a magnet center (center position for scanning) in the bore 211. I have.
[0027]
The main magnetic field magnet unit 212 and the gradient coil unit 213 are composed of a pair of coils facing each other with a space in the bore 211 where the subject 40 is located at the time of examination. Like the main magnetic field magnet unit 212 and the gradient coil unit 213, the RF coil unit 214 includes a pair of coils facing each other across a space in the bore 211, and a so-called bird cage formed in a cylindrical shape. May consist of coils. In particular, cylindrical RF coils are mainly used.
[0028]
The main magnetic field magnet section 212 forms a static magnetic field in the bore 211. The direction of the static magnetic field is, for example, substantially parallel to the body axis direction of the subject 40. That is, a parallel magnetic field is formed. The pair of main magnetic field magnets constituting the main magnetic field magnet unit 212 is configured using, for example, a superconducting electromagnet, a permanent magnet, a normal electromagnet, or the like.
[0029]
The gradient coil unit 213 generates a gradient magnetic field for giving a gradient to the intensity of the static magnetic field formed by the main magnetic field magnet unit 212 so that the magnetic resonance signal received by the receiving RF coil has three-dimensional position information. .
The gradient magnetic field generated by the gradient coil unit 213 is of three types: a slice gradient magnetic field, a read out gradient magnetic field, and a phase encode gradient magnetic field, and corresponds to these three gradient magnetic fields. The gradient coil unit 213 has three gradient coils.
[0030]
The RF coil unit 214 forms a high-frequency magnetic field for exciting spins in the body of the subject 40 in the static magnetic field space formed by the main magnetic field magnet unit 212. Here, forming a high-frequency magnetic field is called transmission of an RF excitation signal. Further, the RF coil unit 214 receives, as a magnetic resonance signal, an electromagnetic wave in which the excited spin occurs in the body of the subject 40.
[0031]
The RF coil unit 214 has a case in which a transmission coil and a reception coil are separately provided, and a case in which transmission and reception are shared. Note that FIG. 1 conceptually illustrates the RF coil unit 214, and the actual state of the coil may be different from the illustrated example. For example, when a transmitting coil and a receiving coil are separately provided, the receiving coil is usually attached separately to the imaging site of the subject 40. In this case, since the receiving RF coil is close to the imaging site of the subject 40, the SNR of the received magnetic resonance signal can be improved.
[0032]
The transmission RF coil receives the protocol-compliant drive signal DR1 supplied by the RF drive unit 22 and forms a high-frequency magnetic field.
On the other hand, the receiving RF coil receives a magnetic resonance signal in which the excited spin occurs in the body of the subject 40.
[0033]
In the magnetic resonance imaging apparatus of the present invention, the transmission coil and the reception coil are separately provided in the RF coil unit 214. Furthermore, the RF coil according to the present invention is a reception-only RF coil. Details of the RF coil according to the present invention will be described later.
[0034]
In the magnetic resonance imaging apparatus of the present embodiment, the transmission coil (or the transmission / reception coil) of the RF coil unit 214 receives the protocol-compliant drive signal DR1 from the RF drive unit 22 and forms a high-frequency magnetic field.
In the magnetic resonance imaging process, the number of pulse sequences (scan sequences) used for each 1TR (repetition cycle in magnetic resonance imaging) differs depending on the protocol set corresponding to each test site.
For example, it is repeated different times, for example, 64 times to 512 times, for each protocol corresponding to the test site such as the head, and view data of 64 views to 512 views is obtained.
[0035]
In the present embodiment, the RF coil unit 214 targets, for example, the head as a test site of the subject. However, the RF coil according to the present invention is not limited to the imaging target of the head of the subject, but may be applied to other parts, for example, a knee, a torso, and the like.
[0036]
The operator console 30 has a data processing unit 31, an operation unit 32, and a display unit 33, as shown in FIG.
[0037]
The data processing unit 31 stores the data acquired from the data collection unit 24 in a memory. A data space is formed in the memory. The data space formed in the memory constitutes a two-dimensional Fourier space.
