Temperature imaging method, system and device based on magnetic hysteresis effect of magnetic nanoparticles

Abstract

The present application belongs to the field of magnetic nanoparticle imaging, and particularly relates to a temperature imaging method, system and device based on the magnetic hysteresis effect of magnetic nanoparticles, aiming at solving the problem that MPI cannot realize real-time accurate temperature imaging in the prior art. The present application comprises: acquiring the magnetization curve of standard concentration magnetic nanoparticles at different temperatures; performing parameter identification to obtain the mapping relationship between the coercive force k and the temperature T; acquiring the magnetization curve sequence of the object to be imaged; performing parameter identification to obtain the coercive force k sequence corresponding to the magnetization curve sequence, and combining the mapping relationship between the coercive force k and the temperature T to obtain the temperature T sequence corresponding to the coercive force k sequence; arranging the temperature T sequence into a two-dimensional image along the trajectory of the magnetic field free point motion, and obtaining the temperature image of the magnetic particle imaging of the object to be imaged. The present application realizes real-time accurate temperature imaging, promotes the combination of MPI and magnetic hyperthermia, and improves the effect of magnetic hyperthermia diagnosis and treatment through accurate temperature monitoring.

Description

Technical Field

[0001] The present invention belongs to the field of magnetic nanoparticle imaging, and in particular relates to a temperature imaging method, system and equipment based on the hysteresis effect of magnetic nanoparticles. Background Art

[0002] Magnetic Particle Imaging (MPI) is a novel medical imaging method that can precisely locate the location of injected magnetic nanoparticle contrast agents, offering the advantages of high sensitivity, high resolution, and zero radiation. Injected magnetic nanoparticles can not only be used for imaging but also for magnetic hyperthermia therapy. Therefore, combining MPI with magnetic hyperthermia to achieve integrated imaging and treatment is a research hotspot in the MPI field.

[0003] Currently, one of the difficulties in integrating MPI with magnetic hyperthermia technology lies in accurately measuring and controlling temperature. Traditional magnetic hyperthermia treatments are not sufficiently precise in temperature measurement and control, and the temperature measurement devices used, such as thermocouples, are significantly affected by magnetic fields. In addition to imaging the concentration distribution of magnetic particles, MPI also has the potential to image temperature.

[0004] Therefore, this field also needs a temperature imaging method based on the hysteresis effect of magnetic nanoparticles, which can accurately measure the temperature and concentration of magnetic nanoparticles in real time, thereby promoting the development of the combination of MPI and magnetic hyperthermia technology. Summary of the Invention

[0005] In order to solve the above-mentioned problem in the prior art, namely, the problem that the prior art MPI cannot achieve real-time and accurate temperature imaging, the present invention provides a temperature imaging method based on the hysteresis effect of magnetic nanoparticles, the temperature imaging method comprising:

[0006] Step S10, heating magnetic nanoparticles with a standard concentration of 1 mg / ml to different temperatures to obtain magnetization curves of the magnetic nanoparticles at different temperatures;

[0007] Step S20, constructing a coercivity parameter identification method for the magnetization curve of the magnetic nanoparticles at any temperature, and performing parameter identification to obtain a mapping relationship between the coercivity k and the temperature T;

[0008] Step S30, obtaining a sequence of magnetization curves along the motion trajectory of the magnetic field free point in the magnetic particle imaging scan of the object to be imaged;

[0009] Step S40, for each magnetization curve corresponding to the magnetic field free point, obtaining a coercive coefficient k sequence corresponding to the magnetization curve sequence by the method corresponding to step S20, and obtaining a temperature T sequence corresponding to the coercive coefficient k sequence based on a mapping relationship between the coercive coefficient k and the temperature T;

[0010] Step S50 , arranging the temperature T sequence into a two-dimensional image along the magnetic field free point motion trajectory to obtain a temperature image of the magnetic particle imaging of the object to be imaged.

[0011] In some preferred embodiments, step S20 includes:

[0012] Step S21, constructing a coercivity parameter identification method for the magnetization curve of the magnetic nanoparticles at any temperature;

[0013] Step S22, setting the initial value of the coercive coefficient to k0 = 100;

[0014] Step S23, optimizing the objective function of the coercive coefficient parameter identification method by the least square method to obtain the coercive coefficient k at the current temperature;

[0015] Step S24 , traverse each temperature to obtain a mapping relationship between the coercive coefficient k and the temperature T.

