JP2002341002A - Magnetic field correction device for nuclear magnetic resonance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sufficient resolution by correcting the distortion of a total magnetic field map by magnetic susceptibility in the central component of an NMR probe in a temperature variable measurement. SOLUTION: In this magnetic field correction device for nuclear magnetic resonance, a static magnetic field map function (room temperature) obtained on the basis of the magnetic susceptibilities xRT21, xRT22, xRT24, xRT25, xRT26, xRT27-xRTn at room temperature of the central parts 21, 22, 24, 25, 26, 27-n of the NMR probe 4 and the shape structure M21, M22, M24, M25, M26, M27-Mn of each part, and a static magnetic field map function (VT temperature) obtained on the basis of magnetic susceptibilities at VT temperature xVT21, xVT22, xVT24, xVT25, xVT26, xVT27-xVTn and the shape structures M21, M22, M24, M25, M26, M27-Mn of the parts are preliminarily registered in a correction function setter 6A. The correction function setter 6A selects map correction data most suitable to the NMR probe 4 from these functions and transmits them to a magnetic field correction device 6, and the magnetic field correction device 6 corrects the total static magnetic field according to the VT temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a nuclear magnetic resonance apparatus for examining the structure of a substance by using a nuclear magnetic resonance phenomenon, and more particularly, to a probe and its probe at the time of variable temperature measurement or ordinary measurement at room temperature. The present invention belongs to the technical field of a magnetic field correction device for nuclear magnetic resonance, which corrects a magnetic field distortion applied to a static magnetic field depending on a change in a measurement temperature or a room temperature in each of the nearby components.

[0002]

2. Description of the Related Art A nuclear magnetic resonance apparatus (hereinafter, also referred to as an NMR apparatus) for examining the structure of a substance using a nuclear magnetic resonance phenomenon is known.
Conventionally, various types have been developed. FIG. 2 shows a conventional general N
FIG. 3 is a diagram schematically showing an MR device, and FIG. 3 is a diagram schematically showing a central portion of an NMR probe of the conventional NMR device shown in FIG. As shown in FIGS. 2 and 3, in this NMR apparatus, a sample tube 1 containing a sample 30 is set in a static magnetic field of a magnet 2, and an RF pulse signal having a resonance frequency corresponding to the magnetic field intensity is applied to the sample 30. Irradiation causes nuclear magnetic resonance phenomenon. In this case, the RF pulse signal is obtained by appropriately amplifying the NMR pulse signal from the oscillator 14 by the power amplifier 13 and inputting it to the NMR probe 4 via the duplexer 9 for switching input and output. Irradiate the sample 30 inside. Then, the sample 30 outputs a signal of the resonance frequency by the nuclear magnetic resonance phenomenon, and the signal is captured by the NMR probe 4.

At this time, when measuring the sample 30 at a certain predetermined temperature, the temperature of the NMR probe 4 is variably controlled by a variable temperature (VT) device 5 controlled by a computer 7.

[0004] After the signal captured by the NMR probe 4 is sent to an amplifier 10 by a duplexer 9 and amplified, the signal is converted to an audio frequency by a demodulation detector 11 and further converted to a digital signal by an A / D converter (ADC) 12. Convert to a signal. Then, the digital signal is taken into the computer 7, and the computer 7 analyzes the signal, thereby analyzing the sample 30, and displaying the analysis result on the display 8. Thus, the structure of the substance is examined by the NMR apparatus.

As shown in FIG. 3, the center portion of the NMR probe 4 includes components such as a sample coil 21, a sample coil bobbin 22, a vacuum double tube 24, and first to third supports 25, 26, 27. Elements).
These parts (elements) 21, 22, 24, 25, 26, 27,
,..., N each have a unique magnetic susceptibility as shown in Table 1.

