JPH1043154A - Marker for mri and production of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a marker which facilitates production and can become a high-accuracy position target, and production therefor. SOLUTION: The marker for MRI is formed by sealing MRI sensitive gell 1, which is formed by absorbing a nickel chloride aqueous solution in a water- holding material, in a sealed container 4 formed from the acrylic resin of a material almost not to be detected by MRI. Since the MRI sensitive gell 1 is in a gell state, the work of sealing into the sealed container 4 is facilitated and further, since air bubbles or the like are not mixed in comparison with a solution, the marker for MRI is functioned as the high-accuracy position target.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an MRI marker to be attached to an MRI apparatus to specify the position of the object when imaging the MRI apparatus, and a method of manufacturing the same.

[0002]

2. Description of the Related Art When performing an operation or the like, a plan for an operation such as a suction tube or an endoscope is specified on an MRI image of a surgical patient collected in advance, and a plan for an operation or the like is made. Surgery and the like for a patient are actually performed on the basis of this. In biomagnetic measurement or the like in which a morphological image cannot be obtained, it is widely performed to superimpose and display a measured biological activity current source on an MRI image. .

In such a case, it is necessary to associate the MRI image with a patient site where a surgical instrument is to be actually inserted into the patient, so that an MRI marker that can be normally detected by an MRI apparatus is attached to the patient's body surface. Imaging is performed, and the two are associated with each other based on the position of the marker.

In biomagnetism measurement and the like, it is necessary to associate a biological activity current source with an MRI image, and an image is taken by attaching an MRI marker detectable by an MRI device to the body surface of a patient. At the same time, a coil is attached to a patient site to which the marker is attached, an electric current is applied, and biomagnetism measurement is performed in that state, thereby associating the two.

[0005] As such an MRI marker, a polyethylene tube having a length of about 5 cm and a diameter of about 2 mm is usually used.
Substances that can be detected by the apparatus, for example, those into which an aqueous solution of nickel chloride is injected (JP-A-3-267054), liver oil balls, and the like are used.

[0006]

However, when a solution containing a substance that can be detected by an MRI apparatus is injected into a polyethylene tube, the sealing operation after the injection is complicated due to liquid leakage or the like.

In addition, when the solution is injected, air bubbles easily enter the tube. In such a case, the substance to be detected is shifted in the tube, the center of gravity of the marker is displaced, and accurate superimposition on the MRI image is required. It will be difficult.

On the other hand, when liver oil globules are used, the components of liver oil cause a chemical shift in MRI,
A position shift occurs in the I captured image itself.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide an MRI marker which can be easily manufactured and which can be used as a highly accurate position index, and a method of manufacturing the same.

[0010]

In order to achieve the above object, the present invention relates to an MRI marker attached to a subject to specify the position of the subject in an image taken by an MRI apparatus. A gel-like substance formed by absorbing a solution containing a substance that can be detected by the device into a water retention material is sealed in a hollow container.

Further, the method of manufacturing an MRI marker according to the present invention is characterized in that a solution containing a substance detectable by an MRI apparatus is absorbed into a water retention material to form a gel substance, and the gel substance is sealed in a hollow container. It is characterized by.

The water-retaining material is either a polymer water-retaining material or absorbent cotton, and the solution containing a substance detectable by the MRI apparatus is a nickel chloride aqueous solution, Gd-DTPA, copper sulfate aqueous solution, PVA (polyvinyl alcohol). Or any one of the following.

[0013]

1 and 2 show an embodiment of the present invention.
It will be described based on. FIG. 1 is a schematic view of an MRI marker according to the present invention, FIG. 1A is an upper half view thereof, and FIG.
FIG. 2 is a sectional view taken along the line AA of FIG. 1A.

As shown in FIG. 1, an MRI marker is provided in a sealed container 4 made of an acrylic resin which is a substance which is hardly detected by an MRI apparatus.
Is formed by encapsulating.

The sealed container 4 is composed of a lid portion 4a and a container portion 4b, and the connection between the two is made by placing the MRI-sensitive gel 1 in the container portion 4b to the very top of the MRI-sensitive gel 1 and using a non-water-soluble adhesive. This is performed by bonding the lid portion 4a and the container portion 4b at the connection portion 4c.

The sealed container 4 has a diameter of 7 mm and a thickness of 3 mm.
It may be formed in a disk shape of about mm to 5 mm. Also,
The smaller the diameter and the depth of the cavity in the container portion 4b for enclosing the MRI-sensitive gel 1, it is preferable in that the position designation error is reduced.
Do not appear on the MRI-captured image, and therefore need to be determined in consideration of imaging conditions and the like as appropriate.

The MRI sensitive gel 1 is a gel-like substance which can be detected by an MRI apparatus formed by absorbing an aqueous solution of a substance which can be detected by the MRI apparatus into a water retaining material.

FIG. 2 shows a manufacturing process of the MRI sensitive gel 1. First, the water retaining material 3 is put in a container 5 in advance at room temperature and normal pressure as shown in FIG. MR
An aqueous solution of a substance that can be detected by the device I, for example, an aqueous nickel chloride solution 2 is poured into the container 5.

At this time, as shown in FIG. 2B, the aqueous nickel chloride solution 2 is absorbed by the water retaining material 3 and finally completely absorbed by the water retaining material 3 as shown in FIG. Expands about 300 to 1000 times the volume of the initial MRI-sensitive gel 1.

In the above-described embodiment, the nickel chloride aqueous solution 2 is used as the aqueous solution of the substance that can be detected by the MRI apparatus, but Gd-DTPA, copper sulfate aqueous solution, PVA (polyvinyl alcohol) and the like can also be used.

The water retaining material 3 is desirably a polymer water retaining material, and absorbent cotton and the like can also be used.

In the above-described embodiment, the sealed container 4 has a disk shape. However, in the present invention, a polygonal plate member such as a quadrangle can be used.

[0023]

According to the present invention, since the substance detected by the MRI apparatus is in a gel state, the enclosing operation in a container becomes easy, and no bubbles or the like are mixed. Function as

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of an MRI marker according to the present invention.

FIG. 2 is an MR sealed in an MRI marker according to the present invention.
It is a figure which shows the manufacturing process of an I sensitive material.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 MRI sensitive gel 2 Nickel chloride aqueous solution 3 Water retention material 4 Sealed container 4a Lid 4b Container 4c Connection 5 Container

Claims (2)

[Claims] 1. An MRI marker attached to a subject in order to specify the position of the subject in an image taken by the MRI apparatus, wherein the marker is formed by absorbing a solution containing a substance detectable by the MRI apparatus into a water retaining material. A marker for MRI, characterized by enclosing the gelled substance in a hollow container. 2. The MRI according to claim 1, wherein a solution containing a substance that can be detected by the MRI apparatus is absorbed by a water retention material to form a gel substance, and the gel substance is sealed in a hollow container. Of manufacturing marker for medical use.