[0016] In some preferred embodiments, the objective function of the coercivity parameter identification method is:

[0017]

[0018] Where F is the objective function of the coercivity parameter identification method, M is the measured magnetization vector curve, The magnetization vector curve calculated by the model in the coercivity parameter identification method, where H is the strength of the external magnetic field and function is the magnetization function.

[0019] In some preferred embodiments, step S30 includes:

[0020] Step S31 , dividing the MPI output voltage in the magnetic particle imaging scan of the object to be imaged into a sequence of voltage signal segments along the magnetic field free point motion trajectory;

[0021] Step S32, integrating the sequence of voltage signal segments with respect to time to obtain a magnetization vector sequence for magnetic particle imaging scanning of the object to be imaged;

[0022] Step S33 : Based on the magnetization vector sequence and in combination with the magnetic particle imaging scanning excitation magnetic field sequence, a magnetization curve sequence along the magnetic field free point motion trajectory in the magnetic particle imaging scanning is obtained.

[0023] In some preferred embodiments, step S33 includes:

[0024] Step S331, obtaining an excitation magnetic field-magnetization vector curve for each magnetic field free point based on the magnetic particle imaging scanning excitation magnetic field sequence and the magnetization vector sequence;

[0025] Step S332 , traversing each magnetic field free point to obtain a sequence of magnetization curves along the motion trajectory of the magnetic field free point in the magnetic particle imaging scan.

[0026] In some preferred embodiments, in the temperature image of the magnetic particle imaging of the object to be imaged, the image pixel value is the corresponding temperature T.

[0027] In some preferred embodiments, the magnetization curves of the magnetic nanoparticles at different temperatures in step S10 are obtained by testing with a magnetic nanoparticle spectrometer.

[0028] Another aspect of the present invention provides a temperature imaging system based on the hysteresis effect of magnetic nanoparticles, the temperature imaging system comprising:

[0029] a module for obtaining a magnetization curve of standard magnetic nanoparticles, configured to heat magnetic nanoparticles of a standard concentration of 1 mg / ml to different temperatures to obtain magnetization curves of the magnetic nanoparticles at different temperatures;

[0030] A coercivity coefficient identification module is configured to construct a coercivity coefficient parameter identification method for the magnetization curve of the magnetic nanoparticles at any temperature, and perform parameter identification to obtain a mapping relationship between the coercivity coefficient k and the temperature T;

[0031] A module for acquiring a sequence of magnetization curves of an object to be imaged, configured to acquire a sequence of magnetization curves along a motion trajectory of a free point in a magnetic field during magnetic particle imaging scanning of the object to be imaged;

[0032] a temperature sequence acquisition module for the object to be imaged, configured to obtain, for each magnetization curve corresponding to a magnetic field free point, a coercive coefficient k sequence corresponding to the magnetization curve sequence through the coercive coefficient identification module, and obtain, based on a mapping relationship between the coercive coefficient k and the temperature T, a temperature T sequence corresponding to the coercive coefficient k sequence;

[0033] The temperature imaging module is configured to arrange the temperature T sequence into a two-dimensional image along the magnetic field free point motion trajectory to obtain a temperature image of the magnetic particle imaging of the object to be imaged.

[0034] A third aspect of the present invention provides an electronic device, comprising:

[0035] at least one processor; and

[0036] a memory communicatively connected to at least one of the processors; wherein,

[0037] The memory stores instructions that can be executed by the processor, and the instructions are used to be executed by the processor to implement the above-mentioned temperature imaging method based on the hysteresis effect of magnetic nanoparticles.

[0038] In a fourth aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to be executed by the computer to implement the above-mentioned temperature imaging method based on the hysteresis effect of magnetic nanoparticles.

[0039] Beneficial effects of the present invention:

[0040] (1) The temperature imaging method based on the hysteresis effect of magnetic nanoparticles in the present invention makes up for the deficiency of the current MPI field that the temperature of magnetic nanoparticles cannot be accurately imaged in real time, and realizes the real-time and accurate temperature imaging of magnetic nanoparticles through the temperature imaging algorithm on the traditional MPI.

