JP4822614B2 - Housing, current supply device, and magnetic resonance imaging device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides a current supply circuit that supplies a current for forming a gradient magnetic field to a magnetic resonance imaging apparatus that accommodates a subject in a static magnetic field space and images a region to be examined using magnetic resonance. The present invention relates to a housing to be accommodated, a current supply device using the housing, and a magnetic resonance imaging apparatus.
[0002]
[Prior art]
In the magnetic resonance imaging process, a spin in a subject is excited with an excitation pulse every 1 repetition time (1TR: repetition time), and a magnetic resonance signal generated thereby is converted into, for example, an echo as a two-dimensional Fourier space. To collect.
The magnetic resonance signal is given different phase encoding for each so-called view, and echo data of a plurality of views having different positions on the phase axis in the two-dimensional Fourier space are collected.
Then, the image is reconstructed by performing two-dimensional inverse Fourier transform on the collected echo data of all views.
[0003]
A magnetic resonance imaging apparatus that performs such magnetic resonance imaging processing includes a magnet system having an internal space (bore) that accommodates a subject.
The magnet system consists of a main magnetic field magnet that forms a static magnetic field in the bore, a gradient coil that forms a gradient magnetic field for grading the strength of the static magnetic field formed by the main magnetic field magnet, and a static magnetic field formed by the main magnetic field magnet. In the space, an RF coil that forms a high-frequency magnetic field for exciting spin in the subject is included.
[0004]
The gradient coils include a Gx coil for forming a gradient magnetic field in the X direction, a Gy coil for forming a gradient magnetic field in the Y direction, and a Gz coil for forming a gradient magnetic field in the Z direction.
A Gx pulse current, a Gy pulse current, and a Gz pulse current are supplied to the Gx coil, the Gy coil, and the Gz coil from a gradient amplifier device that is provided separately from the magnetic resonance imaging apparatus.
[0005]
In the gradient amplifier device, for example, a Gx casing, a Gy casing, a Gz casing, and a power supply casing are sequentially arranged from the top to the bottom in the outermost main casing. Yes.
A Gx amplifier circuit for supplying a current to the Gx coil is accommodated in the Gx casing. A Gy amplifier circuit for supplying a current to the Gy coil is accommodated in the Gy casing. A Gz amplifier circuit for supplying a current to the Gz coil is accommodated in the Gz casing. The Gx casing, the Gy casing, and the Gz casing have the same configuration.
A power supply circuit that supplies power to each amplifier circuit is accommodated in the power supply housing.
[0006]
FIG. 13 is an external view of the Gx casing 200, and FIG. 14 is a diagram for explaining the positional relationship between the Gx casing 200 and the main casing 201.
As shown in FIG. 13 and FIG. 14, the Gx housing 200 is a hollow, substantially rectangular parallelepiped case, and has a ventilation hole 210 and connectors 220, 221, and a flat side surface facing the inner surface of the main housing 201. 222 is arranged.
Connected to the connector 220 is a cable 225 for receiving power from a power supply circuit located below the Gx casing 200.
A cable 226 that outputs a Gx pulse current to the Gx coil is connected to the connector 221.
A cable 2267 for inputting a Gx pulse current from the Gx coil is connected to the connector 221.
The dimensions X1, Y1, and Z1 in the x, y, and z directions of the Gx housing 200 shown in FIG. 13 are 413 mm, 200 mm, and 690 mm, respectively.
[0007]
[Problems to be solved by the invention]
By the way, in the conventional gradient amplifier device described above, from the viewpoint of miniaturization of the device and compatibility with other devices, the thicknesses of the Gx housing, the Gy housing, and the Gz housing (see FIGS. 13 and 13). There is a demand to reduce the vertical width in FIG.
In this case, as shown in FIG. 14, in order to bend the cable 225 connected to the Gx amplifier circuit toward the lower side where the power supply circuit is located, between the Gx casing 200 and the main casing 200, It is necessary to provide a distance of 200 mm or more, and it is difficult to increase the lateral width of the Gx casing 200 in FIG. Therefore, when the thickness of the Gx casing 200 is reduced, there is a problem that all the electronic components constituting the Gx amplifier circuit cannot be accommodated in the Gx casing 200.
Further, when the thickness of the Gx casing, the Gy casing, and the Gz casing is reduced, it becomes difficult to provide a sufficiently large vent hole 120, and the amplifier circuit is insufficiently cooled. There's a problem.
