Spoke image correction method and system based on constant gradient CPMG sequence

Abstract

The invention belongs to the technical field of magnetic resonance signal processing, and aims to provide a spoke image correction method and system based on a constant gradient CPMG sequence. The method comprises the following steps: scanning a specified standard motif by adopting a constant gradient CPMG sequence, and obtaining a frequency-amplitude correction curve according to a scanning result; acquiring a frequency range of a specified standard motif, and fitting the correction curve according to the frequency range to obtain a fitted frequency-amplitude correction curve; a constant gradient CPMG sequence is adopted to scan a to-be-detected sample, and spoke images of the to-be-detected sample at multiple echo moments are obtained; and adopting the fitted frequency-amplitude correction curve to correct the spoke images of the sample to be measured at the plurality of echo moments to obtain the corrected spoke images of the sample to be measured at the plurality of echo moments. The spoke image of the to-be-tested sample can be corrected, and the analysis accuracy of the to-be-tested sample can be improved.

Description

Technical Field

[0001] This invention belongs to the field of magnetic resonance signal processing technology, specifically relating to a spoke image correction method and system based on a constant gradient CPMG sequence. Background Technology

[0002] Magnetic resonance imaging (MRI) is a diagnostic technique that utilizes the nuclear magnetic resonance phenomenon of certain atomic nuclei in a sample (such as human tissue) to reconstruct an image of a certain layer of the human body by processing the obtained magnetic resonance signal through a computer.

[0003] By using a constant gradient CPMG (Carr-Purcell-Meiboom-Gill) sequence (a pulse sequence executed with a constant gradient), the effects of factors such as gradient delay and eddy currents can be reduced during the encoding process. By controlling the direction of the constant gradient, 1D, 2D, or 3D (i.e., 1D-CPMG_Spoke, 2D-CPMG_Radial, or 3D-CPMG_Radial) encoded imaging of the sample can be achieved. Furthermore, the transverse magnetization vector attenuation curve at the corresponding spatial location can be obtained, which is helpful for further T2 inversion operations and sample property analysis at different locations of the sample. For example, imaging using a constant gradient CPMG sequence can be achieved by combining gradients on three axes to realize imaging projection in a specific gradient direction, or by controlling the gradient amplitude to remain consistent within a specific plane or spatial range while continuously rotating the gradient direction, thereby achieving two-dimensional radial (2D-Radial) imaging or three-dimensional radial (3D-Radial) imaging at each echo time.

[0004] However, in using the prior art, the inventors discovered at least the following problems: During CPMG sequence execution, a constant gradient is applied synchronously for slice selection and signal readout. However, due to limitations such as coil bandwidth, RF power amplifier frequency response, RF pulse slice selection profile, and front-end amplifier frequency response, the slice selection profile (the specific imaging layer selected during imaging) is not an ideal rectangle. This results in frequency-dependent signal weighting of proton spin signals acquired at different frequencies. This frequency-dependent signal weighting distorts the signal distribution of the spoke image obtained after Fourier transforming the original k-space data (derived from echo signals collected at different spatial locations), thus affecting the qualitative and quantitative analysis of the components at different locations of the sample under test.

[0005] As an example, Figure 1 (a) shows a schematic diagram of a uniformly distributed spherical substance under ideal conditions. Figure 2(a) and (b) show schematic diagrams of the true signal distribution and the uncorrected image signal distribution during constant gradient CPMG two-dimensional imaging, where, Figure 1 (a) is a schematic diagram of an ideal uniform model. Figure 2 (a) is Figure 1 (a) shows the cross-sectional signal distribution diagram of the 101st row and 101st column, which is displayed as an ideal rectangle; Figure 1 (b) is for Figure 1 (a) A schematic diagram of sample images obtained using the corresponding acquisition method. Figure 2 (b) is Figure 1 (b) A schematic diagram of the cross-sectional signal distribution in row 101 and column 101, for Figure 2 A comparison of the profile signal distribution diagrams in (a) and (b) shows that the uncorrected profile differs significantly from the actual rectangular profile. Summary of the Invention

