WO2023216582A1

WO2023216582A1 - Magnetic resonance chemical exchange saturation transfer imaging method, system and device

Info

Publication number: WO2023216582A1
Application number: PCT/CN2022/137729
Authority: WO
Inventors: 周洋; 魏盼盼; 邹超; 刘新; 郑海荣
Original assignee: 深圳先进技术研究院
Priority date: 2022-05-12
Filing date: 2022-12-08
Publication date: 2023-11-16
Also published as: CN117084658A

Abstract

A magnetic resonance chemical exchange saturation transfer imaging method, a system (400), a device (500), and a storage medium (600). The magnetic resonance chemical exchange saturation transfer imaging method comprises: applying a radio frequency saturation pulse lasting for a first preset time to a region to be detected (S11); applying a radio frequency echo pulse to said region, and acquiring a plurality of gradient echo signals generated after the radio frequency echo pulse is activated (S12); and using a radial sampling mode to read the plurality of gradient echo signals in a preset direction so as to generate a magnetic resonance image (S13). By means of gradient echo reading, the signal acquisition time is effectively shortened; by means of the radial acquisition mode, motion artifacts are effectively inhibited; for the acquired chemical exchange saturation transfer imaging spectrum data, fitting and other post-processing modes are used to separate a water signal from a fat signal, and a target signal is extracted and analyzed.

Description

Magnetic resonance chemical exchange saturation transfer imaging methods, systems and equipment

Technical field

The present application relates to the field of magnetic resonance CEST imaging technology, and in particular to a magnetic resonance chemical exchange saturation transfer imaging method, system, equipment, and storage medium.

Background technique

Research on the magnetic resonance CEST imaging method (Chemical exchange saturation transfer, CEST) began in 2000. Due to its new magnetic resonance contrast mechanism, it quickly attracted widespread attention and became a new and sensitive way to study the chemical exchange and chemical dynamics of macromolecules. The principle is to selectively apply a radio frequency (RF) pulse signal of a special resonance frequency to saturate the corresponding protons (Figure 1, pool B). Under appropriate circumstances, these protons will interact with surrounding water molecules (such as Figure 1, pool A) undergoes chemical exchange, and then transfers part of the saturation to water molecules. The strength of the CEST effect is reflected by detecting the decrease in the signal of water molecules (Figure 1). The loss of proton signal is significantly amplified by the chemical exchange process that occurs during the application of the saturation pulse, and therefore the CEST contrast is more sensitive than direct observation of these protons using magnetic resonance spectroscopy techniques. Compared with other magnetic resonance contrast mechanisms, such as T1, T2 and diffusion-weighted imaging, CEST can explore molecular targets containing exchangeable protons at a certain characteristic frequency and is very sensitive to the intrinsic metabolic substances and microenvironment of the organism. It is a unique molecular imaging method. Since chemical exchange is closely related to the physiological environment of biological tissues, CEST can be used to image many important physiological parameters such as intracellular and extracellular acid-base balance and metabolic characteristics, and is useful in detecting and evaluating metabolic disorders, tissue ischemia, etc. play a key role in disease.

However, when performing abdominal CEST imaging, human body movement (including breathing, involuntary movement, etc.) will introduce motion artifacts to the CEST image. Especially during abdominal scanning, respiratory movement will seriously destroy the consistency of the K-space acquisition data and affect the magnetic field. The quality of resonance image reconstruction causes errors in CEST signal quantification; in some scenarios, the fat signal is too strong, causing serious interference to CEST results.

Contents of the invention

This application mainly provides a magnetic resonance chemical exchange saturation transfer imaging method, system, equipment, and storage medium to solve the problem that traditional magnetic resonance imaging methods easily introduce motion artifacts, affect the reconstruction quality of magnetic resonance images, and interfere with CEST signal quantification by fat signals. question.

In order to solve the above technical problems, one technical solution adopted by this application is to provide a magnetic resonance chemical exchange saturation transfer imaging method. The magnetic resonance chemical exchange saturation transfer imaging method includes:

applying a radio frequency saturation pulse lasting a first preset time to the area to be detected;

Applying radio frequency echo pulses to the area to be detected, and collecting several gradient echo signals generated after activation of the radio frequency echo pulses;

Using a radial sampling method, the plurality of gradient echo signals are read along a preset direction to generate a magnetic resonance image.

According to an implementation provided by this application, the number of radial sampling spokes in the radial sampling method is 151, the first preset time is 50 ms, and the number of gradient echo beams in each radial sampling is 6.

