JP4688830B2 - Phantom for magnetic resonance spectroscopy performance evaluation using magnetic resonance imaging equipment - Google Patents

Description

  The present invention relates to a phantom for testing the Magnetic Resonance Spectroscopy (MRS) efficiency using a magnetic resonance imaging equipment, and more particularly to chemical shift imaging. The present invention relates to a phantom for evaluating magnetic resonance spectroscopy performance using a magnetic resonance imaging equipment capable of quantitatively evaluating the resolution of a spectrum acquired at the time of magnetic resonance spectroscopy measurement.

  In general, magnetic resonance spectroscopy is known as an excellent analytical method used in the fields of chemistry and biochemistry, and since 1990, it has been actively used in the clinical field. It is used in the field of neuroscience that mostly targets the brain, which is an immobile organ, due to technical limitations.

  Magnetic resonance spectroscopy accurately observes the change in magnetic resonance signal (frequency) with respect to an applied RF pulse when a test object is placed in a magnetic field, and quantitatively analyzes the structure, components, and state of the target. It is a method to analyze. Therefore, it is possible to obtain biochemical information based on the mechanical action of metabolites from a specimen given in a manner that is harmless to the measurement target, and such biochemical information is determined by the type of molecular composition in the specimen. Is done.

The principle of magnetic resonance spectroscopy is that the innumerable positives existing in the human body have their own magnetic resonance frequencies due to minute differences, so that individual elemental components can be distinguished analytically and molecular structures can be determined. It is something to be determined.
Magnetic resonance spectroscopy data is represented as a spectrum showing various signal intensities using a reference compound that provides the frequency of the reference point, and each peak position is displayed as a function of frequency (Hz).
Even if the positives constituting each different tissue are the same positives, there is a minute difference in chemical and magnetic properties, that is, a difference in the magnetic field in the local region due to the surrounding environment.
As a result, the resonance frequency also shows a minute difference and can be easily distinguished by the spectrum.

In order to evaluate the performance of a magnetic resonance system, a magnetic resonance phantom has been developed and has been accurately analyzed for errors in the magnetic resonance system.
However, since the announcement of phantoms used for magnetic resonance imaging, there has been no interest in developing more advanced phantoms.
Therefore, it was obtained by multi-voxel spectroscopy (MVS) such as magnetic resonance spectroscopic imaging (MRSI) or magnetic resonance metabolic imaging (MRMI). The evaluation of the spectrum for the voxel of the video has deteriorated reliability.
This is because an exclusive phantom for multi-voxel spectroscopy is not used, but a general MRS phantom in which various metabolites in a single vessel (vial) are mixed is used.
In recent years, multi-voxel spectroscopy has been applied to the clinical medical field for radiosurgery, mapping of brain metabolites, diagnosis of brain diseases, etc., and multi-voxel spectroscopy has been actively developed.
Therefore, the magnetic resonance phantom has been raised to have a new function for performing accurate multi-voxel spectroscopy.

On the other hand, since the structure of the human body is composed of a plurality of types of sites with different metabolic powders, the orthotopic selection process has become an indispensable process for clinical application of magnetic resonance spectroscopy.
If the position selection process is incomplete, the signal is contaminated due to the influence of the tissue outside the region of interest (ROI), and a desired spectrum cannot be obtained from the region of interest.

The localization method, which is one of the orthotopic selection processes, is divided into a unit volume selection method in which a specific single voxel is selected and a magnetic resonance spectrum is acquired only at that site, and a plurality of continuous sections are separated. And a chemical movement selection method for simultaneously acquiring a magnetic resonance spectrum in each section.
The unit volume selection method is simple, can acquire materials in a short time, and the size of the materials is small, so a large-capacity storage medium is unnecessary, is relatively insensitive to shaking artifacts, and does not cause signal contamination. The possibility is small.
On the other hand, the chemical transfer selection method can measure changes in metabolites at multiple sites at the same time, so it can be used for simultaneous comparisons between tissues and has the advantage of being able to calculate selective images of metabolites. .

  When a measurement object enters the equipment during magnetic resonance spectroscopy measurement, the magnetic field becomes non-uniform due to the difference in magnetic susceptibility of each part of the measurement object, so the torsion phenomenon of the magnetic field is compensated and the homogeneity of the magnetic field is restored. In order to achieve this, a magnetic field correction operation, ie shimming, must be performed.