[0006]

[Table 1]

[0007] Each component forms a magnetic field distribution due to the magnetic susceptibility inherent to these components. These magnetic field distributions are combined to form a total static magnetic field distribution (map). In other words, it can be said that the static magnetic field map created by the magnet 2 is distorted by the magnetic field distribution of these components. This total static magnetic field map is dependent on the material of the individual components, ie the material properties (susceptibility; susceptibility at room temperature xRT21, xRT22, xRT24, xRT25, xRT26, xR
T27,... XRTn) and the shape and structure of each material (including the arrangement structure of parts) M21, M22, M24, M25, M26, M27,.

Therefore, conventionally, the distortion of the total static magnetic field map is corrected by correcting the total static magnetic field map with the room temperature shim 3 based on the shape and structure of the material at the center of the NMR probe 4 and the characteristics of the material. Has been corrected. Specifically, a solvent called NMR LOCK, which is generally replaced by a deuterium nucleus, is put into the sample tube 1 together with the sample 30 to be measured, and the NMR signal of the deuterium nucleus is monitored to determine the intensity. By adjusting the room temperature shim 3 so as to increase, the total static magnetic field map is corrected.

Also, parts (elements) 21, 22, 24, 25,
26, 27,..., N are also dealt with by using a nonmagnetic material having extremely small magnetic susceptibility. In this case, the order of the magnetic susceptibility is generally 1/3 of the magnetic susceptibility of copper used as a sample coil material.
To 1/10 magnetic susceptibility, but recent advanced materials may use materials with magnetic susceptibility as small as 1/100 magnetic susceptibility.

[0010]

By the way, the magnetic susceptibility of a substance fluctuates according to the inherent Curie's law when the temperature changes, and the magnetic susceptibility of the material at the center of the NMR probe 4 also fluctuates according to the Curie's law. . That is, each component 21, 22, 24, 25, 26, 27,...
It is an element related to the resolution of the device, and as shown in Table 1, each component 21, 22, 24, 25, 26, 27,.
Susceptibility at room temperature xRT21, xRT22, xRT24, xRT25, xRT26, xRT2
7, ......... xRTn is the measured temperature (VT
Susceptibility xVT21, xVT22, xVT24, xVT25, xVT26, xVT2 at temperature)
7, fluctuates to xVTn. For this reason, it is necessary to always consider this Curie rule in VT measurement performed with a probe for nuclear magnetic resonance.

Therefore, in the VT measurement, the magnetic susceptibility changes at the center of the NMR probe 4 which is naturally exposed to the environment, and the total magnetic field map at a position very close to the sample 30 is greatly distorted. In the conventional case, the correction is simply made by the room temperature shim 3 as described above. However, in the correction using the room temperature shim 3 as described above, each component (element) 21, 22, 24,
The distortion of the details in the total magnetic field map due to the susceptibility fluctuation of 25, 26, 27,..., N cannot be reliably and sufficiently corrected. As a result, there is a problem that a sufficient resolution cannot be obtained.

As described above, each part (element) 21,
Even if 22, 24, 25, 26, 27,..., N are formed of a non-magnetic material having the lowest possible magnetic susceptibility, none of the non-magnetic materials have complete magnetism. Cannot be reliably corrected. In addition, such a material is not only expensive, but also may deteriorate and deteriorate in quality under an unstable environment to lose its original performance. As a result, similarly, there is a problem that a sufficient resolution cannot be obtained.

The present invention has been made in view of such a problem, and an object of the present invention is to provide an NMR spectrometer which performs variable temperature measurement.
A magnetic field for nuclear magnetic resonance capable of more reliably and sufficiently correcting distortion of the total magnetic field map due to magnetic susceptibility fluctuations in the components at the center of the probe, and providing sufficient resolution at low cost. It is to provide a correction device.

[0014]

In order to solve the above-mentioned problems, a magnetic field correction apparatus for nuclear magnetic resonance according to the present invention is characterized in that:
By irradiating a signal of a resonance frequency from a probe to a sample set in a static magnetic field, and capturing a signal of a resonance frequency output by a nuclear magnetic resonance phenomenon with the probe, a nuclear magnetic resonance apparatus that measures the sample, A correction function setting unit that registers a susceptibility change correction function for a temperature prepared in advance based on the temperature-dependent magnetic susceptibility of an element related to the resolution of the nuclear magnetic resonance apparatus. The distortion of the static magnetic field in the nuclear magnetic resonance apparatus due to the change in the magnetic susceptibility of the element based on the optimal magnetic susceptibility change correction function selected in response to the room temperature fluctuation during normal measurement at room temperature. It is characterized in that it is adapted to be corrected.

