JPS60133361A - Measurement of nuclear magnetic resonance - Google Patents

Abstract

PURPOSE:To enable extraction of nuclear magnetic resonance information from a narrow portion using an ordinary probe by surrounding an object to be measured with a sealing member except for the portion requiring measurement to adjust the relative position of the object being measured and the nuclear magnetic resonance coil. CONSTITUTION:An an animal or the like as object to be measured in a test tube 2 is moved, the relative position of the portion requiring measurement and a nuclear magnetic resonance coil 3 is adjusted to make the defined narrow portion requiring measurement face the coil 3. Under such a condition, when a high frequency magnetic field is irradiated through the coil 3, the magnetic field will not reach the part excluding the portion requiring measurement of the animal with a shield material F made up of a thin insulating sheet in the tube 2 and finely-sliced conductors commonly connected to each other like a comb and hence, allowed to reach the portion requiring measurement alone. With such an arrangement, nuclear magnetic resonance information can be extracted from the defined narrow portion using an ordinary probe.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a nuclear magnetic resonance 11JR (NMR) measurement method that allows information to be extracted only from a limited narrow region.

The number of objects that can be measured using NMR equipment is expanding, and recently, small animals such as mice and shoes are being measured while they are still alive. When measuring a localized area of such a small animal, a surface coil method has conventionally been used in order to capture only information from the measurement site. This method involves attaching a small movable coil (surface coil) to the surface of a small animal or a desired location within the body, and emitting high-frequency excitation waves from this coil to cause resonance only in the vicinity of the coil1! It is something that can be measured.

However, in such a surface coil method, NMR is fixedly arranged so as to surround the sample tube.
It was not possible to use a normal NMR probe equipped with a coil, and a dedicated probe had to be prepared.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an NMR measurement method that can extract information from only a limited narrow region using a normal probe.

According to the present invention, a portion of a measurement target other than a required measurement portion is surrounded by a sheet holding on its surface modal strips arranged in a blind shape and connected in common at one end, and the portion to be measured is
Face the MII coil, adjust the relative positional relationship between the object to be measured and the NMR coil, and perform NMR measurement by irradiating excitation high frequency from the NMP coil! This is what makes it special. Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 shows N M for carrying out the method according to the invention.
An example of the R device is shown, and numeral 1 in the figure is a magnet for generating a static magnetic field. Inside the magnet 1, a conventional NMR probe is inserted, in which an NMR coil 3 is arranged around a test tube 2. Reference numeral 4 denotes an oscillator that generates a high frequency wave at the resonant frequency of the measuring section, and the high frequency wave is sent to the NMR coil 3 as a high frequency pulse via gates 1 to 5. The resonance signal induced in the NMR=T quill after irradiation with the high-frequency pulse is sent to the demodulation circuit 7 via the gate 6. The attenuated signal obtained by the demodulation is sent to the arithmetic processing unit 8 and undergoes processing such as Fourier transformation to obtain an NMR spectrum. 9 is a pulse programmer that can control the opening and closing of the -J gate.

In the above-mentioned 4I4 configuration, by appropriately selecting the length of the sample II tube, the color of the sample, and the position of the animal (e.g., a mouse) to be placed inside, the part to be measured is set so that it faces the NMR coil 3. be able to. Inside the sample tube 2 is a sheet called a Faraday shield.
is affixed to areas other than the areas requiring measurement. This Faraday shield consists of narrow conductor strips arranged in a comb-like pattern on a thin insulating sheet, with one end of each strip connected in a common comb-like manner, and has the property of blocking high-frequency electromagnetic fields. Therefore, the high-frequency magnetic field irradiated from the NMR file 3 is applied only to the part to be measured (an animal's head in Figure 1) where the Faraday shield is not attached, and resonance occurs only in that part to be measured. The resonance signal induced in the NMR coil 3 based on the resonance becomes a complete signal containing only information from the target measurement site.

Figure 2 (a) shows the 31P-NMR spectrum obtained by measuring the head of a bull-gagged mouse under the conditions shown in Figure 1, and Figure 2 (b) shows the state with the Faraday shield removed. The dimensions of the 31P-N MR spectrum obtained by measurement are shown. It can be seen that in case (a) where a Faraday shield is installed, the influence from the surroundings is removed, and the wide component of the peak is reduced compared to case (1)).

Normally, the position of 1;t N M rl ':I can be changed, so any part of the animal can be subjected to NMR by changing the position of the animal or appropriately selecting the position U where the Faraday shield is applied. It is possible to face the coil.

In Figure 3(a), the abdomen of the mouse can be measured;
In the same figure (b), the lower abdomen of the mouse can be measured.

