KR20210027049A - Apparatus and Method for Nano Magnetic Particle Imaging - Google Patents

Abstract

Disclosed are a device and method for imaging nanomagnetic particles. The device for imaging nanomagnetic particles according to an embodiment of the present invention may comprise: a measuring head in which a through hole housing a sample containing magnetic nanoparticles is formed, and an excitation coil and a detection coil are installed; a field-free generation unit forming a field-free region in which a magnetic field is sparse within a spaced region between the same magnetic poles facing each other; and a control unit applying a signal to the excitation coil as the measuring head is positioned within the spaced region of the field-free generation unit, controlling the field-free region to move within the sample, and imaging the three-dimensional position distribution of the magnetic nanoparticles included in the sample based on a detection signal outputted from the detection coil.

Description

Apparatus and Method for Nano Magnetic Particle Imaging

The described embodiments relate to an imaging technique for a specific object included in a sample, and more particularly, to a technique for imaging the spatial distribution of a nano magnetic particle (NMP) material.

Magnetic particle imaging (MPI) using nano magnetic particles (NMP) is a next-generation medical device and is currently being developed in the US and Europe. In particular, equipment capable of obtaining images of small animals such as mice is being developed.

Compared with magnetic resonance imaging (MRI) and X-ray, which are currently most widely used, NMP cannot acquire anatomical images, but has the advantage of being able to image specific lesions such as cancer. have. Therefore, it is being researched and developed as a medical imaging device in the form of MRI or CT-X-ray and MultiModal.

On the other hand, until now, Positron Emission Tomography (PET) is known to be the most useful for detecting early symptoms of cancer or Alzheimer's, but its use is severely limited due to radioactive substances. In addition, the type of tracer used as a radioactive substance suitable for tissue or cell analysis is also limited, so there is a limit to its application.

Therefore, since MPI can replace such PET, and theoretically, more than hundreds of thousands of antigens or antibodies that are currently developed can be used, there is an advantage that the scope of use can be broadly extended.

Until now, MPI equipment has been developed by Bruker-Philips in Europe or Magnetic Insight in the United States. To secure a video signal. However, in the conventionally developed MPI equipment, a single electromagnet of a three-dimensional structure is used, or an FFL is generated using a permanent magnet, but an attached electromagnet coil is used to move the FFL. Therefore, almost thousands of KW of power and a very complex 3D coil are essential for 3D movement using an electromagnetic field of an FFL or FFP. In addition, in order to offset the effect of magnetic field distribution depending on the type of MPI used and temperature, calibration that takes several hours to several days before sample analysis is required. Accordingly, the conventional MPI device has a disadvantage in that the size of the device compared to the size of a measurable sample is large enough to require a separate building or place to be provided, and power consumption is large.

Korean Patent Publication No. 10-2009-0060143, published on June 11, 2009 (Name: Quantitative detection method of biomaterials using magnetic nanoparticles and frequency-mixed magnetic reader)

The embodiment aims to reduce power consumption due to 3D distribution imaging of a sample including nano magnetic particles.

The embodiment is to overcome the problem that it is not easy to move the field-free area where the magnetic field is thin.

In the nano-magnetic particle imaging apparatus according to the embodiment, a through hole in which a sample including nano-magnetic particles is received is formed, a measurement head in which an excitation coil and a detection coil are installed, and a magnetic field in a spaced area between the same magnetic poles facing each other. As the field-free generation unit and the measurement head forming the sparse field-free area are located within the spaced area of the field-free generation unit, a signal is applied to the excitation coil, and the field-free area is controlled to move within the sample, and output from the detection coil. It may include a control unit for imaging the three-dimensional position distribution of the nano magnetic particles included in the sample based on the detected signal.

In this case, the excitation coil may include a low-frequency coil and a high-frequency coil, and may generate the mixed magnetic field by mixing a first magnetic field generated in the low-frequency coil and a second magnetic field generated in the high-frequency coil.

In this case, the detection coil may correspond to a differential detection coil in which two coils wound in different directions are connected.

In this case, the field-free area may be a field free point (FFP) or a field free line (FFL).

At this time, the same magnetic poles facing each other may be formed of at least one of a permanent magnet and a DC current coil.

At this time, the permanent magnet may be a neodium magnet.