Further, the invention of claim 2 is characterized in that the susceptibility change correction function includes a temperature-dependent susceptibility of each element related to the resolution of the nuclear magnetic resonance apparatus, and a shape / arrangement of each element. It is characterized by being a function with factors based on structure and properties.

Further, the invention according to claim 3 is characterized in that the susceptibility change correction function includes a temperature-dependent susceptibility of each element related to the resolution of the nuclear magnetic resonance apparatus, and a shape / arrangement of each element. It is characterized by being the sum of functions with factors based on structure and properties. Further, the invention according to claim 4 functions as a temperature measuring device for measuring a temperature at that time based on the susceptibility change correction function corresponding to a change in the static magnetic field due to a temperature change. It is characterized by.

Further, according to the invention of claim 5, based on the susceptibility change correction function corresponding to the change of the static magnetic field due to the temperature change, the magnetic field fluctuation is detected when the room temperature fluctuates with time or temporarily. In addition, it has a function of correcting the disturbance of the magnetic field distribution (map) and correcting the room temperature maintaining device such as an air conditioner. Further, the invention according to claim 6 is characterized in that the nuclear magnetic resonance apparatus is a magnetic resonance imaging apparatus (MRI).

[0018]

In the magnetic field compensator for nuclear magnetic resonance according to the present invention, the temperature dependence of the element related to the resolution of the nuclear magnetic resonance apparatus during the variable temperature measurement or the normal measurement at the fluctuated room temperature is obtained. Magnetic susceptibility changes according to the Curie's law with temperature change.
The distortion of the static magnetic field in the nuclear magnetic resonance apparatus is corrected based on the optimum susceptibility change correction function selected according to the temperature or room temperature fluctuation. As a result, the distortion of the static magnetic field is finely corrected, and the residual magnetic field gradient term is reduced. Therefore, the distortion of the total magnetic field map due to the susceptibility fluctuation is more reliably and sufficiently corrected, and the static magnetic field map (distribution) of the NMR apparatus is highly uniform at the time of VT measurement or normal measurement at room temperature fluctuation. Will be kept at once. This improves the resolution of the NMR apparatus even during VT measurement or measurement at room temperature fluctuation.

In addition, since the data of the susceptibility change correction function prepared in advance is selected and only a slight fine adjustment is performed after the setting, it is easy to improve the resolution with a burden. Furthermore, it is possible to actively use a component having a certain magnetic susceptibility as an element related to the resolution of the nuclear magnetic resonance apparatus, and this element can be inexpensive without using expensive materials as described above. It can be composed of materials. In addition, since a stable material can be preferentially selected, quality is improved.

In particular, according to the invention of claim 4, it is possible to measure the temperature at that time based on the susceptibility change correction function corresponding to the change in the static magnetic field due to the temperature change. Further, in the invention according to claim 5, based on a susceptibility change correction function corresponding to a change in a static magnetic field due to a temperature change, when the room temperature fluctuates with time or temporarily, a magnetic field fluctuation is detected to detect a magnetic field fluctuation. It is possible to perform correction for (map) disturbance and correction for a room temperature maintaining device such as an air conditioner. Further, according to the sixth aspect of the present invention, the magnetic resonance imaging apparatus (MRI) can display an image of a human body, an animal, and an object with higher resolution.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an NM to which an embodiment of a magnetic field correction apparatus for nuclear magnetic resonance according to the present invention is applied.
FIG. 3 is a view similar to FIG. 2, schematically illustrating an R device. In addition,
The same components as those in the conventional example shown in FIGS. 2 and 3 are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 1, the magnetic field correction apparatus for nuclear magnetic resonance according to this embodiment is provided with a correction function setting unit 6A as compared with the above-mentioned conventional example. Then, as shown in Table 2, the magnetic susceptibilities xRT21, xRT22, xRT24, xRT25, xRT26, xRT27,.
…, XRTn data and shape structure of each material M21, M22, M24, M2
Based on the data of 5, M26, M27,..., Mn, all parts (elements) 21, 22, 24, 25, 26, 27,.
, N, for each component, a close static magnetic field map is calculated in advance, and the obtained close static magnetic field map is converted to a static magnetic field map function (a Curie temperature characteristic) correction function for the susceptibility change with respect to temperature (Curie temperature characteristic). Room temperature) f (xRT21, M21), f (xRT22, M22),
f (xRT24, M24), f (xRT25, M25), f (xRT26, M26), f
(XRT27, M27),..., F (xRTn, Mn) are registered in the ROM of the correction function setting unit 6A.