[0041] (2) The temperature imaging method of the present invention based on the hysteresis effect of magnetic nanoparticles can achieve real-time and accurate temperature imaging, which can greatly expand the application field of MPI, promote the combination of MPI and magnetic hyperthermia, and improve the effect of magnetic hyperthermia diagnosis and treatment through accurate temperature monitoring.

[0042] (3) The temperature imaging method based on the hysteresis effect of magnetic nanoparticles in the present invention improves the imaging performance of MPI and its potential for clinical application. Some physiological studies using temperature regulation can be better carried out, such as immune research based on thermosensitive proteins, which will help promote and apply MPI in clinical medicine. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Other features, objects and advantages of the present application will become more apparent upon reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0044] Figure 1 Schematic diagram of the process of the temperature imaging method based on the hysteresis effect of magnetic nanoparticles of the present invention;

[0045] Figure 2 2. This is a schematic diagram of a method for identifying coercive coefficient parameters according to an embodiment of a temperature imaging method based on the hysteresis effect of magnetic nanoparticles of the present invention;

[0046] Figure 3 This is a mapping relationship curve between the coercivity k of magnetic nanoparticles with a standard concentration of 1 mg / ml and the temperature T in one embodiment of the temperature imaging method based on the hysteresis effect of magnetic nanoparticles of the present invention. DETAILED DESCRIPTION

[0047] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the relevant invention and are not intended to limit the invention. It should also be noted that, for ease of description, only portions relevant to the relevant invention are shown in the accompanying drawings.

[0048] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0049] The present invention provides a temperature imaging method based on the hysteresis effect of magnetic nanoparticles. This method, based on the hysteresis effect characteristics of magnetic nanoparticles at different temperatures, obtains the hysteresis loop of the magnetic nanoparticles by using the response signals of the magnetic particles at a field-free point (FFP) under the excitation magnetic field of an MPI. The coercivity k of the hysteresis loop is then calculated using a parameter identification algorithm. The coercivity k is linearly mapped to temperature, and the temperature T of the magnetic particles can be obtained from k. Finally, the obtained temperature is mapped along the movement trajectory of the FFP to produce a temperature image of the MPI.

[0050] The present invention provides a temperature imaging method based on the hysteresis effect of magnetic nanoparticles, the temperature imaging method comprising:

[0051] Step S10, heating magnetic nanoparticles with a standard concentration of 1 mg / ml to different temperatures to obtain magnetization curves of the magnetic nanoparticles at different temperatures;

[0052] Step S20, constructing a coercivity parameter identification method for the magnetization curve of the magnetic nanoparticles at any temperature, and performing parameter identification to obtain a mapping relationship between the coercivity k and the temperature T;

[0053] Step S30, obtaining a sequence of magnetization curves along the motion trajectory of the magnetic field free point in the magnetic particle imaging scan of the object to be imaged;

[0054] Step S40, for each magnetization curve corresponding to the magnetic field free point, obtaining a coercive coefficient k sequence corresponding to the magnetization curve sequence by the method corresponding to step S20, and obtaining a temperature T sequence corresponding to the coercive coefficient k sequence based on a mapping relationship between the coercive coefficient k and the temperature T;

[0055] Step S50 , arranging the temperature T sequence into a two-dimensional image along the magnetic field free point motion trajectory to obtain a temperature image of the magnetic particle imaging of the object to be imaged.

[0056] In order to more clearly illustrate the temperature imaging method based on the hysteresis effect of magnetic nanoparticles of the present invention, the following Figure 1 Each step in the embodiment of the present invention is described in detail.

[0057] The temperature imaging method based on the hysteresis effect of magnetic nanoparticles according to the first embodiment of the present invention includes steps S10 to S50, each of which is described in detail as follows:

[0058] Step S10 , heating magnetic nanoparticles with a standard concentration of 1 mg / ml to different temperatures to obtain magnetization curves of the magnetic nanoparticles at different temperatures.

[0059] The magnetization curves of magnetic nanoparticles at different temperatures were tested using a magnetic particle spectrometer (MPS).

[0060] Step S20 : ​​constructing a coercivity parameter identification method for the magnetization curve of the magnetic nanoparticles at any temperature, and performing parameter identification to obtain a mapping relationship between the coercivity k and the temperature T.