[0006] The present invention aims to solve the above-mentioned technical problems to at least some extent. The present invention provides a spoke image correction method and system based on constant gradient CPMG sequence.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a spoke image correction method based on a constant gradient CPMG sequence, comprising: A constant gradient CPMG sequence was used to scan a specified standard phantom, and the frequency-amplitude correction curve was obtained based on the scanning results. Obtain the frequency range of the specified standard phantom, and fit the correction curve according to the frequency range to obtain the fitted frequency-amplitude correction curve; The constant gradient CPMG sequence is used to scan the sample under test to obtain echo signals at multiple echo times of the sample under test. Then, the echo signals at each echo time are subjected to inverse Fourier transform processing and modulus value processing to obtain spoke images of the sample under test at multiple echo times. The fitted frequency-amplitude correction curve is used to correct the spoke images of the sample under test at multiple echo times, thereby obtaining the corrected spoke images of the sample under test at multiple echo times.

[0008] In one possible design, the signal distribution of the designated standard phantom is symmetrical and uniform along the gradient direction of the constant gradient CPMG sequence; correspondingly, when the imaging sequence type of the constant gradient CPMG sequence is 3D, the designated standard phantom is a spherical phantom; when the imaging sequence type of the constant gradient CPMG sequence is 2D, the designated standard phantom is a spherical phantom or a cylindrical sheet phantom; when the imaging sequence type of the constant gradient CPMG sequence is 1D, the designated standard phantom is a spherical phantom, a cylindrical sheet phantom, or a slender cuboid phantom.

[0009] In one possible design, a constant gradient CPMG sequence is used to scan a specified standard phantom, and the frequency-amplitude correction curve is obtained based on the scanning results, including: The specified standard phantom is scanned using a constant gradient CPMG sequence to obtain echo signals at multiple echo times of the specified standard phantom. The echo signals at multiple echo times of the specified standard model are subjected to inverse Fourier transform and modulus value processing respectively to obtain the spoke images of the specified standard model at multiple echo times. Based on the frequency information of the spoke images at multiple echo times of the specified standard phantom, and the signal intensity at different positions of the spoke images at corresponding echo times of the specified standard phantom, a frequency-amplitude correction curve is obtained.

[0010] In one possible design, the constant gradient CPMG sequence is a constant gradient CPMG sequence with an echo time shorter than a preset time and with an inversion pulse or a saturation pulse.

[0011] In one possible design, the designated standard phantom and the sample to be tested are made of the same substance.

[0012] In one possible design, the fitted frequency-amplitude correction curve is used to correct the spoke images of the sample under test at multiple echo times, resulting in corrected spoke images of the sample under test at multiple echo times, including: Divide the spoke images of the sample under test at multiple echo times by the fitted frequency-amplitude correction curve to obtain the corrected spoke images of the sample under test at multiple echo times.

[0013] In one possible design, after obtaining corrected spoke images of the sample under test at multiple echo times, the method further includes: The corrected spoke images of the sample under test at multiple echo times are subjected to inverse Lardon transform processing to obtain sample images of the sample under test at multiple echo times. The material distribution of the sample is analyzed based on sample images at multiple echo times.

[0014] Secondly, the present invention provides a spoke image correction system based on a constant gradient CPMG sequence, used to implement the spoke image correction method based on a constant gradient CPMG sequence as described in any one of the above claims; the spoke image correction system based on a constant gradient CPMG sequence includes: The calibration curve acquisition module scans a specified standard phantom using a constant gradient CPMG sequence and obtains a frequency-amplitude calibration curve based on the scanning results; it is also used to acquire the frequency range of the specified standard phantom and fit the calibration curve based on the frequency range to obtain a fitted frequency-amplitude calibration curve. The spoke image acquisition module is used to scan the sample under test using the constant gradient CPMG sequence to obtain echo signals at multiple echo times of the sample under test, and then perform inverse Fourier transform processing and modulus value processing on the echo signals at each echo time to obtain spoke images at multiple echo times of the sample under test. The spoke image correction module is communicatively connected to both the correction curve acquisition module and the spoke image acquisition module. It is used to correct the spoke images of the sample under test at multiple echo times using the fitted frequency-amplitude correction curve, thereby obtaining corrected spoke images of the sample under test at multiple echo times.