[0023]

[Table 2]

In addition, when the VT temperature at the time of VT measurement changes, a factor that changes according to the Curie rule is added to V
Magnetic susceptibility xVT21, xVT22, xVT24, xVT25, xVT26, xVT2 at T temperature
7, ………, xVTn data and shape structure of each material M21, M22, M
24, M25, M26, M27,..., Mn, and all parts (elements) 21, 22, 24, 25,
26, 27,..., N, for each component, a close static magnetic field map is calculated in advance, and the obtained close static magnetic field map is
A static magnetic field map function (VT temperature), which is a correction function of magnetic susceptibility change (Curie temperature characteristic) with respect to temperature, f (xVT21, M21), f (xVT22, M22), f (xVT24, M24), f
(XVT25, M25), f (xVT26, M26), f (xVT27, M27), ...
.., F (xVTn, Mn) are registered in the ROM of the correction function setting device 6A. In this case, changes in the shape structures M21, M22, M24, M25, M26, M27,..., Mn due to a temperature change to the VT temperature are ignored.

Further, these temperature-dependent proximity static magnetic field maps are distributed to data developed into magnetic field orders of the x, y, z axes and radial angles of the respective elements of the magnetic field gradient, and a door-like matrix relating to temperature is obtained. Data is created and registered in the correction function setting device 6A. These values are
Since it depends on the structure of the probe 4, the NMR probe 4
Prepare data according to the type of. In that case, when the NMR probe 4 is set, the computer 7
The code of the R probe 4 is read to prepare data of the corresponding NMR probe 4.

As the temperature data, data from the conventional VT device 5 can be used. In this case, when the temperature setting is input in accordance with the temperature information and the data is simultaneously input to the correction function setting device 6A in conjunction therewith, or when the temperature is stabilized, the data is transmitted to the correction function setting device 6A. It is convenient to make it possible to make a selection, for example, when performing data input.

The correction function setting unit 6A is a command signal from the computer 7 and is optimal for the NMR probe 4 based on a static magnetic field map function (room temperature) and a static magnetic field map function (VT temperature) registered in the ROM. Coating or coding the map correction data relating to the x temperature dependence and sending a correction signal to the magnetic field correction device 6 so that the magnetic field correction device 6 corrects the total static magnetic field according to the VT temperature by this correction signal. Has become. Note that the correction function setting device 6A may be provided in the computer 7.

According to the magnetic field compensator for nuclear magnetic resonance of this embodiment having such a configuration, the NMR probe 4 which takes into account a factor that changes in accordance with the Curie rule when changing to VT temperature during variable temperature measurement is used. VT of each component 21, 22, 24, 25, 26, 27,..., N at the center
Temperature dependent magnetic susceptibility xVT21, xVT22, xVT24, xVT25,
The distortion of the total static magnetic field map is determined based on the data of xVT26, xVT27, ..., xVTn and the data of the shape structure M21, M22, M24, M25, M26, M27, ..., Mn of each material. Since the correction is performed, fine correction can be performed, and the residual magnetic field gradient term can be reduced. Therefore, the distortion of the total magnetic field map due to the change in magnetic susceptibility can be corrected more reliably and sufficiently, and the static magnetic field map (distribution) of the NMR apparatus can be maintained at a high degree of uniformity during VT measurement. This improves the resolution of the NMR apparatus even during VT measurement.

