Shim coil detection method, device, storage medium and magnetic resonance imaging system

Abstract

The embodiments of the present application relate to a shim coil detection method, device, storage medium, and magnetic resonance imaging system, wherein the method is used for a magnetic resonance device and includes: applying a preset current to at least one shim coil to determine the magnetic field distribution information generated by the superposition of the magnetic resonance device and the at least one shim coil; determining the magnetic field intensity components of the at least one shim coil based on the magnetic field distribution information; and determining the sensitivity and / or electrical connection accuracy of the at least one shim coil based on the magnetic field intensity components of the at least one shim coil. Compared with the prior art, the shim coil detection method provided by the embodiments of the present application has a faster detection speed and more convenient detection operation when detecting the sensitivity and / or electrical connection accuracy of the shim coil. It can also detect the sensitivity and / or electrical connection accuracy of high-order shim coils and has a wider range of applications.

Description

Technical Field

[0001] The present application relates to the field of magnetic resonance technology, and in particular to a shim coil detection method, device, storage medium, and magnetic resonance imaging system. Background Art

[0002] In magnetic resonance imaging (MRI) systems, the uniformity of the static field (B0 field) is a necessary condition for achieving good results in various scanning applications. Generally, active shimming can be used to make the B0 magnetic field uniform. Active shimming can use the magnetic field generated by the shim coil to compensate for the main magnetic field, thereby improving the uniformity of the B0 magnetic field. Generally, the magnetic field distribution generated by the shim coil in space depends on factors such as its geometric structure, current, and sensitivity. However, the positive and negative electrical connections of the shim coil may be incorrect (such as reversed and / or cross-connected coils), resulting in image confusion and image distortion.

[0003] Related technologies use multiple RF coil units and signal reconstruction results to determine the polarity of the gradient coils, thereby determining whether the polarity of the shim coils is reversed. However, this method can only determine the polarity connection of low-order shim coils, such as linear gradient coils, and cannot detect other characteristics of the shim coils.

[0004] Therefore, the related art urgently needs a detection method that can determine the characteristics of each shim coil. Summary of the Invention

[0005] The embodiments of the present application provide a shim coil detection method, device, storage medium, and magnetic resonance imaging system to at least solve the problem that the shim coil detection method in the related art has a limited scope of application.

[0006] In a first aspect, an embodiment of the present application provides a shim coil detection method for a magnetic resonance device, the method comprising:

[0007] Applying a preset current to at least one shim coil to determine magnetic field distribution information generated by superposition of the magnetic resonance device and the at least one shim coil;

[0008] respectively determining a magnetic field intensity component of the at least one shim coil according to the magnetic field distribution information;

[0009] The sensitivity of the at least one shim coil and / or the accuracy of the electrical connection are determined based on the magnetic field strength component of the at least one shim coil.

[0010] The shim coil detection method provided in the embodiment of the present application mainly determines the magnetic field intensity component of the at least one shim coil through the correspondence between the magnetic field distribution information and the magnetic field intensity component of the at least one shim coil. Then, the sensitivity of the at least one shim coil and / or the accuracy of the electrical connection can be determined based on the magnetic field intensity component of the at least one shim coil. Therefore, compared with the prior art, the shim coil detection method provided in the embodiment of the present application has a faster detection speed and a more convenient detection operation when detecting the sensitivity of the shim coil and / or the accuracy of the electrical connection, and can detect the sensitivity and / or the accuracy of the electrical connection of high-order shim coils, and has a wider range of applications.

[0011] Optionally, in one embodiment of the present application, determining the sensitivity of the shim coil and / or the accuracy of the electrical connection according to the magnetic field strength component of the at least one shim coil includes:

[0012] determining sensitivity information of the at least one shim coil based on a preset relationship between the magnetic field intensity component, the preset current, and the sensitivity information;

[0013] The accuracy of the sensitivity of the at least one shim coil is determined according to the sensitivity information of the at least one shim coil.

[0014] Optionally, in one embodiment of the present application, determining the accuracy of the sensitivity of the at least one shim coil according to the sensitivity information of the at least one shim coil includes:

[0015] obtaining reference sensitivity information of the at least one shim coil;

[0016] The accuracy of the sensitivity of the at least one shim coil is determined according to a comparison result between the sensitivity information and the reference sensitivity information.

[0017] Optionally, in one embodiment of the present application, determining the sensitivity and / or electrical connection accuracy of the at least one shim coil according to the magnetic field strength component of the at least one shim coil includes:

[0018] When the positive and negative polarities of the magnetic field intensity components of the shim coil are different from the positive and negative polarities of the preset current applied by the shim coil, it is determined that the electrical connection of the shim coil is incorrect.

[0019] Optionally, in one embodiment of the present application, determining the sensitivity and / or electrical connection accuracy of the at least one shim coil according to the magnetic field strength component of the at least one shim coil includes:

[0020] When it is determined that the magnetic field intensity component values of the plurality of target shim coils do not match the reference magnetic field intensity component values, it is determined that the currents actually applied by the plurality of target shim coils do not match the preset currents.