At this time, the same magnetic poles facing each other may be two pairs.

At this time, the field-free generation unit includes a hexahedral housing having an opening formed on an upper surface thereof, and permanent magnets are installed on each of two side surfaces and a lower surface facing the housing, and a DC coil may be formed around the opening of the upper surface.

In this case, the measuring head may be moved through the opening and inserted into the housing.

The nano magnetic particle imaging apparatus according to the embodiment may further include a first driving unit that rotates or linearly moves the field-free generation unit.

The nano magnetic particle imaging apparatus according to the embodiment may further include a second driving unit that moves the measurement head to a spaced area of the field-free generation unit.

At this time, the control unit generates a two-dimensional image, which is a two-dimensional position distribution of the nano magnetic particles included in the cross-section of the sample, based on the detection signal, and synthesizes a plurality of two-dimensional images corresponding to a plurality of horizontal cross-sections. 3D images can be created.

At this time, the control unit linearly moves the field-free area in one direction from the cross section of the specimen, and then linearly moves the field-free area in one direction and another direction having a predetermined unit angle, but outputs from the detection signal according to the movement of the field-free area. A sinogram may be generated from the generated signal, and a 2D image may be generated by inverse radon transform of the generated sinogram.

At this time, the control unit may repeat the generation of the 2D image while moving the measurement head by a predetermined unit length in a direction perpendicular to the cross section of the sample.

The nano magnetic particle imaging method according to the embodiment includes applying a signal to an excitation coil installed in a measurement head containing a sample containing nano magnetic particles, and a field in which a magnetic field generated in a spaced region between the same magnetic poles facing is thin. It may include moving the free region within the sample to image the 3D positional distribution of the nano magnetic particles included in the sample based on the detection signal output from the detection coil of the measurement head.

In this case, the detection coil may correspond to a differential detection coil in which two coils wound in different directions are connected.

In this case, the field-free area may be a field free point (FFP) or a field free line (FFL).

At this time, the same magnetic poles facing each other may be formed of at least one of a permanent magnet and a DC current coil.

In this case, the imaging may include generating a two-dimensional image, which is a two-dimensional position distribution of the nano magnetic particles included in the cross-section of the sample, based on the detection signal, and a plurality of two-dimensional images corresponding to a plurality of cross-sections horizontal to each other. And generating a 3D image by synthesizing them.

In this case, in the step of generating the 2D image, the field-free area is linearly moved in one direction from the cross section of the sample, and then the field-free area is linearly moved in one direction and in another direction having a predetermined unit angle, but the field-free area is moved. Accordingly, a sinogram may be generated from a signal output from the detection signal, and the generated sinogram may be inversely radon transformed to generate a 2D image.

In this case, the step of generating the 2D image may be repeated while moving the measuring head by a predetermined unit length in a direction perpendicular to the cross section of the sample.

According to an embodiment, since a magnetic field can be formed only with power applied to the excitation coil to obtain a 3D distribution image for a specific sample, high power consumption can be reduced and the FFL or FFP can be freely moved.

1 is a schematic block diagram of an apparatus for imaging nano magnetic particles according to an embodiment.
2 is a diagram illustrating an example of a structure diagram of an apparatus for imaging nano magnetic particles according to an embodiment.
3 is an exemplary diagram schematically showing a coil structure of a measuring head according to an embodiment.
4 is an exemplary diagram of a bobbin structure in a state in which an excitation coil is installed in a measurement head according to an embodiment.
5 is an exemplary diagram of a bobbin structure in a state in which a detection coil is installed in a measurement head according to an embodiment.
6 is an exemplary view of a sample container according to an embodiment.
7 is an exemplary view of a sample container holder according to an embodiment.
8 is an example of an exploded perspective view of a field-free generation unit according to an embodiment.
9 is a flowchart illustrating a magnetic particle imaging method according to an embodiment.
10 is a flowchart for explaining in detail the step of generating a 2D image of FIG. 9.
11 is an exemplary diagram of a 2D image generated according to an embodiment.
12 is an exemplary diagram of a plurality of sinograms corresponding to a plurality of cross sections according to an embodiment.
13 is an exemplary diagram of a 3D position distribution image of nano magnetic particles generated according to an embodiment.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms different from each other, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to the possessor, and the invention is only defined by the scope of the claims. The same reference numerals refer to the same elements throughout the specification.

