阅读说明：本技术 一种监控活动对象活跃度和温度的磁学方法及装置 (Magnetic method and device for monitoring activity and temperature of moving object ) 是由 刘文中 郭斯琳 于 2019-09-24 设计创作，主要内容包括：本发明公开了一种监控活动对象活跃度和温度的磁学方法及装置,方法包括对被测体进行初次核磁共振成像,得到包含共振频率和波谱半高宽信息的初次核磁共振波谱图像；将磁纳米粒子铺设被测体内直至所述磁纳米粒子抵达目标位置并达到均衡状态；经过被测体的若干个活动周期之后,对被测体再次进行核磁共振成像,得到核磁共振波谱图像；根据两次成像的共振频率和波谱半高宽的变化量与磁纳米粒子浓度和温度的相关关系,得到磁纳米粒子的浓度信息与温度信息；重复上述两步,获取磁纳米粒子浓度与温度随时间的变化情况,实现对被测体活动能力的监控。本发明通过采用磁纳米粒子作为传感器,具有高的空间分辨率与温度分辨率。(The invention discloses a magnetic method and a device for monitoring activity and temperature of a moving object, wherein the method comprises the steps of carrying out primary nuclear magnetic resonance imaging on a measured object to obtain a primary nuclear magnetic resonance spectrum image containing resonance frequency and spectrum half-height width information; laying magnetic nano particles in a detected body until the magnetic nano particles reach a target position and reach an equilibrium state; after a plurality of activity periods of the measured body, performing nuclear magnetic resonance imaging on the measured body again to obtain a nuclear magnetic resonance spectrum image; obtaining concentration information and temperature information of the magnetic nanoparticles according to the correlation between the variation of the resonance frequency and the full width at half maximum of the spectrum of the two imaging and the concentration and the temperature of the magnetic nanoparticles; and repeating the two steps to obtain the change condition of the concentration and the temperature of the magnetic nanoparticles along with time, thereby realizing the monitoring of the activity of the tested body. The invention has high spatial resolution and temperature resolution by using magnetic nano particles as sensors.)

1. A magnetic method of monitoring activity and temperature of a moving object, comprising the steps of:

(1) performing primary nuclear magnetic resonance imaging on a measured body to obtain a primary nuclear magnetic resonance spectrum image containing resonance frequency and spectrum half-height width information;

(2) laying magnetic nano particles in a detected body until the magnetic nano particles reach a target position and reach an equilibrium state;

(3) after a plurality of activity periods of the measured body, performing nuclear magnetic resonance imaging on the measured body again to obtain a nuclear magnetic resonance spectrum image;

(4) obtaining concentration information and temperature information of the magnetic nanoparticles according to the correlation between the variation of the resonance frequency and the full width at half maximum of the spectrum of the two imaging and the concentration and the temperature of the magnetic nanoparticles;

(5) and (5) repeating the steps (3) to (4) to obtain the change condition of the concentration and the temperature of the magnetic nanoparticles along with time, thereby realizing the monitoring of the activity of the tested body.

2. The method of claim 1, wherein the magnetic nanoparticles have an average particle size d₀In the range of d₀< 30nm, having paramagnetism or superparamagnetism, allAt least 90% of the magnetic nano-particles have the particle size in the range of d ∈ [ d [ ]₀-2nm，d₀+2nm]Within the range of (1).

3. The method of claim 2, wherein the magnetic nanoparticles are controlled by an external magnetic field or a targeting marker modified on the surface thereof to reach the position of the specified subject.

4. The method of claim 1, wherein the two images have variations in resonant frequency and spectral full width at half maximum Δ ν (i) and Δ ω_1/2(i) Are respectively formulated as:

Δυ(i)＝υ(0)-υ(i)

Δω_1/2(i)＝ω_1/2(i)-ω_1/2(0)

wherein upsilon (0) and ω_1/2(0) The resonance frequency and the full width at half maximum of the spectrum of the primary nuclear magnetic resonance spectrum image, upsilon (i) and omega_1/2(i) The resonance frequency and the spectrum half-width of the ith nuclear magnetic resonance spectrum image after the monitoring of the initial concentration and the temperature are respectively.