As detailed above, according to the present invention, it is possible to selectively extract information from only the area to be measured without requiring a special NMR probe like the surface coil method.
.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a nuclear magnetic resonance apparatus for carrying out the method according to the present invention, and FIG. 2 is a diagram showing an NMR spectrum for explaining the effects of the present invention. The figure is a diagram showing an example in which the measurement site is changed. 1: Magnet, 2: Sample tube, 3: NMRq illumination, 4: Oscillator, 5, 6: Gates 1 to . 7: demodulation circuit, 8: arithmetic processing unit, F: Faraday shield. Patent application representative: Mr. Ito, Figure 1; Figure 3 (a) Voluntary amendment to the procedure) November 12, 1980 □, 1+-;) Department, Commissioner of the Japan Patent Office 1, Incident Indication of Patent Application No. 242711 of 1982 2, Name of the invention Nuclear magnetic resonance measurement method 3, Relationship with the case of the person making the amendment Patent applicant address 1418 Nakagami-cho, Akishima City, Tokyo < T E L
0425 (43) 1165) Amendment Description 1, Name of the invention Nuclear magnetic resonance measurement method 2, Claims (1) Enclose the part of the measurement target other than the required measurement part with a seal L4, and provide navigation information. Adjust the relative positional relationship between the measurement object and the nuclear magnetic resonance coil so that the measurement site faces the nuclear magnetic resonance coil, and perform Pi magnetic resonance measurement by irradiating excitation high frequency waves from the nuclear magnetic resonance coil. A nuclear magnetic resonance measurement method characterized by: [5 3. Detailed Description of the Invention [Field of Industrial Application J] The present invention relates to a nuclear magnetic resonance (NMR) measurement method that is capable of extracting information from only a limited narrow region. [Prior Art] The objects to be measured by NMR devices are expanding, and recently, for example, small animals such as mice and rats are being measured while they are alive. When measuring a localized area of such a small animal, a surface coil method has conventionally been used in order to capture only information from the measurement site. This is a method in which a small movable coil (surface coil) is attached to the surface of a small animal or a desired location within the body, and the coil emits high-frequency excitation waves to cause resonance only in the vicinity of the coil. It is. [Problems to be Solved by the Invention] However, with such a surface coil method, it is not possible to use a normal NMR probe equipped with an NMR coil fixedly arranged so as to surround the sample tube. , a dedicated probe had to be prepared. The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an NMR measurement method that can extract information from only a limited narrow region using a normal probe. [Means for Solving the Problems] The present invention surrounds the part of the object to be measured other than the part to be measured with a shield member, and connects the part to be measured and the NMR coil so that the part to be measured faces the NMR coil. Adjust the relative positional relationship and irradiate excitation high frequency from the NMR coil to
It is characterized by performing MR measurement. [Example] Hereinafter, an example of the present invention will be described in detail based on the drawings. FIG. 1 shows an example of an NMR apparatus for carrying out the method according to the present invention, and in the figure, 1 is a magnet for generating a static magnetic field. Inside the magnet 1 is inserted a conventional NMR probe in which an NMR coil 3 is arranged around a sample tube 2 . Reference numeral 4 denotes an oscillator that generates a high frequency wave at the resonant frequency of the measurement section, and the high frequency wave is sent to the NMR coil 3 as a high frequency pulse via a gate 5. After irradiation with the high frequency pulse N
The resonance signal induced in the MR coil 3 is sent to the demodulation circuit 7 via the gate 6. The free induction attenuation signal obtained by demodulation is sent to the arithmetic processing unit 8 and subjected to processing such as Fourier transformation to obtain an NMR spectrum. 9 is a pulse programmer that controls the opening and closing of the -F gate. In the above configuration, by appropriately selecting the length of the sample tube or the position of the animal (for example, a mouse) placed in the sample tube 1w, it is possible to set the area to be measured so that it faces the NMR coil 3. . A shield member, for example, a sheet F called a Faraday shield, is attached to the inside of the sample tube 2 except for the area to be measured. This Faraday shield consists of narrow conductor strips arranged in a comb-like pattern on a thin insulating sheet, with one end of each strip connected in common in a comb shape, and has the property of blocking high-frequency electromagnetic fields. Therefore, the high-frequency magnetic field irradiated from the NMR coil 3 is irradiated only to the area to be measured (an animal's head in Figure 1) where the F1 radio shield F is not attached, and resonance occurs only in that area to be measured. Therefore, the resonance signal induced in the NMR coil 3 based on the resonance contains only information from the measurement target site. Figure 2 (a) shows the ``P-NMR slip'' obtained by measuring the head of a newborn mouse under the conditions shown in Figure 1, and Figure 2 (b) shows the P-NMR slip 1 ~ obtained with the Faraday shield removed. The figure shows the 31P-N MR spectrum obtained by measurement under the conditions. In (a) with a F1 radio shield, the shadow field from the surroundings is removed, and in (b) the broad component of the peak is reduced. Since the position of the NMR coil cannot normally be changed, any part of the animal can be connected to the NMR coil by changing the position of the animal or choosing the appropriate position to apply the Fradishield. In the example shown in FIG. 3(a), the abdomen of the mouse can be measured, and in FIG. 3(b), the lower abdomen of the mouse can be measured. Although the shield is used to surround the area other than the area to be measured, other shielding members may be used to surround the area.For example, a conductive ring may be used instead of the Faraday shield as shown in Figure 1 or 3 (a).
, (b), the same effect as a Faraday shield can be obtained. In that case, if the ring is provided separately from the sample tube 2 and its position can be changed mechanically from the outside, the portion to be shielded can be adjusted as appropriate from the outside. [Effects of the Invention] As described in detail above, according to the present invention, information can be selectively extracted only from the site to be measured without requiring a special NMR probe unlike the surface coil method. 4. Brief description of the drawings FIG. 1 is a diagram showing an example of a nuclear magnetic resonance apparatus for implementing the method according to the present invention, FIG. 2 is a diagram showing an NMR spectrum for explaining the effects of the present invention, FIG. 3 is a diagram showing an example in which the measurement site is changed. 1: Magnet 2: Sample tube 3: NMR coil 4: Oscillator 5.6 = gate 7: Demodulation circuit 8: Arithmetic processing unit F: Faraday Shield Special rF applicant JEOL Ltd. Representative 9 Fujio - Husband

Claims (1)

[Claims] Surround the part of the measurement target other than the required measurement part with a sheet holding on the surface conductor strips that are arranged in a blind pattern and have one end connected in common, and measure so that the required measurement part faces the nuclear magnetic resonance coil. 1. A nuclear magnetic resonance measurement method, characterized in that the relative positional relationship between an object and a nuclear magnetic resonance coil is adjusted, and the nuclear magnetic resonance measurement is performed by irradiating excitation high frequency waves from the nuclear magnetic resonance coil.