JP3973379B2 - Receiver coil for magnetic resonance imaging apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a receiving coil for a magnetic resonance imaging apparatus (hereinafter referred to as MRI apparatus), and more particularly to a technique suitable for Interventional MR (hereinafter referred to as I-MR) for performing surgery and treatment while performing imaging.
[0002]
[Prior art]
The MRI apparatus irradiates a subject placed in a static magnetic field with a high-frequency pulse, thereby exciting nuclear spins of nuclei in the subject and generating a nuclear magnetic resonance signal. At this time, positional information is given to the nuclear magnetic resonance signal by applying a gradient magnetic field in a predetermined sequence, and a tomographic image in the subject can be obtained by reconstructing the nuclear magnetic resonance signal. . MRI equipment is not exposed to X-rays, and can obtain arbitrary cross-sectional images depending on the method of applying a gradient magnetic field. Furthermore, it is excellent in resolution of soft tissues such as internal organs and brains. Used for applications.
[0003]
Recently, an open MRI system with magnets (superconducting magnets, permanent magnets, etc.) for generating a static magnetic field arranged vertically is operated and treated from the side of the space where the subject is placed in the operating room. An I-MR procedure is performed.
[0004]
For example, when head surgery is performed, a head (brain) is fixed with a stereotaxic instrument, and an operation for removing a tumor is performed using an endoscope or a microscope. Then, the operation is temporarily interrupted to confirm the removal status of the tumor on the way, the head is removed from the stereotaxic fixture, the reception coil covered with vinyl etc. to hold the clean part is wrapped and moved to the MRI apparatus Take a picture.
[0005]
[Problems to be solved by the invention]
In the above prior art, when moving from surgery to imaging on the MRI apparatus, the stereotaxic fixture must be removed once, and it is a careful work so as not to affect the subject, from surgery to imaging, imaging to surgery It took time to move to. On the other hand, Japanese Patent Laid-Open No. 2000-300580 discloses an apparatus in which a receiving coil is attached to a stereotaxic fixture. According to this, the receiving coil can be attached without removing it from the stereotaxic fixture.
[0006]
However, there is a work to cover the part that touches the stereotaxic fixture with vinyl etc. every time the radiography is taken, and the receiving coil surrounds the outside of the stereotaxic fixture and becomes less sensitive than when wrapped directly around the head. there were.
[0007]
It is an object of the present invention to provide a receiving coil that can be easily attached to a receiving coil, smoothly shifts from surgery to imaging, and transitions from imaging to surgery, and has high sensitivity.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a receiving coil for a magnetic resonance imaging apparatus that is arranged so as to surround an imaging region of a subject placed on a bed and detects a nuclear magnetic resonance signal from the imaging region. A fixture attached to a bed and fixing a subject and partially configured of a non-magnetic and conductive material, a conductor opened on one side of the fixture, a conductor located on the open side of the fixture, and an end of the fixture And a connector for electrically and mechanically connecting the end portion of the conductor and the conductor and forming a loop with the fixture and the conductor.
[0009]
The connector may include a first connector fixed to the fixture and a detachable second connector that connects the first connector and the conductor.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
[0011]
First, the configuration of an MRI apparatus to which the present invention is applied will be described with reference to FIG. An MRI apparatus 1 is arranged in the operating room and radiographing room, and a bed 2 on which the subject 3 is placed is arranged in the vicinity thereof. The bed 2 is used as a bed for photographing and a bed for surgery, and is made of a non-magnetic material (such as a nickel chrome alloy or a titanium alloy) so as not to be affected even if the bed is transported into the MRI apparatus 1. ing. A stereotaxic fixture 8 for fixing the head of the subject 3 is attached to the end of the bed 2. During surgery, the MRI apparatus 1 is retracted to a place where there is no influence of the magnetic field, and is performed using an endoscope (not shown), the microscope 4 or the like. When the endoscope or the microscope 4 is used, it is performed in a place where there is no influence of the magnetic field of the MRI apparatus 1, but in consideration of the influence on the magnetic field of the MRI apparatus 1, it is made of a nonmagnetic material as described above. ing.
[0012]
Surgery or the like is performed with the subject 3 placed on the bed 2, and the bed 2 is conveyed into the MRI apparatus 2 in order to confirm the situation. At that time, an upper receiving coil, which will be described later, is attached to the brain stereotaxic fixture 8, and the whole including the brain stereotaxic fixture 8 is used as a reception coil. The brain stereotaxic fixture 8 does not disturb the magnetic field and needs to be highly conductive in order to be used as a receiving coil. In this embodiment, aluminum is used at a location where the receiving coil is formed. Then, the state of extraction or the like by surgery is confirmed by the in-room monitor 6 attached from the MRI apparatus 1 via the arm 7.
[0013]
Next, details of the stereotaxic instrument and the receiving coil of the present invention will be described.
[0014]
