A method, system and program product for rapid calibration of magnetic resonance radio frequency attenuation

Abstract

The present invention belongs to the field of nuclear magnetic resonance well logging technology, and specifically discloses a method, system and program product for rapid calibration of magnetic resonance radio frequency attenuation, which can collect signals from a target object based on each set radio frequency power attenuation value, using a signal sequence with a layer selection gradient, determine the signal value corresponding to each radio frequency power attenuation value, and then form a data pair for parameter fitting to determine the basic flip angle and basic attenuation value of linear attenuation, which are used to calculate the attenuation value corresponding to any flip angle. The present invention does not require iteration, is not subject to the influence of sample properties, and can determine the variable attenuation signal acquisition sequence used according to the actual application scenario, and can obtain a better flip angle attenuation under different layer selections, thereby improving the quality of magnetic resonance images. At the same time, fewer points can be collected, and radio frequency attenuation calibration can be performed faster and more accurately to determine the radio frequency attenuation corresponding to different flip angles.

Description

Technical Field

[0001] The present invention belongs to the field of nuclear magnetic resonance technology, and in particular relates to a method, system and program product for rapid calibration of magnetic resonance radio frequency attenuation. Background Art

[0002] The calibration of MRI radio frequency attenuation is very important for imaging quality. It can reduce complex echo chains in multi-echo sequences to reduce image artifacts. Existing MRI radio frequency attenuation calibration methods mainly include using a sequence of three pulses, calculating the flip angle through the amplitude of the stimulated echo and the spin echo, and iterating to obtain the 90-degree RF pulse amplitude, or using the FID sequence to measure the FID signal under different RF gains, and fitting to obtain the gain value of the 90-degree RF pulse. This type of method does not fully take into account the imperfect limitations of the magnetic resonance system, such as B1 field uniformity, coil bandwidth and other factors, which often results in differences in the flip angles with and without layer-selective gradients, and requires iteration, which is time-consuming, and the accuracy of attenuation calibration needs to be improved. Summary of the invention

[0003] The purpose of the present invention is to provide a method, system and program product for rapid calibration of magnetic resonance radio frequency attenuation, so as to solve the above problems existing in the prior art.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] In a first aspect, a method for rapid calibration of magnetic resonance radio frequency attenuation is provided, comprising:

[0006] Obtaining several set radio frequency power attenuation values;

[0007] Based on each radio frequency power attenuation value, a set signal sequence with a slice selection gradient is used to perform magnetic resonance scanning on the target object to obtain a corresponding acquisition signal;

[0008] Determine the signal value corresponding to each radio frequency power attenuation value according to each collected signal, and form a data pair with each radio frequency power attenuation value and the corresponding signal value;

[0009] Parameter fitting is performed using each data pair to determine the basic flip angle and basic attenuation value of linear attenuation;

[0010] The attenuation value corresponding to any given flip angle is calculated according to the basic flip angle and the basic attenuation value.

[0011] In a possible design, the signal sequence with slice selection gradient is a FID sequence with slice selection gradient or a gradient echo sequence with slice selection gradient, readout prephasing and readout gradient.

[0012] In a possible design, determining the signal value corresponding to each radio frequency power attenuation value according to each collected signal includes:

[0013] When the signal sequence with layer selection gradient is an FID sequence with layer selection gradient, the mean value of the modulus values ​​of several data points before the acquisition signal is selected as the signal value of the corresponding radio frequency power attenuation value, or after the acquisition signal is inversely Fourier transformed, the mean value of the modulus values ​​of several data points near the data center is selected as the signal value of the corresponding radio frequency power attenuation value;

[0014] When the signal sequence with layer selection gradient is a gradient echo sequence with layer selection gradient, readout pre-phasing and readout gradient, the modulus mean of several data points near the central point of the acquisition signal data is selected as the signal value corresponding to the RF power attenuation value.

