Magnetic particle imaging method and system based on data rearrangement

Abstract

The present invention belongs to the field of magnetic nanoparticle imaging technology, and relates to a magnetic particle imaging method and system based on data rearrangement, which aims to solve the problem of information aliasing between adjacent pixels caused by repeated scanning in the prior art. The method of the present invention includes: generating a first magnetic field and starting a second magnetic field; performing one-dimensional scanning of the first magnetic field and performing image reconstruction: collecting the timing waveform of the second magnetic field and the timing voltage response signal of the magnetic nanoparticles; segmenting the timing waveform of the second magnetic field, extracting fragments of each waveform segmentation and reconstructing them into a sinusoidal sequence while recording the index, rearranging the voltage response signal based on the index, and generating a one-dimensional reconstruction result; constructing a two-dimensional image based on data rearrangement of the one-dimensional image. The present invention extracts fragments of each waveform segmentation for reconstruction, rearranges the spliced timing signals, thereby achieving rearrangement and analysis of the aliased information, reducing deviations and blurring in the reconstruction process, and improving the spatial resolution of the image.

Description

Technical Field

[0001] The present invention belongs to the technical field of magnetic nanoparticle imaging, and in particular relates to a magnetic particle imaging method and system based on data rearrangement. Background Art

[0002] Magnetic particle imaging (MPI), a highly promising non-invasive imaging technology, has garnered widespread attention in recent years in fields such as biomedical imaging. By applying an external magnetic field and utilizing the nonlinear magnetization response of magnetic nanoparticles, MPI captures these signals to determine their in vivo concentration distribution. This signal is then converted into an image of the particle distribution using an imaging algorithm, enabling visualization of the imaging subject, which has important medical applications. The external magnetic field consists of a selection magnetic field and an excitation magnetic field. The selection magnetic field is characterized by a gradient magnetic field with a point-like low-magnetic field region (field-free point, FFP) or a gradient magnetic field with a linear low-magnetic field region (field-free line, FFL). The low-magnetic field region magnetizes the magnetic nanoparticles, while the high-magnetic field region saturates them and prevents magnetization. The excitation magnetic field is characterized by a uniform alternating magnetic field, which drives the scanning of the point-like or linear low-magnetic field region to achieve spatial encoding of the imaging field of view.

[0003] However, during the imaging process, the FFP or FFL's trajectory inevitably involves repeated scanning as it covers the entire imaging field of view. This leads to information aliasing between adjacent pixels, affecting the accuracy of signal analysis, interfering with the image reconstruction process, and potentially reducing the spatial resolution of the image. Effectively analyzing and rearranging this aliased information to further improve imaging quality has become a key technical challenge that needs to be addressed. Summary of the Invention

[0004] In order to solve the above-mentioned problem in the prior art, namely, the problem of information aliasing between adjacent pixels caused by repeated scanning, the first aspect of the present invention proposes a magnetic particle imaging method based on data rearrangement, which analyzes and rearranges the aliased information to improve imaging quality. The method includes the following steps:

[0005] S100, generating a first magnetic field, setting a second magnetic field as an excitation magnetic field and starting the second magnetic field; the first magnetic field is a magnetic field free point or a magnetic field free line;

[0006] S200: driving the first magnetic field to perform one-dimensional scanning and perform image reconstruction:

[0007] S201, collecting a timing waveform of the second magnetic field and a timing voltage response signal of the magnetic nanoparticles, and evenly segmenting the timing waveform and the timing voltage response signal on the amplitude axis to obtain waveform segments and voltage response signal segments; the waveform segments and the voltage response signal segments correspond to each other one by one;

[0008] S202, extracting the waveform segments of each segment and reconstructing them to obtain a reconstructed sinusoidal sequence; assigning a unique index to each sinusoidal sequence and recording the index;

[0009] S203, rearrange the corresponding voltage response signal segments based on the index to obtain a timing rearrangement response signal;

[0010] S204, extracting the maximum value of the timing rearrangement response signal of each segment, and splicing them in the order of the segments to obtain a one-dimensional reconstruction result;

[0011] S300 , constructing a two-dimensional image based on the one-dimensional reconstruction result by adopting a set scanning mode; the set scanning mode includes line-by-line scanning and discrete rotation of multiple angles.

[0012] In some preferred embodiments, the second magnetic field is composed of a superposition of a triangular waveform and a sinusoidal waveform, and the magnetic fields generated by the triangular waveform and the sinusoidal waveform have the same direction.