Although "first" or "second" is used to describe various elements, these elements are not limited by the terms as described above. The terms as described above may be used only to distinguish one component from another component. Accordingly, the first component mentioned below may be a second component within the technical idea of the present invention.

The terms used in the present specification are for explaining examples and are not intended to limit the present invention. In this specification, the singular form also includes the plural form unless specifically stated in the phrase. As used in the specification, “comprises” or “comprising” is implied that the recited component or step does not exclude the presence or addition of one or more other components or steps.

Unless otherwise defined, all terms used in the present specification may be interpreted as meanings that can be commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not interpreted ideally or excessively unless explicitly defined specifically.

Hereinafter, an apparatus and method for imaging nano magnetic particles according to an embodiment will be described in detail with reference to FIGS. 1 to 10.

1 is a schematic block diagram of an apparatus for imaging nano magnetic particles according to an exemplary embodiment, and FIG. 2 is a diagram illustrating an example of a structural diagram of an apparatus for imaging nano magnetic particles according to an exemplary embodiment.

Referring to FIG. 1, a nano magnetic particle imaging apparatus 1 according to an embodiment includes a signal foot measurement head 110, a field-free generation unit 120, and a control unit 130.

The measurement head 110 has a through hole in which a sample containing nano magnetic particles is accommodated, and an excitation coil 111 and a detection coil 112 are installed. At this time, the excitation coil 111 generates a magnetic field in the measurement head 110 into which a sample containing nano magnetic particles is inserted. In this case, the detection coil 112 may acquire a detection signal from a sample present in the through hole of the measurement head 110. A detailed description of the measurement head 110 will be described later with reference to FIGS. 3 to 7.

The field-free generation unit 120 forms a field-free area in which a magnetic field is thin in a spaced area between the same magnetic poles facing each other.

Here, the basic principle of signal acquisition in Magnetic Particle Imaging (MPI) is harmonic due to the nonlinear magnetic properties of the nano magnetic particles (NMP) within the gradient magnetic field. It is based on signals. At this time, by making the two identical magnetic poles face to each other, nonlinear magnetization is not generated and saturation occurs, thereby generating a region in which the magnetic field is thin in a predetermined region of the spaced region. To further explain, the field-free region is moved in space to perform imaging using a location in space where a harmonic signal is generated.

In this case, the field-free area may be a field free point (FFP) or a field free line (FFL).

At this time, the same magnetic poles facing each other may be formed of at least one of a permanent magnet and a direct current (DC) coil. At this time, the permanent magnet may be a neodium magnet (n 30 grade). At this time, the same magnetic poles facing each other may be two pairs.

In this case, when the field-free generator 120 is implemented as a permanent magnet, separate power is not required to apply an electromagnetic field. In addition, even if the field-free generator 120 is implemented as a direct current (DC) coil, the applied power is not large. Therefore, it is possible to significantly reduce power consumption for 3D imaging of the nano magnetic particles.

Meanwhile, as shown in FIG. 2, the field-free generation unit 120 may be implemented such that a permanent magnet or a DC current coil is mounted on a housing having a hexahedral shape in which an inner space is formed. However, the shape of the field-free generator 120 shown in FIG. 2 is only an example, and the present invention is not limited thereto. Further, a detailed structure description of the field-free generation unit 120 will be described later with reference to FIG. 8.

The controller 130 controls the components to control the entire process of imaging nano magnetic particles. Here, the controller 130 may include all types of devices capable of processing data, such as a processor. Here, the'processor' may refer to a data processing device built in hardware having a circuit physically structured to perform a function represented by a code or command included in a program.

According to an embodiment, the control unit 130 applies a signal to the excitation coil 111, and the field-free area moves within the sample, as the measurement head 110 is located within the spaced area of the field-free generation unit 120 By controlling so that the three-dimensional position distribution of the nano magnetic particles included in the sample may be imaged based on the detection signal output from the detection coil 112. Depending on the embodiment, the controller 130 controls the FFP or FFL to move continuously, so that the detection signals detected while the sample overlaps with are aligned and displayed, thereby obtaining 3D image information corresponding to the nano magnetic particles. . For example, the 3D image information may include 3D image information in the form of a contour plot.