These problems also apply to the Gy casing and the Gz casing.
Therefore, conventionally, the thicknesses of the Gx casing, the Gy casing, and the Gz casing cannot be sufficiently reduced.
[0008]
The present invention has been made in view of such circumstances, and includes a current supply circuit that supplies a current to the gradient coil and can be made thinner than the conventional case, and a current supply device using the case. It is another object of the present invention to provide a magnetic resonance imaging apparatus.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a housing according to a first invention is a housing that houses a current supply circuit, and includes a first surface and a second surface that are opposed to each other, and that constitutes the housing. One end is joined to the end of the first surface, and is inclined toward the second surface outside the space formed between the first surface and the second surface, A fourth surface having a connector that is connected to the third surface having a vent hole, the end of the second surface, and the other end of the third surface to which the cable for supplying the current is connected. And having a surface.
[0010]
In the case of the first aspect of the invention, the third surface and the fourth surface are configured as described above, and the thickness of the case can be reduced while providing a sufficiently large vent hole on the third surface. It can be made thinner than before. That is, the distance between the first surface and the second surface can be shortened. In addition to the space formed by the first surface and the second surface, the components of the current supply circuit can be arranged in the space formed by the third surface and the fourth surface. Even if the body is thin, all components of the current supply circuit can be accommodated.
[0011]
In the first aspect of the present invention, preferably, the fourth surface has a connector to which a power supply cable to the current supply circuit is connected.
[0012]
According to a second aspect of the present invention, a current supply device includes a first casing, a current generation circuit that generates a current, and a second casing that is installed in the first casing and houses the current generation circuit. And the second housing has a first surface and a second surface that are located opposite to each other, and one end of the second housing is an end of the first surface. The third surface having a vent hole, which is inclined toward the second surface outside the space formed between the first surface and the second surface, A fourth surface having a connector joined to the end of the second surface and the other end of the third surface and connected to the cable for supplying the current.
[0013]
In the current supply device of the second invention, preferably, the fourth surface further includes a connector to which a cable for supplying power to the current supply circuit is connected.
[0014]
The current supply device of the second invention preferably includes a first current supply circuit that supplies current to the slice gradient magnetic field coil, a second current supply circuit that supplies current to the readout gradient magnetic field coil, A third current supply circuit for supplying a current to the phase encode gradient magnetic field coil; and the three second supply circuits each housing the first current supply circuit, the second current supply circuit, and the third current supply circuit. Housing.
The current supply device of the second invention preferably contains a power supply circuit that supplies power to the first to third current supply circuits, the power supply circuit, and is housed in the first housing. And a third housing.
[0015]
A magnetic resonance imaging apparatus according to a third aspect of the present invention is a magnetic resonance imaging apparatus that constitutes an image based on a magnetic resonance signal obtained by applying a high-frequency magnetic field to a subject to be imaged in a space in which a static magnetic field and a gradient magnetic field are formed. A first housing, a current generating circuit for generating a current in the gradient magnetic field coil that forms the gradient magnetic field, and a second housing that is installed in the first housing and houses the current generating circuit. The second housing includes a first surface and a second surface that are opposed to each other, and one end of the second surface is the first surface. A third surface joined to an end portion, inclined toward the second surface outside a space formed between the first surface and the second surface, and having a vent hole; A connector that is joined to the end of the second surface and the other end of the third surface and to which a cable that supplies the current is connected And a fourth surface having a motor.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a magnetic resonance imaging system according to an embodiment of the present invention will be described with reference to the drawings.
[0017]
First embodiment
FIG. 1 is a diagram for explaining the layout of a magnetic resonance imaging (MRI) system employing a magnetic resonance imaging apparatus according to the present invention, and FIG. 2 is a configuration diagram of the MRI system according to the present invention.
[0018]
In the MRI system 10 according to the present embodiment, as shown in FIG. 1, an MRI apparatus 20 is disposed in a scan room 11 that forms a closed space that prevents leakage of electromagnetic waves radiated from a magnet and entry of disturbance electromagnetic waves, An operator console 30 operated by an operator OP is disposed in an operation room 12 provided adjacent to the scan room 11.
A machine room 13 is provided adjacent to the scan room 11 and the operation room 12, and an RF amplifier device 22 and a gradient amplifier device 23 are disposed in the machine room 13.