First, the brain stereotaxic instrument at the time of surgery will be described with reference to FIG. The subject head 9 is fixed to the brain stereotaxic fixture 8 while the subject is placed on a bed (not shown). The stereotaxic fixture 8 includes a semicircular base portion 16 that follows the shape of the subject head 9, a holding portion 17 that holds the base portion 16 at an arbitrary angle in the circumferential direction, and a holding portion 17. It is configured by a fixing unit 18 that is held parallel to the subject body axis and fixed to the bed. The base portion 16 is provided with a plurality of screw holes at predetermined intervals, and the screw holes are provided with bolts 10 that are in contact with and fixed to the subject head 9. The base portion 16 is made of non-magnetic and highly conductive aluminum so as to form a receiving coil as will be described later, and the other holding portions 17 and fixing portions 18 are non-magnetic and insulated from the base portion 16. It consists of non-conductive carbon fiber or glass fiber. The bolt 10 also needs to be non-magnetic, but a certain level of strength is required, so a titanium alloy or the like is used. At that time, since the bolt 10 and the base portion 16 need to be electrically non-conductive, the screw holes of the bolt 10 or the base portion 16 may be covered with an insulator by plating, coating, or the like. The positions of the holding part 17 and the base part 16 are adjusted according to the content of the operation, the position and orientation of the head, and the position and number of the bolts 10 to be fixed are appropriately adjusted. In a state where the head of the subject 9 is fixed with a bolt, the subject head 9 and the brain stereotaxic fixture 8 are covered with a sterilized cloth 12, and a clean portion is kept from being infected by unnecessary contact. A connector 11 is provided at the end of the base portion 16, and a hole through which the connector 11 passes is provided in the cloth 12. Then, the head frame 13 provided with a through hole at the end is inserted into the connector 11 and fixed to the brain stereotaxic fixture 8. The head frame 13 fixes the skin when the subject head 9 is opened or is used as an arm rest for an operator. When the head frame 13 is fixed, the cloth 12 is sandwiched between the head frame 13 and the stereotaxic fixture 8, so that the head frame 13 is not inadvertently detached. In this state, surgery such as tumor removal is performed.
[0015]
Next, the brain stereotaxic fixture at the time of imaging will be described with reference to FIG. The subject 9 is fixed to the stereotaxic fixture 8 as described above. In this state, the semicircular upper receiving coil 15 is attached to the connector 11 via the sterilized relay connector 14. The connector 11 and the relay connector 14 are both electrically connected. Since the base portion 16 of the stereotaxic fixture 8 made of nonmagnetic and highly conductive aluminum as described above forms the lower receiving coil, the upper receiving coil 15 and the base portion 16 are connected to the connector 11 and the relay connector. By connecting at 14, a loop-shaped receiving coil surrounding the entire subject head 9 is formed. Take a picture in this state to check the tumor removal status. And when imaging | photography is complete | finished and surgery is performed again, the upper receiving coil 15 and the relay connector 14 are removed, and it transfers to surgery. Further, when photographing again, the upper receiving coil 15 is attached by changing the relay connector 14 to another relay connector 14 that has been sterilized.
[0016]
As described above, in this embodiment, the base portion 16 of the stereotaxic fixture 8 is made of aluminum and is connected to the upper receiving coil 15 via the connector 11 and the relay connector 14 to form a loop-shaped receiving coil. Therefore, the coil can be mounted without moving the subject, and the diameter of the receiving coil can be arranged at a position closer to the subject, so that a decrease in sensitivity can be suppressed. Even if the stereotaxic fixture 8 is covered with the cloth 12, it is only necessary to insert the relay connector 14 and the upper receiving coil 15 into the connector 11, so that the coil can be easily mounted while keeping the clean portion. Further, even when the operation and photographing are repeated, it is not necessary to sterilize or replace the entire receiving coil, the cloth 12 or the like, and only the work of replacing the relay connector 14 is required, and the work efficiency is improved.
[0017]
Although the whole base portion 16 of the stereotaxic fixture 8 is made of nonmagnetic and highly conductive aluminum, the base portion 16 is made of nonmagnetic material and is nonmagnetic and highly conductive inside the base portion 16. It may be configured by putting things.
[0018]
【The invention's effect】
According to the present invention, a part of the stereotaxic fixture is made of a nonmagnetic and highly conductive material, and a conductor that forms a receiving coil is attached to the fixture. A receiving coil can be arranged without. Further, since the fixture and the conductor are attached via the connector, the attachment and detachment can be easily performed, and the time required for attaching the receiving coil can be shortened. Furthermore, even if the receiving coil is changed many times, it can be used in a clean state with a simple operation of simply changing the connector.
[Brief description of the drawings]
FIG. 1 is a diagram showing an MRI apparatus using the present invention and a state of use. FIG. 2 is an explanatory diagram of a brain stereotaxic instrument according to the present invention.
Reference Signs List 1 MRI apparatus 2 bed 3 subject 4 microscope 6 in-room monitor 8 brain stereotaxic fixture 9 subject head 10 bolt 11 connector 12 cloth 13 head frame 14 relay connector 15 upper receiving coil 16 base portion 17 holding portion 18 fixing portion

Claims (2)

In a reception coil for a magnetic resonance imaging apparatus for detecting a nuclear magnetic resonance signal from a radiographic part, which is arranged so as to surround the radiographic part of a subject placed on a bed,
A fixture that is attached to the bed and fixes a subject and partially comprises a non-magnetic and conductive material;
A conductor connected to the fixture covered with a cloth ;
A connector to form a loop and electrically and mechanically connected to the fixture and the conductor and an end portion of the end portion and the conductor of the fixture,
Have
The connector includes a first connector provided at an end of the fixture, and a detachable and sterilized second connector that connects the first connector and the conductor. A receiving coil for a magnetic resonance imaging apparatus. A magnetic resonance imaging apparatus using the receiving coil for a magnetic resonance imaging apparatus according to claim 1 .

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