[0021] Optionally, in one embodiment of the present application, after determining that the magnetic field intensity component values of the multiple target shim coils do not match the reference magnetic field intensity component values, and determining that the currents actually applied by the multiple target shim coils do not match the preset currents, the method further includes:

[0022] determining, based on the magnetic field intensity component values of the plurality of target shim coils, a cross-connection relationship of preset currents applied to the plurality of target shim coils, wherein the cross-connection relationship causes the currents actually applied to the plurality of target shim coils to not match the preset currents;

[0023] The cross-connection relationship is corrected to determine the correct connection relationship.

[0024] In a second aspect, an embodiment of the present application further provides a shim coil detection device for use in a magnetic resonance device, the device comprising:

[0025] a magnetic field distribution information determining module, configured to apply a preset current to at least one shim coil to determine magnetic field distribution information generated by the superposition of the magnetic resonance device and the at least one shim coil;

[0026] a magnetic field intensity component determination module, configured to respectively determine the magnetic field intensity components of the at least one shim coil according to the magnetic field distribution information;

[0027] The detection module is configured to determine the sensitivity of the at least one shim coil and / or the accuracy of the electrical connection according to the magnetic field strength component of the at least one shim coil.

[0028] In a third aspect, an embodiment of the present application further provides a magnetic resonance imaging system, comprising a magnetic resonance device, at least one shim coil, and a shim coil detection module, wherein the magnetic resonance device comprises a main magnet, the main magnet is used to generate a main magnetic field, the at least one shim coil is used to generate a shim magnetic field to compensate for the non-uniformity of the main magnetic field, and the shim coil detection module is used to implement the steps of the shim coil detection method described in each of the above embodiments.

[0029] In a fourth aspect, an embodiment of the present application further provides a processing device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the steps of the shim coil detection method described in the above embodiments when executing the computer program.

[0030] In a fifth aspect, an embodiment of the present application further provides a computer-readable storage medium having computer program instructions stored thereon, wherein the computer program instructions, when executed by a processor, implement the steps of the shim coil detection method described in each of the above embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0032] Figure 1 This is a schematic diagram of an application scenario provided by an embodiment of the present application;

[0033] Figure 2 is a method flow chart of the shim coil detection method provided in an embodiment of the present application;

[0034] Figure 3 1 is a schematic diagram of the module structure of the shim coil detection 107 provided in an embodiment of the present application;

[0035] Figure 4 It is a schematic diagram of the module structure of the processing device 400 provided in an embodiment of the present application. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application. In addition, it can also be understood that although the efforts made in this development process may be complex and lengthy, for ordinary technicians in the field related to the contents disclosed in the present application, some changes such as design, manufacturing or production based on the technical contents disclosed in the present application are only conventional technical means and should not be understood as the contents disclosed in the present application being insufficient.

[0037] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it refer to independent or alternative embodiments that are mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments unless there is a conflict.

[0038] Unless otherwise defined, the technical or scientific terms used in this application should have the usual meanings understood by persons of ordinary skill in the technical field to which this application belongs. The words "one", "a", "the" and the like used in this application do not indicate a limit on quantity and may indicate the singular or plural. The terms "include", "comprise", "have" and any variations thereof used in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units that are inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like used in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The term "multiple" used in this application means greater than or equal to two. The terms "first", "second", "third" and the like used in this application are merely used to distinguish similar objects and do not represent a specific ordering of objects.

[0039] In order to clearly illustrate the technical solutions of various embodiments of the present application, Figure 1 An exemplary scenario of an embodiment of the present application is described.

[0040] The present application provides a shim coil detection method that can be applied to Figure 1The magnetic resonance imaging system shown includes a magnetic resonance imaging (MRI) device 101, shim coils 103, coil current controllers 105 corresponding to each shim coil in the shim coils 103, and a shim coil detection device 107. The MRI device 101 can generate a constant main magnetic field, i.e., a static magnetic field (SMF), to provide the required environment for acquiring magnetic resonance images. The MRI device 101 can be, for example, a permanent magnet MRI device, a normal conductive MRI device, a superconducting MRI device, or the like. The shim coils 103 are mounted on the magnetic pole surfaces of the MRI device 101, and the shim magnetic fields they generate can be used to compensate for magnetic field inhomogeneities in the main magnetic field caused by various factors. The input end of the coil current controller 105 can be connected to the shim coil detection device 107. The shim coil detection device 107 can set the current value to be applied to the shim coil 103 based on actual needs and control the coil current controller 105 to apply this current value to the corresponding shim coil in the shim coils 103. The output end of the coil current controller 105 is connected to the corresponding shim coil in the shim coils 103, thereby providing a DC constant current stable current source for each shim coil in the shim coils 103. The shim coil detection device 107 can communicate with the magnetic resonance device 101 to determine the magnetic field distribution information generated by the superposition of the magnetic resonance device 101 and the shim coils 103. Based on this magnetic field distribution information, the magnetic field intensity component corresponding to at least one coil in the shim coils 103 can be determined. Finally, based on the magnetic field intensity component corresponding to the at least one shim coil 103, the sensitivity of the at least one shim coil 103 and / or the accuracy of the electrical connection can be determined. The shim coil detection device 107 may be an electronic device with data processing and data receiving capabilities, and may be a physical device such as a host, rack server, blade server, etc., or a virtual device such as a virtual machine, container, etc.