[0015] In a possible design, there are at least 4 pairs of data pairs, and the method of performing parameter fitting using each data pair to determine the basic flip angle and basic attenuation value of linear attenuation includes:

[0016] Substitute each data pair into the preset fitting formula to obtain the corresponding nonlinear equation group, the fitting formula is:

[0017] y(x)=a·|sin(b·10(cx) / 20 )|+d

[0018] Wherein, x is the RF power attenuation value in the data pair, y(x) is the signal value in the data pair, a represents the linear scaling factor, b represents the basic flip angle, c represents the basic attenuation value, d represents the transverse magnetization vector influence factor, and a, b, c and d are all unknown parameters;

[0019] The initial b and c values ​​are taken, and the least square method is used to perform parameter fitting on the nonlinear equation group to obtain the final linear scaling factor and transverse magnetization vector influence factor, as well as the basic flip angle and basic attenuation value of linear attenuation.

[0020] In a possible design, the signal sequence with the slice selection gradient is a spin echo sequence with the slice selection gradient or a spin echo sequence with the slice selection gradient, readout prephasing and a readout gradient.

[0021] In a possible design, determining the signal value corresponding to each radio frequency power attenuation value according to each collected signal includes:

[0022] When the signal sequence with layer selection gradient is a spin echo sequence with layer selection gradient, the mean value of the modulus values ​​of several data points near the data center point of the acquisition signal is selected as the signal value of the corresponding radio frequency power attenuation value, or after performing inverse Fourier transform on the acquisition signal, the mean value of the modulus values ​​of several data points near the data center point is selected as the signal value of the corresponding radio frequency power attenuation value;

[0023] When the signal sequence with layer selection gradient is a spin echo sequence with layer selection gradient, readout prephasing and readout gradient, the modulus mean of several data points near the central point of the acquisition signal data is selected as the signal value corresponding to the radio frequency power attenuation value.

[0024] In a possible design, there are at least 4 pairs of data pairs, and the method of performing parameter fitting using each data pair to determine the basic flip angle and basic attenuation value of linear attenuation includes:

[0025] Substitute each data pair into the preset fitting formula to obtain the corresponding nonlinear equation group, the fitting formula is:

[0026] y(x)=a·|sin 3 (b·10(cx) / 20 )|+d

[0027] Wherein, x is the RF power attenuation value in the data pair, y(x) is the signal value in the data pair, a represents the linear scaling factor, b represents the basic flip angle, c represents the basic attenuation value, d represents the transverse magnetization vector influence factor, and a, b, c and d are all unknown parameters;

[0028] The initial b and c values ​​are taken, and the least square method is used to perform parameter fitting on the nonlinear equation group to obtain the final linear scaling factor and transverse magnetization vector influence factor, as well as the basic flip angle and basic attenuation value of linear attenuation.

[0029] In a possible design, the attenuation value corresponding to a given arbitrary flip angle is calculated according to the basic flip angle and the basic attenuation value, including:

[0030] A linear attenuation formula is constructed using the basic flip angle and the basic attenuation value. The linear attenuation formula is:

[0031] g=g0-20log 10 (θ / θ0)

[0032] Among them, g represents the calibrated attenuation value, θ represents the input flip angle, g0 represents the basic attenuation value, and θ0 represents the basic flip angle;

[0033] Obtain an arbitrary flip angle θ, substitute the arbitrary flip angle θ into the linear attenuation formula for calculation, and obtain the corresponding calibrated attenuation value g.