At this time, the control unit 130 generates a two-dimensional image, which is a two-dimensional position distribution of the nano magnetic particles included in the cross-section of the sample, based on the detection signal, and a plurality of two-dimensional images corresponding to a plurality of cross-sections horizontal to each other. Can be synthesized to generate a 3D image. At this time, the cross section of the sample may be parallel to the XY plane shown in FIG. 2, for example.

At this time, the control unit 130 linearly moves the field-free area in one direction from the cross section of the sample, and then linearly moves the field-free area in one direction and another direction having a predetermined unit angle, but detects according to the movement of the field-free area. A sinogram may be generated from a signal output from the signal, and a 2D image may be generated by performing inverse radon transformation on the generated sinogram.

At this time, a sinogram is a sequential arrangement of projection data acquired in one direction according to the projection direction, and pixel values of each row are the same as the amplitude at a corresponding position of the corresponding profile. Such a sinogram is a well-known technique and a detailed description thereof will be omitted. In addition, the inverses radon transform is a two-dimensional image generation technique using a cynodram widely used in CT, etc. "Kak, AC, and M. Slaney, Principles of Computerized Tomographic Imaging, New York, NY, IEEE Press. , 1988", so a detailed description will be omitted here.

For example, referring to FIG. 2, the field-free area may be rotated by a predetermined unit angle in the XY plane, or may be linearly moved in a rotated state. This may be referred to as a T-ROUND STAGE movement.

To this end, the nano magnetic particle imaging apparatus 1 according to the embodiment may further include a first driving unit 140 that rotates or linearly moves the field-free generation unit 120.

For example, referring to FIG. 2, the device 1 is provided with a support 20 formed vertically from one end of the base 10, and a first driving unit 140 on the upper surface of the support 20 is a T-ROUND STAGE. It can be combined to be movable. Accordingly, the field-free generation unit 120 is fixedly coupled to the upper portion of the first driving unit 130 and may be moved together as the first driving unit 130 is moved to the T-ROUND STAGE. In addition, as shown in FIG. 2, the field-free generation unit 120 may be installed in a position where a predetermined space is secured from the base 10 so that the T-ROUND STAGE can be moved.

In addition, the controller 130 may repeatedly generate a 2D image while moving the measurement head 110 by a predetermined unit length in a direction perpendicular to the cross-section of the sample. That is, as the measurement head 110 is linearly moved in the Z-axis direction, 2D images of each of the cross sections passing through the field-free area may be obtained.

To this end, the nano magnetic particle imaging apparatus 1 according to the embodiment may further include a second driving unit 150 for moving the measurement head 110 to a spaced area of the field-free generation unit 120.

For example, referring to FIG. 2, the first driving unit 150 may be installed above the table-shaped cradle 30 provided at the other end of the base 10. At this time, the cradle 30 may be installed at a position corresponding to the height of the field-free generating unit 120 so that the measuring head 110 can be inserted into the field-free generating unit 120. have.

At this time, the moving guide 40 having the groove 40a formed on the upper part of the cradle 30 is formed parallel to the Z axis, and the second driving part 150 is a locking part 150a that can be fitted into the groove 41a. May be formed. Accordingly, the second driving unit 150 is moved along the movement guide 40 in a form in which the locking unit 150a is coupled to the groove 40a under the control of the control unit 130, so that the measurement head 110 is field-free. The Z-axis may be moved to the inside of the generation unit 120.

In addition, the nanomagnetic particle imaging apparatus 1 according to an embodiment of the present invention includes an interface unit (not shown) capable of outputting an image of the nanomagnetic particle and receiving an operator's control selection for imaging the nanomagnetic particle. Included or may be connected to the interface unit. The interface unit may have both input and output functions. For example, the input unit may be provided through various methods such as keyboard, mouse, sound recognition, and the like, and the output unit may be provided through a projector, various display panels, sound, and vibration. In addition, the input unit and the output unit may be implemented in the form of an integrated touch panel.