Thus, in order to restore the homogeneity of the magnetic field, a phantom that facilitates accurate error analysis by measuring in advance the spectrum acquired at the time of magnetic resonance spectroscopy measurement is required.
The phantom is an object to be measured by magnetic resonance spectroscopy using a magnetic resonance imaging equipment, and of course the spectrum of metabolites contained in the phantom can be obtained. It is a tool that allows you to grasp the shimming state of the resonance imaging equipment and select the correct position for magnetic resonance spectroscopy measurement.

  Conventionally, a phantom that is a mixture of multiple metabolites is used in the unit volume selection method, and the phantom used in the unit volume selection method is used in the chemical transfer selection method without using a dedicated phantom. However, there is a problem that it is difficult to evaluate the reliability of the spectrum obtained from each voxel, and accurate diagnosis and treatment cannot be performed.

  Therefore, in order to solve the above-described problems, the present invention uses a phantom configured by injecting a wide variety of metabolites into each of a number of inner containers arranged in a matrix and each having the same form. By performing magnetic resonance spectroscopy measurement through chemical moving imaging techniques, and by making it possible to select the position within the magnetic resonance imaging equipment when performing magnetic resonance spectroscopy measurement through acquired spectrum analysis, spectrum It is an object of the present invention to provide a magnetic resonance spectral performance evaluation phantom using a magnetic resonance imaging equipment that can improve the reliability of the image.

  In order to achieve the above object, a magnetic resonance spectral performance evaluation phantom using the magnetic resonance imaging equipment according to the present invention includes an outer container having an open top and an inner part of the outer container. And a plurality of inner containers configured to accommodate metabolites and a cover of the outer container covering the upper part of the outer container.

    An object of the present invention is to provide a cone-shaped phantom used for multi-voxel magnetic resonance spectroscopy, and to evaluate a magnetic resonance spectrum using the cone-shaped phantom.

According to the present invention, the cone-shaped MRS phantom is configured by coupling a plurality of cone-shaped containers.
The cylindrical main body is made of acrylic resin, and the cone-shaped container is made of polyethylene-cone. Each cone of the phantom is charged with various metabolites such as NAA, Cr, Cho, Lac, GABA, Glx, Magnevist (registered trademark).
For example, 1.5T GE and 3T Philips systems have been used for single voxel spectroscopy (SVS) and multi-voxel spectroscopy (MVS).
The process of confirming and quantifying the metabolites in the corn phantom was performed by the SAGE post program.
The original data of the Philips system was analyzed directly on the console.

Magnetic resonance images and spectra of cone-shaped phantoms were obtained from the assigned slice positions.
High-order shimming control was performed, providing improved resolution in single and multi-voxel spectroscopy.
Area and size were proportional to the metabolite volume within the voxel.
Metabolite quantification based on this area and spectrum was more sensitive than metabolite quantification based on the magnitude of the spectrum.

According to the present invention, it can be seen that this cone-shaped phantom is useful for quantification of metabolites.
An object of the present invention is to allow the cone-shaped phantom to use the qualitative control of the magnetic resonance spectrum obtained by single voxel spectroscopy and multi-voxel spectroscopy for evaluation.

  As described above, the magnetic resonance spectroscopy performance evaluation phantom using the magnetic resonance imaging equipment according to the present invention can obtain various spectra for various metabolites through one magnetic resonance spectroscopy measurement. Since various spectrums can be obtained according to the position of the measurement, it is possible to select a position in which the spectrum is not contaminated by the non-uniformity of the magnetic field of the magnetic resonance imaging equipment.

  Hereinafter, examples of the present invention will be described in detail, but the present invention is not limited to the following examples without departing from the gist thereof.

  FIG. 1 is a perspective view showing a phantom for magnetic resonance spectroscopy performance evaluation using a magnetic resonance imaging equipment according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the phantom shown in FIG. , Will be described in relation to each other.

  A magnetic resonance spectral performance evaluation phantom using the magnetic resonance imaging equipment according to the present embodiment has a cylindrical shape with an open top, and an outer container 10 in which the inside of the body is filled with distilled water, and the outer container 10. A plurality of inner containers 30 arranged in a matrix and configured to accommodate metabolites, a plurality of inner container plugs 32 for sealing the inner container 30, and the outer container 10. The cover includes an outer container cover 20 and a fastening means 40 for fastening the outer container 10 and the outer container cover 20 together.