[0041] The shim coil detection method described in this application is described in detail below with reference to the accompanying drawings. Figure 2This is a flow chart of an embodiment of the shim coil detection method provided by the present application. Although the present application provides the method operation steps as shown in the following embodiments or drawings, the method may include more or fewer operation steps based on routine or no creative work. In steps that are not logically necessary for causality, the execution order of these steps is not limited to the execution order provided in the embodiments of the present application. During the actual shim coil detection process or when the method is executed, the method can be executed in the order of the methods shown in the embodiments or drawings or in parallel (for example, in a parallel processor or multi-threaded processing environment).

[0042] Specifically, an embodiment of the shim coil detection method provided by the present application is as follows: Figure 2 As shown, the method may include:

[0043] S201: Applying a preset current to at least one shim coil to determine magnetic field distribution information generated by superposition of the magnetic resonance device and the at least one shim coil.

[0044] In an embodiment of the present application, the number of coils in the shim coil 103 may be one or more. If there are multiple shim coils 103, a preset current of the same magnitude or direction, or different magnitudes or directions, may be applied to the multiple shim coils 103. After applying the preset current to the at least one shim coil 103, magnetic field distribution information generated by the superposition of the magnetic resonance device 101 and the at least one shim coil 103 may be determined. The magnetic field distribution information may be used to represent the distribution pattern of the magnetic field strength around the magnet. In other words, the magnetic field distribution information may include main magnetic field distribution information and shim magnetic field distribution information. The main magnetic field may be generated by a main magnet provided in the magnetic resonance device 101, which may be a superconducting coil or a permanent magnet. The shim magnetic field may be generated by the at least one shim coil 103. Specifically, in one embodiment of the present application, a pulse sequence, such as a 3D gradient double echo sequence, may be used to scan a target object, such as an animal, and different scanned images may be determined based on different echo times. For example, when the echo time is T1, the scan image can be determined to be M1, and when the echo time is T2, the scan image can be determined to be M2. The pulse sequence may include, for example, but is not limited to, a gradient echo (GRE) sequence, a fast spin echo (FSE) sequence, a balanced steady-state free precession (BSSFP) sequence, and a planar echo (EPI) sequence. In an embodiment of the present application, after determining the different scan images, the magnetic field distribution information may be determined based on the phase difference between the different scan images. The phase difference may be determined based on the difference between the phases of the two scan images recorded at different echo times. For example, the magnetic field distribution information may be determined based on the phase difference between the scan images M1 and M2.

[0045] S203: Determine the magnetic field intensity components of the at least one shim coil respectively according to the magnetic field distribution information.

[0046] In an embodiment of the present application, according to the principle of electromagnetic induction, each shim coil 103 will generate a spatially distributed magnetic field after current is passed through it. The spatially distributed magnetic field may include magnetic field intensity components corresponding to Legendre polynomials or spherical harmonic functions. Therefore, after determining the magnetic field distribution information, the magnetic field distribution information can be decomposed by dimensionality reduction methods such as the least squares method to determine magnetic field intensity components of different orders. Then, the magnetic field intensity components corresponding to the at least one shim coil 103 can be determined respectively based on the correspondence between the magnetic field intensity components of different orders and the spatially distributed magnetic field generated by the at least one shim coil 103. Specifically, the magnetic field distribution information can be expanded in the form of Legendre polynomials or spherical harmonic functions. For example, according to Maxwell's equations, the magnetic field distribution information can be expanded in the form of spherical harmonic functions, and the expanded equation is expressed in the rectangular coordinate system as follows:

[0047] B0=B 00 +ax+bx 2 +cx 3 +dy+ey 2 +fy 3 +…

[0048] Wherein, the B0 can be used to represent the magnetic field distribution information, the B 00 is the expanded zero-order term, which may correspond to the magnetic field strength of the main magnetic field. a, b, c, d, e, f, etc. may be magnetic field strength components of various orders. For example, a may be used to represent the magnetic field strength component of a first-order term. In one embodiment of the present application, after applying a preset current to the at least one shim coil 103, the magnetic field vector distribution generated in space by the at least one shim coil 103 may be determined based on the Biot-Savart law or other laws. After determining the magnetic field vector distribution, the magnetic field vector distribution of the at least one shim coil 103 may be sequentially compared with the magnetic field strength components of various orders to determine the magnetic field strength components corresponding to each shim coil 103. For example, in one example, a preset current of 1A may be applied to shim coil 1, a preset current of 2A may be applied to shim coil 2, and a preset current of 3A may be applied to shim coil 3. When different currents are applied to shim coils 1, 2, and 3, different magnetic field vector distributions may be generated in space: 1 Tesla, 2 Tesla, and 3 Tesla, respectively. Afterwards, the magnetic field distribution information can be expanded in the form of spherical harmonics to obtain: B0 = B 00 +1.2x+2.1x 2 +3x 3 +5y+7y 2 +8y 3From this, we can determine that the first-order coefficient 1.2 corresponds to the magnetic field strength component of shim coil 1, the second-order coefficient 2.1 corresponds to the magnetic field strength component of shim coil 2, and the third-order coefficient 3 corresponds to the magnetic field strength component of shim coil 3.