5. The method according to claim 1, wherein the resonance frequency and the full width at half maximum of the spectrum of the nuclear magnetic resonance spectrum image in step (5) reflect the magnetization M of the magnetic nanoparticles, which is proportional to the magnetic nanoparticle concentration N and is influenced by temperature.

6. A magnetic device for monitoring activity and temperature of a moving object, comprising:

the first imaging module is used for carrying out primary nuclear magnetic resonance imaging on a measured body to obtain a primary nuclear magnetic resonance spectrum image containing resonance frequency and spectrum full width at half maximum;

the laying module is used for laying the magnetic nano particles into the measured body until the magnetic nano particles can reach the target position and reach an equilibrium state;

the second imaging module is used for carrying out nuclear magnetic resonance imaging on the measured body again after a plurality of activity periods of the measured body to obtain a nuclear magnetic resonance spectrum image;

the calculation module is used for obtaining concentration information and temperature information of the magnetic nanoparticles according to the correlation between the variation of the resonance frequency and the full width at half maximum of the spectrum of the two imaging times and the concentration and temperature of the magnetic nanoparticles;

and the monitoring module is used for acquiring the change condition of the concentration and the temperature of the magnetic nanoparticles along with time, and monitoring the activity and the temperature of the detected body.

7. The device of claim 6, wherein the magnetic nanoparticles have an average particle size d₀In the range of d₀Less than 30nm, has paramagnetism or superparamagnetism, and at least 90% of all magnetic nano particles have particle size in the d epsilon [ d [ ]₀-2nm，d₀+2nm]Within the range of (1).

8. The device of claim 7, wherein the magnetic nanoparticles are controlled by an external magnetic field or a targeting marker modified on the surface of the magnetic nanoparticles to reach the position of the specified detected body.

9. The apparatus of claim 6, wherein the two imaging resonance frequencies and half widths of the spectra vary by Δ ν (i) and Δ ω_1/2(i) Are respectively formulated as:

Δυ(i)＝υ(0)-υ(i)

Δω_1/2(i)＝ω_1/2(i)-ω_1/2(0)

wherein upsilon (0) and ω_1/2(0) The resonance frequency and the full width at half maximum of the spectrum of the primary nuclear magnetic resonance spectrum image, upsilon (i) and omega_1/2(i) The resonance frequency and the full width at half maximum of the spectrum of the ith nuclear magnetic resonance spectrum image are respectively.

10. The apparatus of claim 6, wherein the resonance frequency and the full width at half maximum of the spectrum of the NMR spectroscopic image reflect the magnetization M of the magnetic nanoparticles, which is proportional to the magnetic nanoparticle concentration N and is affected by temperature.

Technical Field

The invention belongs to the technical field of nuclear magnetic resonance spectrum measurement, and particularly relates to a magnetic method and a magnetic device for monitoring activity and temperature of a moving object.

Background

Cells are the basic building blocks of the structure and function of living bodies, wherein mitochondria and chloroplasts in plants are mainly responsible for generating cellular energy, and the energy is released by controlling the hydrolysis of Adenosine Triphosphate (ATP), wherein the biochemical reaction in which part of ATP is involved can cause the transmembrane potential of mitochondria to change, which is closely related to the generation of heat in cells. Temperature is an important characteristic parameter of cell activity, the proliferation, differentiation, metabolic activity and pathological changes of cells can cause the temperature fluctuation of the cells, and the onset of various human serious diseases is closely related to the imbalance of regulation and control of cell energy metabolism.

In view of the important role of cell temperature in life activities, the related research on cell temperature has been gradually advanced into many fields of life science. As early as 1994, the Kallerhoff team separated normal and cancer tissues from the isomorphic microcalorimeter measurements of temperature changes in cell populations. However, analysis of cell populations often ignores cell-to-cell variability, making the results less accurate. Paulik et al used IR imaging to detect the heat generation process of individual cells, but the IR imager could not obtain effective information due to the non-uniformity and extremely small size of the cells.