[0034] In a second aspect, a magnetic resonance radio frequency attenuation rapid calibration system is provided, comprising an attenuation setting unit, a signal acquisition unit, a data combination unit, a parameter fitting unit and an attenuation calculation unit, wherein:

[0035] An attenuation setting unit, used for obtaining a set number of radio frequency power attenuation values;

[0036] A signal acquisition unit, used to perform magnetic resonance scanning on the target object using a set signal sequence with layer selection gradient based on each radio frequency power attenuation value, to obtain a corresponding acquisition signal;

[0037] A data combination unit, used to determine the signal magnitude corresponding to each radio frequency power attenuation value according to each collected signal, and to form a data pair with each radio frequency power attenuation value and the corresponding signal magnitude;

[0038] A parameter fitting unit, used for performing parameter fitting using each data pair to determine a basic flip angle and a basic attenuation value of linear attenuation;

[0039] The attenuation calculation unit is used to calculate the attenuation value corresponding to a given arbitrary flip angle according to the basic flip angle and the basic attenuation value.

[0040] In a third aspect, a magnetic resonance radio frequency attenuation rapid calibration system is provided, comprising:

[0041] A memory for storing instructions;

[0042] A processor is used to read the instructions stored in the memory and execute any one of the methods described in the first aspect according to the instructions.

[0043] In a fourth aspect, a computer-readable storage medium is provided, wherein instructions are stored on the computer-readable storage medium, and when the instructions are executed on a computer, the computer executes any one of the methods described in the first aspect. In addition, a computer program product is provided, and when the computer program product is executed on a computer, the computer executes any one of the methods described in the first aspect.

[0044] Beneficial effects: The present invention does not require iteration and is not subject to the influence of sample properties. The variable attenuation signal acquisition sequence used can be determined according to the actual application scenario, and a better flip angle attenuation can be obtained under different layer selections, thereby improving the quality of magnetic resonance images. The present invention can collect fewer points by fitting to find the optimum, perform radio frequency attenuation calibration faster and more accurately, and determine the radio frequency attenuation corresponding to different flip angles. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 This is a schematic diagram of the steps of the method in Example 1 of the present invention;

[0047] Figure 2 Schematic diagram of a spin echo sequence with slice selection gradient;

[0048] Figure 3 Schematic diagram of a spin echo sequence with slice selection gradient, readout prephasing and readout gradient;

[0049] Figure 4 Schematic diagram of FID sequence with layer-selected gradient;

[0050] Figure 5 Schematic diagram of a gradient echo sequence for selecting gradients, reading out prephasing, and reading out gradients;

[0051] Figure 6 Schematic diagram of the system structure in Example 3 of the present invention. DETAILED DESCRIPTION

[0052] It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. The specific structures and functional details disclosed herein are only used to describe the exemplary embodiments of the present invention. However, the present invention can be embodied in many alternative forms, and it should not be understood that the present invention is limited to the embodiments set forth herein.

[0053] It should be understood that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments can be understood according to specific circumstances.

[0054] In the following description, certain details are provided to facilitate a complete understanding of the example embodiments. However, it will be appreciated by those of ordinary skill in the art that the example embodiments may be implemented without these certain details. For example, devices may be shown in block diagrams to avoid obscuring the examples with unnecessary details. In other embodiments, well-known processes, structures, and techniques may not be shown in unnecessary detail to avoid obscuring the embodiments.

[0055] Embodiment 1:

[0056] This embodiment provides a method for rapid calibration of magnetic resonance radio frequency attenuation, such as Figure 1 As shown, the method comprises the following steps:

[0057] S1. Obtain several set RF power attenuation values.

[0058] In specific implementation, several RF power attenuation values ​​corresponding to the RF power attenuator can be pre-set, such as selecting some values ​​from the maximum attenuation value to the minimum attenuation value that the device can support for subsequent signal excitation acquisition. In the linear case, no less than 4 RF power attenuation values ​​can be set, and in the nonlinear case, some additional supplementary distribution values ​​can be added. More than 4 RF power attenuation values ​​should be set. In the linear case, the selected RF attenuation value is linearly distributed between the maximum attenuation value and the minimum attenuation value, and in the nonlinear case, more values ​​can be set non-uniformly in the part with smaller attenuation values, because the signal curve obtained at this time changes faster and more dramatically, which is helpful for subsequent parameter fitting.