[0061] like Figure 2 FIG. 1 is a schematic diagram of a method for identifying coercive coefficient parameters according to an embodiment of a temperature imaging method based on the hysteresis effect of magnetic nanoparticles of the present invention. The coercive coefficient parameter identification process for a measured magnetization curve at a current temperature specifically includes:

[0062] Step S21, constructing a coercivity parameter identification method for the magnetization curve of the magnetic nanoparticles at any temperature;

[0063] Step S22, setting the initial value of the coercive coefficient to k0 = 100;

[0064] Step S23, optimizing the objective function of the coercive coefficient parameter identification method by the least square method to obtain the coercive coefficient k at the current temperature;

[0065] Step S24 , traverse each temperature to obtain a mapping relationship between the coercive coefficient k and the temperature T.

[0066] The objective function of the coercivity parameter identification method is shown in formula (1):

[0067]

[0068] Where F is the objective function of the coercivity parameter identification method, M is the measured magnetization vector curve, The magnetization vector curve calculated by the model in the coercivity parameter identification method, where H is the strength of the external magnetic field and function is the magnetization function.

[0069] The magnetization function can be selected as Langevin function, Fokker-Planck function, etc. according to actual needs, and the present invention will not describe them in detail here.

[0070] The objective function of the coercivity parameter identification method is optimized using the least squares method, and the final coercivity k is calculated so that the error between the calculated magnetization curve and the measured magnetization curve is minimized.

[0071] like Figure 3As shown, this is a mapping curve of the coercive coefficient k of magnetic nanoparticles with a standard concentration of 1 mg / ml and temperature T in an embodiment of the temperature imaging method based on the hysteresis effect of magnetic nanoparticles of the present invention, where the horizontal axis represents the temperature T (unit: degrees Celsius) and the vertical axis represents the coercive coefficient k.

[0072] Step S30, obtaining a sequence of magnetization curves along the motion trajectory of the magnetic field free point in the magnetic particle imaging scan of the object to be imaged, specifically includes:

[0073] Step S31 , dividing the MPI output voltage in the magnetic particle imaging scan of the object to be imaged into a sequence of voltage signal segments along the magnetic field free point motion trajectory;

[0074] Step S32, integrating the sequence of voltage signal segments with respect to time to obtain a magnetization vector sequence for magnetic particle imaging scanning of the object to be imaged;

[0075] Step S33 : Based on the magnetization vector sequence and in combination with the magnetic particle imaging scanning excitation magnetic field sequence, a magnetization curve sequence along the magnetic field free point motion trajectory in the magnetic particle imaging scanning is obtained.

[0076] Wherein step S33 comprises:

[0077] Step S331, obtaining an excitation magnetic field-magnetization vector curve for each magnetic field free point based on the magnetic particle imaging scanning excitation magnetic field sequence and the magnetization vector sequence;

[0078] Step S332 , traversing each magnetic field free point to obtain a sequence of magnetization curves along the motion trajectory of the magnetic field free point in the magnetic particle imaging scan.

[0079] Step S40 , for each magnetization curve corresponding to a magnetic field free point, obtain a coercive coefficient k sequence corresponding to the magnetization curve sequence by the method corresponding to step S20 , and based on the mapping relationship between the coercive coefficient k and temperature T, obtain a temperature T sequence corresponding to the coercive coefficient k sequence.

[0080] Step S50 , arranging the temperature T sequence into a two-dimensional image along the magnetic field free point motion trajectory to obtain a temperature image of the magnetic particle imaging of the object to be imaged.

[0081] In the temperature image of the magnetic particle imaging of the object to be imaged, the image pixel value is the corresponding temperature T.

[0082] Although the various steps in the above embodiment are described in the above-mentioned order, those skilled in the art will understand that in order to achieve the effect of this embodiment, different steps do not have to be executed in such an order. They can be executed simultaneously (in parallel) or in a reverse order. These simple changes are within the scope of protection of the present invention.