[0013] In some preferred embodiments, the amplitude of the sinusoidal waveform is for:

[0014] ;

[0015] The amplitude of the triangular waveform for:

[0016] ;

[0017] Wherein, L is the side length of the imaging field of view, the imaging field of view is a square, and the image size is N×N; G is the first magnetic field gradient.

[0018] In some preferred embodiments, the second magnetic field timing waveform is evenly segmented on the amplitude axis, the length of each segment is L / N, and the segmentation results are discrete waveform segments.

[0019] In some preferred embodiments, each waveform segment is extracted and reconstructed into a sinusoidal sequence by:

[0020] Determine the cycle length of the sinusoidal waveform, and define the length of one cycle as W;

[0021] For each waveform segment to be processed, divide it according to the length W to obtain multiple segments;

[0022] The obtained multiple segments are augmented and spliced along the column direction to reconstruct a sinusoidal sequence.

[0023] In some preferred embodiments, the splicing method is to add signal values.

[0024] In some preferred embodiments, the first magnetic field is a magnetic field free point, and the two-dimensional image is constructed by:

[0025] Using Cartesian trajectories, the one-dimensional reconstruction results are arranged in rows or columns to construct a two-dimensional image.

[0026] In some preferred embodiments, the first magnetic field is a magnetic field free line, and the two-dimensional image is constructed by:

[0027] A discrete rotation trajectory is used for multi-angle scanning; the one-dimensional reconstruction results at multiple angles are used to construct a sinusoidal image, and then a two-dimensional image is constructed through filtered back projection.

[0028] In some preferred embodiments, the filtered back projection uses a Cosine filter or an RL filter.

[0029] A second aspect of the present invention provides a magnetic particle imaging system based on data rearrangement, the system comprising:

[0030] a power supply module configured to provide power to the coil magnet and other modules in the entire imaging system;

[0031] a control module configured to generate a control signal;

[0032] a magnetic field generating module configured to generate a first magnetic field according to the control signal, set a second magnetic field as an excitation magnetic field and start the second magnetic field, and then drive the first magnetic field to perform one-dimensional scanning;

[0033] a signal processing and acquisition module configured to acquire the timing waveform of the second magnetic field and the timing voltage response signal of the magnetic nanoparticles and perform preprocessing on the collected data, and to send the preprocessed timing waveform and the timing voltage response signal to the image reconstruction and visualization module;

[0034] a memory storage module configured to store the collected second magnetic field time waveform, the time-series voltage response signal of the magnetic nanoparticles, and the constructed two-dimensional image;

[0035] An image reconstruction and visualization module is configured to perform image reconstruction based on the received timing waveform and the received timing voltage response signal:

[0036] Evenly segmenting the time series waveform and the time series voltage response signal on the amplitude axis to obtain waveform segments and voltage response signal segments; extracting and reconstructing the waveform segments of each segment to obtain a reconstructed sinusoidal sequence; assigning a unique index to each sinusoidal sequence and recording the index;

[0037] The corresponding voltage response signal segments are rearranged based on the index to obtain a time-rearranged response signal; the maximum value of the time-rearranged response signal of each segment is extracted and spliced in the segment order to obtain a one-dimensional reconstruction result; based on the one-dimensional reconstruction result, a two-dimensional image is constructed using line-by-line scanning or discrete rotation multi-angle scanning.

[0038] Beneficial effects of the present invention:

[0039] The present invention segments the time-series waveform of the second magnetic field, extracts fragments of each waveform segment for reconstruction and simultaneously records indexes, rearranges and splices the time-series signals based on the recorded indexes, generates a one-dimensional reconstruction result, rearranges and analyzes the aliased information, and thus improves the imaging quality and image spatial resolution.