  The configuration of the magnetic resonance spectral performance evaluation phantom using the magnetic resonance imaging equipment according to the present embodiment will be described in detail as follows.

The outer container 10 forming the outer shape of the phantom according to the present embodiment has a cylindrical structure made of a transparent acrylic material and having an open top.
In addition, the outer container 10 is provided with a fixing plate 12 that separates the body of the outer container 10 across the width direction at a portion separated from the lower portion by a predetermined distance. A number of fixing grooves 14 are formed so that the position of the inner container 30 can be fixed at the same time.
In this embodiment, the outer container 10 has a diameter of 25 cm.

  The outer container 10 is filled with distilled water in a portion other than a region occupied by a large number of inner containers 30.

The inner container 30 is made of a polymer resin series material and is arranged in an n × n matrix in the outer container 10. In this embodiment, the inner container 30 is in an 8 × 8 matrix. Arranged.
The inner container 30 can be configured in various forms, and by dividing and injecting various metabolites into each container, various spectrum images can be obtained through one magnetic resonance spectroscopy measurement. In this embodiment, the cone type having a diameter of 2 cm and a height of 8 cm was used.
In the present embodiment, the reason why the inner container 30 is formed in the cone type is that when the cone type container is used, the amount of the metabolite contained in the cross-sectional area of the measurement varies depending on the height of the inner container 30, so that magnetic resonance This is for performing magnetic resonance spectroscopic measurement while changing the position so that an optimum spectrum can be obtained at the time of spectroscopic measurement, and detailed description will be described later in the description of FIG. .

  The upper part of the inner container 30 is configured to be sealed with a plug 32 of a cylindrical inner container.

  The stopper 32 of the inner container is for sealing the upper end of the inner container 30 in order to prevent the metabolites injected into the inner container 30 from flowing to the outside. Made of rubber material.

  The inner container 30 is fixed by being sandwiched between fixing grooves 14 formed in the lower fixing plate 12 of the outer container 10.

  The outer container cover 20 is made of a material such as the outer container 10, and is a distillation that fills the outer container 10 at a position where the outer container cover 20 and the outer container 10 are coupled. A rubber packing 22 is formed so that water does not flow to the outside.

Further, a direction display means 24 for displaying the direction of the phantom according to the present embodiment is formed on the upper surface of the cover 20 of the outer container.
Since the outer container 10 of the phantom according to the present embodiment has a cylindrical shape, and the inner container 30 mounted inside the outer container 10 is arranged in an n × n matrix, the inner container 30 In order to grasp the type of metabolite to be injected, another direction display means 24 is necessary.

The fastening means 40 tightens the outer container 10 and the cover 20 of the outer container so that the distilled water filled in the outer container 10 does not leak to the outside.
In this embodiment, the fastening means 40 is a screw.

  A method for measuring magnetic resonance spectroscopy using a magnetic resonance spectroscopy performance evaluation phantom using the magnetic resonance imaging equipment having the above-described configuration will be described with reference to the accompanying drawings. .

  FIG. 3 is a conceptual diagram showing an example of an internal container into which various kinds of metabolites are injected in a magnetic resonance spectroscopy performance evaluation phantom using the magnetic resonance imaging equipment according to an embodiment of the present invention.

  First, in this example, the inner container was arranged in an 8 × 8 matrix, and the inner container was formed in a cone type. Metabolites injected into the internal container are mainly composed of metabolites constituting the brain, and the metabolites described in [Table 1] and [Table 2] below were used as the metabolites. .

The metabolites described in [Table 1] are the objects of magnetic resonance spectroscopy measurement, and in this example, the same metabolite was injected into four adjacent inner containers in the same manner.
This is to prevent an undesired spectrum from being acquired from the influence of other adjacent metabolites during the measurement of magnetic resonance spectroscopy.
Further, the metabolites described in [Table 2] are mixed together and injected into the remaining internal containers except the internal container into which the metabolite described in [Table 1] is injected.
The solution in which the metabolites described in [Table 2] are mixed together is mixed in a proportion similar to the metabolites constituting the human brain, and at least one of the metabolites described in [Table 1] is mixed. When the magnetic resonance spectroscopy of the metabolites in [Table 1] is measured, the influence from metabolites injected into the surrounding internal container is mitigated.