With the development of nanotechnology, many novel effective thermometry techniques emerge. The luminous cell thermometer integrates the existing imaging technology, reflects the cell temperature actually through the fluorescence intensity, the maximum emission wavelength or the fluorescence life change of the temperature measuring probe, and has better spatial resolution, temperature resolution and data collection capability. In 2011, a Uchiyama team obtains the spatial resolution of 200nm based on a fluorescent polymer thermometer through a fluorescence lifetime urban and rural microscope, and the temperature resolution is 0.18-0.58 ℃. However, the fluorescence temperature measurement result has a large influence on the attenuation of the signal by the target surrounding tissue, which is not favorable for the temperature detection of the cells in the living body, and the organic fluorescent substance has a high requirement on the physiological environment of the cells, and is easily limited by photobleaching, so that the temperature cannot be detected for a long time. Wang et al focused the thermocouple results on a nanoscale tip, using a microscope and micromanipulator to visualize the single cell thermometry function of a platinum dock thermocouple. Although thermometry tools based on the thermoelectric effect offer great advantages in temperature resolution and time resolution, such thermometry methods tend to compromise cell integrity.

In the field of cell metabolism, the conventional biochemical analysis methods such as division, enzymology, chromatography or mass spectrometry are difficult to realize real-time tracking of metabolite changes, and although the emerging Positron Emission Tomography (PET) can acquire related information of molecular chemical changes in organisms and dynamically and quantitatively measure pathophysiological changes and metabolic processes in human or animal bodies at the molecular level, nuclides required by PET examination have certain radioactivity and have certain potential hazards even though the dosage is small.

Therefore, under the condition that the spatial resolution and the sensitivity of the existing methods are mutually constrained, the ceiling of the cell temperature measurement and metabolism monitoring imaging with the resolution of 1 ℃ @1mm is difficult to break through by using the methods.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a magnetic method and a magnetic device for monitoring the activity and the temperature of a moving object, and aims to solve the problems that the activity condition of a moving part in a tested body is difficult to accurately monitor and the error of the temperature detection result is large.

In order to achieve the above object, the present invention provides a magnetic method for monitoring activity and temperature of a moving object, comprising the steps of:

(1) performing primary nuclear magnetic resonance imaging on a measured body to obtain a primary nuclear magnetic resonance spectrum image containing resonance frequency and spectrum half-height width information;

(2) laying magnetic nano particles into a tested body until the magnetic nano particles can reach a target position and reach an equilibrium state;

(3) after a plurality of activity periods of the measured body, performing nuclear magnetic resonance imaging on the measured body again to obtain a nuclear magnetic resonance spectrum image;

(4) obtaining concentration information and temperature information of the magnetic nanoparticles according to the correlation between the variation of the resonance frequency and the full width at half maximum of the spectrum of the two imaging and the concentration and the temperature of the magnetic nanoparticles;

(5) and (5) repeating the steps (3) to (4), obtaining the change condition of the concentration and the temperature of the magnetic nano particles along with time, and realizing the monitoring of the activity and the temperature of the tested body.

Preferably, the magnetic nanoparticles have an average particle diameter d₀In the range of d₀Less than 30nm, and since the magnetic nanoparticle sample actually contains a large number of magnetic nanoparticles, it is required that at least 90% of the particles have a particle size in the d e [ d ∈ [ ]₀-2nm，d₀+2nm]To ensure that the magnetic nanoparticle sample has paramagnetism or superparamagnetism and that the particle size distribution does not cause additional interference with the nmr spectroscopy results. The particle size of the small-particle-size magnetic nanoparticles with concentrated particle size distribution should not influence the normal activity state of the tested body.

Preferably, the magnetic nanoparticles are controlled by an external magnetic field or targeted markers modified on the surfaces of the magnetic nanoparticles to ensure that the particles can reach a target position to be monitored.

Further, the resonance frequency and the half-width of the spectrum of the two imaging changes Δ ν (i) and Δ ω_1/2(i) Are respectively formulated as:

Δυ(i)＝υ(0)-υ(i)

Δω_1/2(i)＝ω_1/2(i)-ω_1/2(0)

wherein upsilon (0) and ω_1/2(0) The resonance frequency and the spectral full width at half maximum, upsilon (i) and ω, respectively, of the primary NMR spectral image of the original sample without particle injection_1/2(i) Respectively the resonance frequency and the half-height width of the spectrum of the ith nuclear magnetic resonance spectrum image, wherein the initial measurement results after the magnetic nano-particles are laid are the resonance frequency upsilon (1) and the half-height width of the spectrum omega_1/2(1). The magnetic resonance information when the number of the magnetic nanoparticles in the measured body is the maximum is obtained through measurement, and in a later cycle, the magnetic nanoparticles in the measured body are gradually consumed by the activity of the subject.