[0040] Index-based rearrangement ensures the correspondence between the signal and the excitation magnetic field timing waveform. Through waveform segmentation and grouping, signal rearrangement, and amplitude extraction, the accuracy and efficiency of imaging are improved, and information that is aliased due to repeated scanning is accurately separated. According to the optimal logical sequence required for imaging, the errors and interference caused by information aliasing are effectively eliminated, providing a reliable foundation for subsequent image reconstruction. When reconstructing two-dimensional images, based on the rearranged data, the actual distribution of magnetic nanoparticles in the body can be more accurately restored, reducing deviations and ambiguities in the reconstruction process. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] 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:

[0042] Figure 1 is a flow chart of a magnetic particle imaging method based on data rearrangement in an embodiment of the present invention;

[0043] Figure 2 is a schematic diagram of a timing waveform of the second magnetic field in an embodiment of the present invention;

[0044] Figure 3 is a schematic diagram of one of the waveform segments after the second magnetic field is segmented according to amplitude in an embodiment of the present invention;

[0045] Figure 4Schematic diagram of using waveform segments to construct a sinusoidal sequence in an embodiment of the present invention; the upper diagram shows the waveform segments grouped at equal distances in a time series, and the lower diagram shows the segments grouped in the upper diagram augmented and spliced into a sinusoidal sequence by columns;

[0046] Figure 5 2 is a schematic diagram comparing the response signals of magnetic nanoparticles before and after rearrangement according to an embodiment of the present invention, wherein a unit magnetic nanoparticle sample is placed at the center of the field of view in a one-dimensional scan, the left side shows the response signal before data rearrangement, and the right side shows the response signal after data rearrangement;

[0047] Figure 6 1 is a schematic diagram of a scanning process of a two-dimensional imaging field of view when the first magnetic field is a magnetic field free point in an embodiment of the present invention;

[0048] Figure 7 Schematic diagram of one-dimensional scanning and two-dimensional multi-angle scanning of the magnetic field free line in an embodiment of the present invention. DETAILED DESCRIPTION

[0049] 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.

[0050] 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.

[0051] The present invention performs secondary grouping on the segmented waveforms, splices the segments into a sinusoidal sequence by column augmentation, rearranges the timing signal based on the index of the sinusoidal sequence, and then constructs a two-dimensional image based on the data rearrangement of the one-dimensional image, analyzes and rearranges the aliased information, thereby improving the imaging quality.

[0052] In order to more clearly illustrate the magnetic particle imaging method based on data rearrangement of the present invention, the following Figure 1 Each step in the embodiment of the present invention is described in detail.

[0053] A magnetic particle imaging method based on data rearrangement according to a first embodiment of the present invention comprises steps S100 to S300:

[0054] S100 , generating a first magnetic field, setting a second magnetic field as an excitation magnetic field and starting the second magnetic field; the first magnetic field is a magnetic field free point or a magnetic field free line.

[0055] Preferably, the second magnetic field is composed of a superposition of a triangular waveform and a sine waveform.

[0056] Preferably, the amplitude of the sinusoidal waveform is for:

[0057] ;

[0058] The amplitude of the triangular waveform for:

[0059] ;

[0060] Wherein, L is the side length of the imaging field of view, the imaging field of view is a square, and the image size is N×N; G is the first magnetic field gradient.

[0061] Preferably, the magnetic fields generated by the triangular waveform and the sine waveform have the same direction.

[0062] S200, driving the first magnetic field to perform one-dimensional scanning and performing image reconstruction; the image reconstruction method is:

[0063] S201, collecting a time-series waveform of a second magnetic field and a time-series voltage response signal of the magnetic nanoparticles, and evenly segmenting the time-series waveform and the time-series voltage response signal on an amplitude axis to obtain waveform segments and voltage response signal segments; the waveform segments and the voltage response signal segments correspond one to one;

[0064] Furthermore, the second magnetic field time series waveform is evenly segmented on the amplitude axis, with the length of each segment being L / N, and the segmentation results being discrete waveform segments;

[0065] S202, extracting the waveform segments of each segment and reconstructing them to obtain a reconstructed sinusoidal sequence; assigning a unique index to each sinusoidal sequence and recording the index;

[0066] S203, rearrange the corresponding voltage response signal segments based on the index to obtain a timing rearrangement response signal;

[0067] S204 , extracting the maximum value of the timing rearrangement response signal of each segment, and splicing them into a one-dimensional reconstruction result according to the segment sequence.

[0068] Preferably, each waveform segment is extracted and reconstructed into a sinusoidal sequence by:

[0069] Determine the cycle length of the sinusoidal waveform, and define the length of one cycle as W;

[0070] For each waveform segment to be processed, divide it according to the length W to obtain multiple segments;

[0071] The obtained multiple segments are augmented and spliced along the column direction to reconstruct a sinusoidal sequence.

[0072] S300 , constructing a two-dimensional image based on the one-dimensional reconstruction result by adopting line-by-line scanning or discrete rotation multi-angle scanning.

[0073] 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.