According to an implementation provided by this application, the signal attenuation models of the plurality of gradient echo signals are:

Among them, S _n represents the echo signal strength at the echo time TE _n , n = 1, 2,..., N ≥ 3, N represents the number of echoes; ρ _ω represents the water signal strength; ρ _f represents the fat signal Intensity; P represents the number of peak components of fat, and the relative amplitude of each component is α _p , which satisfies

represents its corresponding chemical shift; f _B =γΔB is the local magnetization intensity; f _F,p represents the chemical shift of the p-th fat wave peak component relative to water.

According to an embodiment provided by this application, the magnetic resonance chemical exchange saturation transfer imaging method further includes:

Acquire several magnetic resonance images of several gradient echo signals;

Using a preset water-fat separation algorithm, divide the magnetic resonance water image and the magnetic resonance fat image from the plurality of magnetic resonance images;

The magnetic resonance water image is used for signal quantification, and concentration information is obtained based on the signal quantification results.

According to an embodiment provided by the present application, the preset water-fat separation algorithm is a self-checking field map estimation algorithm based on multi-resolution local growth.

According to an embodiment provided by the present application, before using the magnetic resonance water image for signal quantification, the magnetic resonance chemical exchange saturation transfer imaging method further includes:

In response to a user instruction, a region of interest corresponding to the user instruction is selected in the magnetic resonance water image.

According to an embodiment provided by this application, using the magnetic resonance water image to perform signal quantification includes:

Based on the magnetic resonance water image, obtain the Z spectrum of the pixels in the area of interest;

The Z spectrum was subjected to post-processing correction, symmetry analysis and multi-cell Lorentzian fitting.

In order to solve the above technical problems, another technical solution adopted by this application is to provide a magnetic resonance chemical exchange saturation transfer imaging system. The magnetic resonance chemical exchange saturation transfer imaging system includes: a pulse module, an echo module and an imaging module; in,

The pulse module is used to apply a radio frequency saturation pulse lasting a first preset time to the area to be detected;

The echo module is used to apply radio frequency echo pulses to the area to be detected, and collect several gradient echo signals generated after the radio frequency echo pulses are activated;

The imaging module is used to read the plurality of gradient echo signals along a preset direction using a radial sampling method to generate a magnetic resonance image.

In order to solve the above technical problems, another technical solution adopted by this application is to provide a magnetic resonance chemical exchange saturation transfer imaging device. The magnetic resonance chemical exchange saturation transfer imaging device includes a memory and a processor coupled to the memory. ;

Wherein, the memory is used to store program data, and the processor is used to execute the program data to implement the above magnetic resonance chemical exchange saturation transfer imaging method.

In order to solve the above technical problems, another technical solution adopted by this application is to provide a computer storage medium. The computer storage medium is used to store program data. When the program data is executed by the computer, it is used to implement the above Magnetic resonance chemical exchange saturation transfer imaging method.

The present application provides a magnetic resonance chemical exchange saturation transfer imaging method, system, equipment, and storage medium. The magnetic resonance chemical exchange saturation transfer imaging method includes: applying a radio frequency saturation pulse lasting a first preset time to the area to be detected; Apply a radio frequency echo pulse to the area to be detected, and collect a number of gradient echo signals generated after the activation of the radio frequency echo pulse; use a radial sampling method to read the number of gradient echo signals along a preset direction, to generate magnetic resonance images. Through the above method, this application effectively shortens the signal acquisition time through gradient echo readings, effectively suppresses motion artifacts through radial acquisition methods, and applies post-processing methods such as fitting to the collected chemical exchange saturation transfer imaging spectrum data. Separates water and fat signals, effectively suppresses fat signal interference, and extracts and analyzes target signals.

Description of the drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can also be obtained based on these drawings without exerting creative efforts, among which:

Figure 1 is a timing diagram of the mGRE-CEST magnetic resonance sequence provided by this application;

Figure 2 is a schematic flow chart of an embodiment of the magnetic resonance chemical exchange saturation transfer imaging method provided by the present application;

Figure 3 is a schematic diagram of sequential radial K-space sampling provided by this application;

Figure 4 is a schematic flow chart of another embodiment of the magnetic resonance chemical exchange saturation transfer imaging method provided by the present application;

Figure 5 is a schematic diagram of the Z spectrum comparison before and after water-fat separation provided by this application;

Figure 6 is a comparison chart between mGRE-CEST and FSE-CEST provided by this application;