Further, since it is only necessary to call the data prepared in advance, it is only necessary to make a slight fine adjustment after the setting, and it is possible to easily improve the resolution with a burden. Furthermore,
Each component 21, 22, 2 at the center of the NMR probe 4
4, 25, 26, 27,..., N, a part having a certain magnetic susceptibility can be actively used, and the NMR probe 4 can be used without using expensive parts as described above. Can be constituted. In addition, since stable parts can be preferentially selected, quality is improved. Other configurations, other operations, and other effects of the NMR apparatus of this example are the same as those of the above-described conventional example.

The magnetic field correction device for nuclear magnetic resonance according to the present invention is not limited to the above-described example, and various modifications are possible. For example, in the above-described example, the static magnetic field map function (room temperature) and the static magnetic field map function (VT temperature) are obtained for the individual components shown in Table 2, and correction is performed for each individual component using these functions. , The sum of the static magnetic field map function (room temperature) and the static magnetic field map function (VT temperature) shown in Table 2 Σf (xRT _i , M _i ) = S _RT and Σf (x
By taking (VT _i , M _i ) = S _VT , correction can be made for the entire part.

[0031] That is, to calculate the sum proximity field map S _RT of XRT _i and M _i at room temperature in advance associated all products. The obtained total proximity magnetic field map _SRT is registered in the ROM of the correction function setting unit 6A as a static magnetic field map function (room temperature). Moreover, to calculate the sum proximity field map S _VT of XVT _i and M _i of at VT temperature in consideration of the factors which vary according to Curie's law when changes to VT temperature during VT measurement.
The obtained total proximity magnetic field map _SVT is registered as a static magnetic field map function (VT temperature) in the ROM of the correction function setting unit 6A. Other configurations, other operations, and other operational effects of the NMR apparatus of this example are the same as those of the above-described example.

In each of the above-described examples, only the temperature-dependent magnetic susceptibility of each part at the center of the NMR probe 4 taking into account a factor that changes according to the Curie rule is used. Has a temperature-dependent magnetic susceptibility that changes in accordance with the Curie's law, similarly to the components at the center. That is, the sample tube 1 is also an element related to the resolution of the NMR apparatus. Therefore, also for the sample tube 1, the static magnetic field map function (room temperature) and the static magnetic field map function (VT temperature) are obtained and registered in the correction function setting unit 6A in the same manner as described above. In this case, the data of various sample tubes 1 is a commonly used general model of 2.5.
Typical items such as mmφ, 3 mmφ, 5 mmφ, 8 mmφ, 10 mmφ, etc. are prepared. By allowing the computer 7 and the correction function setting unit 6A to recognize the static magnetic field map function (room temperature) and the static magnetic field map function (VT temperature) in the sample tube 1, it is possible to respond to the flexibility on the user side. it can.

Furthermore, the sample 30 also has a temperature-dependent magnetic susceptibility that changes according to the Curie rule. Similarly, the sample 30 is an element related to the resolution of the NMR apparatus. Therefore, also for this sample 30, the static magnetic field map function (room temperature) and the static magnetic field map function (VT temperature) are obtained and registered in the correction function setting unit 6A in the same manner as described above. In this case, the data of various samples 30 is 2.5 mmφ, 3 mm, which is a commonly used general model.
Representative items such as φ, 5 mmφ, 8 mmφ, and 10 mmφ are prepared. Further, the capacity of the sample 30 is modeled by several types so that an approximate value can be selected. Then, the computer 7 and the correction function setting unit 6A recognize the static magnetic field map function (room temperature) and the static magnetic field map function (VT temperature) of the sample 30.
It can respond to user flexibility.