3 is an exemplary diagram schematically schematically illustrating a coil structure of a measurement head according to an embodiment, FIG. 4 is an exemplary view of a bobbin structure in a state in which an excitation coil is installed in the measurement head according to the embodiment, and FIG. It is an exemplary diagram of a bobbin structure in a state in which a detection coil is installed in the measuring head according to the present invention, FIG. 6 is an exemplary diagram of a sample container according to an embodiment, and FIG. 7 is an exemplary view of a sample container holder according to the embodiment.

Referring to FIG. 3, the measurement head 110 may include excitation coils 111a and 111b and detection coils 120.

At this time, the excitation coils 111a and 111b are solenoid coils that generate magnetic fields, respectively, and may generate a mixed magnetic field of two magnetic fields generated from each.

At this time, the excitation coils 111a and 111b may be a low-frequency coil 111a and a high-frequency coil 111b.

At this time, the low frequency coil 111a is located at the outermost of the measuring head 110, the high frequency coil 111b is located inside the low frequency coil 111a, and the detection coil 120 is inside the high frequency coil 111b. Can be located. That is, by including one low-frequency coil 111a and one high-frequency coil 111b in the measurement head 110, a magnetic field generated by a low-frequency signal and a magnetic field generated by a high-frequency signal can be generated to generate a mixed magnetic field. In this case, a process of calibrating the low-frequency coil 111a and the high-frequency coil 111b may be performed according to the mixed magnetic field for the embodiment.

In addition, the low frequency coil 111a may receive a signal from a power source corresponding to a low frequency voltage, and the high frequency coil 111b may receive a signal from a power source corresponding to a high frequency voltage.

In this case, the electromotive force output from the detection coil 112 may correspond to the detection signal. In this case, the detection coil 112 may correspond to a differential detection coil in which two coils wound in different directions are connected. Accordingly, the detection coil 112 may obtain a sum of signals detected from two coils wound in different directions as a detection signal.

As a result, two different frequencies are used in the excitation coil to obtain a harmonic signal on a nonlinear FFL or FFP, and at the same time, one side of the differential coil is saturated with a strong magnetic field to maintain the effect of differential detection, but on both sides of the detection coil. All of them can attenuate the appearance of the signal.

4, the measuring head 110 has a structure in which a high-frequency coil is wound inside and a low-frequency coil is wound outside.

Referring to FIG. 5, the upper part of the detection coil has a differential structure in which the coil is wound in a clockwise direction and the lower part is in a counterclockwise direction.

The detection coil of FIG. 5 is inserted into the coil of FIG. 4 to physically cancel signals generated from the high-frequency and low-frequency coils, and receive only signals generated from materials located inside the detection coil.

<Table 1> shows the width, inner radius, and height of each of the detection coil, middle HF coil, and outer LF coil installed in this structure. And details of the wire diameter.

Detection Coil Middle HF Coil Outer LF Coil Width(mm) 40 101 101 Inner radius(mm) 21 26.5 27.5 Height(mm) 1.75 0.81 3.81 Wire diameter(mm) 0.3 0.4 0.4

Meanwhile, referring to FIG. 3, a through hole 110a is formed in the measurement head 110, and a sample including nano magnetic particles may be accommodated in the through hole 110a. At this time, as shown in FIG. 6, after inserting the sample into the sample container 160 in the form of a PCR tube, the sample container 160 is opened with the opening 171 of the plastic cylindrical sample holder 170 as shown in FIG. Can be put on. Then, the sample holder 170 may be inserted into the through hole 110a of the measurement head 110. However, this is only an example and the present invention is not limited thereto. That is, this can be used when the sample is not a solid, and when the sample is an experimental rat or other solid sample, it is directly inserted into the through hole 110a without a separate sample container 160 and a sample holder 170 Can be. 8 is an example of an exploded perspective view of a field-free generation unit according to an embodiment.

Referring to FIG. 8, the field-free generation unit 120 includes a hexahedral housing 121, and an opening 122 may be formed on an upper surface. Accordingly, the measurement head 110 may be inserted and received through the opening 122.

Accordingly, permanent magnets 123-1, 123-2, and 123-3 are installed on each of the two side surfaces and the lower surface facing from the housing 121, but the DC current coil 124-4 is not a permanent magnet on the upper surface. ) Is installed, so that the opening 122 can be formed on the upper surface.