Figure 7 is a schematic structural diagram of an embodiment of the magnetic resonance chemical exchange saturation transfer imaging system provided by the present application;

Figure 8 is a schematic structural diagram of an embodiment of the magnetic resonance chemical exchange saturation transfer imaging device provided by the present application;

Figure 9 is a schematic structural diagram of an embodiment of a computer storage medium provided by this application.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

It should be noted that if there are directional instructions (such as up, down, left, right, front, back...) in the embodiments of the present application, the directional instructions are only used to explain the position of a certain posture (as shown in the accompanying drawings). The relative positional relationship, movement conditions, etc. between the components under the display). If the specific posture changes, the directional indication will also change accordingly.

In addition, if there are descriptions involving “first”, “second”, etc. in the embodiments of this application, the descriptions of “first”, “second”, etc. are only for descriptive purposes and shall not be understood as indications or implications. Its relative importance or implicit indication of the number of technical features indicated. Therefore, features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In addition, the technical solutions in various embodiments can be combined with each other, but it must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that such a combination of technical solutions does not exist. , nor is it within the scope of protection required by this application.

CEST sequences generally include a saturation module and an acquisition module. Apply a saturation pulse for a certain period of time so that the solute molecules are fully saturated, and a chemical exchange occurs between the free water hydrogen protons and the solute hydrogen protons. Therefore, the saturation is transferred from the solute to the free water. After a period of accumulation, it causes the attenuation of the free water signal. . By detecting changes in water signals, information about the substance is indirectly reflected.

Human body motion will introduce motion artifacts into CEST images. Especially during abdominal scanning, respiratory motion will seriously destroy the consistency of K-space acquisition data, affect the quality of magnetic resonance image reconstruction, and cause quantitative errors in CEST signals.

Since the respiratory movement and fat deposition in the abdomen interfere with CEST magnetic resonance images, most of the existing technologies are suitable for scanning the brain and limbs, but not the abdomen. When images are acquired with FSE sequences, flow and motion artifacts increase. When collecting images of the liver, due to the uncontrollable breathing of the abdomen, motion artifacts will appear in the collected images, and motion artifacts will cause errors in CEST signal quantification. In addition, the FSE sequence will enhance the signal of fat tissue, and the presence of fat signal will overlap with the CEST signal on the Z spectrum, which is not conducive to the accurate quantification of the CEST signal.

In view of the shortcomings of the existing technology in abdominal scanning, this application designed a new CEST sequence (mGRE-CEST), as shown in Figure 1. This sequence retains the advantages of the radial acquisition method and effectively suppresses motion artifacts.

In this regard, this application provides a specific magnetic resonance chemical exchange saturation transfer imaging method. Please refer to Figure 2 for details. Figure 2 is a schematic flow chart of an embodiment of the magnetic resonance chemical exchange saturation transfer imaging method provided by the present application.

As shown in Figure 2, the magnetic resonance chemical exchange saturation transfer imaging method in the embodiment of the present application may specifically include the following steps:

Step S11: Apply a radio frequency saturation pulse lasting a first preset time to the area to be detected.

Step S12: Apply a radio frequency echo pulse to the area to be detected, and collect several gradient echo signals generated after the radio frequency echo pulse is activated.

In the embodiment of this application, the sequence diagram of the design sequence used is shown in Figure 1. In the design of the saturation module, a Gaussian saturation pulse is first applied with a duration of 50ms. After sufficient presaturation, continue to apply a 90° radio frequency pulse. After the radio frequency pulse is excited, several echoes will be generated, such as the six echoes shown in Figure 1. The signals of the several echoes decrease in sequence, and their signal attenuation model is as follows. The following formula is shown:

Among them, γ=42.576MHz/T is the gyromagnetic ratio of hydrogen protons.

In this step, a new CEST image acquisition sequence is designed. This sequence uses gradient echo (Gradient Echo, GRE) readings. This acquisition method does not require repeated application of excitation pulses. After one excitation pulse, multiple echoes can be collected, which is effective Reduce signal acquisition time.

Step S13: Use the radial sampling method to read several echo signals along a preset direction to generate a magnetic resonance image.

In this embodiment of the present application, the K-space sampling method adopted is sequential radial sampling, as shown in Figure 3 . In radial sampling, "spokes" continuously pass through the central area, causing the center of K-space data to be oversampled. Over-sampling the central area of K-space will lead to the averaging of artifacts, and the self-gating effect of radial acquisition will also Further enhances resistance to motion artifacts. If the signal data in the K-space center of the radially collected data changes, the redundancy of the signal can be used to correct the impact of motion on the collected data.