[0074] In a magnetic particle imaging method based on data rearrangement according to a second embodiment of the present invention, the first magnetic field adopts a magnetic field free point, and the gradient is set to 1 T / m. The imaging field of view is set to 40 mm × 40 mm. The second magnetic field is used as an excitation magnetic field, and the waveform is as shown in the attached figure. Figure 2 As shown, the second magnetic field waveform is composed of a triangular waveform superimposed on a sine waveform. The horizontal axis is the time axis, representing the time series of the second magnetic field waveform, and the vertical axis is the amplitude axis, representing the change in the field strength of the second magnetic field. The triangular waveform amplitude is set to 40mT, the frequency is set to 1Hz, and only the half-cycle from the negative peak to the positive peak is used. The sine waveform amplitude is set to 4mT, and the frequency is set to 3000Hz.

[0075] After the particle to be tested is placed in the imaging field of view, the excitation magnetic field is started; the triangular waveform in the excitation magnetic field drives the magnetic field free point to move slowly and uniformly from the leftmost side of the imaging field of view to the rightmost side. At the same time, the superimposed sine wave drives the magnetic field free point to oscillate at high frequency to excite the nanoparticles to generate a nonlinear response signal, and the timing voltage signal is obtained by collecting the sensor.

[0076] In this embodiment, the particle to be measured is set as a point-shaped particle phantom, placed in the center of the imaging field of view, and a one-dimensional scan is performed. The magnetic nanoparticle time-series voltage response signal obtained by the scanning is shown in the attached figure. Figure 5 The left figure shows a wide envelope. The timing waveform of the excitation magnetic field and the timing voltage response signal of the magnetic nanoparticles are collected; the timing waveform of the excitation magnetic field is collected, as shown in the attached figure. Figure 2 As shown in FIG, the timing waveform is segmented on the amplitude axis, and the segment length is 12 excitation cycles. The extracted waveform segment is shown in FIG. Figure 3 As shown, the horizontal axis is the time axis representing the time series of the waveform segment, and the vertical axis is the amplitude axis representing the amplitude of the waveform segment; two time windows are magnified, the lower time window is the maximum peak segment of the rearranged and constructed sine sequence, and the upper time window is the middle segment of the rearranged and constructed sine sequence close to the maximum peak.

[0077] Reconstruct each extracted waveform segment. The reconstruction process is as shown in the attached figure. Figure 4 As shown in Figure 2. According to the length of 12 excitation cycles, the waveform segments are divided into 8 groups. Figure 4The upper middle figure shows the waveform fragments of the second magnetic field, which are divided into 8 groups with equal distances in the time series. The lower figure shows the 8 groups of fragments in the upper figure being spliced into a sine sequence by column augmentation to construct a new sine sequence, and the corresponding rearranged indexes are recorded at the same time.

[0078] According to the index obtained after rearranging the excitation magnetic field, the time sequence voltage signal is rearranged to obtain a rearranged signal, as shown in the attached figure. Figure 5 As shown in the figure on the right: a unit magnetic nanoparticle sample is placed in the center of the field of view in a one-dimensional scan. The left side shows the response signal before data rearrangement, and the right side shows the response signal after data rearrangement. For the signal after rearrangement, the maximum value of each segment is taken as the signal amplitude, and the signals are sequentially spliced into a one-dimensional reconstruction result. After completing the scanning and reconstruction of a row, the phantom under test is moved forward by one pixel unit to scan and reconstruct the second row. According to this mode, the scanning and reconstruction of all rows in the two-dimensional field of view are completed, and all rows are spliced together to construct a two-dimensional image. The two-dimensional scanning trajectory is shown in the attached figure. Figure 6 shown.

[0079] Preferably, in this embodiment, the splicing method is signal value addition.

[0080] In the third embodiment of the present invention, a magnetic particle imaging method based on data rearrangement is provided. The first magnetic field adopts a magnetic field free line, and the magnetic field parameter settings of the first magnetic field and the second magnetic field are the same as those in the second embodiment. In the one-dimensional encoding process, the magnetic field free line is different from the magnetic field free point. After completing the same scanning and reconstruction process, a projection at a certain angle is obtained. The process of one-dimensional scanning of the magnetic field free line is shown in the attached figure. Figure 7 As shown in the left figure. After completing the one-dimensional scanning and projection, the discrete rotation trajectory is used, as shown in the attached figure. Figure 7 As shown in the picture on the right.

