Magnetic resonance molecular imaging method and system for dynamically reading CEST signal accumulation

Abstract

The present invention discloses a magnetic resonance molecular imaging method and system for dynamically reading the accumulation of CEST signals. The method includes: applying N CEST saturation pulses for an object to be detected within each repetition time by a magnetic resonance imaging device; after each of the first N-1 CEST saturation pulses, a low-resolution, small-angle reading method is used to read the signal to obtain N-1 first-class signals; after the Nth CEST saturation pulse, a high-resolution, large-angle reading method is used to read the signal to obtain a second-class signal to compensate for the first-class signal, and N saturation-weighted magnetic resonance images of the object to be detected are obtained based on the compensated first and second-class signals. The method can improve the signal-to-noise ratio and robustness of CEST imaging, and can dynamically change according to the N readout signals, with better quantitativeness, such as reducing the influence of tissue longitudinal relaxation (T1) to obtain a proton exchange rate image.

Description

Technical Field

[0001] The present invention relates to the field of magnetic resonance imaging technology, and in particular to a magnetic resonance molecular imaging method and system for dynamically reading CEST signal accumulation. Background Art

[0002] Chemical Exchange Saturation Transfer (CEST) MRI (Magnetic Resonance Imaging) can detect proteins and peptides, sugars and lipids, and metabolic small molecules such as creatine phosphate and glutamate in tissues. It can also image exogenous molecular probes containing "exchangeable protons." Imaging can be performed directly on the MRI machine by adding pulse sequences, seamlessly integrating with existing MRI capabilities and possessing enormous potential for application.

[0003] CEST technology has drawbacks such as long acquisition times. CEST uses frequency-selective saturated radiofrequency pulses for specific labeling and signal amplification through proton exchange between solute molecules and water, achieving sensitivity over 1,000 times that of MRS (Magnetic Resonance Spectrum). However, CEST saturation pulses typically require more than 1 second to allow sufficient time for the exchangeable protons on the solute molecules to undergo hundreds or thousands of proton exchanges with water, transferring the signal to the water for amplification. Summary of the Invention

[0004] The present invention aims to at least partially address one of the technical problems in the related art. To this end, a first object of the present invention is to propose a specific high-resolution magnetic resonance molecular imaging method that dynamically reads accumulated CEST signals. This method improves the signal-to-noise ratio and robustness of CEST imaging. Furthermore, based on the dynamic changes of N readout signals, it can remove the T1 effect of water and obtain higher-resolution proton exchange rate images.

[0005] A second object of the present invention is to provide a computer-readable storage medium.

[0006] The third object of the present invention is to provide a specific high-resolution magnetic resonance molecular imaging system that dynamically reads CEST signal accumulation.

[0007] To achieve the above-mentioned objectives, an embodiment of the first aspect of the present invention proposes a specific high-resolution magnetic resonance molecular imaging method for dynamically reading CEST signal accumulation, comprising the following steps: applying N CEST saturation pulses for the object to be detected within each repetition time through a magnetic resonance imaging device; after each CEST saturation pulse in the first N-1 CEST saturation pulses, using a low-resolution, small-angle reading method to read the signal, and obtaining N-1 first-type signals; after the Nth CEST saturation pulse, using a high-resolution, large-angle reading method to read the signal at the same time, and obtaining a second-type signal; using the second-type signal to compensate for the N-1 first-type signals, and obtaining N saturation-weighted magnetic resonance images of the object to be detected based on the compensated first-type signals and the second-type signals.

[0008] To achieve the above objectives, the second embodiment of the present invention proposes a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the above-mentioned specific high-resolution magnetic resonance molecular imaging method of dynamically reading CEST signal accumulation is implemented.

[0009] To achieve the above-mentioned objectives, an embodiment of the third aspect of the present invention proposes a specific high-resolution magnetic resonance molecular imaging system for dynamically reading CEST signal accumulation, comprising: an application module for applying N CEST saturation pulses for the object to be detected within each repetition time through a magnetic resonance imaging device; a reading module for reading the signal using a low-resolution, small-angle reading method after each CEST saturation pulse in the first N-1 CEST saturation pulses to obtain N-1 first-type signals; and after the Nth CEST saturation pulse, reading the signal using a high-resolution, large-angle reading method to obtain a second-type signal; a compensation module for compensating the N-1 first-type signals using the second-type signal, and obtaining N saturation-weighted magnetic resonance images of the object to be detected based on the compensated first-type signal and the second-type signal.