The data processing unit 31 performs a two-dimensional inverse Fourier transform of the data in the two-dimensional Fourier space, that is, a conversion from the Fourier frequency space to the real space, and generates (reconstructs) an image of the subject 40.
Note that the two-dimensional Fourier space is also called a k-space.
[0038]
The control unit 25 is connected to the data processing unit 31 and is located above the control unit 25 and controls it.
An operation unit 32 and a display unit 33 are connected to the data processing unit 31.
[0039]
The operation unit 32 includes a keyboard, a mouse, and the like including a pointing device, and outputs an operation signal corresponding to an operation of the operator OP to the data processing unit 31. In addition, for example, the above-described protocol to be executed is input from the operation unit 32. The data processing unit 31 supplies information on the protocol (protocol number and the like) input from the operation unit 32 to the control unit 25.
[0040]
The display unit 33 is configured by a graphic display or the like, and displays predetermined information according to the operation state of the MRI apparatus 20 according to an operation signal from the operation unit 32.
[0041]
Hereinafter, a specific configuration of the receiving RF coil used in the magnetic resonance imaging apparatus of the present embodiment will be described with reference to the drawings.
[0042]
FIG. 2 is a configuration diagram illustrating a specific example of the receiving RF coil 100 used in the MRI apparatus 20 of the present embodiment.
As shown in the figure, the receiving RF coil 100 of the present embodiment is composed of eight coil elements 101, 102,... The coil elements 101 to 104 are configured in a single loop, and four single loop coils are assembled into a cylindrical shape. Similarly, the coil elements 105 to 108 are also configured in a single loop, and four single loop coils are assembled in a cylindrical shape. The two cylindrical RF coils thus formed are arranged in the direction of the long axis of the cylinder to form an RF coil of eight channels as a whole.
[0043]
FIG. 3 is a cross-sectional view of the RF coil shown in FIG. 2 as viewed from the long axis direction and the lateral direction. FIG. 3A is a cross-sectional view of the RF coil viewed from a long axis direction A, and FIG. 3B is a cross-sectional view of the RF coil viewed from a horizontal direction B perpendicular to the long axis.
[0044]
As shown in FIG. 3, the single-loop coil elements 101 to 104 and 105 to 108 assembled in a cylindrical shape are arranged so that adjacent coil elements overlap with each other along the circumferential direction (overlap). ing. The area of the overlapping portion corresponds to about 10% of the area of the entire coil.
Further, two coil elements adjacent to each other in the long axis direction of the cylindrical shape are also arranged so as to overlap each other.
Further, in the overlap portion, the distance between the respective coils is substantially equal.
[0045]
In the RF coil 100 shown in FIGS. 2 and 3, the ground potential (ground potential GND) of two adjacent coil elements is shared.
FIG. 4 is a diagram showing common ground potential between two adjacent coils. 4, the coil element C1 indicates, for example, the coil element 101, 103, 105 or 107 shown in FIG. 2, and the coil element C2 indicates, for example, the coil element 102, 104, 106 or 108 shown in FIG.
[0046]
As shown in FIG. 4, the coil elements C1 and C2 each form a loop, and a part of the loop formed by the coil elements C1 and C2 overlaps. The area of the overlap corresponds to about 10% of the loop area.
In each loop of the coil, one terminal is connected to the ground potential, and the other terminal is connected to the input terminal of the RF excitation signal. For example, as shown in FIG. 4, the terminal _Tc1 is an RF excitation signal input terminal of the coil element C1, and the terminal _Tc2 is an RF excitation signal input terminal of the coil element C2.
Since the input terminals _Tc1 and _Tc2 are connected to the data collection unit 24 shown in FIG. 1, the RF excitation signals output from the coil elements C1 and C2 are input to the data collection unit 24, respectively.
[0047]
As shown in FIG. 4, the ground terminals of the two coil elements are connected to a common ground line in the overlapping portion of the coil elements C1 and C2, whereby the grounds of the two coil elements C1 and C2 are made common. .
