Specific absorption rate determination method and device, equipment, storage medium and program product

Abstract

The invention relates to a specific absorption rate determination method and device, equipment, a storage medium and a program product. The method comprises the following steps: acquiring a sensitivity distribution matrix of a patient and radio frequency coil port parameters of magnetic resonance equipment; based on the sensitivity distribution matrix and the radio frequency coil port parameters, acquiring the absorption power proportion of the patient; and determining the specific absorption rate of the patient according to the ratio of the total absorption power of the magnetic resonance equipment to the absorption power of the patient. The method can be applied to any transmitting mode.

Description

Technical Field

[0001] The present application relates to the field of magnetic resonance technology, and in particular to a method, device, equipment, storage medium and program product for determining a specific absorption rate. Background Art

[0002] In ultra-high field magnetic resonance equipment, a multi-channel transmission system is often required to perform radio frequency field homogenization in order to improve the uniformity of the radio frequency field.

[0003] In the related art, the specific absorption rate corresponding to the patient is mainly found from the specific absorption rates corresponding to multiple preset emission modes by looking up a table based on the emission model of the magnetic resonance device. However, the method of the related art is only applicable to the preset emission mode and cannot be applied to any emission mode. Summary of the invention

[0004] Based on this, it is necessary to provide a method, device, equipment, storage medium and program product for determining a specific absorption rate in response to the above technical problems, which can be applicable to any emission mode.

[0005] In a first aspect, the present application provides a method for determining a specific absorption rate, comprising:

[0006] Obtaining a sensitivity distribution matrix of a patient and radio frequency coil port parameters of a magnetic resonance device;

[0007] Based on the sensitivity distribution matrix and the radio frequency coil port parameters, the absorbed power ratio of the patient is obtained;

[0008] The specific absorption rate of the patient is determined based on the ratio of the total absorbed power of the magnetic resonance device to the absorbed power of the patient.

[0009] In one embodiment, obtaining a sensitivity distribution matrix of a patient and radio frequency coil port parameters of a magnetic resonance device includes:

[0010] Obtaining radio frequency shimming parameters of the patient during the pre-scan process;

[0011] According to the patient's physiological characteristic information and radio frequency shimming parameters, the patient's sensitivity distribution matrix and the radio frequency coil port parameters of the magnetic resonance device are found from the parameter database.

[0012] In one embodiment, the method further comprises:

[0013] Constructing radio frequency coil models for multiple radio frequency coils on a magnetic resonance device;

[0014] Using the radio frequency coil model to perform three-dimensional electromagnetic field simulation on multiple human body models, and obtaining the sensitivity distribution matrix of the multiple human body models and the radio frequency coil port parameters of the magnetic resonance device;

[0015] The sensitivity distribution matrices of the multiple human body models and the radio frequency coil port parameters of the magnetic resonance device are stored in a parameter database.

[0016] In one embodiment, obtaining the absorbed power ratio of the patient based on the sensitivity distribution matrix and the radio frequency coil port parameters includes:

[0017] Acquire the patient's physiological characteristic information and radio frequency shimming parameters during the pre-scan process;

[0018] The absorbed power ratio of the patient is calculated based on the sensitivity distribution matrix, radio frequency coil port parameters, physiological characteristic information of the patient, scanning position of the patient and radio frequency shim parameters.

[0019] In one embodiment, the patient's specific absorption rate includes a systemic specific absorption rate;

[0020] Determine the patient's specific absorption rate based on the ratio of total absorbed power to the patient's absorbed power, including:

[0021] Calculate the product of the total absorbed power and the patient's proportion of absorbed power;

[0022] The ratio of the product to the patient's mass is taken as the patient's systemic specific absorption rate.

[0023] In one embodiment, the patient's SAR also includes a partial body SAR;

[0024] Determine the patient's specific absorption rate based on the ratio of total absorbed power to the patient's absorbed power, including:

[0025] Obtaining a ratio of a partial body sensitivity distribution matrix to a whole body sensitivity distribution matrix of the patient;

[0026] The product of the ratio and the patient's whole body SAR is taken as the patient's partial body SAR.

[0027] In a second aspect, the present application also provides a device for determining a specific absorption rate, comprising:

[0028] An acquisition module, used for acquiring a sensitivity distribution matrix of a patient and radio frequency coil port parameters of a magnetic resonance device;

[0029] A first determination module is used to obtain the patient's absorbed power ratio based on the sensitivity distribution matrix and the radio frequency coil port parameters;

[0030] The second determination module is used to determine the specific absorption rate of the patient according to the ratio of the total absorption power of the magnetic resonance device to the absorption power of the patient.