[0015] Thirdly, the present invention provides an electronic device, comprising: Memory, used to store computer program instructions; and, A processor is configured to execute the computer program instructions to perform the operation of the spoke image correction method based on a constant gradient CPMG sequence as described in any of the preceding embodiments.

[0016] Fourthly, the present invention provides a computer program product, including a computer program or instructions, wherein the computer program or instructions, when executed by a computer, implement the spoke image correction method based on a constant gradient CPMG sequence as described in any one of the preceding claims.

[0017] The beneficial effects of this invention are as follows: This invention discloses a spoke image correction method, system, device, and product based on a constant gradient CPMG sequence. It can correct the spoke image of the sample to be tested, and can reduce or eliminate the influence of spin frequency-related signal weighting in the image, so as to ensure that the final sample image can truly and accurately reflect the distribution of the sample. Specifically, in the implementation of this invention, firstly, a constant gradient CPMG sequence is used to scan a specified standard phantom, and a frequency-amplitude correction curve is obtained based on the scanning results; then, the frequency range of the specified standard phantom is obtained, and the correction curve is fitted based on the frequency range to obtain a fitted frequency-amplitude correction curve; next, the constant gradient CPMG sequence is used to scan the sample under test to obtain echo signals at multiple echo times of the sample under test, and then the echo signals at each echo time are subjected to inverse Fourier transform processing and modulus value processing to obtain spoke images of the sample under test at multiple echo times; finally, the fitted frequency-amplitude correction curve is used to correct the spoke images of the sample under test at multiple echo times to obtain corrected spoke images of the sample under test at multiple echo times. In this process, the present invention corrects the spoke images of the sample under test at multiple echo times by scanning the frequency-amplitude correction curve obtained by scanning the specified standard phantom. This can solve the problem of signal distribution distortion in the spoke images of the sample under test at multiple echo times, thereby ensuring that the final obtained sample image can truly and accurately reflect the distribution of the sample, thus improving the accuracy of the analysis of the sample under test.

[0018] Other beneficial effects of the present invention will be further explained in the specific embodiments. Attached Figure Description

[0019] Figure 1 These are schematic diagrams of an ideal uniform phantom and schematic diagrams of sample images acquired from the ideal uniform phantom. Figure 2 It is an example of a pair Figure 1 A schematic diagram of the cross-sectional signal distribution in the 101st row and 101st column of the ideal uniform phantom and the acquired sample image; Figure 3 This is a flowchart of the spoke image correction method based on constant gradient CPMG sequence in Example 1; Figure 4 This is a block diagram of the spoke image correction system based on constant gradient CPMG sequence in Example 2; Figure 5 This is a block diagram of the electronic device in Example 3. Detailed Implementation

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be briefly introduced below in conjunction with the accompanying drawings and descriptions of the embodiments or the prior art. Obviously, the following description of the structure of the accompanying drawings is only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. It should be noted that the description of these embodiments is for the purpose of helping to understand the present invention, but does not constitute a limitation of the present invention.

[0021] Example 1: This embodiment discloses a spoke image correction method based on a constant gradient CPMG sequence, which can be executed, but is not limited to, by a computer device or virtual machine with certain computing resources, such as a personal computer, smartphone, personal digital assistant or wearable device, or by a virtual machine.

[0022] like Figure 3 As shown, a spoke image correction method based on a constant gradient CPMG sequence may include, but is not limited to, the following steps: S1. A specified standard phantom is scanned using a constant gradient CPMG sequence, and a frequency-amplitude correction curve is obtained based on the scanning results. It should be noted that the constant gradient CPMG sequence is a nuclear magnetic resonance technique that combines a CPMG sequence and a constant gradient field. This sequence achieves spatially encoded imaging by introducing a constant gradient field into the CPMG pulse sequence.