[0049] Through the above embodiment, the magnetic field intensity components corresponding to the at least one shim coil 103 can be determined respectively according to the correspondence between the magnetic field intensity components of different orders and the spatially distributed magnetic field generated by the at least one shim coil 103, thereby providing auxiliary conditions and reference basis for subsequent shim coil detection.

[0050] S205: Determine the sensitivity and / or electrical connection accuracy of the at least one shim coil according to the magnetic field strength component of the at least one shim coil.

[0051] In practical applications, each shim coil 103 generates a spatially distributed magnetic field corresponding to Legendre polynomials or spherical harmonic components. The shim coils 103 work together to dynamically adjust the non-uniform fields generated by all spherical harmonic terms or other terms that need to be eliminated in the main magnetic field. Because the spatial magnetic field distribution generated by the shim coils 103 depends on factors such as their geometry, current, and sensitivity, the shimming effect will be affected if the sensitivity or electrical connection of any of the shim coils 103 does not meet the expected settings or anomalies occur. In one embodiment of the present application, the sensitivity and / or electrical connection accuracy of the at least one shim coil 103 can be determined based on the magnetic field intensity components corresponding to the at least one shim coil 103, thereby determining whether the at least one shim coil 103 can achieve a good shimming effect. Specifically, in one embodiment of the present application, the sensitivity of the at least one shim coil 103 can be determined based on a preset correlation between the magnetic field intensity components of the at least one shim coil 103 and the sensitivity. The preset correlation can be represented in the form of a correlation function, a correlation table, a correlation diagram, or the like. The preset association relationship may include a positive correlation between the magnetic field intensity component of the at least one shim coil 103 and the sensitivity. For example, in one example, the positive correlation relationship may include a positive correlation coefficient between the magnetic field intensity component of the at least one shim coil 103 and the sensitivity.

[0052] In an embodiment of the present application, the current direction of the preset current applied to the shim coil 103 can affect the positive or negative value of the magnetic field intensity component. In one embodiment of the present application, the correctness of the electrical connection of the shim coil 103 can be determined by the positive or negative value of the magnetic field intensity component. Specifically, when the positive or negative value of the magnetic field intensity component corresponding to the shim coil 103 meets the preset requirements, it can be determined that the electrical connection of the at least one shim coil 103 is correct. The positive or negative value of the magnetic field intensity component meeting the preset requirements can include that the direction corresponding to the positive or negative value of the magnetic field intensity component is the same as the X-axis direction of the shim coil 103, or the same as the Y-axis direction of the shim coil. In the magnetic resonance imaging system, the shim coil 103 can include magnetic fields in three orthogonal directions of X, Y, and Z, and the X-axis direction of the shim coil 103 can be the positive direction of the X-axis. In another embodiment of the present application, the positive and negative polarity of the magnetic field intensity component corresponding to the shim coil 103 meeting the preset requirements may also include the positive and negative polarity of the magnetic field intensity component being the same as the positive and negative polarity of the preset current applied by the shim coil 103, which is not limited in this application. Of course, if the positive and negative polarity of the magnetic field intensity component does not meet the preset requirements, it can be determined that the electrical connection of the shim coil 103 is incorrect.

[0053] The shim coil detection method provided in the embodiments of the present application primarily determines the magnetic field intensity components of the at least one shim coil 103 by using the correspondence between magnetic field distribution information and the magnetic field intensity components of the at least one shim coil 103. The sensitivity and / or electrical connection accuracy of the at least one shim coil 103 can then be determined based on the magnetic field intensity components of the at least one shim coil 103. Therefore, compared to the prior art, the shim coil detection method provided in the embodiments of the present application offers faster detection speeds, more convenient detection operations, and can detect the sensitivity and / or electrical connection accuracy of high-order shim coils, thus having a wider range of applications.

[0054] In practical applications, the uniformity of the main magnetic field is a necessary condition for achieving good results in various application scans of magnetic resonance imaging systems. Since the distribution of the magnetic field generated in space by the shim coil depends on factors such as its geometric structure, current, and sensitivity, if the sensitivity of the shim coil is inaccurate or does not meet expectations, the magnetic field generated by the shim coil cannot achieve the expected shim effect. In some embodiments of the present application, the shim effect can be determined by the accuracy of the sensitivity of the shim coil 103. Specifically, in one embodiment of the present application, determining the sensitivity of the shim coil and / or the accuracy of the electrical connection based on the magnetic field strength component of the at least one shim coil may include:

[0055] S301: Determine sensitivity information of the at least one shim coil based on a preset relationship between the magnetic field intensity component, the preset current, and sensitivity information;

[0056] S303: Determine the accuracy of the sensitivity of the at least one shim coil according to the sensitivity information of the at least one shim coil.