[0031] In a third aspect, the present application further provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the content of any one embodiment of the method for determining the specific absorption rate in the first aspect is implemented.

[0032] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the content of any one embodiment of the method for determining the specific absorption rate in the first aspect above.

[0033] In a fifth aspect, the present application further provides a computer program product, including a computer program, which, when executed by a processor, implements the content of any one embodiment of the method for determining the specific absorption rate in the first aspect above.

[0034] The above-mentioned method, device, equipment, storage medium and program product for determining the specific absorption rate obtain the sensitivity distribution matrix of the patient and the radio frequency coil port parameters of the magnetic resonance device; obtain the patient's absorption power ratio based on the sensitivity distribution matrix and the radio frequency coil port parameters; and determine the patient's specific absorption rate according to the total absorption power of the magnetic resonance device and the patient's absorption power ratio. In different transmission modes, the transmission amplitude, phase difference, the sensitivity distribution matrix of the patient and the radio frequency coil port parameters of the magnetic resonance device cause the specific absorption rate of the patient in different transmission modes to be completely different, that is, the method of calculating the specific absorption rate can be applied to various transmission models. In addition, by obtaining the sensitivity distribution matrix and the radio frequency coil port parameters in the method, the magnetic resonance scanning process of the patient in the corresponding transmission mode can be accurately predicted. Then, based on the sensitivity distribution matrix and the radio frequency coil port parameters, the patient's absorption power ratio can be accurately predicted, so that the specific absorption rate of the patient in different transmission modes can be accurately determined based on the absorption power ratio and the total absorption power. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments of the present application or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0036] FIG1 is a diagram showing an application environment of a method for determining a specific absorption rate in one embodiment;

[0037] FIG2 is a schematic flow chart of a method for determining specific absorption rate in one embodiment;

[0038] FIG3 is a schematic flow chart of a method for determining specific absorption rate in one embodiment;

[0039] FIG4 is a schematic flow chart of a method for determining specific absorption rate in one embodiment;

[0040] FIG5 is a schematic flow chart of a method for determining specific absorption rate in one embodiment;

[0041] FIG6 is a schematic flow chart of a method for determining specific absorption rate in one embodiment;

[0042] FIG7 is a schematic block diagram of a plurality of radio frequency coils of a magnetic resonance device according to an embodiment;

[0043] FIG8 is a schematic flow chart of a method for determining specific absorption rate in one embodiment;

[0044] FIG9 is a schematic flow chart of a method for determining specific absorption rate in one embodiment;

[0045] FIG10 is a schematic flow chart of a method for determining specific absorption rate in one embodiment;

[0046] FIG11 is a schematic flow chart of a method for determining specific absorption rate in one embodiment;

[0047] FIG12 is a schematic flow chart of a method for determining specific absorption rate in one embodiment;

[0048] FIG13 is a schematic flow chart of a method for determining specific absorption rate in one embodiment;

[0049] FIG14 is a schematic flow chart of a method for determining specific absorption rate in one embodiment;

[0050] FIG15 is a schematic flow chart of a method for determining specific absorption rate in one embodiment;

[0051] FIG16 is a flow chart of a method for determining specific absorption rate in one embodiment;

[0052] FIG. 17 is a structural block diagram of a device for determining a specific absorption rate in one embodiment. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0054] Before introducing the technical solution of the present application in detail, a brief introduction to the background technology of the present application is first given.

[0055] Magnetic resonance equipment is generally composed of a magnet, a gradient system, a radio frequency transmission system (including a radio frequency transmission coil), a receiving system (including a receiving coil), and related peripheral equipment (such as a hospital bed, a human-computer interface, an electronic cabinet, and a computer, etc.). Among them, the magnet is used to generate the main magnetic field (B0 field); the gradient system is used to generate the gradient field of spatial encoding; the radio frequency transmission system is used to generate the radio frequency field (B1 field); and the receiving system is used to receive magnetic resonance signals.

[0056] In order to improve the imaging signal-to-noise ratio of the magnetic resonance imaging process, the magnetic field strength of the B0 field can be increased. As the magnetic field strength of the B0 field increases, the frequency of the B1 field will also increase. However, due to the existence of dielectric effects, the uniformity of the B1 field inside the human body will decrease as the field strength increases. In order to alleviate the problem of uneven uniformity of the B1 field, multi-channel transmission technology can be used, that is, multiple transmitting coils are set in the radio frequency transmission system of the magnetic resonance device, and the uniformity of the ultra-high field radio frequency transmission B1 field is adjusted by adjusting the transmission amplitude and phase of each transmission channel.