In this case, the DC current coil 124-4 is a solenoid coil in which a coil of about 1.3MM is wound about 1000 times (TURN), and DC power may be applied.

At this time, separate cases (124-1, 124-2, 124-3) accommodating the permanent magnets (123-1, 123-2, 123-3) are provided, and two removable covers 124-1a, The permanent magnet 123-1 may be stored between 124-1b) and mounted on the housing 121.

In this case, grooves 125-1 and 125-2 for accommodating the permanent magnets 123-1 and 123-2 may be formed in the housing 121. In this case, as shown in FIG. 8, a relatively wide and shallow groove 125-1 may be formed on a side surface, and a relatively narrow and deep groove 125-2 may be formed on a lower surface.

Accordingly, the cases 124-1 and 124-2 in which the permanent magnets 123-1 and 123-2 are stored may be mounted in the grooves 125-1 and 125-2. In this case, the cases 124-1 and 124-2 may be fastened to the housing 121 through screw coupling or the like.

By the way, although FIG. 8 shows that permanent magnets are mounted on two sides, according to another embodiment, permanent magnets may be mounted on the other two sides.

At this time, when the permanent magnets 123-1 and 123-3 are disposed so that the N pole faces each other, the S pole is disposed on the surface where the permanent magnet 123-2 faces the upper surface, and the DC coil 122 ), the direction of the applied current can be controlled so that the S pole is formed on the lower surface.

9 is a flowchart illustrating a magnetic particle imaging method according to an embodiment. In this case, the magnetic particle imaging method is performed by the magnetic particle imaging apparatus described above with reference to FIGS. 1 to 8, and contents overlapping with the above description will be omitted.

Referring to FIG. 9, in the nanomagnetic particle imaging method according to the embodiment, the step of applying a signal to an excitation coil installed in a measurement head containing a sample including nanomagnetic particles (S210) and the same magnetic poles facing each other Imaging the three-dimensional position distribution of the nano magnetic particles included in the sample based on the detection signal output from the detection coil of the measurement head by moving the field-free area in the sample where the magnetic field generated in the separated area is thin (S220~ S230) may be included.

In this case, the imaging may include generating a two-dimensional image, which is a two-dimensional position distribution of the nano magnetic particles included in the cross-section of the sample, based on the detection signal (S220), and a plurality of cross-sections corresponding to a plurality of cross-sections horizontal to each other. A step S230 of generating a 3D image by synthesizing 2D images may be included. In this case, in the step of generating the 2D image (S220), after linearly moving the field-free area in one direction from the cross-section of the sample, the field-free area is linearly moved in one direction and in another direction having a predetermined unit angle, A sinogram may be generated from a signal output from the detection signal according to the movement of the free region, and the generated sinogram may be inversely radon transformed to generate a 2D image. A detailed description of this will be described later with reference to FIG. 10.

In addition, the step of generating the 2D image (S220) may be repeated while moving the measuring head by a predetermined unit length in a direction perpendicular to the cross-section of the sample.

10 is a flow chart for explaining the step of generating a 2D image of FIG. 9 in detail, FIG. 11 is an exemplary diagram of a 2D image generated according to an embodiment, and FIG. 12 is a diagram corresponding to a plurality of cross sections according to the embodiment. It is an exemplary diagram of a plurality of sinograms, and FIG. 13 is an exemplary diagram of a three-dimensional position distribution image of nano magnetic particles generated according to an embodiment.

Referring to FIG. 10, first, the control unit 130 adjusts the linear movement of the measurement head 110 (S221). That is, the position of the sample in the Z-axis direction is adjusted. Initially, the FFL or FFP is adjusted to pass the highest or lowest point of the sample.

만큼 회전시킨다(S222). 즉, 필드프리 생성부(120)에 의해 생성된 FFL 또는 FFP가 시료의 일 단면(XY 평면)에서

만큼 회전된다. Then, the control unit 130 moves the field-free generation unit 120 to a predetermined angle.

Rotate as much (S222). That is, the FFL or FFP generated by the field-free generation unit 120 is

Rotated by

The controller 130 continuously moves the field-free generation unit 120 forward-linearly and acquires a signal detected by the detection coil 112 at predetermined unit time intervals (S223).

Then, the control unit 130 performs a backward-linear movement as opposed to the forward linear movement of the field-free generation unit 120 to return to the original position (S224).