[0057] In an embodiment of the present application, after determining the magnetic field intensity components corresponding to the at least one shim coil 103 through the above steps, the sensitivity information of the shim coil 103 can be determined based on a preset relationship between the magnetic field intensity components, the preset current applied to the shim coil 103, and the sensitivity information. The sensitivity information can be used to indicate the shimming capability of the shim coil 103. In one embodiment of the present application, the preset relationship can include that the product of the preset current and the sensitivity information is the same as or matches the magnetic field intensity component. For example, in one example, the preset relationship between the preset current I, the sensitivity information A, and the magnetic field intensity component Bx is Bx = I × A. Based on the known preset current I and the determined magnetic field intensity component Bx, the sensitivity information A can be determined. After determining the sensitivity information, the sensitivity information can be compared with the sensitivity properties of the shim coil 103 itself, and the electrical connection of the shim coil can be determined based on the comparison result. Specifically, in one embodiment of the present application, determining the accuracy of the sensitivity of the at least one shim coil based on the sensitivity information of the at least one shim coil can include:

[0058] S401: Acquire reference sensitivity information of the at least one shim coil;

[0059] S403: Determine the accuracy of the sensitivity of the at least one shim coil according to a comparison result between the sensitivity information and the reference sensitivity information.

[0060] In an embodiment of the present application, the reference sensitivity information may be the sensitivity set during the manufacture of the shim coil 103, or may be a sensitivity obtained based on theoretical calculations. For example, the reference sensitivity information may be obtained by calculating the image between coil units using an adaptive algorithm for coil sensitivity information. Specifically, the reference sensitivity information of the shim coil 103 may be obtained from the system of the manufacturer of the shim coil 103. After obtaining the reference sensitivity information of the at least one shim coil 103, the accuracy of the sensitivity of the at least one shim coil 103 may be determined based on a comparison result between the sensitivity information and the reference sensitivity information. In one embodiment of the present application, if the sensitivity information of the target shim coil is identical to or matches the reference sensitivity information, the sensitivity of the target shim coil may be determined to be accurate. Of course, in some application scenarios, if the difference between the sensitivity information of the target shim coil and the reference sensitivity information meets a preset threshold, the sensitivity of the target shim coil may also be determined to be accurate.

[0061] Through the above embodiment, the accuracy of the sensitivity of the at least one shim coil 103 can be determined based on the comparison result between the reference sensitivity information and the sensitivity information. Compared with the existing technology, the sensitivity of the at least one shim coil 103 can be determined more quickly and simply, providing a reference basis for obtaining a good shim effect in subsequent use.

[0062] In actual applications, during the process of applying a preset current to the shim coil, the connection direction of the current may be different from the preset current connection direction, resulting in the shim coil failing to achieve the expected shim effect. Based on this, in one embodiment of the present application, it is possible to determine whether the electrical connection of the shim coil 103 is incorrect based on the obtained magnetic field strength component so as to make timely corrections to ensure the shim effect. Based on this, in one embodiment of the present application, determining the sensitivity and / or electrical connection accuracy of the at least one shim coil based on the magnetic field strength component of the at least one shim coil may include:

[0063] S501 : When the positive and negative polarities of the magnetic field intensity components of the shim coil are different from the positive and negative polarities of the preset current applied by the shim coil, determine that an electrical connection of the shim coil is incorrect.

[0064] In an embodiment of the present application, the shim coil detection device 107 can set the current value and current polarity to be applied to the shim coil 103, and control the coil current controller 105 to apply the current value to the corresponding shim coil in the shim coil 103 according to the current polarity. Due to the positive and negative relationship between the current polarity, the coefficients of different orders obtained by expanding the magnetic field distribution information are positive and negative, and therefore the magnetic field intensity components corresponding to the shim coil 103 are also positive and negative. In one embodiment of the present application, the positive and negative polarity of the magnetic field intensity components of the shim coil 103 can be compared with the positive and negative polarity of the preset current applied by the shim coil 103. If it is determined that the positive and negative polarity of the magnetic field intensity components of the shim coil 103 is different from the positive and negative polarity of the preset current applied by the shim coil 103, it can be determined that the electrical connection of the shim coil 103 is incorrect. For example, in one example, when the magnetic field intensity component corresponding to the shim coil 1 is -1.1 Tesla and the preset current applied by the shim coil 1 is 0.5 A, it can be determined that the electrical connection of the shim coil 1 is wrong.

[0065] Through the above embodiment, an electrical connection error of the shim coil 103 can be determined based on a comparison result of the positive and negative polarities of the magnetic field intensity components of the shim coil 103 and the positive and negative polarities of the preset current applied by the shim coil 103. Compared with the methods for determining the accuracy of electrical connection in the prior art, this method is more efficient and provides more accurate detection results.