[0057] The amplitude and phase of each transmission channel are determined based on the pre-scan of the specific scanned patient. For different scanned patients, different patients and different scanned parts may have different transmission amplitude ratios and phase differences of each channel, which makes the transmission amplitude ratios and phase differences of each channel vary greatly. The transmission amplitude ratios and phase differences of each channel can be collectively referred to as RF shimming parameters.

[0058] Different RF shimming parameters bring great challenges to the management of specific absorption rate (SAR). The basic calculation principle of SAR is to monitor the forward power and reverse power of RF transmission. The total absorption power can be obtained by using the forward power and reverse power, and then the SAR of the patient is calculated based on the total absorption power. Among them, the total absorption power is divided into several parts: (1) power is lost by the transmitting coil itself, for example, the heat generated by the electronic devices and conductors of the transmitting coil and its structural parts is converted into heat energy; (2) power is radiated into the surrounding space, resulting in radiation loss; (3) power is absorbed by the scanned patient. For the absorption power of the scanned patient, since the RF field is not uniform inside the human body, the absorption ratio of each part of the patient's body is inconsistent, and different RF shimming parameters will change the distribution of the RF field, thereby also affecting the proportion of net human body absorption power in the total absorption power.

[0059] The conventional practice in the management of specific absorption rate is to measure through a directional coupler and its data acquisition link to obtain the forward power and reverse power. The ratio of the net absorbed power of the human body to the total absorbed power using the preset RF shim parameters can be obtained by pre-measurement or calculation, and the absorption ratio of each part of the human body can be simulated in advance. For field strengths of 3T and below, the B1 field inhomogeneity is not obvious, and a limited number of preset RF shim parameters can be used to optimize the same scanning part of different patients. With the increase of the B0 field, the inhomogeneity of the B1 field gradually increases. The limited RF shim parameters cannot meet the clinical scanning requirements, and the B1 field needs to be optimized for different patients in real time, that is, the RF shim parameters will not be confirmed in the development stage, which means that all RF shim parameter information cannot be obtained when the model of specific absorption rate is established. It is necessary to consider any combination of the amplitude ratio and phase difference of each channel emission, which brings huge challenges to the establishment and development of the model of specific absorption rate.

[0060] In the related art, the specific absorption rate corresponding to the patient is mainly found from the specific absorption rates corresponding to multiple preset emission modes by looking up a table based on the emission model of the magnetic resonance device.

[0061] In view of the above problems, the present application provides a method, device, equipment, storage medium and program product for determining a specific absorption rate. The method for determining a specific absorption rate can be applied to any emission mode. Of course, the technical solution provided in the embodiments of the present application is not limited to solving only the above problems, and there are other technical effects. For details, please refer to the following embodiment description. The technical solution of the present application is described in detail below.

[0062] The method for determining the specific absorption rate provided in the embodiment of the present application can be applied in the application environment as shown in Figure 1. The computer device in the application environment can be a server, a personal computer, a laptop computer, a smart phone, a tablet computer, a smart mobile phone, etc. The computer device may include a processor, a memory and a network interface connected via a system bus or wirelessly. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device may include a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data in the process of determining the specific absorption rate. The network interface of the computer device is used to communicate with an external terminal through a network connection, and the computer program is executed by the processor to implement a method for determining the specific absorption rate.

[0063] In an exemplary embodiment, as shown in FIG2 , a method for determining a specific absorption rate is provided, which is described by taking the method applied to the computer device in FIG1 as an example, and includes the following steps 201 to 203. Among them:

[0064] S201, obtaining a sensitivity distribution matrix of a patient and radio frequency coil port parameters of a magnetic resonance device.

[0065] The sensitivity distribution matrix refers to the corresponding relationship between the change of conductivity distribution in the patient and the change of induced electric field in the receiving coil. The RF coil port parameters refer to the parameters at multiple RF coil ports of the magnetic resonance device. For example, the port parameters can be scattering parameters, impedance parameters, reflection parameters, etc.

[0066] In an embodiment of the present application, the computer device can analyze the relevant information of the patient during the scanning process of the magnetic resonance device based on the calculation method of the sensitivity distribution matrix to determine the sensitivity distribution matrix of the patient. Alternatively, a plurality of different types of sensitivity distribution matrices are stored in the parameter database, and the computer device can use the relevant information of the patient during the scanning process of the magnetic resonance device to match the plurality of different types of sensitivity distribution matrices respectively, and use the successfully matched sensitivity matrix as the sensitivity distribution matrix of the patient. The embodiment of the present application does not limit the method for obtaining the sensitivity distribution matrix of the patient.