[0081] The discrete rotation angles are recorded as the angle vector, the initial angle is recorded as 0, and the subsequent rotation angles are recorded in the angle vector. After completing the multi-angle scanning process, a sinusoidal graph is constructed using the results of multi-angle scanning and reconstruction. The sinusoidal graph is filtered and back-projected to obtain a two-dimensional reconstructed image.

[0082] Optionally, in this embodiment, the back-projection angle uses the recorded angle vector, the filter uses a Cosine filter or an RL filter, and the back-projection interpolation parameter algorithm uses a spline interpolation spline.

[0083] A fourth aspect of the present invention provides a magnetic particle imaging system based on data rearrangement, the system comprising:

[0084] a power supply module configured to provide power to the coil magnet and other modules in the entire imaging system;

[0085] a control module configured to generate a control signal;

[0086] a magnetic field generating module configured to generate a first magnetic field according to the control signal, set a second magnetic field as an excitation magnetic field and start the second magnetic field, and then drive the first magnetic field to perform one-dimensional scanning;

[0087] a signal processing and acquisition module configured to acquire the timing waveform of the second magnetic field and the timing voltage response signal of the magnetic nanoparticles and perform preprocessing on the collected data, and to send the preprocessed timing waveform and the timing voltage response signal to the image reconstruction and visualization module;

[0088] a memory storage module configured to store the collected second magnetic field time waveform, the time-series voltage response signal of the magnetic nanoparticles, and the constructed two-dimensional image;

[0089] An image reconstruction and visualization module is configured to perform image reconstruction based on the received timing waveform and the received timing voltage response signal:

[0090] Evenly segmenting the time series waveform and the time series voltage response signal on the amplitude axis to obtain waveform segments and voltage response signal segments; extracting and reconstructing the waveform segments of each segment to obtain a reconstructed sinusoidal sequence; assigning a unique index to each sinusoidal sequence and recording the index;

[0091] The corresponding voltage response signal segments are rearranged based on the index to obtain a time-rearranged response signal; the maximum value of the time-rearranged response signal of each segment is extracted and spliced in the segment order to obtain a one-dimensional reconstruction result; based on the one-dimensional reconstruction result, a two-dimensional image is constructed using line-by-line scanning or discrete rotation multi-angle scanning.

[0092] It should be noted that the data rearrangement-based magnetic particle imaging system provided in the above embodiment is merely illustrated by the division of the above-mentioned functional modules. In actual applications, the above-mentioned 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-mentioned embodiments can be combined into a single 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 the purpose of distinguishing the modules or steps and are not to be construed as undue limitations on the present invention.

[0093] 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.

[0094] An electronic device according to a fifth embodiment of the present invention includes:

[0095] at least one processor; and

[0096] a memory communicatively connected to at least one of the processors; wherein,

[0097] 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 magnetic particle imaging method based on data rearrangement.

[0098] A sixth 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 magnetic particle imaging method based on data rearrangement.

[0099] 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 electronic device and computer-readable storage medium described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0100] Those skilled in the art should be able to appreciate that the modules and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented in 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 above description has generally described the components and steps of each example according to their functions. 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 may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0101] Computer program code for performing the operations of the present application may be written in one or more programming languages, or a combination thereof, including object-oriented programming languages such as Java, Smalltalk, C++, and conventional procedural programming languages such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., through the Internet using an Internet service provider).

[0102] The flow charts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present application. In this regard, each box in the flow chart or block diagram can represent a module, program segment or a part of code, and the module, program segment or a part of code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order than that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented by a dedicated hardware-based system that performs the specified function or operation, or can be implemented by a combination of dedicated hardware and computer instructions.

[0103] The terms "first", "second", etc. are used to distinguish similar objects, rather than to describe or indicate a particular order or sequence.

[0104] 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.

[0105] 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 magnetic particle imaging method based on data rearrangement, characterized in that: The method comprises the following steps: S100, generating a first magnetic field, setting a second magnetic field as an excitation magnetic field and starting the second magnetic field; the first magnetic field is a magnetic field free point or a magnetic field free line; S200: driving the first magnetic field to perform one-dimensional scanning and perform image reconstruction: S201, collecting a timing waveform of the second magnetic field and a timing voltage response signal of the magnetic nanoparticles, and evenly segmenting the timing waveform and the timing voltage response signal on the amplitude axis to obtain waveform segments and voltage response signal segments; the waveform segments and the voltage response signal segments correspond to each other one by one; S202, extracting the waveform segments of each segment and reconstructing them to obtain a reconstructed sinusoidal sequence; assigning a unique index to each sinusoidal sequence and recording the index; S203, rearrange the corresponding voltage response signal segments based on the index to obtain a timing rearrangement response signal; S204, extracting the maximum value of the timing rearrangement response signal of each segment, and splicing them in the order of the segments to obtain a one-dimensional reconstruction result; S300 , constructing a two-dimensional image based on the one-dimensional reconstruction result by adopting a set scanning mode; the set scanning mode includes line-by-line scanning and discrete rotation of multiple angles.