[0010] The magnetic resonance molecular imaging method and system for dynamically reading CEST signal accumulation according to the embodiments of the present invention utilizes a magnetic resonance imaging device to apply N CEST saturation pulses to the object to be detected within each repetition time. Based on the first N-1 CEST saturation pulses, N-1 first-class signals are obtained. This reduces acquisition time by dividing the CEST saturation time into N parts. Furthermore, the dynamic changes and accumulation of CEST signals can be efficiently captured. The signal accumulation curve characteristics can help quantify proton exchange rates, specifically detect microenvironmental pH changes, and distinguish different molecules. Furthermore, a second-class signal is obtained based on the Nth CEST saturation pulse, and this second-class signal is used to compensate for the first-class signal, thereby overcoming the shortcomings of the first-class signal, such as low image signal-to-noise ratio, low spatial resolution, and the inherent distortion and artifacts inherent in EPI.

[0011] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a flow chart of a specific high-resolution magnetic resonance molecular imaging method for dynamically reading CEST signal accumulation according to one embodiment of the present invention;

[0013] Figure 2 This is a flowchart of a specific high-resolution magnetic resonance molecular imaging method for dynamically reading CEST signal accumulation according to one embodiment of the present invention;

[0014] 3(a), (b), (c), and (d) are schematic diagrams showing the results of a specific high-resolution magnetic resonance molecular imaging method for dynamically reading CEST signal accumulation according to an example of the present invention;

[0015] Figure 4 This is a workflow diagram of a specific high-resolution magnetic resonance molecular imaging method for dynamically reading CEST signal accumulation according to another embodiment of the present invention;

[0016] Figure 5 This is a working schematic diagram of a specific high-resolution magnetic resonance molecular imaging method for dynamically reading CEST signal accumulation according to an example of the present invention;

[0017] Figure 6 This is a structural block diagram of a specific high-resolution magnetic resonance molecular imaging system for dynamically reading CEST signal accumulation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0018] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0019] The following describes a magnetic resonance molecular imaging method and system for dynamically reading CEST signal accumulation according to an embodiment of the present invention with reference to the accompanying drawings.

[0020] Figure 1 The flowchart of a specific high-resolution magnetic resonance molecular imaging method for dynamically reading CEST signal accumulation according to an embodiment of the present invention.

[0021] like Figure 1 As shown, the specific high-resolution magnetic resonance molecular imaging method for dynamically reading CEST signal accumulation includes the following steps:

[0022] S11 , applying N CEST saturation pulses to the object to be detected within each repetition time through a magnetic resonance imaging device.

[0023] Specifically, see Figure 2 Each repetition time is divided into N saturation read times and one delay time, with the N saturation read times corresponding to the N modules. Within each module is a CEST saturation module, within which a CEST saturation pulse is applied. This CEST saturation pulse targets the target object, such as a molecule to be detected. Within each of the N modules are read modules, each read module being positioned after the corresponding saturation module. The first N-1 modules are identical, and the read module in the Nth module is distinct from the read modules in the previous N-1 modules.

[0024] The value of N may be 5 to 8. The duration of the CEST saturation pulse may be greater than 100 ms. The CEST saturation pulse occurs at the resonance frequency of the exchangeable protons of the object to be detected.

[0025] S12, after each of the first N-1 CEST saturation pulses, read the signal using a low-resolution, small-angle reading method to obtain N-1 first-category signals.

[0026] Specifically, see Figure 2In the reader module, an excitation pulse with a flip angle of a is applied. This excitation pulse is an RF (Radio Frequency) pulse, and the flip angle a is a small flip angle. After the RF pulse is stopped, the magnetic resonance signal generated by the proton relaxation process is received. Then, a flip pulse with a flip angle of -a is applied to maintain the longitudinal magnetization, as shown in Figure 3(a). This allows magnetic resonance signal readout to be performed within each reader module.