The number of radial sampling spokes designed in this application is 151, and the number of gradient echoes for each radial sampling is 6. Using this parameter can ensure image quality and shorten the sampling time. In other embodiments, other numbers of radial sampling spoke numbers and gradient echo numbers may be designed, which will not be described again here.

The K-space sampling method used in this step is sequential radial filling, which can effectively suppress motion artifacts. In other embodiments, other sequential radial sampling methods may be designed, which will not be described again here.

In the embodiment of the present application, the magnetic resonance chemical exchange saturation transfer imaging method includes: applying a radio frequency saturation pulse lasting a first preset time to the area to be detected; applying a radio frequency echo pulse to the area to be detected, and collecting the A number of echo signals generated after the radio frequency echo pulse is activated; using a radial sampling method, the number of echo signals are read along a preset direction to generate a magnetic resonance image. Through the above method, this application effectively shortens the signal acquisition time through gradient echo readings, and effectively suppresses motion artifacts through the sequential radial acquisition method.

Furthermore, there is a problem of fat deposition in the abdomen, and the overlap of the target CEST signal with the fat signal on the Z spectrum will also cause quantification errors. Therefore, this application adds a water-fat separation algorithm to the image preprocessing to eliminate the interference caused by fat signals on CEST signal quantification.

Please refer to FIG. 4 for details. FIG. 4 is a schematic flow chart of another embodiment of the magnetic resonance chemical exchange saturation transfer imaging method provided by the present application.

As shown in Figure 4, the magnetic resonance chemical exchange saturation transfer imaging method according to the embodiment of the present application may specifically include the following steps:

Step S14: Acquire several magnetic resonance images of several gradient echo signals.

Step S15: Use the preset water-fat separation algorithm to divide the magnetic resonance water image and the magnetic resonance fat image from several magnetic resonance images.

In the embodiment of this application, in order to effectively remove fat signals, this application uses a self-checking field map estimation algorithm based on multi-resolution local growth to achieve water-fat separation. This method can independently complete the selection and local growth of seed points, and uses a self-checking mechanism to merge field maps at different resolutions to ensure the positivity of the field map estimates of seed points. This method can effectively solve the problem of water-fat separation. The problem of water-lipid inversion caused by lipid ambiguity.

The self-checking field map estimation algorithm based on multi-resolution local growth is used to calculate the magnetic resonance image and the correct field map is obtained. Combined with the following formula, the magnetic resonance water image and magnetic resonance fat image are obtained:

Among them, S=[S ₁ , S ₂ ,…, S _N ] ^T , A= [A ₁ ; A ₂ ;…; A _N ],

I is an N×N matrix, W is the magnetic resonance water image, and F is the magnetic resonance fat image.

In other embodiments, other mature water-fat separation algorithms may also be used, which are not listed here.

In this step, the water-fat separation algorithm is used to preprocess the CEST image. The water-fat separation algorithm divides the CEST image into a water map and a fat map. This method can effectively remove fat signals in the image.

Step S16: Use the magnetic resonance water image to perform signal quantification, and obtain concentration information based on the signal quantification results.

In the embodiment of this application, for the collected magnetic resonance water image, the staff can select the area of interest on the magnetic resonance water image, thereby automatically generating the average Z spectrum of the pixels in the area of interest, where the Z spectrum needs to be B0 Offset correction and asymmetry analysis. The processed Z-spectrum shows a Lorentzian linear distribution.

In order to eliminate the DS effect (water saturation effect) and MT effect (magnetization transfer effect), it is necessary to perform multi-cell Lorentz fitting on the Z spectrum after the above preprocessing. The expression of the Lorentz function is as shown in the following formula:

Among them, S(Δω) is the marker frequency signal, which is a function relative to the water offset frequency (Δω), S ₀ is the signal strength without applying the saturation frequency, A _i , ω _i , σ _i respectively represent the i-th peak Amplitude, frequency offset, line width, N represents the number of fitting peaks.

When quantizing the signal, you need to set the amplitude of the CEST signal in the target to zero, and use the Lorentzian line type to fit each falling position in the Z spectrum.

In this step, the multi-cell Lorentz fitting method can effectively remove the direct water saturation effect (Direct Saturation, DS) and magnetization transfer effect (Magnetization Transfer, MT), and use this method to achieve quantification of the target signal.