Further, the resonance frequency and the half-height width of the spectrum of the nuclear magnetic resonance spectrum image in the step (5) reflect the magnetization M of the magnetic nanoparticles, the magnetization M of the magnetic nanoparticles and the concentration of the magnetic nanoparticlesN is proportional and affected by temperature. The magnetization of the magnetic nanoparticles obeys:

wherein the Langevin equation is

Magnetic moment m of magnetic nanoparticles_s＝M_sV，M_sIs the saturation magnetization of the magnetic nanoparticles, V is the volume of the magnetic nanoparticles, N is the concentration of the magnetic nanoparticles, k is the Boltzmann constant, T is the absolute temperature, H is the amplitude of the excitation magnetic field, μ₀Is a vacuum magnetic permeability.

For nuclear magnetic resonance spectrum, the relationship between the change of resonance frequency and the magnetic susceptibility of the magnetic nanoparticles isWherein, χ_SMagnetic nanoparticle magnetic susceptibility; when the sample direction is perpendicular to the magnetic field direction, α ═ 2 pi; when the sample direction is parallel to the magnetic field direction, α is 0.

For nuclear magnetic resonance spectrum, the relation between the full width at half maximum of the waveform and the transverse relaxation rate is

The apparent transverse relaxation time of water molecules measured by the nuclear magnetic resonance equipment is based on

And the magnetic nano particles mainly influence the diffusion of water molecules, so that the variation quantity delta omega of the spectral information obtained by the ith cell metabolism detection measurement_1/2(i)＝ω_1/2(i)-ω_1/2(0) Which reflects the change Δ R in apparent transverse relaxation rate after the diffusion of water molecules is affected_{2 diffusion}(i)＝Δω_1/2(i)·π。

According to the external diffusion model, water molecules cannot pass through or combine with the magnetic nanoparticles in the diffusion process, but bypass the diffusion process. Then water moleculeThe contribution of diffusion to the apparent transverse relaxation rate can be expressed as

Wherein r is the radius of the magnetic nanoparticle, N₀Is an Avogastron constant, M_pThe molar concentration of the particles is N ═ N₀M_p×10^-3，τ_D＝r²D is the molecular diffusion time, D is the diffusion coefficient,

thus, a system of equations can be constructed:

order to

Then N is equal to A²/B，

Iterative approaches can then be used to solve for the temperature information.

According to another aspect of the present invention there is also provided a magnetic device for monitoring activity and temperature of a moving object, comprising:

the first imaging module is used for carrying out primary nuclear magnetic resonance imaging on a measured body to obtain a primary nuclear magnetic resonance spectrum image containing resonance frequency and spectrum full width at half maximum;

the laying module is used for laying the magnetic nano particles into the measured body until the magnetic nano particles can reach the target position and reach an equilibrium state;

the second imaging module is used for carrying out nuclear magnetic resonance imaging on the measured body again after a plurality of activity periods of the measured body to obtain a nuclear magnetic resonance spectrum image;

the calculation module is used for obtaining the concentration information and the temperature information of the magnetic nanoparticles according to the linear relation between the variation of the resonance frequency and the full width at half maximum of the spectrum of the two imaging and the concentration and the temperature of the magnetic nanoparticles;

and the monitoring module is used for acquiring the change condition of the concentration and the temperature of the magnetic nanoparticles along with time, and monitoring the activity and the temperature of the detected body.

Preferably, the magnetic nanoparticles have a particle diameter d₀In the range of d₀< 30nm and since the sample actually contains a large number of magnetic nanoparticles, it is required that at least 90% of the particles have a size in the d e [ d ]₀-2nm，d₀+2nm]To ensure that the magnetic nanoparticle sample has paramagnetism or superparamagnetism and that the particle size distribution does not cause additional interference with the nmr spectroscopy results. The particle size of the small-particle-size magnetic nanoparticles with concentrated particle size distribution should not influence the normal activity state of the tested body.

Preferably, the magnetic nanoparticles are controlled by an external magnetic field or targeted markers modified on the surfaces of the magnetic nanoparticles to ensure that the particles can reach a target position to be monitored.