2. The magnetic particle imaging method based on data rearrangement according to claim 1, characterized in that: The second magnetic field is composed of a triangular waveform and a sine waveform superimposed, and the directions of the magnetic fields generated by the triangular waveform and the sine waveform are the same.

3. The magnetic particle imaging method based on data rearrangement according to claim 2, characterized in that: The amplitude of the sinusoidal waveform for: ； The amplitude of the triangular waveform for: ； Wherein, L is the side length of the imaging field of view, the imaging field of view is a square, and the image size is N×N; G is the first magnetic field gradient.

4. The method for magnetic particle imaging based on data rearrangement according to claim 3, characterized in that: The second magnetic field time series waveform is evenly segmented on the amplitude axis, with the length of each segment being L / N. The segmentation results are discrete waveform segments.

5. The method for magnetic particle imaging based on data rearrangement according to claim 4, characterized in that: Extract each waveform segment and reconstruct it into a sine sequence using the following method: Determine the cycle length of the sinusoidal waveform, and define the length of one cycle as W; For each waveform segment to be processed, divide it according to the length W to obtain multiple segments; The obtained multiple segments are augmented and spliced along the column direction to reconstruct a sinusoidal sequence.

6. The method for magnetic particle imaging based on data rearrangement according to claim 5, characterized in that: The splicing method is to add signal values.

7. The method for magnetic particle imaging based on data rearrangement according to claim 1, characterized in that: The first magnetic field is a magnetic field free point, and a two-dimensional image is constructed by: Using Cartesian trajectories, the one-dimensional reconstruction results are arranged in rows or columns to construct a two-dimensional image.

8. The method for magnetic particle imaging based on data rearrangement according to claim 1, characterized in that: The first magnetic field is a magnetic field free line, and a two-dimensional image is constructed by: A discrete rotation trajectory is used for multi-angle scanning; the one-dimensional reconstruction results at multiple angles are used to construct a sinusoidal image, and then a two-dimensional image is constructed through filtered back projection.

9. The method for magnetic particle imaging based on data rearrangement according to claim 8, characterized in that: The filtered back projection adopts a Cosine filter or an RL filter.

10. A magnetic particle imaging system based on data rearrangement, according to a magnetic particle imaging method based on data rearrangement according to any one of claims 1 to 9, characterized in that: The system comprises: a power supply module configured to provide power to the coil magnet and other modules in the entire imaging system; a control module configured to generate a control signal; a magnetic field generating module configured to generate a first magnetic field according to the control signal, set a second magnetic field as an excitation magnetic field and start the second magnetic field, and then drive the first magnetic field to perform one-dimensional scanning; a signal processing and acquisition module configured to acquire the timing waveform of the second magnetic field and the timing voltage response signal of the magnetic nanoparticles and perform preprocessing on the collected data, and to send the preprocessed timing waveform and the timing voltage response signal to the image reconstruction and visualization module; a memory storage module configured to store the collected second magnetic field time waveform, the time-series voltage response signal of the magnetic nanoparticles, and the constructed two-dimensional image; An image reconstruction and visualization module is configured to perform image reconstruction based on the received timing waveform and the received timing voltage response signal: Evenly segmenting the time series waveform and the time series voltage response signal on the amplitude axis to obtain waveform segments and voltage response signal segments; extracting and reconstructing the waveform segments of each segment to obtain a reconstructed sinusoidal sequence; assigning a unique index to each sinusoidal sequence and recording the index; The corresponding voltage response signal segments are rearranged based on the index to obtain a time-rearranged response signal; the maximum value of the time-rearranged response signal of each segment is extracted and spliced in the segment order to obtain a one-dimensional reconstruction result; based on the one-dimensional reconstruction result, a two-dimensional image is constructed using line-by-line scanning or discrete rotation multi-angle scanning.

Images