In the phantom experiment, a phantom with a fat content of 20% was used. A single section with a thickness of 3 mm was selected, the readout resolution was 1 mm, and the saturation power (Saturation Power, B1-sat) was set to 0.2 μT. The number of acquisition spokes in K space is 151, the minimum value is selected for the TE mode, the flip angle (FA) = 35°, the number of echoes is 6, and the TR is 66.32 milliseconds. The frequency offset range is -5ppm to +5ppm, the step size is 0.2ppm, the number of scans is 51 (a total of 51 images), and the total scanning time of 51 images is 8.36 minutes. When scanning the S0 image, set B1-sat to 0, that is, no more proton saturation, and set the frequency offset range to -100ppm to -100ppm, and the number of scans is 3.

The results of the body simulation experiment are shown in Figure 5. Use the sequence proposed in this application to scan under a 3T magnetic resonance system to obtain a phantom CEST image, and make Z spectra before and after water-fat separation. After water-fat separation, the CEST effect of fat signal basically disappears on the Z spectrum. Therefore, this method can effectively deal with the problem of abdominal fat deposition and eliminate the impact of fat signal on CEST signal quantification.

In animal experiments, SD male rats aged 6-8 weeks were used. A single section with a thickness of 2.5 mm was selected, the readout resolution was 1 mm, and the saturation power (Saturation Power, B1-sat) was set to 0.1 μT. The number of acquisition spokes in K space is 151, the minimum value is selected for the TE mode, the flip angle (FA) = 35°, the number of echoes is 6, and the TR is 66.32 milliseconds. The frequency offset range is -4ppm to +4ppm, the step size is 0.2ppm, the number of scans is 41 (a total of 51 images), and the total scanning time of 41 images is 6.69 minutes. When scanning the S0 image, set B1-sat to 0, that is, no more proton saturation, and set the frequency offset range to -100ppm to -100ppm, and the number of scans is 3.

In animal experiments, the sequence designed in this application was used to collect CEST images of the animal's abdomen, and a region of interest (ROI) was selected to make its Z spectrum, and compared with the currently commonly used FSE sequence. As shown in Figure 6, the signal-to-noise ratio of two adjacent CEST images obtained by the traditional magnetic resonance imaging method suddenly changes. The sequence designed in this application can effectively suppress motion artifacts and obtain a stable Z spectrum. The results of animal experiments prove that the sequence designed in this application can effectively suppress motion artifacts.

Those skilled in the art can understand that in the above-mentioned methods of specific embodiments, the writing order of each step does not mean a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be based on its function and possible The internal logic is determined.

Please continue to refer to FIG. 7 , which is a schematic structural diagram of an embodiment of the magnetic resonance chemical exchange saturation transfer imaging system provided by the present application. The magnetic resonance chemical exchange saturation transfer imaging system 400 in the embodiment of the present application includes a pulse module 41 , an echo module 42 and an imaging module 43 .

Wherein, the pulse module 41 is used to apply a radio frequency saturation pulse lasting a first preset time to the area to be detected.

The echo module 42 is used to apply radio frequency echo pulses to the area to be detected, and collect several gradient echo signals generated after the radio frequency echo pulses are activated.

The imaging module 43 is used to read the plurality of gradient echo signals along a preset direction using a radial sampling method to generate a magnetic resonance image.

Please continue to refer to FIG. 8 , which is a schematic structural diagram of an embodiment of the magnetic resonance chemical exchange saturation transfer imaging device provided by the present application. The magnetic resonance chemical exchange saturation transfer imaging device 500 in the embodiment of the present application includes a processor 51, a memory 52, an input and output device 53, and a bus 54.

The processor 51, the memory 52, and the input and output device 53 are respectively connected to the bus 54. The memory 52 stores program data. The processor 51 is used to execute the program data to achieve the magnetic resonance chemical exchange saturation transfer imaging described in the above embodiment. method.

In the embodiment of this application, the processor 51 may also be called a CPU (Central Processing Unit). The processor 51 may be an integrated circuit chip with signal processing capabilities. The processor 51 can also be a general-purpose processor, a digital signal processor (DSP, Digital Signal Process), an application specific integrated circuit (ASIC, Application Specific Integrated Circuit), a field programmable gate array (FPGA, Field Programmable Gate Array) or other available Programmed logic devices, discrete gate or transistor logic devices, discrete hardware components. The general processor may be a microprocessor or the processor 51 may be any conventional processor or the like.