  FIG. 3 is an example showing a state in which the metabolites described in [Table 1] and [Table 2] are injected into the inner container, and the numbered parts are described in [Table 1]. The metabolites injected into the inner container are shown, and the part not numbered represents the inner container into which the metabolite mixed solution described in [Table 2] is injected. Here, the part with the same number represents the inner container into which the same metabolite is injected.

As shown in FIG. 3, the reason for injecting the metabolite into the inner container is that if the position selection is incomplete, the signal is contaminated in the inner container outside the region of interest, and an unwanted signal appears on the spectrum. In order to prevent this, the same metabolite is injected into each of the four adjacent inner containers, and the other inner containers are injected with a mixed solution in which various metabolites are mixed. This is to prevent the signal from being contaminated by the metabolites injected into the surrounding internal containers.
That is, among the metabolites described in [Table 1], the same metabolite is injected into each of four adjacent inner containers, and the metabolite selected as a measurement target at the time of magnetic resonance spectroscopy measurement is: Minimize the influence of other metabolites injected into the surrounding internal container, and use a mixed solution configured to contain at least one of the metabolites described in [Table 1]. By injecting into the internal container, it is possible to alleviate the contamination of the spectrum of the metabolite injected into the internal container to be subjected to the magnetic resonance spectroscopy measurement from the influence of the peripheral metabolite.

  FIG. 4 is a cross-sectional view of a magnetic resonance imaging performance evaluation phantom using a magnetic resonance imaging equipment according to an embodiment of the present invention. FIG. 5 is a conceptual diagram illustrating an example in which magnetic resonance spectroscopy is performed while changing the cross-sectional position of the inner container in order to obtain a spectrum having an optimal resolution because the contents of metabolites are different.

In this embodiment, by using a large number of inner containers made in the same form, various spectra can be obtained at one time by performing one magnetic resonance spectroscopy measurement, and the inner container is used in a cone type. Thus, a desired spectrum can be obtained while changing the measurement position of magnetic resonance spectroscopy.
If the inner container is used in a corn type, the distance between the inner containers increases as it goes to the end of the inner container, thus preventing the signal from being contaminated by metabolites injected into the surrounding inner containers. Can do.
However, at the time of magnetic resonance spectroscopy measurement, the amount of metabolite decreases toward the end of the inner container, and the resolution of the acquired spectrum may be lowered.
Therefore, in order to solve this, as shown in FIG. 4, when magnetic resonance spectroscopy is performed while changing the cross-sectional position of the inner container, a cross-section that appropriately contains a metabolite is selected, A spectrum with optimal resolution can be obtained.

  By performing the magnetic resonance spectroscopic measurement by the method as described above, it is possible to analyze the acquired spectrum and select the position where the optimum spectrum can be acquired in the magnetic resonance imaging equipment.

  In this way, before performing magnetic resonance spectroscopy measurement on the human body, the spectrum obtained by magnetic resonance spectroscopy measurement of the phantom is analyzed using the phantom to determine whether or not the orientation is correctly selected. Thus, it is possible to grasp the distribution state of the magnetic field according to the resolution of the spectrum and select the correct position for the magnetic resonance spectroscopy measurement.

  In the following, examples of the present invention are described.

First Example: Metabolite Quantification with Single Voxel Spectroscopy Metabolite quantification with single voxel spectroscopy was performed at 1.5T GE at Gangnam St. Mary's Hospital (located in Gangnam-gu, Korea). This was performed using an MRI / MRS system (model name: Twinspeed).
This study was focused on the NAA metabolite with optimal shimming conditions, which is the center of the study.
At 1.5T, NAA represents the longest T1 delay time from 1,300 to 1,400 ms. Therefore, for all of the series of magnetic resonance spectra obtained at 1.5T, the 7,009 ms TR guaranteed a completely delayed spectrum.
In a single voxel study, based on a scout scan, a cubic volume of interest (VOI) was selected to partially surround the container.
Before data is obtained using the manufacturer's built-in linear shimming (auto-shimming), shimming for a single voxel spectroscopy is performed on each volume of interest, Water suppression was performed using a chemical shift imaging (CHESS) sequence.
In this study, the effect of partial volume was essential, but we expected that the results of MRS were eliminated. The single voxel spectroscopic parameters are as follows:
In other words, this single voxel spectroscopic parameter is room temperature, pulse sequence = STEM (stimulated echo acquisition mode), TE / TR = 30 / 2,000 ms, NEX = 8, voxel size = 20 × 20 × 20 mm ³ , The frequency bandwidth was set to 2500 Hz and the number of data positions was set to 2,048.