Further, in addition to the use of the static magnetic field map function as a correction device for correcting a static magnetic field as described above, the present invention can also be used as a temperature measuring device for measuring a temperature change from a magnetic field change. That is, each static magnetic field map function at the VT temperature (VT temperature) f (xVT21, M21), f (xVT22, M22), f
(XVT24, M24), f (xVT25, M25), f (xVT26, M26), f
(XVT27, M27), ………, f (xVTn, Mn) is known,
Or each static magnetic field map function at VT temperature (VT temperature)
Since the sum Σf (xVT _i , M _i ) = S _VT is known, the temperature can be known from the map change of the magnetic field due to the temperature change. That is, the magnetic field correction device for nuclear magnetic resonance of the present invention can also function as a temperature measuring device.

In particular, when there is a component having a specific temperature dependency, it is effective to use a specific change in the temperature characteristic of the static magnetic field map as a temperature measuring device. For example, assuming that the component of the third support 27 gives a specific static magnetic field map change with respect to temperature dependence, when this specific static magnetic field map change occurs, this change is applied to other components. Is a change that cannot be seen, so it can be easily recognized as such. By comparing this result with data that is known in advance, the temperature at that time can be determined.

Further, in each of the above-mentioned examples, the shape structure M21, M22, M24, M25, M26, M27,...
Although it has been described that the change in n is ignored, a change in the shape factor M (for example, a change in dimension) due to this temperature change is predicted / calculated in advance, and the change in the shape factor M due to the temperature change is added as a parameter. Thus, it goes without saying that the present invention can be carried out in the same manner as described above.

Further, in the magnetic field correction apparatus for nuclear magnetic resonance of the present invention, even when the room temperature fluctuates with time or temporarily,
The magnetic field fluctuation is detected, and based on the magnetic susceptibility change correction function corresponding to the change of the static magnetic field due to the temperature change, the correction for the disturbance of the magnetic field distribution (map) and the correction for the room temperature maintaining device such as an air conditioner are performed. You can also.

Further, in each of the above-described examples, the substance is described from the viewpoint of the material of the NMR apparatus. However, the magnetic field correction apparatus for nuclear magnetic resonance of the present invention is used as a nuclear magnetic resonance apparatus to measure the inside of a human body. The present invention can also be applied to a magnetic resonance imaging apparatus (MRI) used for measurement inside an animal or inside an object. For example, the present invention relates to an MR for measuring the inside of a human body.
When applied to I, the above-described components 21 to n correspond to each part of the human body. Then, the magnetic susceptibility of each part of the human body is registered as the average data of a human or the average data of a healthy person in the same manner as the aforementioned components 21 to n,
The map of the temperature of each part is handled as magnetic field fluctuation data for diagnosing normal / abnormal of a human body (sample). The measurement of animals and other objects is the same as that of the human body measurement. Thus, the magnetic resonance imaging apparatus (M
By RI), the inside of a human body, the inside of an animal, and the inside of an object can be displayed with higher resolution.

Furthermore, as described above, an operation method of not only reading the ROM but also comparing the recognized temperature information with the static magnetic field map information to obtain an optimum value and writing the optimum value into the RAM can be adopted.

[0040]

As is apparent from the above description, according to the magnetic field correction apparatus for nuclear magnetic resonance according to the present invention, the resolution of the nuclear magnetic resonance apparatus is not affected by the variable temperature measurement or the measurement at the so-called room temperature fluctuation. Even if the temperature-dependent magnetic susceptibility of the element changes according to the Curie law, the distortion of the static magnetic field in the nuclear magnetic resonance apparatus is determined based on the optimum magnetic susceptibility change correction function selected according to the VT temperature or room temperature change. Is corrected, distortion of the static magnetic field can be finely corrected, and the residual magnetic field gradient term can be reduced. Therefore, the distortion of the total magnetic field map due to the fluctuation of the magnetic susceptibility can be more reliably and sufficiently corrected, and the static magnetic field map (distribution) of the NMR apparatus can be maintained at a high degree of uniformity at the time of VT measurement or at the time of so-called room temperature fluctuation. Thereby, V
The resolving power of the NMR apparatus is improved even at the time of T measurement or at the time of measurement with a temporal change or a temporary change at room temperature.