Further, the resonance frequency and the half-width of the spectrum of the two imaging changes Δ ν (i) and Δ ω_1/2(i) Are respectively formulated as:

Δυ(i)＝υ(0)-υ(i)

Δω_1/2(i)＝ω_1/2(i)-ω_1/2(0)

wherein upsilon (0) and ω_1/2(0) The resonance frequency and the full width at half maximum of the spectrum of the primary nuclear magnetic resonance spectrum image, upsilon (i) and omega_1/2(i) Respectively the resonance frequency and the half-height width of the spectrum of the ith nuclear magnetic resonance spectrum image, wherein the initial measurement results after the magnetic nano-particles are laid are the resonance frequency upsilon (1) and the half-height width of the spectrum omega_1/2(1)。

Further, the resonance frequency and the spectral full width at half maximum of the nuclear magnetic resonance spectrum image reflect the magnetization M of the magnetic nanoparticles, which is proportional to the magnetic nanoparticle concentration N and affected by temperature.

Through the above technical solution conceived by the present invention, compared with the prior art, the following can be obtained:

has the advantages that:

1. the magnetic nano particles are used as the sensor, the activity condition of the body to be detected is effectively monitored in a magnetic mode, the magnetic induction intensity of the magnetic nano particles in the body to be detected is only influenced by concentration and temperature, the chemical structure of the magnetic nano particles is stable, and the magnetic nano particles can be kept for a long time in the body to be detected, so that the magnetic nano particles can be used for acquiring and collecting signals with longer duration and more clearness and obtaining more accurate signals than an ordinary measuring mode, and have higher spatial resolution and temperature resolution;

2. the invention utilizes the influence of magnetic nano particles on target nuclear magnetic resonance signals to solve the condition of temperature and concentration of the magnetic nano particles in a body to be detected, and the magnetic nano particles have small particle size and can be controlled by an external magnetic field or modified by a target probe to control the magnetic nano particles to reach a target position, so the magnetic nano particles can not damage the body to be detected, and the magnetic nano particles are usually nano ferroferric oxide, so the technology can not damage cells or cause harm to the detected body even if being used for metabolism and temperature monitoring of body cells.

Drawings

FIG. 1 is a schematic flow diagram of a magnetic method for monitoring activity and temperature of a moving object according to the present invention;

FIG. 2 is a graph of transverse relaxation rate at 24 deg.C and 3T of the present invention as a function of magnetic nanoparticle iron concentration;

FIG. 3 is a graph of transverse relaxation time versus temperature for magnetic nanopatterns with an iron concentration of 0.1mg/ml in accordance with the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

One aspect of the present invention provides a magnetic method for monitoring activity and temperature of a moving object, as shown in fig. 1, comprising the steps of:

(1) performing primary nuclear magnetic resonance imaging on a measured body to obtain a primary nuclear magnetic resonance spectrum image containing resonance frequency and spectrum half-height width information;

(2) laying magnetic nano particles into a tested body until the magnetic nano particles can reach a target position and reach an equilibrium state;

(3) after a plurality of activity periods of the measured body, performing nuclear magnetic resonance imaging on the measured body again to obtain a nuclear magnetic resonance spectrum image;

(4) obtaining concentration information and temperature information of the magnetic nanoparticles according to the correlation between the variation of the resonance frequency and the full width at half maximum of the spectrum of the two imaging and the concentration and the temperature of the magnetic nanoparticles;

(5) and (5) repeating the steps (3) to (4), obtaining the change condition of the concentration and the temperature of the magnetic nano particles along with time, and realizing the monitoring of the activity and the temperature of the tested body.

In particular, the particle diameter d of the magnetic nanoparticles₀In the range of d₀< 30nm and since the sample actually contains a large number of magnetic nanoparticles, it is required that at least 90% of the particles have a size in the d e [ d ]₀-2nm，d₀+2nm]To ensure that the magnetic nanoparticle sample has paramagnetism or superparamagnetism and that the particle size distribution does not cause additional interference with the nmr spectroscopy results. The particle size of the small-particle-size magnetic nanoparticles with concentrated particle size distribution should not influence the normal activity state of the tested body.

Specifically, the magnetic nanoparticles are controlled by an external magnetic field or targeted markers modified on the surfaces of the magnetic nanoparticles, so as to ensure that the particles can reach a target position to be monitored.