[0059] S2. Based on each radio frequency power attenuation value, a set signal sequence with layer selection gradient is used to perform magnetic resonance scanning on the target object to obtain a corresponding acquisition signal.

[0060] In specific implementation, after setting each RF power attenuation value, the target object can be subjected to magnetic resonance scanning by using the set signal sequence with layer selection gradient according to each RF power attenuation value through the corresponding device to obtain the corresponding acquisition signal. The signal sequence with layer selection gradient can be as follows: Figure 2 The spin echo sequence with slice selection gradient shown in ①, or Figure 3 A spin echo sequence with slice selection gradient, readout prephasing and readout gradient as shown in ②, or Figure 4 The FID (Free Induction Decay) sequence with layer selection gradient ③ shown in FIG. 1 , or Figure 5The gradient echo sequence ④ with layer selection gradient, readout pre-phasing and readout gradient is shown. The target object of signal acquisition can be a part of the human body, and the above sequence can be used to acquire the signal of the part. The selection of the above sequence mainly depends on which sequence is needed for subsequent scanning imaging. For spin echo sequences, sequence ① or sequence ② can be used for signal acquisition, and for gradient echo sequences, sequence ③ or sequence ④ can be used for signal acquisition. The parameters of the sequence should be kept consistent with the parameters of the actual imaging sequence to be scanned, such as the intensity of the layer selection gradient, the readout pre-phasing gradient, the duration and amplitude of the readout gradient, the time of the signal acquisition window, etc. Sequence ① and sequence ② correspond to spin echo sequences, which use two pulses, and the flip angle of the second pulse is set to twice that of the first pulse.

[0061] S3. Determine the signal magnitude corresponding to each RF power attenuation value according to each collected signal, and form a data pair with each RF power attenuation value and the corresponding signal magnitude value.

[0062] In a specific implementation, when the signal sequence with layer selection gradient is an FID sequence with layer selection gradient, the mean modulus value of several data points before the acquisition signal is selected as the signal value of the corresponding RF power attenuation value, or after performing inverse Fourier transform on the acquisition signal, the mean modulus value of several data points near the data center is selected as the signal value of the corresponding RF power attenuation value.

[0063] When the signal sequence with layer selection gradient is a gradient echo sequence with layer selection gradient, readout pre-phasing and readout gradient, the modulus mean of several data points near the central point of the acquisition signal data is selected as the signal value corresponding to the RF power attenuation value.

[0064] When the signal sequence with layer selection gradient is a spin echo sequence with layer selection gradient, the mean modulus value of several data points near the data center point of the acquisition signal is selected as the signal value of the corresponding radio frequency power attenuation value, or after performing inverse Fourier transform on the acquisition signal, the mean modulus value of several data points near the data center point is selected as the signal value of the corresponding radio frequency power attenuation value.

[0065] When the signal sequence with layer selection gradient is a spin echo sequence with layer selection gradient, readout prephasing and readout gradient, the modulus mean of several data points near the central point of the acquisition signal data is selected as the signal value corresponding to the radio frequency power attenuation value.

[0066] The data center point refers to the position center point of the corresponding signal sampling point. For example, if the number of sampling points of the spin echo signal (SE) is 128, the data center point refers to the 65th position data point. Generally, the average of the signal modulus values ​​of the three or so data points near the data center point is selected as the final signal value for fitting. After determining the signal value corresponding to each RF power attenuation value, each RF power attenuation value and the corresponding signal value can be combined into a data pair, and there are at least 4 pairs of data pairs.

[0067] S4. Perform parameter fitting using each data pair to determine the basic flip angle and basic attenuation value of linear attenuation.