[0023] In this embodiment, the signal distribution of the designated standard phantom is symmetrical and uniform in the gradient direction of the constant gradient CPMG sequence, that is, it remains uniform, constant and consistent in the gradient direction of the constant gradient CPMG sequence. Correspondingly, when the imaging sequence type of the constant gradient CPMG sequence is 3D, the designated standard phantom adopts a spherical phantom; when the imaging sequence type of the constant gradient CPMG sequence is 2D, the designated standard phantom adopts a spherical phantom or a cylindrical sheet phantom; when the imaging sequence type of the constant gradient CPMG sequence is 1D, the designated standard phantom adopts a spherical phantom, a cylindrical sheet phantom or a slender cuboid phantom.

[0024] Specifically, in step S1, a constant gradient CPMG sequence is used to scan a specified standard phantom, and a frequency-amplitude correction curve is obtained based on the scanning results, including: S101. The specified standard phantom is scanned using a constant gradient CPMG sequence to obtain echo signals at multiple echo times of the specified standard phantom; S102. Perform inverse Fourier transform and modulus value processing on the echo signals of the specified standard model at multiple echo times to obtain the spoke images of the specified standard model at multiple echo times. S103. Based on the frequency information of the spoke images at multiple echo times of the specified standard phantom, and the signal intensity at different positions (different spatial positions correspond to different spin frequencies) of the spoke images at the corresponding echo times of the specified standard phantom, a frequency-amplitude correction curve is obtained. This curve is a frequency-amplitude correlation curve and is used to correct the spoke images in subsequent steps.

[0025] As another implementation method for obtaining the frequency-amplitude correction curve, in this embodiment, the designated standard phantom can also be set as a point sample. In this case, it can be assumed that the magnetic field within the range of the designated standard phantom is very uniform. For example, when different magnitudes of gradients are applied in the horizontal direction, the sample should be located in the horizontal direction so that different spin frequencies are obtained due to the change in gradient magnitude. Similarly, when different magnitudes of gradients are applied in the vertical direction, the sample should be located in the vertical direction so that it has different spin frequencies as the gradient changes. Correspondingly, in step S1, when the designated standard phantom is scanned using a constant gradient CPMG sequence and the frequency-amplitude correction curve is obtained based on the scanning results, only the gradient in the sample placement direction is applied, and the signal amplitude of the sample at different frequencies is measured by changing the gradient, thereby obtaining the frequency-amplitude correction curve.

[0026] In this embodiment, the constant gradient CPMG sequence is a constant gradient CPMG sequence with an echo time shorter than a preset time and containing either a reversal pulse or a saturation pulse. It should be noted that a constant gradient CPMG sequence with an echo time shorter than a preset time can also be called a constant gradient CPMG sequence with an ultra-short echo interval. The preset time can be determined based on common echo times and is not limited here.

[0027] Furthermore, in this embodiment, the designated standard phantom and the sample to be tested are made of the same material. This arrangement minimizes the impact of the complex echo train obtained by scanning the designated standard phantom on the differential magnetic resonance image of the sample to be tested.

[0028] S2. Obtain the frequency range of the specified standard phantom, and fit the correction curve according to the frequency range to obtain the fitted frequency-amplitude correction curve. It should be noted that, due to the possible changes in gradient magnitude and sample size during the actual scanning of the sample to be tested, the actual discrete frequency points of the specified standard phantom may not be completely consistent with the discrete frequency points in the spoke images at each echo time obtained based on the sample to be tested. Fitting the correction curve first, and then performing subsequent correction based on the fitted frequency-amplitude correction curve, can ensure better accuracy.

[0029] S3. The constant gradient CPMG sequence is used to scan the sample under test to obtain echo signals at multiple echo times of the sample under test. Then, the echo signals at each echo time are subjected to inverse Fourier transform processing and modulus value processing to obtain spoke images of the sample under test at multiple echo times. It should be noted that the sample under test is also an object with unknown distribution, and its spoke images can be corrected by fitting a frequency-amplitude correction curve.