[0027] Furthermore, a first type of signal is obtained based on the magnetic resonance signal, and a low-resolution image is obtained based on the first type of signal using an EPI (Echo Planar Imaging) method. Of course, other preset reconstruction algorithms, such as the reconstruction algorithm provided by the MR scanner, can also be used to obtain a low-resolution image.

[0028] The low-resolution, small-angle reading method is a combination of small-angle gradient echo and K-space downsampling. The duration of each of the first N-1 signal readings is less than 50 ms. The reading method for each of the first N-1 signal readings may vary, such as by different K-space line values.

[0029] It should be noted that the above signal reading occurs at the water frequency. The time and intensity of each CEST saturation module can also be changed to simultaneously detect objects with different exchange rates and chemical shifts.

[0030] Thus, N-1 small-angle echoplanar reads are used to rapidly read N-1 first-class signals. This allows for high-throughput rapid reading. Because the CEST signal has reached or nearly reached steady state in the last few readout modules, multiple signals can be rapidly read within the same repetition time, and signal superposition improves robustness to noise and motion. Furthermore, the dynamic changes and accumulation of CEST signals can be efficiently captured. The signal accumulation curve characteristics can help quantify proton exchange rates, specifically detecting microenvironmental pH changes and distinguishing different molecules. Furthermore, using the same EPI method with a small flip angle and short readout time minimizes interference with saturation labeling and CEST signals.

[0031] S13, after the Nth CEST saturation pulse, a high-resolution, large-angle reading method is used to read the signal to obtain a second type of signal.

[0032] Specifically, see Figure 2In the Nth readout module, or high-resolution readout module, after applying the excitation pulse, a high-resolution, wide-angle readout method is used to obtain the second type of signal. The high-resolution, wide-angle readout method mentioned above can be any of 2D-TSE, Multislice-TSE, 3D-TSE, GRE, GRASE, or TFE. For example, if TES is used, the result is shown in Figure 3(b); if GRASE is used, the result is shown in Figure 3(c); and if TFE is used, the result is shown in Figure 3(d).

[0033] Furthermore, after obtaining the second type of signal, the second type of signal is converted into an image using a preset reconstruction algorithm, such as a reconstruction algorithm provided by the MR scanner, to obtain a high-resolution image.

[0034] It should be noted that the above signal reading occurs at the water frequency.

[0035] Therefore, a high-resolution, large-angle reading method can be used after the Nth CEST saturation pulse. For example, the angle and duration limits can be eliminated to obtain the second type of signal with better detail structure in the image domain.

[0036] S14 , compensating N−1 first-category signals by using the second-category signals, and obtaining N saturation-weighted magnetic resonance images of the object to be detected based on the compensated first-category signals and the second-category signals.

[0037] Specifically, the high-frequency portion of the first-type signal domain is derived from the curve relationship between the high-frequency portion (detailed structure) in the second-type signal domain and the low-frequency portion in the first-type signal domain, where n is an integer from 1 to N. This allows for compensation of the high-frequency portion of the first-type signal domain. After compensation is complete, N high-spatial-resolution saturation-weighted magnetic resonance images of the subject can be obtained based on the compensated first- and second-type signals.

[0038] Among them, the above compensation can be the migration of the high-frequency part in the second type signal image domain to the high-frequency part in the first type signal image domain. The migration can be mainly based on the high-frequency part in the second type signal image domain and the curve relationship of the low-frequency part signal in the first type signal image domain changing with n (where n is an integer from 1 to N). Through image interpolation, or based on the learning model, the mapping of the first type signal from low frequency to high frequency is established to obtain N-1 high-frequency parts in the first type signal image domain. The migration process can be seen in Figure 5 As shown, the signals recovered from each first-class signal are obtained by migration, and are combined with the first-class signal to obtain the migrated first-class image. Figure 5The first type of signal and the second type of signal before and after migration are shown only for ease of understanding.