[0066] In actual applications, during the actual process of applying a preset current to the shim coil, the magnitude or direction of the current may be different from the preset current magnitude or direction due to some factors, resulting in the shim coil failing to achieve the expected shim effect. In one embodiment of the present application, it is possible to determine whether the electrical connection of the shim coil is correct based on the obtained magnetic field strength component so as to make timely corrections to ensure the shim effect. Specifically, determining the sensitivity and / or electrical connection accuracy of the at least one shim coil based on the magnetic field strength component of the at least one shim coil may include:

[0067] S601: When it is determined that the magnetic field intensity component values of the plurality of target shim coils do not match the reference magnetic field intensity component values, determine that the currents actually applied by the plurality of target shim coils do not match the preset currents.

[0068] In an embodiment of the present application, the reference magnetic field intensity components of the at least one shim coil 103 can be determined based on the preset current and reference sensitivity applied by the at least one shim coil 103. For example, the reference magnetic field intensity components can be determined based on the product value of the preset current and the reference sensitivity. Then, based on the multiple reference magnetic field intensity components, the magnetic field intensity components corresponding to the at least one shim coil 103 can be determined. In one embodiment of the present application, the magnetic field intensity components corresponding to the at least one shim coil 103 can be compared with the reference magnetic field intensity components. When it is determined that the magnetic field intensity component values of the multiple target shim coils do not match the reference magnetic field intensity component values, it can be determined that the currents actually applied by the multiple target shim coils do not match the preset currents. The situation where the applied current does not match the preset current may include that the magnitude of the applied current does not match the magnitude of the preset current. In one embodiment of the present application, the reason why the magnitude of the applied current does not match the magnitude of the preset current may be that the magnitude of the current applied by the coil current controller 105 is inaccurate, or that the multiple currents applied to the multiple target shim coils are cross-connected, for example, the preset current that should be applied to the shim coil 1 is mistakenly connected to the shim coil 2. In this case, it is necessary to determine the multiple cross-connected currents and determine the correct connection relationship. Specifically, in one embodiment of the present application, in the case of determining that the magnetic field strength component values of the multiple target shim coils do not match the reference magnetic field strength component values, after determining that the current actually applied by the multiple target shim coils does not match the preset current, it may also include:

[0069] S701: Determining, based on the magnetic field intensity component values of the multiple target shim coils, a cross-connection relationship of preset currents applied to the multiple target shim coils, wherein the cross-connection relationship causes the currents actually applied to the multiple target shim coils to not match the preset currents;

[0070] S703: Correct the cross-connection relationship to determine a correct connection relationship.

[0071] In an embodiment of the present application, after determining that the current actually applied by the multiple target shim coils does not match the preset current, the cross-connection relationship of the preset current applied to the multiple target shim coils can be determined based on the magnetic field strength component values of the multiple target shim coils. In one embodiment of the present application, the actual current value applied to each target shim coil can be determined separately based on the corresponding magnetic field strength component values of each target shim coil. By comparing the multiple actual current values with the multiple preset current values, the correct correspondence between the multiple preset currents and the multiple target shim coils can be determined. Afterwards, the connection relationship of the preset currents applied to the multiple target shim coils can be adjusted correctly based on the correct correspondence. For example, in one example, the cross-connection relationship of the preset currents of shim coil 1, shim coil 2, and shim coil 3 can be determined based on the magnetic field strength component values of the target shim coil, such as the preset current 1 originally applied to shim coil 1 is connected to shim coil 2, the preset current 2 originally applied to shim coil 2 is connected to shim coil 3, and the preset current 3 originally applied to shim coil 3 is connected to shim coil 1. After determining the cross-connection relationship, the preset current 1 originally applied to shim coil 1 can be connected to shim coil 1, the preset current 2 originally applied to shim coil 2 can be connected to shim coil 2, and the preset current 3 originally applied to shim coil 3 can be connected to shim coil 3, thereby adjusting the current connection relationship among shim coil 1, shim coil 2, and shim coil 3 to a correct connection relationship.

[0072] Through the above embodiment, an incorrect current connection relationship can be adjusted to a correct current connection relationship according to the magnetic field intensity component values of the multiple target shim coils, so that the shimming effect of the shim coil 103 can achieve the expected effect.

[0073] The above describes in detail the shim coil detection method provided by the present application. Figure 3 , describing the shim coil detection device 107 provided in the present application, the shim coil detection device 107 is used in a magnetic resonance device, and the shim coil detection device 107 includes:

[0074] a magnetic field distribution information determining module 1071, configured to apply a preset current to at least one shim coil to determine magnetic field distribution information generated by the superposition of the magnetic resonance device and the at least one shim coil;

[0075] a magnetic field intensity component determination module 1073, configured to determine the magnetic field intensity components of the at least one shim coil according to the magnetic field distribution information;

[0076] The detection module 1075 is configured to determine the sensitivity and / or electrical connection accuracy of the at least one shim coil according to the magnetic field strength component of the at least one shim coil.

[0077] Optionally, in one embodiment of the present application, determining the sensitivity of the shim coil and / or the accuracy of the electrical connection according to the magnetic field strength component of the at least one shim coil includes:

[0078] determining sensitivity information of the at least one shim coil based on a preset relationship between the magnetic field intensity component, the preset current, and the sensitivity information;

[0079] The accuracy of the sensitivity of the at least one shim coil is determined according to the sensitivity information of the at least one shim coil.