[0068] In specific implementation, each data pair can be substituted into the preset fitting formula to obtain the corresponding nonlinear equation group. When the FID sequence with layer selection gradient ③ or the gradient echo sequence with layer selection gradient, readout pre-phase and readout gradient ④ is used for signal acquisition, the corresponding fitting formula is

[0069] y(x)=a·|sin(b·10(cx) / 20 )|+d

[0070] Among them, x is the RF power attenuation value in the data pair, y(x) is the signal value in the data pair, a represents the linear scaling factor including the thermal steady-state longitudinal magnetization vector modulus and the transverse magnetization vector relaxation attenuation, b represents the basic flip angle, c represents the basic attenuation value, and d represents the transverse magnetization vector influence factor, that is, the non-zero minimum value caused by B1 field inhomogeneity, RF field inhomogeneity and other reasons.

[0071] When a spin echo sequence with slice selection gradient ① or a spin echo sequence with slice selection gradient, readout prephasing and readout gradient ② is used for signal acquisition, the corresponding fitting formula is:

[0072] y(x)=a·|sin 3 (b·10(cx) / 20 )|+d

[0073] Among them, x is the RF power attenuation value in the data pair, y(x) is the signal value in the data pair, a represents the linear scaling factor including the thermal steady-state longitudinal magnetization vector modulus and the transverse magnetization vector relaxation attenuation, b represents the basic flip angle, c represents the basic attenuation value, and d represents the transverse magnetization vector influence factor, that is, the non-zero minimum value caused by B1 field inhomogeneity, RF field inhomogeneity and other reasons.

[0074] When x and y(x) are known, the unknown parameters to be fitted are a, b, c and d, but in reality b and c are not independent of each other but correspond one to one. Therefore, the parameter to be fitted can be reduced by one, such as preferably giving an initial value b=π / 2, keeping c as the parameter to be fitted, and then the parameters to be fitted are only a, c and d. When b=π / 2 is preferably given, the least squares method can be used to solve the values ​​of parameters a, c, d to prevent the fitting of the parameters from falling into the local optimal value, and finally obtain the global optimal value. Considering that the least squares method needs to set the initial value of each parameter and then iterate according to the error term, and the initial value of c has a greater impact on the solution effect, fortunately c is a quantity with actual physical meaning. When b is set to π / 2, c corresponds to the RF attenuation value corresponding to the 90-degree flip angle, and its upper and lower limits are clear, that is, the range of RF attenuation values ​​determined by the RF link (that is, the range of values ​​of the independent variable x). A series of initial values ​​c can be set to accelerate the search for the optimal parameter group. Finally, the least square method is used to fit the parameters of the nonlinear equation group to obtain the final linear scaling factor and transverse magnetization vector influence factor, as well as the basic flip angle and basic attenuation value of linear attenuation.

[0075] S5. Calculate the attenuation value corresponding to any given flip angle according to the basic flip angle and the basic attenuation value.

[0076] In specific implementation, a linear attenuation formula can be constructed using the basic flip angle and the basic attenuation value. The linear attenuation formula is:

[0077] g=g0-20log 10 (θ / θ0)

[0078] Among them, g represents the calibrated attenuation value, θ represents the input flip angle, g0 represents the basic attenuation value, which corresponds to the basic attenuation value c obtained by fitting in the previous step, and θ0 represents the basic flip angle, which corresponds to the basic flip angle b in the previous step. After that, any flip angle θ can be substituted into the linear attenuation formula for calculation to obtain the corresponding calibrated attenuation value g.

[0079] The method of this embodiment does not require iteration and is not subject to the influence of sample properties. The variable attenuation signal acquisition sequence used can be determined according to the actual application scenario, and a better flip angle attenuation can be obtained under different layer selections, thereby improving the quality of magnetic resonance images. At the same time, by fitting to find the optimum, fewer points can be collected, and the radio frequency attenuation calibration can be performed faster and more accurately to determine the radio frequency attenuation corresponding to different flip angles.