This application also provides a computer storage medium. Please continue to refer to Figure 9. Figure 9 is a schematic structural diagram of an embodiment of the computer storage medium provided by this application. The computer storage medium 600 stores program data 61. The program data 61 is in When executed by the processor, it is used to implement the magnetic resonance chemical exchange saturation transfer imaging method of the above embodiment.

When the embodiments of the present application are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or contributes to the existing technology, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium , including several instructions to cause a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor to execute all or part of the steps of the method described in each embodiment of the application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or optical disk and other media that can store program code. .

The above are only embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the description and drawings of the present application, or directly or indirectly applied to other related technologies fields are equally included in the scope of patent protection of this application.

Claims

A magnetic resonance chemical exchange saturation transfer imaging method, characterized in that the magnetic resonance chemical exchange saturation transfer imaging method includes:

applying a radio frequency saturation pulse lasting a first preset time to the area to be detected;

Applying radio frequency echo pulses to the area to be detected, and collecting several gradient echo signals generated after activation of the radio frequency echo pulses;

Using a radial sampling method, the plurality of gradient echo signals are read along a preset direction to generate a magnetic resonance image.
The magnetic resonance chemical exchange saturation transfer imaging method according to claim 1, characterized in that,

The number of radial sampling spokes in the radial sampling method is 151, the first preset time is 50 ms, and the number of gradient echoes for each radial sampling is 6.
The magnetic resonance chemical exchange saturation transfer imaging method according to claim 1, characterized in that,

The signal attenuation models of several gradient echo signals are:

Among them, S n represents the echo signal strength at the echo time TE n , n = 1, 2,..., N ≥ 3, N represents the number of echoes; ρ ω represents the water signal strength; ρ f represents the fat signal Intensity; P represents the number of peak components of fat, and the relative amplitude of each component is α p , which satisfies
represents its corresponding chemical shift; f B =γΔB is the local magnetization intensity; f F,p represents the chemical shift of the p-th fat wave peak component relative to water.
The magnetic resonance chemical exchange saturation transfer imaging method according to claim 1, characterized in that the magnetic resonance chemical exchange saturation transfer imaging method further includes:

Acquire several magnetic resonance images of several gradient echo signals;

Using a preset water-fat separation algorithm, divide the magnetic resonance water image and the magnetic resonance fat image from the plurality of magnetic resonance images;

The magnetic resonance water image is used for signal quantification, and concentration information is obtained based on the signal quantification results.
The magnetic resonance chemical exchange saturation transfer imaging method according to claim 4, wherein the preset water-fat separation algorithm is a self-checking field map estimation algorithm based on multi-resolution local growth.
The magnetic resonance chemical exchange saturation transfer imaging method according to claim 4, characterized in that before using the magnetic resonance water image to perform signal quantification, the magnetic resonance chemical exchange saturation transfer imaging method further includes:

In response to a user instruction, a region of interest corresponding to the user instruction is selected in the magnetic resonance water image.
The magnetic resonance chemical exchange saturation transfer imaging method according to claim 6, characterized in that,

The use of the magnetic resonance water image for signal quantification includes:

Based on the magnetic resonance water image, obtain the Z spectrum of the pixels in the area of interest;

The Z spectrum was subjected to post-processing correction, symmetry analysis and multi-cell Lorentzian fitting.
A magnetic resonance chemical exchange saturation transfer imaging system, characterized in that the magnetic resonance chemical exchange saturation transfer imaging system includes: a pulse module, an echo module and an imaging module; wherein,

The pulse module is used to apply a radio frequency saturation pulse lasting a first preset time to the area to be detected;

The echo module is used to apply radio frequency echo pulses to the area to be detected and collect several gradient echo signals generated after activation of the radio frequency echo pulses;

The imaging module is used to read the plurality of gradient echo signals along a preset direction using a radial sampling method to generate a magnetic resonance image.
A magnetic resonance chemical exchange saturation transfer imaging device, characterized in that the magnetic resonance chemical exchange saturation transfer imaging device includes a memory and a processor coupled to the memory;

Wherein, the memory is used to store program data, and the processor is used to execute the program data to implement the magnetic resonance chemical exchange saturation transfer imaging method according to any one of claims 1 to 7.
A computer storage medium, characterized in that the computer storage medium is used to store program data. When the program data is executed by a computer, the program data is used to implement the magnetic resonance chemical exchange according to any one of claims 1 to 7. Saturation transfer imaging method.