The image and spectrum were obtained while changing the position of the slice.
As the position of the voxel changed in the same corn-like container, the volume of metabolites in the voxel also changed.
Quantification of NAA metabolites was performed by determining the volume of metabolites in the voxel.
Data processing was performed using SAGE 7.0, which is a research version of SAGE (Spectroscopy Analysis of GE).
Peak fitting was performed according to the Gaussian function, and the area, size, and FWHM (full width half maximum) were calculated.
Prior to the Fourier transform, the data was processed using a Lorentz function to provide phase correction and baseline correction.
Quantification of NAA metabolites was performed according to peak size and the area for each case was calculated.

FIG. 5 shows the voxel position and NAA spectrum of a T1-weighted magnetic resonance scout image.
(A) in FIG. 5, the volume of (B), and the estimated metabolites in the volume of interest shown in (C), respectively, 4.8433cm ^3, 2.4871cm ^3, and 0.9163Cm ³ It is.
The size, area, and FWHM of the NAA peak shown in FIG. 5A are 0.01147, 0.06675, and 3.7048, respectively.
The size, area, and FWHM of the NAA peak shown in FIG. 5B are 0.00669, 0.0295, and 2.8078, respectively.
The size, area, and FWHM of the NAA peak shown in FIG. 5C are 0.00272, 0.00381, and 0.8926, respectively.
As shown in FIG. 6, it can be seen that the relationship between the voxel area, size, and metabolite volume is a linear relationship.
That is, as shown in FIG. 6, the area and size are proportional to the volume of the metabolite in the voxel. It can be seen that quantification of metabolites using the area of the spectrum is even more sensitive than using its size.
Referring to FIG. 7, it can be seen that a solution diluted with a single type of metabolite is darker than solutions in other containers due to the short T1 effect by Magnevist.

Second Example: Evaluation of Multi-Voxel Spectroscopy Multi-voxel spectroscopy was performed using a 3T Philips magnetic resonance scanner (model name: Achiva) at Dongseo New Medical Hospital in Gyeongsang National University (located in South Korea). .
Since the magnetic resonance system used for quantification of metabolites in single voxel spectroscopy has an automatic primary shimming control mode, multi-voxel spectroscopy experiments were not possible.
Multi-voxel spectroscopy studies were performed with a second-order shimming setup. As is known in brain research, using higher order shimming can yield approximately 30% or more of brain tissue volume for spectroscopic imaging compared to using linear terms. Can be obtained through accurate shimming.
Local analysis also showed that the homogeneity within a specific region of the brain was sufficiently improved and prominent near the skull.
Therefore, for 2D multi-voxel spectroscopy, an in-house developed shimming process was employed and used for the primary and secondary shimming coils of the scanner described above. After the shimming process, an axial scout scan was performed to localize the calibration vessel and the phantom was evaluated using a 2D PRES (point resolved spectroscopy) MRS pulse sequence.
The single voxel spectral parameters are as follows:
That is, this single voxel spectral parameter is: room temperature, TE / TR = 40 / 1,500 ms, 20 × 20 array CSI grid, voxel size = 15 × 15 × 30 mm ³ , NEX = 1, data position The number is set to 1,024.
Multi-voxel spectroscopic data was transferred offline and processed by the Philips console system program.
This confirmed the availability of the phantom for 2D multi-voxel spectroscopy and 3D multi-voxel spectroscopy.

A spectrum of metabolites was obtained from a cone-shaped phantom.
Clear peaks of NAA (2.0 ppm), Cr (3.0 ppm), and Cho (3.2 ppm) were observed for the brain mimicking dilution spectrum.
Although there was slight noise, characteristic peaks were observed in the NAA, Cr, and Cho spectra (see FIG. 7).
FIG. 7 is a diagram showing the position of selected voxels on a 20 × 20 grid and the spectrum of metabolites.
It can be seen that the spectrum of metabolites in the center is clearer than the spectrum of metabolites in the periphery due to shimming conditions formed by phantom moisture.