[0080] Embodiment 2:

[0081] This embodiment provides a magnetic resonance radio frequency attenuation rapid calibration system, including an attenuation setting unit, a signal acquisition unit, a data combination unit, a parameter fitting unit and an attenuation calculation unit, wherein:

[0082] An attenuation setting unit, used for obtaining a set number of radio frequency power attenuation values;

[0083] A signal acquisition unit, used to perform magnetic resonance scanning on the target object using a set signal sequence with layer selection gradient based on each radio frequency power attenuation value, to obtain a corresponding acquisition signal;

[0084] A data combination unit, used to determine the signal magnitude corresponding to each radio frequency power attenuation value according to each collected signal, and to form a data pair with each radio frequency power attenuation value and the corresponding signal magnitude;

[0085] A parameter fitting unit, used for performing parameter fitting using each data pair to determine a basic flip angle and a basic attenuation value of linear attenuation;

[0086] The attenuation calculation unit is used to calculate the attenuation value corresponding to a given arbitrary flip angle according to the basic flip angle and the basic attenuation value.

[0087] Embodiment 3:

[0088] This embodiment provides a magnetic resonance radio frequency attenuation rapid calibration system. Figure 6 As shown, at the hardware level, it includes:

[0089] Data interface, used to establish data connection between the processor and the external data terminal;

[0090] A memory for storing instructions;

[0091] The processor is used to read the instructions stored in the memory and execute the magnetic resonance radio frequency attenuation rapid calibration method in Example 1 according to the instructions.

[0092] Optionally, the system further includes an internal bus, through which the processor, the memory and the data interface can be interconnected, and the internal bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc.

[0093] The memory may include, but is not limited to, random access memory (RAM), read only memory (ROM), flash memory, first input first output (FIFO) and / or first in last out (FILO) memory, etc. The processor may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components.

[0094] Embodiment 4:

[0095] This embodiment provides a computer-readable storage medium, on which instructions are stored, and when the instructions are executed on a computer, the computer executes the magnetic resonance radio frequency attenuation rapid calibration method in Embodiment 1. The computer-readable storage medium refers to a carrier for storing data, which may include but is not limited to a floppy disk, an optical disk, a hard disk, a flash memory, a USB flash drive, and / or a memory stick, etc., and the computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices.

[0096] This embodiment also provides a computer program product, which, when executed on a computer, executes the magnetic resonance radio frequency attenuation rapid calibration method in Embodiment 1. The computer may be a general-purpose computer, a special-purpose computer, a computer network or other programmable devices.

[0097] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for rapid calibration of magnetic resonance radio frequency attenuation, characterized in that: include: Obtaining several set radio frequency power attenuation values; Based on each radio frequency power attenuation value, a set signal sequence with a slice selection gradient is used to perform magnetic resonance scanning on the target object to obtain a corresponding acquisition signal; Determine the signal value corresponding to each radio frequency power attenuation value according to each collected signal, and form a data pair with each radio frequency power attenuation value and the corresponding signal value, wherein there are at least 4 pairs of data pairs; Utilize each data pair to perform parameter fitting to determine the basic flip angle and basic attenuation value of linear attenuation; including: substituting each data pair into a preset fitting formula to obtain a corresponding nonlinear equation group, wherein the fitting formula is: y(x)=a·|sin(b·10 (c-x) / 20 )|+d, Wherein, x is the RF power attenuation value in the data pair, y(x) is the signal value in the data pair, a represents the linear scaling factor, b represents the basic flip angle, c represents the basic attenuation value, d represents the transverse magnetization vector influence factor, and a, b, c and d are all unknown parameters; take the initial b value and c value, and use the least squares method to perform parameter fitting on the nonlinear equation group to obtain the final linear scaling factor and transverse magnetization vector influence factor, as well as the basic flip angle and basic attenuation value of linear attenuation; Calculating the attenuation value corresponding to a given arbitrary flip angle according to the basic flip angle and the basic attenuation value; including: constructing a linear attenuation formula using the basic flip angle and the basic attenuation value, the linear attenuation formula is: g=g0-20log 10 (θ / θ0), Among them, g represents the calibrated attenuation value, θ represents the input flip angle, g0 represents the basic attenuation value, and θ0 represents the basic flip angle; obtain an arbitrary flip angle θ, substitute the arbitrary flip angle θ into the linear attenuation formula for calculation, and obtain the corresponding calibrated attenuation value g.

