JPH0329639A - Surface coil for magnetic resonance imaging photographing - Google Patents

Abstract

PURPOSE:To enable the subject coil to be freely curved while following the outer shape of a testee by integrally forming a conductive coil composed of litz wires and a shape memory resin cover covering the said conductive coil. CONSTITUTION:Magnetic resonance signals which are excited when exciting high frequency magnetic fields and inclined magnetic fields are applied to a testee placed in an electrostatic magnetic field, are received by a surface coil 1 for magnetic resonance imaging photographing. In this case, a conductive coil 2 composed of litz wires and a shape memory resin cover 3 which is applied over the coil 2, are integrated into the coil 1. As a result, this enables close arrangement to the testee as desired, thereby extremely contributing to the improvement of S/N.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention is directed to a test object placed in a static magnetic field, which is excited by applying an excitation high-frequency magnetic field and a gradient magnetic field. The present invention relates to a surface coil for magnetic resonance imaging (hereinafter referred to as a surface film for MRI) that receives magnetic resonance signals, and particularly relates to a technique for creating a structure suitable for placement in close contact with a subject.

(Prior art) Conventionally, this type of MRI surface coil has a structure in which a conductor coil is mounted on a resin plate, or a conductor coil is molded with silicone rubber, etc., and it is made to follow the external shape of the subject. It was a hard material that could not be bent or bent.

(Problem to be Solved by the Invention) Therefore, in the case of conventional surface coils for MRI of this type, even if it is attempted to make them come into close contact to improve the S/N, the hardness is high as described above, and the However, there was a problem in that it was not possible to place them in close contact.

The present invention has been made in view of such circumstances, and its purpose is to provide a surface coil for MRI that can be freely curved to follow the external shape of a subject.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention has an integral structure of a conductor coil made of litz wire or copper foil and a shape memory resin cover coated on the conductor coil. It is characterized by certain things.

(Function) Litz wire and copper foil are highly flexible conductor wire materials,
In addition, there are shape memory resin materials that can return to their initial shape at high temperatures and can be freely deformed at temperatures of 20 to 40 degrees Celsius, which is about the body temperature of the subject.

Therefore, as in the present invention, if the MRI surface coil is configured by forming a conductor coil with litz wire or copper foil and covering the conductor coil with a shape memory resin cover, it can be made to follow the external shape of the subject. It can be curved in a straight line.

When such an MRI surface coil according to the present invention is used for receiving magnetic resonance signals, it can be placed in close contact with the imaged area of the subject, so it can be used for reproduction with improved S/N than before. A constituent image can be obtained.

(Example) FIG. 1 is a perspective view showing the structure of a surface coil for MRl according to an example to which the present invention is applied.

The MRI surface coil 1 of this embodiment has an integral structure of a conductor coil 2 made of litz wire and a shape memory resin cover 3 covering the conductor coil 2, and is equipped with an automatic tuning mechanism 4. There is.

The Litz wire that forms the conductor coil 2 is highly flexible, and the shape memory resin that is the material of the shape memory resin cover 3 returns to its initial shape at high temperatures and has a resistance to the body temperature of the subject. A material that can be freely deformed at 20 to 40"C was applied.

Therefore, the MRI surface coil 1 can be freely curved to follow the external shape of the subject, and at this time, even if the capacitance component (C) and the inductance component (L) change, the MRI surface coil 1 can be curved freely. An automatic tuning mechanism 4 is provided at the terminal of the conductor coil 2 so that tuning can be achieved.

Note that the conductor coil 2 may be formed of copper foil instead of the litz wire.

Next, regarding one embodiment of the present invention, its operation is shown in Fig. 2 (
This will be explained with reference to A) to (C).

FIG. 2(A) shows the flat plate state in which the MRI surface coil 1 has returned to its initial shape. MR in this flat state
Since the I surface coil 1 deforms freely with the body temperature of the subject, the arm PA of the subject as shown in FIG. 2(B)
The MRI surface coil 1 is freely deformed to follow the outer shape of the coil 1, so that the MRI surface coil 1 is arranged in close contact with the desired shape. In this state,
For example, MRI imaging is performed using an MRI apparatus as shown in FIG. After the MHI imaging is completed, hot air is sent to the MRI surface coil 1 by, for example, a dryer 5 as shown in FIG. 2(C), and then the MRI surface coil in a flat plate state as shown in FIG. 2(A) is again generated. It becomes 1.

The MRI apparatus shown in FIG. 3 uses the MRI surface coil 1 for applying a high-frequency magnetic field for excitation and for receiving magnetic resonance signals, and uses a computer system 6 as the control center for the entire system, and a sequencer 7. It is operated in sequence.

That is, when the subject P wearing the MRI surface coil 1 is placed in the static magnetic field obtained by the main magnet 8, the MRI surface coil 1 driven by the transmitter 9 is A high frequency magnetic field for excitation is applied, and a gradient magnetic field power supply 10 is applied.
By applying a gradient magnetic field from the gradient magnetic coil 11 driven by, a magnetic resonance phenomenon is caused in the subject P,
The excited magnetic resonance signals are received by a receiver 12 by the MRI surface coil 1, an image is reconstructed based on the collected magnetic resonance signals in a computer system 6, and the reconstructed image is displayed on a monitor 13. ing.

On the other hand, as explained according to FIGS. 1 and 2, MR
The I surface coil 1 is freely curved to follow the external shape of the subject P, and is placed in close contact with the subject P.

Therefore, the rate at which artifacts are included in the magnetic resonance signals collected by the computer system 6 is significantly lower than in the past, and as a result, the reconstructed images obtained by the computer system 6 have an improved S/N ratio. is displayed on the monitor 13.

〔Effect of the invention〕

As explained above, the MRI surface coil of the present invention is
Using litz wire or copper foil as the wire material of the conductor coil,
Since this conductor coil is coated with a shape memory resin cover that can be freely bent to follow the external shape of the subject, it is possible to place it in close contact with the subject as desired, and the S/N is low.
It is extremely useful for improvement.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the configuration of an MHI surface coil according to an embodiment of the present invention, Fig. 2 is an explanatory diagram for handling the MRI surface coil, and Fig. 3 is a configuration diagram schematically showing the MHI device. It is. 1... MRI surface coil 2... Conductor coil 3... Shape memory resin cover 4... Automatic tuning mechanism

Claims (3)

[Claims] (1) A surface coil for magnetic resonance imaging that receives magnetic resonance signals excited by applying a high-frequency magnetic field for excitation and a gradient magnetic field to a subject placed in a static magnetic field, which is connected to a litz wire. 1. A surface coil for magnetic resonance imaging, characterized in that it has an integral structure of a conductor coil and a shape memory resin cover covering the conductor coil. (2) A surface coil for magnetic resonance imaging that receives the magnetic resonance signal, the surface coil for magnetic resonance imaging having an integral structure of a conductor coil made of copper foil and the shape memory resin cover. surface coil. (3) The surface coil for magnetic resonance imaging according to claim 1 or 2, characterized in that the surface coil for magnetic resonance imaging is equipped with an automatic tuning mechanism.