[0039] In this way, the shortcomings of the N-1 low-resolution images, such as low image signal-to-noise ratio, low spatial resolution, and the inherent deformation and artifacts of EPI, can be overcome.

[0040] Further, see Figure 2 A delay time is set after the Nth module to wait for the longitudinal magnetization vector to reach the equilibrium state. After the longitudinal magnetization vector reaches the equilibrium state, the image acquisition process is completed, the current scan ends, and then the next saturation frequency can be scanned.

[0041] In one embodiment of the present invention, the specific high-resolution magnetic resonance molecular imaging method for dynamically reading the accumulated CEST signal further includes: applying a water saturation pulse for water before applying the first CEST saturation pulse in each repetition time by the magnetic resonance imaging device. Figure 4 As shown, the starting point of each saturation frequency magnetic resonance signal reading can be approximately zero, avoiding the mutual influence of signals between adjacent repetition times, thereby shortening the delay time and allowing the longitudinal magnetization vector to reach an equilibrium state within a shorter delay time.

[0042] Among them, see Figure 4 , the duration of the CEST saturation pulse is greater than 50ms, and the duration of each signal reading in the first N-1 signal readings is less than 20ms.

[0043] Thus, the acquisition time of CEST can be reduced.

[0044] In summary, the specific high-resolution magnetic resonance molecular imaging method for dynamic reading of CEST signal accumulation in the embodiments of the present invention uses a magnetic resonance imaging device to apply N CEST saturation pulses targeted to the object to be detected within each repetition time. Based on the first N-1 CEST saturation pulses, N-1 low-resolution images are obtained. This method, by dividing the CEST saturation time into N parts, reduces acquisition time and improves robustness to noise and motion through high-throughput rapid reading. Furthermore, the dynamic changes and accumulation of the CEST signal can be efficiently captured. The signal accumulation curve characteristics can help quantify proton exchange rates, specifically detect microenvironmental pH changes, and distinguish different molecules. Furthermore, using the same EPI method with a small flip angle and short read time minimizes interference with the saturation labeling process and the CEST signal. Furthermore, a high-resolution image is obtained based on the Nth CEST saturation pulse, and the high-frequency portion of this high-resolution image is transferred to the high-frequency portion of the low-resolution image, thereby overcoming the shortcomings of the N-1 low-resolution images, such as low signal-to-noise ratio, low spatial resolution, and the inherent distortion and artifacts of EPI.

[0045] Furthermore, the present invention provides a computer-readable storage medium.

[0046] In an embodiment of the present invention, a computer program is stored on a computer-readable storage medium. When the computer program is executed by a processor, the above-mentioned specific high-resolution magnetic resonance molecular imaging method of dynamically reading CEST signal accumulation is implemented.

[0047] A computer-readable storage medium according to an embodiment of the present invention, when executed by a processor, applies N CEST saturation pulses to the subject within each repetition time through a magnetic resonance imaging device. This results in N-1 low-resolution images generated based on the first N-1 CEST saturation pulses. This reduces acquisition time by dividing the CEST saturation time into N parts, and improves robustness to noise and motion through high-throughput rapid readout. Furthermore, the dynamic changes and accumulation of the CEST signal can be efficiently captured. The signal accumulation curve characteristics facilitate quantification of proton exchange rates, specifically detecting microenvironmental pH changes, and distinguishing between different molecules. Furthermore, the use of an identical EPI method with a small flip angle and short readout time minimizes interference with the saturation labeling process and the CEST signal. Furthermore, a high-resolution image is generated based on the Nth CEST saturation pulse, and the high-frequency portion of this high-resolution image is transferred to the high-frequency portion of the low-resolution image. This overcomes the shortcomings of the N-1 low-resolution images, such as low signal-to-noise ratio, low spatial resolution, and the inherent distortion and artifacts inherent in EPI.

[0048] Figure 6 This is a structural block diagram of a specific high-resolution magnetic resonance molecular imaging system for dynamically reading CEST signal accumulation according to an embodiment of the present invention.

[0049] like Figure 6 As shown, the specific high-resolution magnetic resonance molecular imaging system 100 for dynamically reading CEST signal accumulation includes: an application module 101 , a reading module 102 , and a compensation module 103 .