[0030] S4. The fitted frequency-amplitude correction curve is used to correct the spoke images of the sample under test at multiple echo times, resulting in corrected spoke images of the sample under test at multiple echo times. It should be noted that the corrected spoke images of the sample under test at multiple echo times are also the spoke images after signal distribution distortion correction.

[0031] Specifically, in step S4 of this embodiment, the spoke images at multiple echo times of the sample under test are corrected using the fitted frequency-amplitude correction curve to obtain corrected spoke images at multiple echo times of the sample under test, including: Divide the spoke images of the sample under test at multiple echo times by the fitted frequency-amplitude correction curve to obtain the corrected spoke images of the sample under test at multiple echo times.

[0032] In step S4, after obtaining the corrected spoke images of multiple echo times of the sample under test, the method further includes: S5. Perform inverse Radon transform on the corrected spoke images of the sample under test at multiple echo times to obtain sample images of the sample under test at multiple echo times. S6. Perform material distribution analysis on the sample based on sample images at multiple echo times of the sample to be tested.

[0033] This embodiment can correct the spoke images of the sample under test, reducing or eliminating the influence of spin frequency-related signal weighting in the image, to ensure that the final acquired sample image can truly and accurately reflect the distribution of the sample. Specifically, in the implementation process of this embodiment, firstly, a constant gradient CPMG sequence is used to scan a specified standard phantom, and a frequency-amplitude correction curve is obtained based on the scanning results; then, the frequency range of the specified standard phantom is obtained, and the correction curve is fitted based on the frequency range to obtain a fitted frequency-amplitude correction curve; next, the constant gradient CPMG sequence is used to scan the sample under test to obtain echo signals at multiple echo times of the sample under test, and then the echo signals at each echo time are subjected to inverse Fourier transform processing and modulus value processing to obtain spoke images of the sample under test at multiple echo times; finally, the fitted frequency-amplitude correction curve is used to correct the spoke images of the sample under test at multiple echo times to obtain corrected spoke images of the sample under test at multiple echo times. In this process, this embodiment corrects the spoke images of the sample under test at multiple echo times by scanning the frequency-amplitude correction curve obtained from the specified standard phantom. This can solve the problem of signal distribution distortion in the spoke images of the sample under test at multiple echo times, thereby ensuring that the final obtained sample image can truly and accurately reflect the distribution of the sample, thus improving the accuracy of the analysis of the sample under test.

[0034] Example 2: This embodiment discloses a spoke image correction system based on a constant gradient CPMG sequence, used to implement the spoke image correction method based on a constant gradient CPMG sequence in Embodiment 1; as follows: Figure 4 As shown, the spoke image correction system based on constant gradient CPMG sequences includes: The calibration curve acquisition module scans a specified standard phantom using a constant gradient CPMG sequence and obtains a frequency-amplitude calibration curve based on the scanning results; it is also used to acquire the frequency range of the specified standard phantom and fit the calibration curve based on the frequency range to obtain a fitted frequency-amplitude calibration curve. The spoke image acquisition module is used to scan the sample under test using the constant gradient CPMG sequence to obtain echo signals at multiple echo times of the sample under test, and then perform inverse Fourier transform processing and modulus value processing on the echo signals at each echo time to obtain spoke images at multiple echo times of the sample under test. The spoke image correction module is communicatively connected to both the correction curve acquisition module and the spoke image acquisition module. It is used to correct the spoke images of the sample under test at multiple echo times using the fitted frequency-amplitude correction curve, thereby obtaining corrected spoke images of the sample under test at multiple echo times.

[0035] It should be noted that the working process, working details and technical effects of the spoke image correction system based on constant gradient CPMG sequence provided in this embodiment 2 can be found in embodiment 1, and will not be repeated here.