2. The method for rapid calibration of magnetic resonance radio frequency attenuation according to claim 1, characterized in that: The signal sequence with slice selection gradient is a FID sequence with slice selection gradient or a gradient echo sequence with slice selection gradient, readout prephasing and readout gradient.

3. The method for rapid calibration of magnetic resonance radio frequency attenuation according to claim 2, characterized in that: The step of determining the signal value corresponding to each radio frequency power attenuation value according to each collected signal includes: When the signal sequence with layer selection gradient is an FID sequence with layer selection gradient, the mean value of the modulus values ​​of several data points before the acquisition signal is selected as the signal value of the corresponding radio frequency power attenuation value, or after the acquisition signal is inversely Fourier transformed, the mean value of the modulus values ​​of several data points near the data center is selected as the signal value of the corresponding radio frequency power attenuation value; When the signal sequence with layer selection gradient is a gradient echo sequence with layer selection gradient, readout pre-phasing and readout gradient, the modulus mean of several data points near the central point of the acquisition signal data is selected as the signal value corresponding to the RF power attenuation value.

4. The method for rapid calibration of magnetic resonance radio frequency attenuation according to claim 1, characterized in that: The signal sequence with slice selection gradient is a spin echo sequence with slice selection gradient or a spin echo sequence with slice selection gradient, readout prephasing and readout gradient.

5. The method for rapid calibration of magnetic resonance radio frequency attenuation according to claim 4, characterized in that: The step of determining the signal value corresponding to each radio frequency power attenuation value according to each collected signal includes: When the signal sequence with layer selection gradient is a spin echo sequence with layer selection gradient, the mean value of the modulus values ​​of several data points near the data center point of the acquisition signal is selected as the signal value of the corresponding radio frequency power attenuation value, or after performing inverse Fourier transform on the acquisition signal, the mean value of the modulus values ​​of several data points near the data center point is selected as the signal value of the corresponding radio frequency power attenuation value; When the signal sequence with layer selection gradient is a spin echo sequence with layer selection gradient, readout prephasing and readout gradient, the modulus mean of several data points near the central point of the acquisition signal data is selected as the signal value corresponding to the radio frequency power attenuation value.

6. The method for rapid calibration of magnetic resonance radio frequency attenuation according to claim 4, characterized in that: The method of performing parameter fitting using each data pair to determine the basic flip angle and basic attenuation value of linear attenuation also includes: Substitute each data pair into the preset fitting formula to obtain the corresponding nonlinear equation group, the fitting formula is: y(x)=a·|sin 3 (b·10 (c-x) / 20 )|+d Wherein, x is the RF power attenuation value in the data pair, y(x) is the signal value in the data pair, a represents the linear scaling factor, b represents the basic flip angle, c represents the basic attenuation value, d represents the transverse magnetization vector influence factor, and a, b, c and d are all unknown parameters; The initial b value and a value are taken, and the least square method is used to perform parameter fitting on the nonlinear equation group to obtain the final linear scaling factor and transverse magnetization vector influence factor, as well as the basic flip angle and basic attenuation value of linear attenuation.

7. A magnetic resonance radio frequency attenuation rapid calibration system, characterized in that: include: A memory for storing instructions; A processor is used to read the instructions stored in the memory and execute the magnetic resonance radio frequency attenuation rapid calibration method according to any one of claims 1 to 6.

8. A computer program product, characterized in that When the computer program product is run on a computer, the magnetic resonance radio frequency attenuation rapid calibration method according to any one of claims 1 to 6 is executed.

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