[0050] Specifically, the application module 101 is used to apply N CEST saturation pulses to the object to be detected within each repetition time through the magnetic resonance imaging device; the reading module 102 is used to read the signal using a low-resolution, small-angle reading method after each CEST saturation pulse in the first N-1 CEST saturation pulses to obtain N-1 first-type signals; and after the Nth CEST saturation pulse, the signal is read using a high-resolution, large-angle reading method to obtain a second-type signal; the compensation module 103 is used to compensate the N-1 first-type signals using the second-type signal, and obtain N saturation-weighted magnetic resonance images of the object to be detected based on the compensated first-type and second-type signals.

[0051] The applying module 101 is further configured to apply a water saturation pulse for water before applying the first CEST saturation pulse in each repetition time through the magnetic resonance imaging device.

[0052] Specifically, first, N CEST saturation pulses are applied to the object to be detected within each repetition time by a magnetic resonance imaging device.

[0053] Specifically, each repetition time is divided into N saturation read times and one delay time, with the N saturation read times corresponding to N modules. A CEST saturation module is provided within each module, and a CEST saturation pulse is applied within each CEST saturation module. This CEST saturation pulse is targeted at the target to be detected, such as a molecule to be detected. Read modules are provided within the first N-1 modules, with each read module being provided after the corresponding saturation module. The first N-1 modules are identical, and the read module in the Nth module is distinct from the read modules in the previous N-1 modules.

[0054] The value of N may be 5 to 8. The duration of the CEST saturation pulse may be greater than 100 ms. The CEST saturation pulse occurs at the resonance frequency of the exchangeable protons of the object to be detected.

[0055] Furthermore, after each of the first N-1 CEST saturation pulses, a low-resolution, small-angle reading method is used to perform signal reading to obtain N-1 first-category signals.

[0056] Specifically, an excitation pulse with a flip angle of a (a), a small flip angle, is applied to the reader module. After terminating the RF pulse, the magnetic resonance signal generated by the protons during relaxation is received. A flip pulse with a flip angle of -a is then applied to maintain the longitudinal magnetization. This allows for magnetic resonance signal readout within each reader module.

[0057] Furthermore, a first type of signal is obtained according to the magnetic resonance signal, and then an EPI (Echo Planar Imaging) method is used to obtain a low-resolution image according to the first type of signal. Of course, other preset reconstruction algorithms can also be used to obtain a low-resolution image.

[0058] The low-resolution, small-angle reading method is a small-angle gradient echo combined with K-space downsampling. The duration of each signal reading in the first N-1 signal readings is less than 50 ms.

[0059] It should be noted that the above signal reading occurs at the water frequency.

[0060] Thus, by rapidly reading N-1 first-class signals through N-1 small-angle echoplanar readouts, high-throughput and rapid readout is achieved, improving robustness to noise and motion. Furthermore, the dynamic changes and accumulation of CEST signals can be efficiently captured. The signal accumulation curve characteristics can help quantify proton exchange rates, specifically detecting microenvironmental pH changes and distinguishing different molecules. Furthermore, using the same EPI method with a small flip angle and short readout time minimizes interference with saturation labeling and CEST signals.

[0061] Furthermore, after the Nth CEST saturation pulse, a high-resolution, large-angle reading method is used to read the signal at that time to obtain a second type of signal.

[0062] Specifically, in the Nth reading module, i.e., the high-resolution reading module, after applying the excitation pulse, a high-resolution, large-angle reading method is used to obtain the second type of signal. The above-mentioned high-resolution, large-angle reading method is: any one of 2D-TSE, Multislice-TSE, 3D-TSE, GRE, GRASE, or TFE reading can also be used.

[0063] Furthermore, after obtaining the second type of signal, the second type of signal is converted into an image using a reconstruction algorithm to obtain a high-resolution image.

[0064] It should be noted that the above signal reading occurs at the water frequency.

[0065] Therefore, a high-resolution, large-angle reading method can be adopted after the Nth CEST saturation pulse, for example, the angle and duration limits can be cancelled, so as to obtain the second information with better structural information.