[0048]
As described above, in the RF coil unit 214 used in the magnetic resonance imaging apparatus of the present embodiment, the receiving coil is formed by the eight coil elements 101 to 104 and 105 to 108. Of the eight coil elements, adjacently arranged coil elements form a pair, and each pair has a common ground potential as shown in FIG.
By sharing the ground potential of adjacent coil elements, the coil elements 101 to 104 and 105 to 108 have virtually the same ground position, so that the stability of the formed RF coil is improved.
[0049]
As described above, by sharing the ground potential of the adjacent coil elements, the stabilization of the electrical characteristics of the entire RF coil is improved.
In addition, since a pair of coil elements forming a pair are arranged so as to overlap each other, the magnitude of the electromagnetic induction caused by the mutual inductance between the adjacent coil elements is the same, and the polarities are opposite. The mutual inductance becomes almost zero due to the cancellation.
Similarly, since two coil elements adjacent to each other in the long axis direction of the cylindrical shape are also arranged so as to overlap each other, the mutual inductance between the coil elements adjacent to each other in the long axis direction is almost zero.
[0050]
Further, in the present embodiment, since the receiving RF coil 100 is configured by eight-channel coil elements, it is possible to receive the RF excitation signal in a desired phase direction.
[0051]
Next, the overall operation of the magnetic resonance imaging apparatus of the present embodiment having the above-described configuration will be described.
[0052]
This pulse sequence for magnetic resonance imaging includes a so-called spin echo (SE: Spin Echo) method, a gradient echo (GRE: GRADIENT ECHO) method, a fast spin echo (FSE: Fast Spin Echo) method, and a fast recovery SE (Fast Recovery Spin Echo). ) Method and echo planer imaging (EPI: Echo Planar Imaging) method.
[0053]
Here, among the pulse sequences of the respective imaging methods, the pulse sequence of the SE method will be described with reference to FIG.
FIG. 5A shows a sequence of 90 ° pulse and 180 ° pulse for RF excitation in the SE method, and corresponds to a drive signal DR1 applied to the RF coil unit 214 by the RF drive unit 22.
FIGS. 5B, 5C, 5D, and 5E show the sequence of the slice gradient Gs, the readout gradient Gr, the phase encoding gradient Gp, and the spin echo MR, respectively. The pulses of the gradient Gr and the phase encoding gradient Gp correspond to the drive signal DR2 applied to the gradient coil unit 213 by the gradient drive unit 23.
[0054]
As shown in FIG. 5A, a 90 ° pulse is applied to the transmitting coil (or the transmitting / receiving coil) of the RF coil unit 214 by the RF driving unit 22 to excite the spin at 90 °. At this time, as shown in FIG. 5B, a slice gradient pulse Gs is applied to the gradient coil unit 213 by the gradient driving unit 23, and selective excitation is performed for a predetermined slice.
As shown in FIG. 5A, a predetermined time after the 90 ° excitation, a 180 ° pulse is applied to the RF coil unit 214 by the RF driving unit 22 to perform 180 ° excitation, that is, spin inversion. Also at this time, as shown in FIG. 5B, the gradient driving unit 23 applies a slice gradient pulse Gs to the gradient coil unit 213, and selectively inverts the same slice.
[0055]
As shown in FIGS. 5C and 5D, during the period between the 90 ° excitation and the spin inversion, the gradient driving unit 23 supplies the readout gradient pulse Gr and the phase encode gradient pulse Gp to the gradient coil unit 213. Is applied.
Then, spin dephase is performed by the readout gradient pulse Gr, and phase encoding of the spin is performed by the phase encode gradient pulse Gp.
[0056]
After the spin reversal, as shown in FIG. 5B, the readout gradient pulse Gr is applied to the gradient coil unit 213 by the gradient driving unit 23, and the spin is rephased in response to the readout gradient pulse Gr. As shown in ()), a spin echo MR is generated. The signal intensity of the spin echo MR becomes maximum at a time point after TE (echo time) from the 90 ° excitation.