The scan rule 11 and the operation room 12 are partitioned by a wall 14, and a door 15 and a window glass 16 are provided on the wall 14.
[0019]
As shown in FIG. 2, the MRI apparatus 20 includes a magnet system 21, a data collection unit 24, and a cradle 26.
[0020]
As shown in FIG. 2, the magnet system 21 has a substantially cylindrical inner space (bore) 211, and a cradle 26 on which the subject 50 is placed via a cushion is conveyed in the bore 211 (not shown). It is carried in by the department.
[0021]
In the magnet system 21, as shown in FIG. 2, a main magnetic field magnet unit 212, a gradient coil unit 213, and an RF coil unit 214 are arranged around a magnet center (scanning center position) in the bore 211. Yes.
[0022]
Each of the main magnetic field magnet section 212, the gradient coil section 213, and the RF coil section 214 is composed of a pair of coils facing each other across a space in the bore 211 where the subject 50 is located at the time of examination.
[0023]
A high frequency current for forming a high frequency magnetic field is supplied to the RF coil unit 214 via the cable 165 from the RF amplifier device 22 arranged in the machine room 13.
Further, a pulse current for forming a gradient magnetic field is supplied from the gradient amplifier device 23 to the gradient coil unit 213 via the cables 166_Gx, 166_Gy, 166_Gz.
[0024]
FIG. 3 is a diagram for explaining an arrangement configuration example of the main magnetic field magnet unit 212, the gradient coil unit 213, and the RF coil unit 214 in the magnet system 21 according to the present embodiment.
[0025]
As shown in FIG. 3, the magnet system 21 includes an upper yoke 215 and a lower yoke 216 arranged so as to face each other via a space S (bore 211), and the upper yoke 215 and the lower yoke 216 are connected by a side yoke 217. ing.
Main magnetic field magnets 212a and 212b constituting the main magnetic field magnet unit 212 are provided on the respective surfaces where the upper yoke 215 and the lower yoke 216 face each other.
A magnetic circuit that generates a static magnetic field in the bore 211 is formed by the upper yoke 215, the lower yoke 216, the side yoke 217, and one main magnetic field magnet 212a, 212b.
[0026]
As described above, the main magnetic field magnet unit 212 forms a static magnetic field in the bore 211. The direction of the static magnetic field is, for example, generally parallel or perpendicular to the body axis direction of the subject 50. That is, a parallel magnetic field is formed. The main magnetic field magnets 212a and 212b constituting the main magnetic field magnet unit 212 are configured using, for example, a superconducting electromagnet, a permanent magnet, a normal conducting electromagnet, or the like.
[0027]
A gradient coil portion 213 is provided on each surface where the main magnetic field magnets 212a and 212b face each other.
Specifically, a pair of pole pieces 218a for uniformizing the static magnetic field of the bore 211 into which the subject 50 included in the gradient coil unit 213 is inserted on each surface where the main magnetic field magnets 212a and 212b face each other. 218b is provided.
In the internal space of the pair of pole pieces 218a and 218b, a pair of gradient coils 213a and 213b for generating a gradient magnetic field and passive boats 219a and 219b for adjusting the uniformity of the static magnetic field are provided in a stacked manner. Yes.
[0028]
The gradient coil unit 213 having such a configuration gives a gradient to the strength of the static magnetic field formed by the main magnetic field magnet unit 212 so that the magnetic resonance signal received by the RF coil unit 214 has three-dimensional position information. Generate a gradient magnetic field.
As shown in FIG. 4, the gradient coil unit 213 forms a Gx coil 250 for forming a gradient magnetic field in the X direction, a Gy coil 251 for forming a gradient magnetic field in the Y direction, and a gradient magnetic field in the Z direction. And a Gz coil 252.
[0029]
In the present embodiment, the supply of the Gx pulse current to the Gx coil 250, the supply of the Gy pulse current to the Gy coil 251 and the supply of the Gz pulse current to the Gz coil 252 are controlled from the processing unit 31 of the operator console 30. This is performed by the gradient amplifier device 23 shown in FIGS. 1 and 2 based on the signal S161.
[0030]
A pair of accommodating portions 220a and 220b are formed on the opposing surfaces of the pair of gradient coil portions 213, and RF coils 214a and 214b are provided in the space between the pair of accommodating portions 220a and 220b. Yes.