  As described above, according to the present invention, an 8 × 8 matrix cone phantom was manufactured and evaluated in order to determine the accuracy of single voxel spectroscopy and multi-voxel spectroscopy of the magnetic resonance system.

First, single voxel spectroscopy was evaluated through quantification of NAA metabolites.
As a result, focusing on the NAA peak (2.0 ppm), other peaks (especially those with >> 2.0 ppm) were ignored because only NAA was present in the volume of interest.
As shown in FIG. 5, unexpected peaks were generated due to the inhomogeneity of the B ₀ or B ₁ field of the MRS system.
In order to remove such unexpected peaks, high-order shimming and a uniform phantom were required.
Using the relationship between the shimming state of the magnetic resonance system and the quality of the magnetic resonance spectrum, the shimming performance of each magnetic resonance system using the MRT phantom could be evaluated.
Therefore, it can be expected that the 8 × 8 matrix cone-shaped phantom can exhibit such a function.
High-order shimming depends on the capabilities of the magnetic resonance system, and phantom uniformity can be achieved by reducing the thickness of the internal cone-like container.
Through quantification of NAA metabolites in single voxel spectroscopy, it was confirmed that the relationship between the amount of metabolite and the MRS peak specification was almost linear.
Furthermore, it was confirmed that the quantification of metabolites using the peak area gives higher resolution than using the peak size.
These results therefore mean that the partial volume effect was hardly affected by the MRS peak.
According to the present invention, quantification of metabolites was performed using NAA, which is a representative metabolite of ¹ H-MRS. Quantification is performed.

Magnevist is diluted in a brain mimicking solution, and since moisture is contained in copper sulfate, T1 time is shortened.
Thus, the solution diluted in a single type of metabolite is darker than the solution in other containers. (See Figure 7)

As the next step, the evaluation of multi-voxel spectroscopy was performed as an analysis of the spectrum of NAA, Cho, Cr, and brain mimicking solutions.
Since multi-voxel spectroscopy determines chemical movement, the inhomogeneity of the magnetic field B ₀ did not cause spatial distortion of the image (especially in the first order).
Shimming worsened, resulting in damage to solvent suppression and worsened video slice profiles.
This results in incomplete radio frequency pulses with slice selectivity, which causes problems with spectra from voxels near the outside of the CSI volume.
Therefore, in order to investigate an 8 × 8 matrix cone-shaped phantom, high-order shimming is required. The higher the order of shimming, the higher the quality and the more accurate the result.
According to the present invention, the region of interest for multi-voxel spectroscopy was selected in its central region in consideration of shimming.

The spectrum of NAA, Cho, Cr, and brain mimicking solutions appeared in the region of interest in multi-voxel spectroscopy.
The NAA spectrum of multi-voxel spectroscopy is similar to the NAA spectrum of single voxel spectroscopy.
The Cr and Cho spectra are similar to those extracted from a brain mimicking solution (see FIG. 7).
Therefore, these results show that the 8 × 8 matrix cone phantom of the present invention is useful not only for multi-voxel spectroscopy but also for single voxel spectroscopy.
Metabolite quantification has also become possible with multi-voxel spectroscopy as well as single voxel spectroscopy.
If the region of interest for multi-voxel spectroscopy is selected in the central region and other major metabolites are selected, if the shimming order is higher, other metabolites can be selected in the external region Become.

According to the present invention, since the phantom includes the container of the corn-like metabolite, the metabolite can be quantified with respect to the volume in the voxel.
Furthermore, the phantom was optimized by constructing an 8 × 8 array of containers.
In addition, by using such a function, various magnetic resonance systems can be compared and evaluated quantitatively.
For example, the spectral resolution can be compared by the tesla intensity of the magnetic resonance system, and shimming tests can be performed using such phantoms.
Consequently, the purpose of the 8 × 8 matrix cone phantom is to obtain optimal performance of the magnetic resonance system by often confirming this.

Currently, the use of metabolite and functional group imaging methods is increasing in clinical medicine.
According to many literatures, it is very important to ensure the accuracy of information on metabolites.
In the case of multi-voxel spectroscopy, one of the most promising techniques, the accuracy of the measured metabolite intensity and the accuracy of the resulting voxel quantification index must be ensured.
Thus, the present invention provides an efficient method for the evaluation of magnetic resonance spectroscopy.
Further, the present invention makes it possible for such quality assurance processing to be easily reproduced by magnetic resonance researchers and spectrographers.
This can be done on a regular basis (approximately every year), as part of the installation of a new scanner, or when updating software and pulse sequences such as ultra-fast EPSI.