Then, the controller 130 updates a sinogram capable of expressing a predetermined image signal based on the signal output from the detection coil 120 (S225).

의 누적값이 180도 미만인지를 판단한다(S226). Then, the control unit 130 is the rotated angle

It is determined whether the accumulated value of is less than 180 degrees (S226).

의 누적값이 180도 미만일 경우, 제어부(130)는 S222 내지 S225가 반복 수행되도록 제어한다. 반면, S225의 판단 결과 회전된 각도

의 누적값이 180도 미만이 아닐 경우, 제어부(130)는 생성된 사이노그램(Sinogram)을 역 라돈 변환(Inverse Radon Transformation)시켜, 시료의 현재 높이에서의 단면(XY 평면)에 대한 2차원 영상화가 이루어지도록 한다(S227). As a result of the judgment of S226, the rotated angle

When the accumulated value of is less than 180 degrees, the controller 130 controls S222 to S225 to be repeatedly performed. On the other hand, as a result of the judgment of S225, the rotated angle

If the cumulative value of is not less than 180 degrees, the control unit 130 performs an inverse radon transformation on the generated sinogram, and the two-dimensional cross section (XY plane) at the current height of the sample The imaging is performed (S227).

For example, referring to FIG. 11, a sinogram 311 having a predetermined cross section based on the Z-axis direction is generated through S222 to S226. Here, since the two samples target two samples on both sides, the sinogram 311 appears in the shape of an X.

A two-dimensional image 321 in which the sinogram 311 is inverse radon transformed is generated through S227. However, as illustrated in FIG. 11, when the 2D image 321 is blurred, post processing may be performed to generate a sharper 2D image 331. In this case, the post-processing may be processing such that only images within a predetermined distance appear based on the centers of the two samples appearing in the 2D image 321 or only signals having a signal strength equal to or greater than a predetermined threshold remain.

Thereafter, the control unit 130 determines whether the measurement head 110 should be linearly moved (S228). That is, if the FFL starts after passing the highest point of the sample, whether the FFL reaches the lowest point, or if the FFL starts after passing the lowest point of the sample, it is determined whether the FFL reaches the highest point.

As a result of the determination of S228, when the measurement head 110 is to be linearly moved, the controller 130 controls S221 to S227 to be repeatedly performed. On the other hand, as a result of the determination of S228, if the measurement head 110 does not need to be linearly moved, the above-described step S230 is performed.

That is, as S221 to S227 are repeatedly performed, a plurality of sinograms 310 corresponding to a plurality of cross-sections horizontal to each other as shown in FIG. 12 are generated, and a plurality of sinograms 310 are generated as shown in FIG. A plurality of 2D images 320 in which the sinograms 310 are inverse radon transformed are generated. As described above, post-processed 2D images 330 may be generated from the plurality of 2D images 320. Looking at the 2D images 320 and 330, the signal becomes weaker toward the bottom of the Z-axis, because the sample is conical.

In S230, a plurality of 2D images 330 may be synthesized to generate a 3D image 340 for two conical samples.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those of ordinary skill in the art to which the present invention pertains can be implemented in other specific forms without changing the technical spirit or essential features of the present invention. You can understand that there is. Therefore, it should be understood that the embodiments described above are illustrative and non-limiting in all respects.

1: Nano magnetic particle imaging device
110: measuring head
111: excitation coil 112: detection coil
120: field-free generation unit 130: control unit
140: first driving unit 150: second driving unit

Claims (20)