[0080] Optionally, in one embodiment of the present application, determining the accuracy of the sensitivity of the at least one shim coil according to the sensitivity information of the at least one shim coil includes:

[0081] obtaining reference sensitivity information of the at least one shim coil;

[0082] The accuracy of the sensitivity of the at least one shim coil is determined according to a comparison result between the sensitivity information and the reference sensitivity information.

[0083] Optionally, in one embodiment of the present application, determining the sensitivity and / or electrical connection accuracy of the at least one shim coil according to the magnetic field strength component of the at least one shim coil includes:

[0084] When the positive and negative polarities of the magnetic field intensity components of the shim coil are different from the positive and negative polarities of the preset current applied by the shim coil, it is determined that the electrical connection of the shim coil is incorrect.

[0085] Optionally, in one embodiment of the present application, determining the sensitivity and / or electrical connection accuracy of the at least one shim coil according to the magnetic field strength component of the at least one shim coil includes:

[0086] When it is determined that the magnetic field intensity component values of the plurality of target shim coils do not match the reference magnetic field intensity component values, it is determined that the currents actually applied by the plurality of target shim coils do not match the preset currents.

[0087] Optionally, in one embodiment of the present application, after determining that the magnetic field intensity component values of the multiple target shim coils do not match the reference magnetic field intensity component values, and determining that the currents actually applied by the multiple target shim coils do not match the preset currents, the method further includes:

[0088] determining, based on the magnetic field intensity component values of the plurality of target shim coils, a cross-connection relationship of preset currents applied to the plurality of target shim coils, wherein the cross-connection relationship causes the currents actually applied to the plurality of target shim coils to not match the preset currents;

[0089] The cross-connection relationship is corrected to determine the correct connection relationship.

[0090] According to the embodiments of the present application, the shim coil detection device 107 may correspond to executing the methods described in the embodiments of the present application, and the above-mentioned and other operations and / or functions of each module in the shim coil detection device 107 are respectively for implementing the corresponding processes of the methods provided in the above-mentioned embodiments. For the sake of brevity, they are not described here in detail.

[0091] It should also be noted that the embodiments described above are merely illustrative, wherein the modules described as separate components may or may not be physically separate, and the components displayed as modules may or may not be physical modules, that is, they may be located in one place, or they may be distributed across multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment. In addition, in the drawings of the device embodiments provided in this application, the connection relationship between the modules indicates that there is a communication connection between them, which can be specifically implemented as one or more communication buses or signal lines.

[0092] On the other hand, the present application also provides a magnetic resonance imaging system, including a magnetic resonance device, at least one shim coil, and a shim coil detection module. The magnetic resonance device includes a main magnet, the main magnet is used to generate a main magnetic field, the at least one shim coil is used to generate a shim magnetic field to compensate for the non-uniformity of the main magnetic field, and the shim coil detection module is used to implement the steps of the shim coil detection method described in each of the above embodiments.

[0093] On the other hand, the present application further provides a processing device, including a memory and a processor, wherein the memory stores computer program instructions, and the processor is configured to run the computer program instructions to execute the shim coil detection method described in each of the above embodiments.

[0094] The processing device may be a physical device or a cluster of physical devices, or a virtualized cloud device, such as at least one cloud computing device in a cloud computing cluster. For ease of understanding, this application uses the processing device as an independent physical device to illustrate the structure of the processing device.

[0095] like Figure 4As shown, the processing device 400 includes: a processor and a memory for storing processor computer program instructions; wherein the processor is configured to implement the above-mentioned device when executing the computer program instructions. The processing device 400 includes a memory 401, a processor 403, a bus 405 and a communication interface 407. The memory 401, the processor 403 and the communication interface 407 communicate with each other through the bus 405. The bus 405 can be a peripheral component interconnect standard (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 4 The bus is represented by only one thick line, but it does not mean that there is only one bus or one type of bus. The communication interface 407 is used for communicating with the outside.

[0096] The processor 403 may be a central processing unit (CPU). The memory 401 may include a volatile memory, such as a random access memory (RAM). The memory 401 may also include a non-volatile memory, such as a read-only memory (ROM), a flash memory, a HDD, or an SSD.

[0097] Those skilled in the art will understand that Figure 4 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0098] On the other hand, the present application further provides a chip, comprising at least one processor, wherein the processor is configured to run computer program instructions stored in a memory to execute the steps of the shim coil detection method described in each of the above embodiments.

[0099] On the other hand, the present application further provides a computer-readable storage medium having computer program instructions stored thereon. When the computer program instructions are executed by a processor, the steps of the shim coil detection method described in each of the above embodiments are implemented.

[0100] A computer-readable storage medium can be a tangible device that can hold and store instructions used by an instruction execution device. A computer-readable storage medium can be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination thereof. More specific examples (non-exhaustive list) of computer-readable storage media include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disc (DVD), a memory stick, a floppy disk, a mechanical encoding device, a punch card or a raised structure in a groove on which instructions are stored, and any suitable combination thereof.