Further, the data of the susceptibility change correction function prepared in advance is selected, and after the setting, only a slight fine adjustment is performed. Therefore, the burdened resolution can be easily improved. Further, factors related to the resolution of the nuclear magnetic resonance apparatus include:
Since it becomes possible to positively use parts having a certain magnetic susceptibility, this element can be made of an inexpensive material without using an expensive material as described above. In addition, since a stable material can be preferentially selected, quality can be improved.

In particular, according to the invention of claim 4, it is possible to measure the temperature at that time based on the susceptibility change correction function corresponding to the change in the static magnetic field due to the temperature change.
According to the invention of claim 5, when the room temperature fluctuates with time or temporarily, the magnetic field fluctuation is detected based on the magnetic susceptibility change correction function corresponding to the change of the static magnetic field due to the temperature change. It is possible to perform correction for disturbance of the distribution (map) and correction for a room temperature maintaining device such as an air conditioner. Further, according to the sixth aspect of the present invention, the magnetic resonance imaging apparatus (MRI) can display an image of a human body, an animal, and an object with higher resolution.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing an NMR apparatus to which an example of an embodiment of a magnetic field correction apparatus for nuclear magnetic resonance according to the present invention is applied.

FIG. 2 is a diagram schematically showing a conventional general NMR apparatus.

FIG. 3 is a diagram schematically showing a central part of an NMR probe of the conventional NMR apparatus shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sample tube, 2 ... Magnet (static magnetic field), 3 ... Room temperature shim, 4 ... NMR probe, 5 ... Temperature variable (VT) device,
6 magnetic field correction device, 7 computer, 8 display device, 1
4 oscillator, 21 sample coil, 22 sample coil bobbin, 24 vacuum double tube, 25 first support,
26 ... second support, 27 ... third support, 30 ... sample

Claims (6)

[Claims] A nucleus for measuring the sample by irradiating a sample set in a static magnetic field with a signal of a resonance frequency from a probe and capturing a signal of a resonance frequency output by a nuclear magnetic resonance phenomenon with the probe. The magnetic resonance apparatus includes a correction function setting unit that registers a susceptibility change correction function for temperature prepared in advance based on the temperature-dependent susceptibility of an element related to the resolution of the nuclear magnetic resonance apparatus. Based on the optimal susceptibility change correction function selected in response to the measurement variable temperature or in response to room temperature fluctuation during normal measurement at room temperature, the nuclear magnetic resonance apparatus according to the change in susceptibility of the element. A magnetic field correction device for nuclear magnetic resonance, wherein the device corrects distortion of a static magnetic field. 2. The susceptibility change correction function includes a temperature-dependent susceptibility of an individual element related to the resolution of the nuclear magnetic resonance apparatus, a factor based on a shape, an arrangement structure, and a characteristic of the individual element. 2. The magnetic field correction apparatus for nuclear magnetic resonance according to claim 1, wherein the function is a function of 3. The magnetic susceptibility change correction function includes a temperature-dependent magnetic susceptibility of each element related to the resolution of the nuclear magnetic resonance apparatus, a factor based on a shape, an arrangement structure, and a characteristic of each of the elements. 2. The magnetic field correction apparatus for nuclear magnetic resonance according to claim 1, wherein the sum is the sum of the following functions: 4. A temperature measuring device for measuring a temperature at that time based on the susceptibility change correction function corresponding to a change in the static magnetic field due to a temperature change. A magnetic field correction device for nuclear magnetic resonance according to claim 1. 5. A magnetic field distribution (map) based on the magnetic susceptibility change correction function corresponding to a change in the static magnetic field due to a temperature change, detecting a magnetic field fluctuation when the room temperature fluctuates with time or temporarily. 5. The magnetic field correction apparatus for nuclear magnetic resonance according to claim 1, wherein the apparatus has a function of performing correction for disturbance of air and correction for a room temperature maintaining device such as an air conditioner. 6. The magnetic field correction apparatus for nuclear magnetic resonance according to claim 1, wherein said nuclear magnetic resonance apparatus is a magnetic resonance imaging apparatus (MRI).