[0031]
The RF coil unit 214 having the pair of housing units 220a and 220b and the RF coils 214a and 214b generates a high-frequency magnetic field for exciting spins in the body of the subject 50 in the static magnetic field space formed by the main magnetic field magnet unit 212. Form. Here, the formation of a high-frequency magnetic field is called transmission of an RF excitation signal. The RF coil unit 214 receives an electromagnetic wave generated by the excited spin as a magnetic resonance signal.
The RF coil unit 214 includes a transmission coil and a reception coil (not shown). As the transmission coil and the reception coil, either the same coil or a dedicated coil is used.
[0032]
In this embodiment, in order to generate the RF excitation signal, the pulse current RF_DR1 is supplied from the RF amplifier device 22 shown in FIGS. 1 and 2 to the RF coil unit 214 based on the control signal S160 from the processing unit 31. .
[0033]
The data collection unit 24 captures the reception signal received by the RF coil unit 214, collects it as view data, and outputs it to the processing unit 31 of the operator console 30.
[0034]
As shown in FIG. 2, the operator console 30 includes a processing unit 31, an operation unit 32, and a display unit 33.
[0035]
The processing unit 31 uses the RF coil unit 214 to generate a pulse current RF_DR1 in which a predetermined pulse sequence is repeated a predetermined number of times within a predetermined repetition time TR in accordance with a protocol to be executed corresponding to the test site of the subject 50. Is controlled by the control signal S160.
Similarly, the processing unit 31 applies Gx, Gy, and Gz pulse currents of a predetermined pattern to the Gx coil 250, the Gy gradient magnetic field coil 251 and the Gz gradient magnetic field coil 252 in 1TR according to the protocol to be executed. The gradient amplifier device 23 is controlled by the control signal S161 so as to be applied to.
Further, the processing unit 31 captures the reception signal received by the RF coil unit 214, collects the received signal as view data, and outputs the data to the processing unit 31 of the operator console 30 according to the control signal S31a. The collection unit 24 is controlled.
[0036]
Note that the protocol to be executed by the processing unit 31 is determined in accordance with the region to be examined of the subject 50 in order to perform magnetic resonance imaging, and a pulse sequence within 1TR (repetition time) for each protocol. The number of repetitions of is different.
[0037]
The pulse sequence for magnetic resonance imaging includes a so-called spin echo (SE) method, a gradient echo (GYE) method, a fast spin echo (FSE) method, a fast recovery spin echo (FSE) method. ), Echo Planar Imaging (EPI: Echo Planar)
It differs depending on each photographing method such as an imaging method.
[0038]
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 the pulse current RF_DR 1 that the RF amplifier device 22 applies to the RF coil unit 214.
FIGS. 5B, 5C, 5D, and 5E are sequences of Gs pulse current, Gr pulse current, Gp pulse current, and spin echo MR, respectively.
The Gs pulse current is a pulse current for forming a slice gradient magnetic field, the Gr pulse current is a pulse current for forming a read out gradient magnetic field, and the Gp pulse current is a phase encoding (phase).
encode) is a pulse current for forming a gradient magnetic field.
[0039]
As shown in FIG. 5A, a 90 ° pulse current is applied to the RF coil unit 214 by the RF amplifier device 22, and 90 ° excitation of the spin is performed. At this time, as shown in FIG. 5B, a gradient amplifier device 23 applies a Gz pulse current to any of the Gx coil 250, Gy coil 251, and Gz coil 252, and selective excitation is performed for a predetermined slice. Done.
As shown in FIG. 5A, after a predetermined time from 90 ° excitation, a 180 ° pulse current is applied to the RF coil unit 214 by the RF amplifier device 22, and 180 ° excitation, that is, spin inversion is performed. Also at this time, as shown in FIG. 5B, the Gs pulse current is applied to any of the Gx coil 250, the Gy coil 251, and the Gz coil 252 by the gradient amplifier device 23, and the same slice is selectively used. Inversion is performed.
[0040]
As shown in FIGS. 5C and 5D, during the period between 90 ° excitation and spin reversal, the gradient amplifier device 23 applies Gr to any of the Gx coil 250, Gy coil 251, and Gz coil 252 coils. A pulse current is applied, and a Gp pulse current is applied to any of the Gx coil 250, Gy coil 251, and Gz coil 252 by the gradient amplifier device 23.