A measurement head in which a through hole for receiving a sample including nano magnetic particles is formed, and an excitation coil and a detection coil are installed;
A field-free generation unit that forms a field-free area in which a magnetic field is thin in a spaced area between the same magnetic poles facing each other; And
As the measurement head is located within the spaced area of the field-free generation unit, a signal is applied to the excitation coil, and the field-free area is controlled to move within the sample, and the nanomagnetic included in the sample is based on the detection signal output from the detection coil. Control unit to image the three-dimensional position distribution of particles
Nano magnetic particle imaging apparatus comprising a. The method of claim 1, wherein the excitation coil,
A nano magnetic particle imaging apparatus comprising: a low-frequency coil and a high-frequency coil, and generating the mixed magnetic field by mixing a first magnetic field generated in a low-frequency coil and a second magnetic field generated in a high-frequency coil. The method of claim 1, wherein the detection coil,
A nano magnetic particle imaging apparatus, characterized in that corresponding to a differential detection coil in which two coils wound in different directions are connected. The method of claim 1, wherein the field-free area,
A nano magnetic particle imaging device, characterized in that it is a field free point (FFP) or a field free line (FFL). The method of claim 1, wherein the same magnetic poles facing are,
Nano magnetic particle imaging apparatus, characterized in that formed of at least one of a permanent magnet and a DC current coil. The method of claim 5, wherein the permanent magnet,
Nano magnetic particle imaging apparatus, characterized in that the neodium magnet (NEODIUM magnet). The method of claim 1, wherein the same magnetic poles facing are,
Nano magnetic particle imaging device, characterized in that two pairs. The method of claim 1, wherein the field-free generation unit,
Including a hexahedral housing with an opening formed on the upper surface,
Permanent magnets are installed on each of the two sides and bottom faces of the housing,
A DC coil is formed around the opening on the upper surface,
The measuring head,
Nano magnetic particle imaging apparatus, characterized in that it is moved through the opening and inserted into the interior of the housing. The method of claim 1,
The nano magnetic particle imaging apparatus, further comprising a first driving unit for rotating or linearly moving the field-free generation unit. The method of claim 1,
Nano magnetic particle imaging apparatus, characterized in that it further comprises a second driving unit for moving the measurement head to the spaced area of the field-free generation unit. The method of claim 1, wherein the control unit,
Based on the detection signal, a two-dimensional image, which is a two-dimensional position distribution of the nano magnetic particles included in the cross section of the sample, is generated,
A nano magnetic particle imaging apparatus, characterized in that for generating a 3D image by synthesizing a plurality of 2D images corresponding to a plurality of horizontal cross sections. The method of claim 11, wherein the control unit,
After linearly moving the field-free area in one direction from the cross section of the sample, the field-free area is linearly moved in one direction and another direction having a predetermined unit angle,
A method for imaging nano magnetic particles, comprising generating a sinogram from a signal output from a detection signal according to movement of a field-free region, and generating a two-dimensional image by inverse radon transforming the generated sinogram. The method of claim 11,
A method of imaging nano magnetic particles, characterized in that it repeats generating a two-dimensional image while moving the measuring head by a predetermined unit length in a direction perpendicular to the cross section of the sample. Applying a signal to an excitation coil installed in a measurement head accommodating a sample including nano magnetic particles; And
The three-dimensional position distribution of the nano magnetic particles included in the sample based on the detection signal output from the detection coil of the measurement head by moving the field-free area in the sample where the magnetic field generated in the spaced area between the same magnetic poles facing each other within the sample Nano magnetic particle imaging method comprising the step of imaging. The method of claim 14, wherein the detection coil,
A method of imaging nano magnetic particles, characterized in that it corresponds to a differential detection coil in which two coils wound in different directions are connected. The method of claim 14, wherein the field-free area,
A nano magnetic particle imaging method, characterized in that it is a field free point (FFP) or a field free line (FFL). The method of claim 14, wherein the same magnetic poles facing are,
Nano magnetic particle imaging method, characterized in that formed of at least one of a permanent magnet and a DC current coil. The method of claim 14, wherein the imaging step,
Generating a two-dimensional image, which is a two-dimensional position distribution of the nano magnetic particles included in the cross-section of the sample, based on the detection signal; And
And generating a 3D image by synthesizing a plurality of 2D images corresponding to a plurality of horizontal cross sections. The method of claim 14, wherein generating the 2D image comprises:
After linearly moving the field-free area in one direction from the cross section of the sample, the field-free area is linearly moved in one direction and another direction having a predetermined unit angle,
A method for imaging nano magnetic particles, comprising generating a sinogram from a signal output from a detection signal according to movement of a field-free region, and generating a two-dimensional image by inverse radon transforming the generated sinogram. The method of claim 14, wherein generating the 2D image comprises:
Nano magnetic particle imaging method, characterized in that it repeats while moving the measurement head by a predetermined unit length in a direction perpendicular to the cross section of the sample.

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