As described above, in the detailed description of the present invention, specific examples have been described, but it goes without saying that various modifications are possible within the scope of the present invention.
Accordingly, the scope of the present invention should not be determined by being limited to the embodiments described, but must be determined not only by the claims of the present specification but also by the equivalents of the claims.

The perspective view which showed the phantom for magnetic resonance spectroscopy performance evaluation using the magnetic resonance imaging equipment which concerns on one Example of this invention. FIG. 2 is a sectional view of the phantom shown in FIG. 1. The conceptual diagram which shows an example of the internal containers which inject | poured various metabolites in the magnetic resonance spectroscopy performance evaluation phantom using the magnetic resonance imaging equipment which concerns on one Example of this invention. The figure for demonstrating the method of performing a magnetic resonance spectroscopy measurement using the phantom for magnetic resonance spectroscopy performance evaluation using the magnetic resonance imaging equipment which concerns on one Example of this invention. FIG. 5 is a diagram showing the position of a voxel and the spectrum of NAA, and together with these spectra, quantification of the metabolite performed by the volume of the metabolite in the voxel is shown. A is a volume of the metabolite of 4.8433 cm ³ The figure which shows a case. It is a figure which shows the position of a voxel and the spectrum of NAA, The quantification of the metabolite performed by the volume of the metabolite in a voxel is shown with these spectra, The figure which shows the case where B is 2.44871 cm < ³ > . It is a figure which shows the position of a voxel and the spectrum of NAA, and quantification of the metabolite performed by the volume of the metabolite in a voxel is shown with these spectra, The figure which shows the case where C is 0.9163cm < ³ > . It is a figure which shows the quantification of the NAA metabolite using the cone-shaped phantom of 8x8 matrix, and the area and the magnitude (amplitude) have a linear relationship with the volume of the metabolite in the voxel. FIG. It is a figure which shows the position of a voxel and the spectrum of a metabolite, and each metabolite in the position of a voxel can be confirmed based on Table 2 and Table 5, and A is a spectrum (NAA) in the mimic solution of the brain. , Cr, and Cho peaks are clearly observed). It is a figure which shows the position of a voxel and the spectrum of a metabolite, and each metabolite in the position of a voxel can be confirmed based on Table 2 and Table 5, and B is a spectrum (only NAA peak is NAA peak). The figure which is clearly observed). It is a figure which shows the position of a voxel and the spectrum of a metabolite, and each metabolite in the position of a voxel can be confirmed based on Table 2 and Table 5, and C is the spectrum of a Cho cone (only Cho peak is The figure which is clearly observed). It is a figure which shows the position of a voxel and the spectrum of a metabolite, and each metabolite in the position of a voxel can be confirmed based on Table 2 and Table 5, and D is a spectrum of Cr cone (only Cr peak is The figure which is clearly observed).

Explanation of symbols

10: outer container 12: fixing plate 14: fixing groove
20: Cover of outer container
22: Rubber packing
24: Direction display means 30: Inner container
32: Inner container stopper 40: Fastening means.

Claims (2)

In the magnetic resonance spectroscopy performance evaluation phantom used to evaluate the resolution of the spectrum acquired at the time of magnetic resonance spectroscopy measurement using the magnetic resonance imaging equipment,
A cylindrical outer container with an open top;
Each of them is a plurality of inner containers formed in a cone shape with the same size and shape, and arranged inside the outer container in a matrix so that the inner containers are in close contact with each other. A plurality of inner containers configured to accommodate
A stopper of the inner container sealing the upper part of the inner container;
A cover of the outer container covering the upper part of the outer container;
Fastening means for fastening the outer container and the cover of the outer container;
A fixing plate provided at a lower portion of the outer container and formed with a plurality of fixing grooves for fixing the inner container .
Phantom for magnetic resonance spectroscopy performance evaluation using magnetic resonance imaging equipment. The phantom for magnetic resonance spectroscopy performance evaluation using the magnetic resonance imaging equipment according to claim 1 , wherein the inner containers are arranged in an 8 × 8 matrix.

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