[0066] Furthermore, the second type of signal is used to compensate N-1 first type of signals, and N saturation weighted magnetic resonance images of the detection object are obtained based on the compensated first type of signals and second type of signals.

[0067] Specifically, since the second type of signal has better detail structure information than the first type of signal, that is, the high-frequency part in the image domain, the high-frequency part in the image domain of the second type of signal is migrated and applied to the high-frequency part in the image domain of the first type of signal, that is, the detail structure information of the second type of signal is used to compensate for each first type of signal, so that the first type of signal has better detail structure information.

[0068] Among them, the above compensation can be the migration of the high-frequency part in the second type signal image domain to the high-frequency part in the first type signal image domain. The migration can be mainly based on the high-frequency part in the second type signal image domain and the curve relationship of the low-frequency part signal in the first type signal image domain changing with n (where n is an integer from 1 to N). Through image interpolation, or based on the learning model, the mapping of the first type signal from low frequency to high frequency is established to obtain N-1 high-frequency parts in the first type signal image domain. The migration process can be seen in Figure 5 As shown, the signals recovered from each first-class signal are obtained by migration, and are combined with the first-class signal to obtain the migrated first-class image. Figure 5 The first type of signal and the second type of signal before and after migration are shown only for ease of understanding.

[0069] In this way, the shortcomings of the N-1 low-resolution images, such as low image signal-to-noise ratio, low spatial resolution, and the inherent deformation and artifacts of EPI, can be overcome.

[0070] Furthermore, a delay time is set after the Nth module to wait for the longitudinal magnetization vector to reach an equilibrium state. After the longitudinal magnetization vector reaches an equilibrium state, the image acquisition process is completed, the current scan ends, and the next saturation frequency can be scanned.

[0071] Optionally, a water saturation pulse can be applied to the water by the MRI device before the first CEST saturation pulse is applied within each repetition time. This ensures that the starting point of the magnetic resonance signal read at each saturation frequency is approximately zero, preventing signal interaction between adjacent repetition times. This shortens the delay time and allows the longitudinal magnetization vector to reach equilibrium within a relatively short delay time.

[0072] At this time, the duration of the CEST saturation pulse is greater than 50 ms, and the duration of each signal reading in the first N-1 signal readings is less than 20 ms.

[0073] It should be noted that for other specific implementations of the specific high-resolution magnetic resonance molecular imaging system 101 for dynamically reading CEST signal accumulation according to an embodiment of the present invention, reference may be made to the above-mentioned specific high-resolution magnetic resonance molecular imaging method for dynamically reading CEST signal accumulation.

[0074] The specific high-resolution magnetic resonance molecular imaging system with dynamic reading of CEST signal accumulation according to the present invention uses a magnetic resonance imaging device to apply N CEST saturation pulses to the target object within each repetition time. Based on the first N-1 CEST saturation pulses, N-1 low-resolution images are obtained. This reduces acquisition time by dividing the CEST saturation time into N parts, and improves robustness to noise and motion through high-throughput rapid reading. Furthermore, the dynamic changes and accumulation of the CEST signal can be efficiently captured. The signal accumulation curve characteristics can help quantify proton exchange rates, specifically detect microenvironmental pH changes, and distinguish different molecules. Furthermore, the use of the same EPI method with a small flip angle and short read time minimizes interference with the saturation labeling process and the CEST signal. Furthermore, a high-resolution image is obtained based on the Nth CEST saturation pulse, and the high-frequency portion of this high-resolution image is transferred to the high-frequency portion of the low-resolution image, thereby overcoming the shortcomings of the N-1 low-resolution images, such as low signal-to-noise ratio, low spatial resolution, and the inherent distortion and artifacts of EPI.

[0075] It should be noted that the logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device), or in conjunction with such instruction execution system, apparatus, or device. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transmit a program for use by an instruction execution system, apparatus, or device, or in conjunction with such instruction execution system, apparatus, or device. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection portion having one or more wires (electronic device), a portable computer disk cartridge (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and programmable read-only memory (EPROM or flash memory), fiber optic devices, and portable compact disc read-only memory (CDROM). Furthermore, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing it in another suitable manner if necessary, and then storing it in a computer memory.