[0036] Example 3: Based on Embodiment 1 or 2, this embodiment discloses an electronic device, which may be a smartphone, tablet computer, laptop computer, or desktop computer, etc. The electronic device may be referred to as a user terminal, portable terminal, desktop terminal, etc. Figure 5 As shown, the electronic device includes: Memory, used to store computer program instructions; and, A processor is configured to execute the computer program instructions to perform the operation of the spoke image correction method based on a constant gradient CPMG sequence as described in any of Embodiment 1.

[0037] Specifically, processor 301 may include one or more processing cores, such as a quad-core processor or an octa-core processor. Processor 301 may be implemented using at least one hardware form of DSP (Digital Signal Processing), FPGA (Field-Programmable Gate Array), or PLA (Programmable Logic Array). Processor 301 may also include a main processor and a coprocessor. The main processor, also known as a CPU (Central Processing Unit), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, processor 301 may integrate a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content required to be displayed on the screen.

[0038] The memory 302 may include one or more computer-readable storage media, which may be non-transitory. The memory 302 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In some embodiments, the non-transitory computer-readable storage media in the memory 302 are used to store at least one instruction, which is executed by the processor 301 to implement the spoke image correction method based on a constant gradient CPMG sequence provided in Embodiment 1 of this application.

[0039] In some embodiments, the terminal may also optionally include a communication interface 303 and at least one peripheral device. The processor 301, memory 302, and communication interface 303 can be connected via a bus or signal line. Each peripheral device can be connected to the communication interface 303 via a bus, signal line, or circuit board. Specifically, the peripheral device includes at least one of a radio frequency circuit 304, a display screen 305, and a power supply 306.

[0040] The communication interface 303 can be used to connect at least one I / O (Input / Output) related peripheral device to the processor 301 and the memory 302. In some embodiments, the processor 301, the memory 302, and the communication interface 303 are integrated on the same chip or circuit board; in some other embodiments, any one or two of the processor 301, the memory 302, and the communication interface 303 can be implemented on separate chips or circuit boards, which is not limited in this embodiment.

[0041] The radio frequency (RF) circuit 304 is used to receive and transmit RF (Radio Frequency) signals, also known as electromagnetic signals. The RF circuit 304 communicates with communication networks and other communication devices via electromagnetic signals.

[0042] Display screen 305 is used to display the UI (User Interface). The UI may include graphics, text, icons, videos, and any combination thereof.

[0043] Power supply 306 is used to supply power to various components in electronic devices.

[0044] Example 4: Based on any one of the embodiments 1 to 3, this embodiment discloses a computer program product, including a computer program or instructions, which, when executed by a computer, implements the spoke image correction method based on a constant gradient CPMG sequence as described in any one of Embodiment 1.

[0045] Obviously, those skilled in the art will understand that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Optionally, they can be implemented using computer-executable program code, thereby storing them in a storage device for execution by a computing device, or fabricating them separately as individual integrated circuit modules, or fabricating multiple modules or steps as a single integrated circuit module. Thus, the present invention is not limited to any particular hardware and software combination.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A spoke image correction method based on a constant gradient CPMG sequence, characterized in that, include: A constant gradient CPMG sequence was used to scan a specified standard phantom, and the frequency-amplitude correction curve was obtained based on the scanning results. Obtain the frequency range of the specified standard phantom, and fit the correction curve according to the frequency range to obtain the fitted frequency-amplitude correction curve; The constant gradient CPMG sequence is used to scan the sample under test to obtain echo signals at multiple echo times of the sample under test. Then, the echo signals at each echo time are subjected to inverse Fourier transform processing and modulus value processing to obtain spoke images of the sample under test at multiple echo times. The fitted frequency-amplitude correction curve is used to correct the spoke images of the sample under test at multiple echo times, thereby obtaining the corrected spoke images of the sample under test at multiple echo times.