The spin echo MR is received by the above-described receiving RF coil 100 and is collected by the data collection unit 24 as view data. Then, the view data collected by the data collection unit 24 is output to the data processing unit 31 of the operator console 30.
[0057]
In the data processing unit 31, data input from the data collection unit 24 is stored in a memory, and a data space is formed in the memory. The data processing section 31 performs a two-dimensional inverse Fourier transform on the data in the two-dimensional Fourier space to generate (reconstruct) an image of the test site of the subject 40.
[0058]
As described above, according to the receiving RF coil 100 of the present embodiment and the magnetic resonance imaging apparatus using the same, by stabilizing the electrical characteristics of the entire RF coil by sharing the ground potential of the adjacent coil elements. Is improved. In addition, since a pair of coil elements forming a pair are arranged so as to overlap each other, the magnitude of the electromagnetic induction caused by the mutual inductance between the adjacent coil elements is the same, and the polarities are opposite. There is no effect due to cancellation.
[0059]
Further, in the present embodiment, since the receiving RF coil 100 is configured by coil elements of eight channels, it is possible to receive the RF excitation signal in a desired phase direction.
Thereby, magnetic resonance imaging can be performed without receiving interference due to mutual inductance between adjacent coils. In addition, by adopting the configuration shown in FIG. 4, the opening area of each coil element can be increased, so that an RF signal can be transmitted and received with high sensitivity to the deep part of the living tissue of the subject to be imaged. A high-quality image can be generated.
[0060]
The receiving RF coil of the present invention can be used not only as a so-called head coil for imaging the head of the subject, but also as a knee or torso RF coil. In each case, by appropriately designing the shape and dimensions of each coil element constituting the receiving RF coil, a receiving RF coil suitable for each imaging site can be configured.
[0061]
For example, when used as a receiving RF coil for imaging a knee of a subject, as shown in FIG. 6, an RF coil unit is formed using eight-channel coil elements 201 to 204 and 205 to 208 designed to be long in the long axis direction. 100a can be configured. As a result, an RF coil having dimensions adapted to the length of the knee of the subject can be configured, and the entire imaging region can be imaged, and the RF excitation signal receiving efficiency can be maintained over the entire imaging region. can do.
[0062]
Furthermore, the cylindrical cross section of the RF coil can be designed according to the shape of the imaging region of the subject. For example, in the case of an RF coil for imaging the torso of the subject, the cross-sectional shape can be an ellipse or a similar shape instead of a perfect circle as shown in FIG. By doing so, the distance between each coil element constituting the RF coil unit 100b and the imaging target site of the subject is reduced, and the efficiency of receiving the RF excitation signal can be improved.
[0063]
【The invention's effect】
As described above, according to the RF coil of the present invention and the magnetic resonance imaging apparatus using the same, the stabilization of the electrical characteristics of the entire RF coil is improved by sharing the ground potential of the adjacent coil elements. You. In addition, since a pair of coil elements forming a pair are arranged so as to overlap each other, the magnitude of the electromagnetic induction caused by the mutual inductance between the adjacent coil elements is the same, and the polarities are opposite. There is no effect due to cancellation.
Further, in the present embodiment, since the RF coil unit is configured by the coil elements of eight channels, there is an advantage that the RF excitation signal can be received in a desired phase direction.
[Brief description of the drawings]
FIG. 1 is a configuration diagram illustrating an embodiment of a magnetic resonance imaging system including a magnetic resonance imaging apparatus according to the present invention.
FIG. 2 is a configuration diagram illustrating an example of a receiving RF coil used in the magnetic resonance imaging apparatus of the present embodiment.
FIG. 3 is a cross-sectional view showing a specific example of a receiving RF coil used in the magnetic resonance imaging apparatus of the present embodiment.
FIG. 4 is a conceptual diagram showing a specific example of common use of the ground potential of adjacent coils in a receiving RF coil used in the magnetic resonance imaging apparatus of the present embodiment.
FIG. 5 is a waveform chart showing signal waveforms at the time of imaging by the magnetic resonance imaging apparatus of the present embodiment.