Specifically, the resonance frequency and the half-height width of the spectrum of the two imaging changes Δ ν (i) and Δ ω_1/2(i) Are respectively formulated as:

Δυ(i)＝υ(0)-υ(i)

Δω_1/2(i)＝ω_1/2(i)-ω_1/2(0)

wherein upsilon (0) and ω_1/2(0) The resonance frequency and the spectral full width at half maximum, upsilon (i) and ω, respectively, of the primary NMR spectral image of the original sample without particle injection_1/2(i) Respectively the resonance frequency and the half-height width of the spectrum of the ith nuclear magnetic resonance spectrum image, wherein the initial measurement results after the magnetic nano-particles are laid are the resonance frequency upsilon (1) and the half-height width of the spectrum omega_1/2(1). The magnetic resonance information when the number of the magnetic nanoparticles in the measured body is the maximum is obtained through measurement, and in a later cycle, the magnetic nanoparticles in the measured body are gradually consumed by the activity of the subject.

Further, the resonance frequency and the full width at half maximum of the spectrum of the nuclear magnetic resonance spectroscopic image in step (5) reflect the magnetization M of the magnetic nanoparticles, which is proportional to the magnetic nanoparticle concentration N and affected by temperature. The magnetization of the magnetic nanoparticles obeys:

wherein the Langevin equation isMagnetic moment m of magnetic nanoparticles_s＝M_sV，M_sIs the saturation magnetization of the magnetic nanoparticles, V is the volume of the magnetic nanoparticles, N is the concentration of the magnetic nanoparticles, k is the Boltzmann constant, T is the absolute temperature, H is the amplitude of the excitation magnetic field, μ₀Is a vacuum magnetic permeability.

For nuclear magnetic resonance spectrum, the relationship between the change of resonance frequency and the magnetic susceptibility of the magnetic nanoparticles is

Wherein, χ_SMagnetic nanoparticle magnetic susceptibility; when the sample direction is perpendicular to the magnetic field direction, α ═ 2 pi; when the sample direction is parallel to the magnetic field direction, α is 0.

For nuclear magnetic resonance spectrum, the relation between the full width at half maximum of the waveform and the transverse relaxation rate is

The apparent transverse relaxation time of water molecules measured by the nuclear magnetic resonance equipment is based on

And the magnetic nano particles mainly influence the diffusion of water molecules, so that the variation quantity delta omega of the spectral information obtained by the ith cell metabolism detection measurement_1/2(i)＝ω_1/2(i)-ω_1/2(0) Which reflects the change Δ R in apparent transverse relaxation rate after the diffusion of water molecules is affected_{2 diffusion}(i)＝Δω_1/2(i)·π。

According to the external diffusion model, water molecules cannot pass through or combine with the magnetic nanoparticles in the diffusion process, but bypass the diffusion process. The contribution of water molecule diffusion to the apparent transverse relaxation rate can be expressed asWherein r is the radius of the magnetic nanoparticle, N₀Is an Avogastron constant, M_pThe molar concentration of the particles is N ═ N₀M_p×10-³，τ_D＝r²D is the molecular diffusion time, D is the diffusion coefficient,

thus, a system of equations can be constructed:

order to

Then N is equal to A²/B，

Iterative approaches can then be used to solve for the temperature information.

In another aspect, the present invention provides a magnetic device for monitoring activity and temperature of a moving object, comprising:

the first imaging module is used for carrying out primary nuclear magnetic resonance imaging on a measured body to obtain a primary nuclear magnetic resonance spectrum image containing resonance frequency and spectrum full width at half maximum;

the laying module is used for laying the magnetic nano particles into the measured body until the magnetic nano particles can reach the target position and reach an equilibrium state;

the second imaging module is used for carrying out nuclear magnetic resonance imaging on the measured body again after a plurality of activity periods of the measured body to obtain a nuclear magnetic resonance spectrum image;

the calculation module is used for obtaining the concentration information and the temperature information of the magnetic nanoparticles according to the linear relation between the variation of the resonance frequency and the full width at half maximum of the spectrum of the two imaging and the concentration and the temperature of the magnetic nanoparticles;

and the monitoring module is used for acquiring the change condition of the concentration and the temperature of the magnetic nanoparticles along with time, and monitoring the activity and the temperature of the detected body.