Then, spin dephase is performed by the Gr pulse current, and spin phase encoding is performed by the Gp pulse current.
[0041]
After the spin reversal, as shown in FIG. 5B, a Gr pulse current is applied to any of the Gx coil 250, Gy coil 251, and Gz coil 252 by the gradient amplifier device 23 and rephased. As shown in FIG. 5E, a spin echo MR is generated.
The spin echo MR is collected as view data by the data collection unit 24.
[0042]
In such a pulse sequence, the processing unit 31 repeats the control signals S31a, S160, and S161, for example, 64 to 512 times with a period TR according to the execution protocol, respectively, with the RF amplifier device 22, the gradient amplifier device 23, and the data. These are output to the collection unit 24 to control them.
In addition, the processing unit 31 performs control so as to change the Gz pulse current each time it is repeated and perform different phase encoding each time.
A cable 160 for transmitting a control signal S160 is disposed between the operator console 30 and the RF amplifier device 22, and a control signal S161 is transmitted between the operator console 30 and the gradient amplifier device 23. Cable 161 is provided.
A cable 165 for transmitting the pulse current RF_DR1 is disposed between the RF amplifier device 22 and the magnet system 21.
Between the RF amplifier device 22 and the magnet system 21, a Gx pulse current transmission cable 166_Gx, a Gy pulse current transmission cable 166_Gy, and a Gz pulse current transmission cable 166_Gz are disposed. Yes.
[0043]
Further, the processing unit 31 stores the data fetched from the data collecting 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 processing unit 31 generates (reconstructs) an image of the subject 50 by performing two-dimensional inverse Fourier transform on the data in the two-dimensional Fourier space.
The two-dimensional Fourier space is also referred to as k space.
[0044]
An operation unit 32 and a display unit 33 are connected to the processing unit 31.
[0045]
The operation unit 32 includes a keyboard, a mouse, and the like equipped with a pointing device, and outputs an operation signal corresponding to the operation of the operator OP to the processing unit 31. Also. For example, the above-described protocol to be executed is input from the operation unit 32.
[0046]
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 in accordance with an operation signal from the operation unit 32.
[0047]
Hereinafter, the gradient amplifier device 23 shown in FIGS. 1 and 2 will be described in detail.
FIG. 6 is a diagram for explaining the configuration of the side surface side of the gradient amplifier device 23, and FIG. 7 is a diagram for explaining the back surface of the gradient amplifier device 23.
As shown in FIGS. 6 and 7, the gradient amplifier device 23 includes a Gx casing 101, a Gy casing 102, a Gz casing 103, and a power supply casing in a rectangular parallelepiped main casing 100. 104 is accommodated.
Here, the gradient amplifier device 23 corresponds to the current supply device of the present invention, the main housing 100 corresponds to the first housing of the present invention, the Gx housing 101, the Gy housing 102, and the Gz housing. The body 103 corresponds to the second housing of the present invention.
The main housing 100 is provided with a plurality of ventilation holes 180.
A plurality of support columns 110 are provided in the main housing 100.
[0048]
The Gx casing 101, the Gy casing 102, the Gz casing 103, and the power supply casing 104 are fixed to the column 110 in the main casing 100.
The Gx casing 101 houses a Gx current amplifier circuit 111 that generates a Gx current. Here, the Gx current amplifier circuit 111 corresponds to the first current supply circuit of the present invention.
The Gy casing 102 houses a Gy current amplifier circuit 112 that generates a Gy current. Here, the Gy current amplifier circuit 112 corresponds to the second current supply circuit of the present invention.
The Gz casing 103 houses a Gz current amplifier circuit 113 that generates a Gz current. Here, the Gz current amplifier circuit 113 corresponds to the third current supply circuit of the present invention.
The power supply housing 104 accommodates a power supply circuit 114.
The Gx casing 101, the Gy casing 102, and the Gz casing 103 have the same configuration.
[0049]
Hereinafter, the Gx casing 101 will be described.
8 and 9 are external views of the Gx casing 101. FIG.
As shown in FIGS. 8 and 9, the Gx casing 101 is constituted by surfaces 120 to 126.
Here, the surface 120 corresponds to the first surface of the present invention, the surface 121 corresponds to the second surface of the present invention, the surface 125 corresponds to the third surface of the present invention, and the surface 126 corresponds to the present invention. This corresponds to the fourth surface.