[0083] A temperature imaging system based on the hysteresis effect of magnetic nanoparticles according to a second embodiment of the present invention comprises:

[0084] A module for obtaining a magnetization curve of standard magnetic nanoparticles is configured to heat magnetic nanoparticles with a standard concentration of 1 mg / ml to different temperatures to obtain magnetization curves of the magnetic nanoparticles at different temperatures;

[0085] A coercivity coefficient identification module is configured to construct a coercivity coefficient parameter identification method for the magnetization curve of the magnetic nanoparticles at any temperature, and perform parameter identification to obtain a mapping relationship between the coercivity coefficient k and the temperature T;

[0086] A module for acquiring a sequence of magnetization curves of an object to be imaged, configured to acquire a sequence of magnetization curves along a motion trajectory of a free point in a magnetic field during magnetic particle imaging scanning of the object to be imaged;

[0087] a temperature sequence acquisition module for the object to be imaged, configured to obtain, for each magnetization curve corresponding to a magnetic field free point, a coercive coefficient k sequence corresponding to the magnetization curve sequence through the coercive coefficient identification module, and obtain, based on a mapping relationship between the coercive coefficient k and the temperature T, a temperature T sequence corresponding to the coercive coefficient k sequence;

[0088] The temperature imaging module is configured to arrange the temperature T sequence into a two-dimensional image along the magnetic field free point motion trajectory to obtain a temperature image of the magnetic particle imaging of the object to be imaged.

[0089] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working process and related instructions of the system described above can refer to the corresponding process in the aforementioned method embodiment and will not be repeated here.

[0090] It should be noted that the temperature imaging system based on the hysteresis effect of magnetic nanoparticles provided in the above embodiment is only illustrated by the division of the above functional modules. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the modules or steps in the embodiments of the present invention can be further decomposed or combined. For example, the modules in the above embodiment can be combined into one module or further divided into multiple sub-modules to complete all or part of the functions described above. The names of the modules and steps involved in the embodiments of the present invention are merely for distinguishing the modules or steps and are not to be considered as improper limitations of the present invention.

[0091] An electronic device according to a third embodiment of the present invention includes:

[0092] at least one processor; and

[0093] a memory communicatively connected to at least one of the processors; wherein,

[0094] The memory stores instructions that can be executed by the processor, and the instructions are used to be executed by the processor to implement the above-mentioned temperature imaging method based on the hysteresis effect of magnetic nanoparticles.

[0095] A fourth embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to be executed by the computer to implement the above-mentioned temperature imaging method based on the hysteresis effect of magnetic nanoparticles.

[0096] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes and related instructions of the storage device and processing device described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0097] Those skilled in the art should be able to appreciate that, in conjunction with the modules and method steps of each example described in the embodiments disclosed herein, it is possible to implement them with electronic hardware, computer software, or a combination of the two, and the programs corresponding to the software modules and method steps can be placed in random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium known in the art. In order to clearly illustrate the interchangeability of electronic hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in electronic hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0098] The terms "first", "second", etc. are used to distinguish similar objects, rather than to describe or indicate a particular order or sequence.

[0099] The term "comprise" or any other similar term is intended to cover non-exclusive inclusion such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0100] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A temperature imaging method based on the hysteresis effect of magnetic nanoparticles, characterized in that: The temperature imaging method comprises: Step S10, heating magnetic nanoparticles with a standard concentration of 1 mg / ml to different temperatures to obtain magnetization curves of the magnetic nanoparticles at different temperatures; Step S20: construct a coercivity parameter identification method for the magnetization curve of the magnetic nanoparticles at any temperature, and perform parameter identification to obtain the coercivity. and temperature The mapping relationship is: Step S21, constructing a coercivity parameter identification method for the magnetization curve of the magnetic nanoparticles at any temperature; Step S22: Set the initial value of the coercivity coefficient to ; Step S23, optimizing the objective function of the coercivity parameter identification method by the least squares method to obtain the coercivity at the current temperature ; Step S24, traverse each temperature and obtain the coercivity and temperature The mapping relationship; Step S30, obtaining a sequence of magnetization curves along the motion trajectory of the magnetic field free point in the magnetic particle imaging scan of the object to be imaged; Step S40: for each magnetization curve corresponding to the magnetic field free point, obtain the coercivity corresponding to the magnetization curve sequence by the method corresponding to step S20. sequence, and based on the coercivity and temperature The mapping relationship is used to obtain the coercivity coefficient. Temperature corresponding to the sequence sequence; Step S50: moving the temperature along the magnetic field free point motion trajectory The sequence is arranged into a two-dimensional image to obtain a temperature image of the magnetic particle imaging of the object to be imaged; The objective function of the coercivity parameter identification method is: ； in, is the objective function of the coercivity parameter identification method, is the measured magnetization vector curve, The magnetization vector curve calculated by the model in the coercivity parameter identification method, is the strength of the external magnetic field, is the magnetization function.