[0101] The computer program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer program instructions from the network and forwards the computer program instructions to be stored in the computer-readable storage medium in the respective computing / processing device.

[0102] The computer program instructions for performing the operations of the present application may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages such as Smalltalk, C++, and conventional procedural programming languages such as "C" or similar programming languages. The computer program instructions may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider). In some embodiments, by utilizing the status information of computer program instructions to personalize an electronic circuit, such as a programmable logic circuit, a field-programmable gate array (FPGA), or a programmable logic array (PLA), the electronic circuit can execute the computer program instructions, thereby implementing various aspects of the present application.

[0103] Various aspects of the present application are described herein with reference to flowcharts and / or block diagrams of methods and apparatus according to embodiments of the present application. It should be understood that each block of the flowcharts and / or block diagrams, and combinations of blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions.

[0104] These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, thereby producing a machine, so that when these instructions are executed by the processor of the computer or other programmable data processing device, a device is generated to implement the functions / actions specified in one or more blocks in the flowchart and / or block diagram. These computer program instructions can also be stored in a computer-readable storage medium, where these instructions cause the computer, programmable data processing device, and / or other equipment to operate in a specific manner. Thus, the computer-readable medium storing the instructions comprises an article of manufacture, which includes instructions for implementing various aspects of the functions / actions specified in one or more blocks in the flowchart and / or block diagram.

[0105] Computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device so that a series of operational steps are performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to implement the functions / actions specified in one or more blocks in the flowchart and / or block diagram.

[0106] The flow charts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, systems and methods according to multiple embodiments of the present application. In this regard, each box in the flow chart or block diagram can represent a part of a module, program segment or instruction, and the part of the module, program segment or instruction comprises one or more executable instructions for realizing the logical function of the specification. In some alternative implementations, the functions marked in the box can also occur in a sequence different from that marked in the accompanying drawings. For example, two continuous boxes can actually be executed substantially in parallel, and they can sometimes also be executed in the opposite order, depending on the functions involved.

[0107] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A shim coil detection method for a magnetic resonance device, characterized in that: The method comprises: Applying a preset current to at least one shim coil to determine magnetic field distribution information generated by superposition of the magnetic resonance device and the at least one shim coil; determining, according to the magnetic field distribution information, respectively a magnetic field intensity component of the at least one shim coil corresponding to a Legendre polynomial; The accuracy of the electrical connection of the at least one shim coil is determined based on the magnetic field strength component of the at least one shim coil.

2. The method according to claim 1, characterized in that Determining the accuracy of the electrical connection of the at least one shim coil according to the magnetic field strength component of the at least one shim coil includes: When the positive and negative polarities of the magnetic field intensity components of the shim coil are different from the positive and negative polarities of the preset current applied by the shim coil, it is determined that the electrical connection of the shim coil is incorrect.

3. The method according to claim 1, characterized in that Determining the accuracy of the electrical connection of the at least one shim coil according to the magnetic field strength component of the at least one shim coil includes: When it is determined that the magnetic field intensity component values of the plurality of target shim coils do not match the reference magnetic field intensity component values, it is determined that the currents actually applied by the plurality of target shim coils do not match the preset currents.

4. The method according to claim 3, characterized in that After determining that the magnetic field intensity component values of the target shim coils do not match the reference magnetic field intensity component values and determining that the currents actually applied by the target shim coils do not match the preset currents, the method further includes: determining, based on the magnetic field intensity component values of the plurality of target shim coils, a cross-connection relationship of preset currents applied to the plurality of target shim coils, wherein the cross-connection relationship causes the currents actually applied to the plurality of target shim coils to not match the preset currents; The cross-connection relationship is corrected to determine the correct connection relationship.

5. A shim coil detection device for magnetic resonance equipment, characterized in that: The device comprises: a magnetic field distribution information determining module, configured to apply a preset current to at least one shim coil to determine magnetic field distribution information generated by the superposition of the magnetic resonance device and the at least one shim coil; a magnetic field intensity component determination module, configured to determine the magnetic field intensity components corresponding to Legendre polynomials of the at least one shim coil according to the magnetic field distribution information; The detection module is configured to determine the accuracy of the electrical connection of the at least one shim coil according to the magnetic field strength component of the at least one shim coil.

6. A magnetic resonance imaging system, characterized in that The method comprises a magnetic resonance device, at least one shim coil, and a shim coil detection module, wherein the magnetic resonance device comprises a main magnet, the main magnet is used to generate a main magnetic field, the at least one shim coil is used to generate a shim magnetic field to compensate for the non-uniformity of the main magnetic field, and the shim coil detection module is used to implement the steps of the shim coil detection method according to any one of claims 1 to 4.

7. A processing device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the shim coil detection method according to any one of claims 1 to 4 are implemented.

8. A computer-readable storage medium having computer program instructions stored thereon, characterized in that: When the computer program instructions are executed by a processor, the steps of the shim coil detection method according to any one of claims 1 to 4 are implemented.

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