FIG. 6 is a diagram showing another modification of the RF coil used in the magnetic resonance imaging apparatus of the embodiment.
FIG. 7 is a diagram showing another modification of the RF coil used in the magnetic resonance imaging apparatus of the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... MRI system, 20 ... MRI apparatus, 21 ... Magnet system, 100 ... Reception RF coil, 211 ... Gap, 212a, 212b ... Main magnetic field magnet part, 213a, 213b ... Gradient coil part, 214 ... RF coil part, 22 ... RF drive unit, 23 ... Gradient drive unit, 24 ... Data collection unit, 25, 25A to 25C ... Control unit, 26 ... Cradle, 30 ... Operator console, 31 ... Data processing unit, 32 ... Operation unit, 33 ... Display unit , 40... Subject, 101 to 104, 105 to 108... Coil elements constituting an RF coil.

Claims (12)

As a set of coils, each of which has a cylindrical shape including four single loop coil elements that are substantially cylindrical, two sets of the cylindrical coils are arranged side by side in the longitudinal direction of the cylindrical shape,
An RF coil in which, in each of the sets of coils, two adjacent single loop coil elements form a pair, and two single loop coil elements in each pair are commonly grounded. 2. The RF coil according to claim 1, wherein in the single loop coil element, adjacent coil elements are arranged so as to overlap each other such that mutual inductance between two adjacent coil elements is substantially zero. 2. The RF according to claim 1, wherein the two single loop coil elements adjacent to each other in the long axis direction of the cylindrical shape are arranged such that adjacent coil elements overlap each other such that mutual inductance between the coil elements is substantially zero. coil. 2. The RF according to claim 1, wherein in the single-loop coil element, two adjacent coil elements overlap with each other, and an area of the overlapping portion is equal to an area of an overlapping portion between other adjacent coil elements. 3. coil. 2. The RF coil according to claim 1, wherein in the single loop coil element, two adjacent coil elements overlap each other, and an area of the overlapped portion is about 10% of an area of the entire coil element. 3. . 2. The RF coil according to claim 1, wherein in the single loop coil element, an interval between two adjacent coil elements is formed equal to an interval between other two adjacent coil elements. 3. A magnetic resonance imaging apparatus that generates an image of a subject based on a magnetic resonance signal received by applying a high-frequency magnetic field to a subject to be imaged under a static magnetic field and a gradient magnetic field,
An RF coil for receiving the magnetic resonance signal excited by the subject by the high-frequency magnetic field,
The RF coil is configured such that a cylindrical shape including four single-loop coil elements forming a substantially cylindrical shape is a set of coils, and two sets of the cylindrical coils are arranged in a longitudinal direction of the cylindrical shape,
A magnetic resonance imaging apparatus wherein two adjacent single-loop coil elements form a pair in each of the coils of each set, and the two single-loop coil elements in each pair are commonly grounded. 8. The magnetic resonance imaging apparatus according to claim 7, wherein in the single loop coil element, adjacent coil elements are arranged so as to overlap each other such that mutual inductance between two adjacent coil elements is substantially zero. 8. The magnetic device according to claim 7, wherein the two single loop coil elements adjacent to each other in the long axis direction of the cylindrical shape are arranged such that adjacent coil elements overlap each other so that mutual inductance between the coil elements becomes substantially zero. Resonance imaging device. 8. The magnetic device according to claim 7, wherein in the single loop coil element, two adjacent coil elements overlap each other, and an area of the overlapping portion is formed to be equal to an area of an overlapping portion between other adjacent coil elements. Resonance imaging device. 8. The magnetic resonance according to claim 7, wherein in the single loop coil element, two adjacent coil elements overlap each other, and an area of the overlapped portion is about 10% of an area of the entire coil element. Imaging device. 8. The magnetic resonance imaging apparatus according to claim 7, wherein in the single loop coil element, an interval between two adjacent coil elements is formed to be equal to an interval between other two adjacent coil elements.

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