The surfaces 120 and 121 have the same shape and are located opposite to each other. In addition, the surface 122 and the surface 123 have the same shape and are opposed to each other.
Vent holes 122a and 123a are provided in the surfaces 122 and 123, respectively.
The end of the heat sink 150 accommodated in the space formed between the surfaces 120 and 121 is exposed on the surface 124.
The surface 124 is provided with a connector 130 to which a cable 161 for communicating with the processing unit 31 of the operator console 30 shown in FIG. 2 is connected.
[0050]
One end of the surface 125 is joined to the end of the surface 120, the other end on the opposite side is joined to the end of the surface 126, and a space formed between the surface 120 and the surface 121. It is inclined toward the surface 121 on the outside.
Further, the surface 125 is also bonded to the ends of the surface 122 and the surface 123.
The surface 125 is provided with a vent hole 126a.
[0051]
The surface 126 is joined to the end of the surface 121 and the other end of the surface 125.
The surface 126 is also joined to the ends of the surface 122 and the surface 123.
The surface 126 has a connector 140 to which a power supply cable 155_1 from the power supply circuit 114 is connected, a connector 141a that outputs a Gx pulse current to the Gx coil 250, and a connector 141b that inputs a Gx pulse current from the Gx coil 250. And are provided. That is, the cable 166_Gx shown in FIG. 1 is connected to the connector 141a and the connector 141b.
[0052]
In the present embodiment, as shown in FIG. 8, for example, the internal angle between the surface 120 and the surface 125 is 150 degrees, the internal angle between the surface 125 and the surface 126 is 90 degrees, and the surface 126 and the surface The interior angle with respect to 121 is 120 degrees.
Further, the dimensions X2, Y2, and Z2 in the x, y, and z directions of the Gx casing 101 shown in FIG. 8 are 401 mm, 129 mm, and 700 mm, respectively.
[0053]
FIG. 10 is an external view of the Gx current amplifier circuit 111 housed in the Gx casing 101.
As shown in FIG. 10, a heat sink 150, a capacitor 151, a controller 152, and the like constituting the Gx current amplifier circuit 111 are disposed in the Gx casing 101.
[0054]
The configuration of the Gx casing 101 has been described in detail above, but the Gy casing 102 and the Gz casing 103 have the same configuration as the Gx casing 101. However, from the surface 126 of the Gy housing 102, a connector 140 to which a power supply cable 155_2 from the power supply circuit 114 is connected, a connector 141a that outputs a Gy pulse current to the Gy coil 251, and a Gy coil 251 are connected. A connector 141b for inputting a Gy pulse current is provided. Further, a connector 140 to which a power supply cable 155_3 from the power supply circuit 114 is connected, a connector 141a that outputs a Gz pulse current to the Gz coil 252, and a Gz coil 252 are connected to the surface 126 of the Gz casing 103. A connector 141b for inputting a Gz pulse current is provided.
[0055]
Hereinafter, the operation of the MRI system 10 shown in FIG. 1 will be described with reference to the flowchart of FIG.
[0056]
Step ST1:
The subject 50 placed on the cradle 26 via the cushion is carried into the bore 211 of the magnet system 21 of the MRI apparatus 20 by a transport unit (not shown).
[0057]
Step ST2:
The test site of the test object 50 is positioned at the magnet center in the bore 211. At this time, a static magnetic field by the main magnetic field magnet unit 212 is formed in a predetermined region in the bore 211 including the magnet center.
[0058]
Then, based on the control signal S160 generated according to the operation by the operator OP, the pulse current RF_DR1 is supplied from the RF amplifier device 22 via the cable 165, and the RF coil unit 214 forms a high-frequency magnetic field in the static magnetic field. Is done.
Further, based on the control signal S161 generated according to the operation by the operator OP, the Gx pulse current, the Gy pulse current, and the Gz pulse current are respectively transmitted from the gradient amplifier device 23 through the cables 166_Gx, 166_Gy, 166_Gz to the Gx coil. 250, the Gy coil 251 and the Gz coil 252 are supplied.
Thereby, a gradient magnetic field is formed in the static magnetic field.
Then, electromagnetic waves generated by spins excited at the test site of the subject 50 are extracted as magnetic resonance signals, collected by the data collection unit 24, and output to the processing unit 31 of the operator console 30 as test result data. .