[0076] It should be understood that various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above-described embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0077] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0078] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0079] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0080] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0081] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0082] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A specific high-resolution magnetic resonance molecular imaging method for dynamically reading CEST signal accumulation, characterized in that: The following steps are involved: Applying N CEST saturation pulses to the object to be detected within each repetition time by a magnetic resonance imaging device; After each of the first N-1 CEST saturation pulses, a low-resolution, small-angle reading method is used to read the signal, obtaining N-1 first-category signals; After the Nth CEST saturation pulse, a high-resolution, large-angle reading method is used to read the signal and obtain the second type of signal; Compensating the N-1 first-category signals by using the second-category signals, and obtaining N saturation-weighted magnetic resonance images of the object to be detected based on the compensated first-category signals and the second-category signals; The low-resolution, small-angle reading method is: a small-angle gradient echo combined with K-space downsampling; The high-resolution, large-angle reading method is any one of 2D-TSE, Multislice-TSE, 3D-TSE, GRE, GRASE, and TFE; The method of compensating the N-1 first-type signals by using the second-type signals comprises the following steps: n The dynamic curve relationship is used to obtain the high-frequency part of the first type of signal image domain, where n 1 to N An integer.

2. The specific high-resolution magnetic resonance molecular imaging method for dynamically reading CEST signal accumulation according to claim 1, characterized in that: The CEST saturation pulse occurs at the resonance frequency of exchangeable protons of the object to be detected, and the signal reading occurs at the water frequency.

3. The specific high-resolution magnetic resonance molecular imaging method for dynamically reading CEST signal accumulation according to any one of claims 1 to 2, characterized in that: The duration of the CEST saturation pulse is greater than 100 ms, and the duration of each signal reading in the first N-1 signal readings is less than 50 ms.

4. The specific high-resolution magnetic resonance molecular imaging method for dynamically reading CEST signal accumulation according to any one of claims 1 to 2, characterized in that: The method further comprises: A water saturation pulse for water is applied by the magnetic resonance imaging apparatus before the first CEST saturation pulse is applied within each repetition time.

5. The specific high-resolution magnetic resonance molecular imaging method for dynamically reading CEST signal accumulation according to claim 4, characterized in that: The duration of the CEST saturation pulse is greater than 50 ms, and the duration of each signal reading in the first N-1 signal readings is less than 20 ms.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the specific high-resolution magnetic resonance molecular imaging method for dynamically reading CEST signal accumulation according to any one of claims 1 to 5 is implemented.

7. A specific high-resolution magnetic resonance molecular imaging system for dynamically reading CEST signal accumulation, characterized in that: include: An applying module, configured to apply N CEST saturation pulses to the object to be detected within each repetition time through a magnetic resonance imaging device; a reading module configured to read the signal using a low-resolution, small-angle reading method after each of the first N-1 CEST saturation pulses to obtain N-1 first-type signals; and to read the signal using a high-resolution, large-angle reading method after the Nth CEST saturation pulse to obtain a second-type signal; a compensation module, configured to compensate the N-1 first-category signals using the second-category signals, and obtain N saturation-weighted magnetic resonance images of the object to be detected based on the compensated first-category signals and the second-category signals; The low-resolution, small-angle reading method is: a small-angle gradient echo combined with K-space downsampling; The high-resolution, large-angle reading method is any one of 2D-TSE, Multislice-TSE, 3D-TSE, GRE, GRASE, and TFE; The method of compensating the N-1 first-type signals by using the second-type signals comprises the following steps: n The dynamic curve relationship is used to obtain the high-frequency part of the first type of signal image domain, where n 1 to N An integer.

8. The specific high-resolution magnetic resonance molecular imaging system for dynamically reading CEST signal accumulation according to claim 7, characterized in that: The applying module is further configured to: A water saturation pulse for water is applied by the magnetic resonance imaging apparatus before the first CEST saturation pulse is applied within each repetition time.

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