2. The temperature imaging method based on the hysteresis effect of magnetic nanoparticles according to claim 1, characterized in that: Step S30 includes: Step S31 , dividing the MPI output voltage in the magnetic particle imaging scan of the object to be imaged into a sequence of voltage signal segments along the magnetic field free point motion trajectory; Step S32, integrating the sequence of voltage signal segments with respect to time to obtain a magnetization vector sequence for magnetic particle imaging scanning of the object to be imaged; Step S33 : Based on the magnetization vector sequence and in combination with the magnetic particle imaging scanning excitation magnetic field sequence, a magnetization curve sequence along the magnetic field free point motion trajectory in the magnetic particle imaging scanning is obtained.

3. The temperature imaging method based on the hysteresis effect of magnetic nanoparticles according to claim 2, characterized in that: Step S33 includes: Step S331, obtaining an excitation magnetic field-magnetization vector curve for each magnetic field free point based on the magnetic particle imaging scanning excitation magnetic field sequence and the magnetization vector sequence; Step S332 , traversing each magnetic field free point to obtain a sequence of magnetization curves along the motion trajectory of the magnetic field free point in the magnetic particle imaging scan.

4. The temperature imaging method based on the hysteresis effect of magnetic nanoparticles according to claim 1, characterized in that: In the temperature image of the magnetic particle imaging of the object to be imaged, the image pixel value corresponds to the temperature .

5. The temperature imaging method based on the hysteresis effect of magnetic nanoparticles according to claim 1, characterized in that: The magnetization curves of the magnetic nanoparticles at different temperatures in step S10 are obtained by testing with a magnetic nanoparticle spectrometer.

6. A temperature imaging system based on the hysteresis effect of magnetic nanoparticles, characterized in that: The temperature imaging system comprises: a module for obtaining a magnetization curve of standard magnetic nanoparticles, configured to heat magnetic nanoparticles of a standard concentration of 1 mg / ml to different temperatures to obtain magnetization curves of the magnetic nanoparticles at different temperatures; The coercivity coefficient identification module is configured to construct a coercivity coefficient parameter identification method for the magnetization curve of magnetic nanoparticles at any temperature, and perform parameter identification to obtain the coercivity coefficient. and temperature The mapping relationship; A module for acquiring a sequence of magnetization curves of an object to be imaged, configured to acquire a sequence of magnetization curves along a motion trajectory of a free point in a magnetic field during magnetic particle imaging scanning of the object to be imaged; The temperature sequence acquisition module of the object to be imaged is configured to obtain the coercive coefficient corresponding to the magnetization curve sequence for each magnetic field free point through the coercive coefficient identification module. sequence, and based on the coercivity and temperature The mapping relationship is used to obtain the coercivity coefficient. Temperature corresponding to the sequence sequence; The temperature imaging module is configured to measure the temperature along the trajectory of the magnetic field free point. The sequence is arranged into a two-dimensional image to obtain a temperature image of the magnetic particle imaging of the object to be imaged; Among them, for the magnetization curve of magnetic nanoparticles at any temperature, a coercivity parameter identification method is constructed, and parameter identification is performed to obtain the coercivity and temperature The mapping relationship includes: A coercivity parameter identification method is constructed for the magnetization curve of magnetic nanoparticles at any temperature. Set the initial value of the coercivity to ; The objective function of the coercivity coefficient parameter identification method is optimized by the least squares method to obtain the coercivity coefficient at the current temperature. ; Traverse each temperature and obtain the coercivity and temperature The mapping relationship; The objective function of the coercivity parameter identification method is: ； in, is the objective function of the coercivity parameter identification method, is the measured magnetization vector curve, The magnetization vector curve calculated by the model in the coercivity parameter identification method, is the strength of the external magnetic field, is the magnetization function.

7. An electronic device, characterized in that: include: at least one processor; as well as a memory communicatively connected to at least one of the processors; wherein, The memory stores instructions that can be executed by the processor, and the instructions are used to be executed by the processor to implement the temperature imaging method based on the hysteresis effect of magnetic nanoparticles according to any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer instructions, and the computer instructions are used to be executed by the computer to implement the temperature imaging method based on the hysteresis effect of magnetic nanoparticles according to any one of claims 1 to 5.

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