That is, imaging of the test site is performed.
[0059]
Step ST4:
In the 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. In the processing unit 31, these two-dimensional Fourier space data are subjected to two-dimensional inverse Fourier transform to generate (reconstruct) an image of the test region of the subject 50.
[0060]
Step ST5:
When the data collection of the test site of the test object 50 is completed, the test object 50 is carried out of the bore 211 together with the cradle 26 by a transport unit (not shown).
[0061]
As described above, according to the gradient amplifier device 23, the dimensions X2, Y2 in the x, y, and z directions of the Gx casing 101, the Gy casing 102, and the Gz casing 103 are shown in FIG. , Z2 can be set to 401 mm, 129 mm, and 700 mm, respectively.
That is, according to the gradient amplifier device 23, as shown in FIG. 12, the thickness in the y direction of the Gx casing 101, the Gy casing 102, and the Gz casing 103 can be reduced by 71 mm as compared with the conventional case. As well as compatibility with other devices.
[0062]
Further, according to the gradient amplifier device 23, as shown in FIG. 12, the lengths in the z direction of the Gx casing 101, the Gy casing 102, and the Gz casing 103 are directed toward the inner surface of the main casing 100. Thus, the length can be increased by 68.8 mm compared to the conventional case. Therefore, even if the thickness in the y direction of the Gx casing 101, the Gy casing 102, and the Gz casing 103 is made thinner than the conventional one, all the electronic components constituting the current amplifier circuit can be accommodated.
In this way, the length in the z direction of the Gx casing 101, the Gy casing 102, and the Gz casing 103 can be increased compared to the conventional case as shown in FIG. 6 and FIG. By tilting downward, the amount of bending of the cables 155 </ b> _ <b> 1-155 </ b> _ <b> 3 can be reduced, and sufficient space is secured between the Gx casing 101, the Gy casing 102, the Gz casing 103, and the inner surface of the main casing 100. This is because it can.
[0063]
Further, according to the gradient amplifier device 23, the surface 125 provided with the vent hole 125a and the surface 126 provided with the connectors 140, 141a, 141b are configured as shown in FIG. Even when the y-direction thickness of the body 101, the Gy casing 102, and the Gz casing 103 is made thinner than before, a sufficiently large vent hole 125a can be provided to sufficiently cool the current amplifier circuit. it can.
[0064]
The present invention is not limited to the embodiment described above.
For example, the inner angle between the surface 120 and the surface 125 and the inner angle between the surface 126 and the surface 121 shown in FIG. 8 are such that the surface 125 faces the surface 121, and the surface 125 and the surface 126 are the surfaces 120 and 121. If it joins on the outer side of the space formed between, it will not be specifically limited.
Moreover, the dimension shown in FIG. 8 is an example.
[0065]
【The invention's effect】
As described above, according to the present invention, the current supply circuit that supplies current to the gradient coil is accommodated, and the casing can be made thinner than the conventional one, and the current supply device and magnetic resonance using the casing An imaging device can be provided.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining a layout of a magnetic resonance imaging (MRI) system employing a magnetic resonance imaging apparatus according to an embodiment of the present invention.
FIG. 2 is a configuration diagram of the MRI system shown in FIG. 1;
FIG. 3 is a diagram for explaining an arrangement configuration example of a main magnetic field magnet unit, a gradient coil unit, and an RF coil in the magnet system shown in FIG. 2;
4 is a diagram for explaining the gradient coil section shown in FIG. 3; FIG.
FIG. 5 is a diagram for explaining a photographing method in the magnet system shown in FIG. 2;
6 is a diagram for explaining a configuration of a side surface of the gradient amplifier device shown in FIGS. 1 and 2. FIG.
FIG. 7 is a diagram for explaining the back surface of the gradient amplifier device shown in FIG. 6;
8 is an external view of the Gx casing shown in FIGS. 6 and 7. FIG.
9 is an external view of the Gx casing shown in FIGS. 6 and 7. FIG.
FIG. 10 is a diagram for explaining a Gx current amplifier circuit housed in the Gx casing shown in FIG. 8;
FIG. 11 is a diagram for explaining the overall operation of the MRI system shown in FIG. 1;
FIG. 12 is a diagram for explaining the effect of the gradient amplifier device shown in FIG. 1;
FIG. 13 is an external view of a conventional Gx housing.