2. The spoke image correction method based on a constant gradient CPMG sequence according to claim 1, characterized in that, The signal distribution of the designated standard phantom is symmetrical and uniform in the gradient direction of the constant gradient CPMG sequence. Correspondingly, when the imaging sequence type of the constant gradient CPMG sequence is 3D, the designated standard phantom is a spherical phantom; when the imaging sequence type of the constant gradient CPMG sequence is 2D, the designated standard phantom is a spherical phantom or a cylindrical sheet phantom; when the imaging sequence type of the constant gradient CPMG sequence is 1D, the designated standard phantom is a spherical phantom, a cylindrical sheet phantom, or a slender cuboid phantom.

3. The spoke image correction method based on a constant gradient CPMG sequence according to claim 2, characterized in that, A constant gradient CPMG sequence is used to scan a specified standard phantom, and the frequency-amplitude correction curve is obtained based on the scanning results, including: The specified standard phantom is scanned using a constant gradient CPMG sequence to obtain echo signals at multiple echo times of the specified standard phantom. The echo signals at multiple echo times of the specified standard model are subjected to inverse Fourier transform and modulus value processing respectively to obtain the spoke images of the specified standard model at multiple echo times. Based on the frequency information of the spoke images at multiple echo times of the specified standard phantom, and the signal intensity at different positions of the spoke images at corresponding echo times of the specified standard phantom, a frequency-amplitude correction curve is obtained.

4. The spoke image correction method based on a constant gradient CPMG sequence according to claim 1, characterized in that, The constant gradient CPMG sequence uses a constant gradient CPMG sequence with an echo time shorter than a preset time and either an inversion pulse or a saturation pulse.

5. The spoke image correction method based on a constant gradient CPMG sequence according to claim 1, characterized in that, The specified standard phantom and the sample to be tested are the same substance.

6. The spoke image correction method based on a constant gradient CPMG sequence according to claim 1, characterized in that, The fitted frequency-amplitude correction curve is used to correct the spoke images of the sample under test at multiple echo times, resulting in corrected spoke images of the sample under test at multiple echo times, including: Divide the spoke images of the sample under test at multiple echo times by the fitted frequency-amplitude correction curve to obtain the corrected spoke images of the sample under test at multiple echo times.

7. The spoke image correction method based on a constant gradient CPMG sequence according to claim 1, characterized in that, After obtaining the corrected spoke images of the sample under test at multiple echo times, the method further includes: The corrected spoke images of the sample under test at multiple echo times are subjected to inverse Lardon transform processing to obtain sample images of the sample under test at multiple echo times. The material distribution of the sample is analyzed based on sample images at multiple echo times.

8. A spoke image correction system based on a constant gradient CPMG sequence, characterized in that, A method for implementing the spoke image correction method based on a constant gradient CPMG sequence as described in any one of claims 1 to 7; the spoke image correction system based on a constant gradient CPMG sequence comprises: The calibration curve acquisition module scans a specified standard phantom using a constant gradient CPMG sequence and obtains a frequency-amplitude calibration curve based on the scanning results; it is also used to acquire the frequency range of the specified standard phantom and fit the calibration curve based on the frequency range to obtain a fitted frequency-amplitude calibration curve. The spoke image acquisition module is used to scan the sample under test using the constant gradient CPMG sequence to obtain echo signals at multiple echo times of the sample under test, and then perform inverse Fourier transform processing and modulus value processing on the echo signals at each echo time to obtain spoke images at multiple echo times of the sample under test. The spoke image correction module is communicatively connected to both the correction curve acquisition module and the spoke image acquisition module. It is used to correct the spoke images of the sample under test at multiple echo times using the fitted frequency-amplitude correction curve, thereby obtaining corrected spoke images of the sample under test at multiple echo times.

9. An electronic device, characterized in that, include: Memory is used to store computer program instructions; as well as, A processor for executing the computer program instructions to perform the operation of the spoke image correction method based on a constant gradient CPMG sequence as described in any one of claims 1 to 7.

10. A computer program product, comprising a computer program or instructions, characterized in that, When the computer program or the instructions are executed by the computer, they implement the spoke image correction method based on a constant gradient CPMG sequence as described in any one of claims 1 to 7.

Images