FIG. 14 is a diagram for explaining the positional relationship between the Gx casing and the main casing shown in FIG. 13;
[Explanation of symbols]
22 ... RF amplifier device, 23 ... Gradient amplifier device, 160, 161, 166_Gx, 166_Gy, 166_Gz ... Cable, 212a, 212b ... Main magnetic field magnet, 213a, 213b ... Gradient coil unit, 214a, 214b ... RF coil unit, 250 ... Gx coil, 251 ... Gy coil, 252 ... Gz coil, 100 ... main housing, 101 ... Gx housing, 102 ... Gy housing, 103 ... Gz housing, 110 ... post, 111 ... Gx current amplifier circuit , 112... Gy current amplifier circuit, 113... Gz current amplifier circuit, 120 to 126... Surface, 130.

Claims (10)

A housing that houses a current supply circuit that supplies a current to a gradient coil that forms a gradient magnetic field in a static magnetic field space in a magnetic resonance imaging apparatus,
A first surface and a second surface located opposite to each other, constituting the housing;
One end is joined to the end of the first surface, and is inclined toward the second surface outside the space formed between the first surface and the second surface, A third surface having a vent;
A housing having a fourth surface having a connector joined to an end portion of the second surface and the other end portion of the third surface and to which a cable supplying the current is connected. The housing according to claim 1, wherein the fourth surface further includes a connector to which a power supply cable to the current supply circuit is connected. A first housing;
A current generation circuit that generates a current to be supplied to a gradient coil that forms a gradient magnetic field in a static magnetic field space in the magnetic resonance imaging apparatus;
A second housing that is installed in the first housing and houses the current generating circuit;
The second housing is
A first surface and a second surface located opposite to each other, constituting the second housing;
One end is joined to the end of the first surface, and is inclined toward the second surface outside the space formed between the first surface and the second surface, A third surface having a vent;
A current supply device having a fourth surface having a connector joined to an end portion of the second surface and the other end portion of the third surface and connected to a cable for supplying the current. The current supply device according to claim 3, wherein the fourth surface further includes a connector to which a power supply cable to the current supply circuit is connected. a first current supply circuit for supplying a current to a gradient coil that forms a gradient magnetic field in the x direction;
a second current supply circuit for supplying a current to the gradient coil that forms a gradient magnetic field in the y direction;
a third current supply circuit for supplying a current to a gradient coil that forms a gradient magnetic field in the z direction;
5. The current supply device according to claim 3, further comprising three second housings each housing the first current supply circuit, the second current supply circuit, and the third current supply circuit. 6. A power supply circuit for supplying power to the first to third current supply circuits;
The current supply device according to claim 5, further comprising a third housing that houses the power supply circuit and is housed in the first housing. In a magnetic resonance imaging apparatus that configures an image based on a magnetic resonance signal obtained by applying a high-frequency magnetic field to a subject to be imaged in a space where a static magnetic field and a gradient magnetic field are formed,
A first housing;
A current generating circuit for generating a current in a gradient coil that forms the gradient magnetic field;
A second housing that is installed in the first housing and houses the current generating circuit;
The second housing is
A first surface and a second surface located opposite to each other, constituting the second housing;
One end is joined to the end of the first surface, and is inclined toward the second surface outside the space formed between the first surface and the second surface, A third surface having a vent;
A magnetic resonance imaging apparatus comprising: a fourth surface having a connector connected to an end portion of the second surface and the other end portion of the third surface and to which a cable supplying the current is connected. The magnetic resonance imaging apparatus according to claim 7, wherein the fourth surface further includes a connector to which a power supply cable to the current supply circuit is connected. a first current supply circuit for supplying a current to a gradient coil that forms a gradient magnetic field in the x direction;
a second current supply circuit for supplying a current to the gradient coil that forms a gradient magnetic field in the y direction;
a third current supply circuit for supplying a current to a gradient coil that forms a gradient magnetic field in the z direction;
9. The magnetic resonance according to claim 7, further comprising three second housings each housing the first current supply circuit, the second current supply circuit, and the third current supply circuit. 10. Shooting device. A power supply circuit for supplying power to the first to third current supply circuits;
The magnetic resonance imaging apparatus according to claim 9, further comprising a third housing that houses the power supply circuit and is housed in the first housing.

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