[0067] For the radio frequency coil port parameters of the magnetic resonance device, the computer device may obtain the radio frequency coil port parameters from the public parameters of the magnetic resonance device, or determine the radio frequency coil port parameters by inferring the public parameters of the magnetic resonance device. Alternatively, a plurality of radio frequency coil port parameters are stored in the parameter database, and the computer device matches the public parameters of the magnetic resonance device with the plurality of radio frequency coil port parameters, and uses the successfully matched radio frequency coil port parameters as the radio frequency coil port parameters of the magnetic resonance device.

[0068] S202, obtaining the patient's absorbed power ratio based on the sensitivity distribution matrix and the radio frequency coil port parameters.

[0069] During the scanning process, the transmitting coil itself will lose part of the absorbed power, and the surrounding space will also lose part of the absorbed power. The remaining absorbed power will be absorbed by the patient. The patient's absorbed power ratio refers to the ratio between the patient's absorbed power and all absorbed powers.

[0070] In an embodiment of the present application, the computer device may input the sensitivity distribution matrix and the radio frequency coil port parameters into a preset ratio prediction model, predict the ratio between all absorbed powers of the patient's absorbed power through the ratio prediction model, and output the patient's absorbed power ratio. Alternatively, the computer device may bring the sensitivity distribution matrix and the radio frequency coil port parameters into the calculation formula of the absorbed power ratio to calculate the patient's absorbed power ratio.

[0071] S203, determining the specific absorption rate of the patient according to the ratio of the total absorption power of the magnetic resonance device to the absorption power of the patient.

[0072] In the embodiment of the present application, the computer device can analyze the ratio of the total absorption power of the magnetic resonance device and the absorption power of the patient based on the calculation method of the specific absorption rate to obtain the specific absorption rate of the patient. During the magnetic resonance scanning process, the patient's whole body can be scanned, or the patient's local scan can be performed. Therefore, the specific absorption rate of the patient at least includes the specific absorption rate of the whole body, the specific absorption rate of the local area, the specific absorption rate of the head, and the specific absorption rate of part of the body.

[0073] In the above-mentioned method for determining the specific absorption rate, the sensitivity distribution matrix of the patient and the radio frequency coil port parameters of the magnetic resonance device are obtained; based on the sensitivity distribution matrix and the radio frequency coil port parameters, the absorbed power ratio of the patient is obtained; and according to the total absorbed power of the magnetic resonance device and the absorbed power ratio of the patient, the specific absorption rate of the patient is determined. In different transmission modes, the transmission amplitude, phase difference, the sensitivity distribution matrix of the patient and the radio frequency coil port parameters of the magnetic resonance device result in completely different specific absorption rates of the patient in different transmission modes, that is, the method of calculating the specific absorption rate can be applied to various transmission models. In addition, by obtaining the sensitivity distribution matrix and the radio frequency coil port parameters in the method, the magnetic resonance scanning process of the patient in the corresponding transmission mode can be accurately predicted. Then, based on the sensitivity distribution matrix and the radio frequency coil port parameters, the absorbed power ratio of the patient can be accurately predicted, so that based on the absorbed power ratio and the total absorbed power, the specific absorption rate of the patient in different transmission modes can be accurately determined.

[0074] The process of obtaining the sensitivity distribution matrix of the patient and the radio frequency coil port parameters is a key step in calculating the specific absorption rate of the patient. Therefore, in one embodiment, as shown in FIG3 , the specific content of obtaining the sensitivity distribution matrix of the patient and the radio frequency coil port parameters of the magnetic resonance device is introduced, and the specific content includes the following steps:

[0075] S301, obtaining radio frequency shimming parameters of the patient during a pre-scan process.

[0076] The radio frequency shimming parameters refer to the amplitude and phase of each transmission channel of the magnetic resonance device during the magnetic resonance pre-scanning of the patient.

[0077] In the embodiment of the present application, if the pre-scan process of the patient has been completed in advance, and the radio frequency shimming parameters in the pre-scan process are stored in the shimming parameter database, then the computer device can search for the relevant parameters identical to the identification information from the shimming parameter database according to the patient's identification information, and use the relevant parameters identical to the identification information as the radio frequency shimming parameters of the patient during the scanning process.

[0078] Optionally, if the patient has not undergone pre-scanning and the patient has made preparations for pre-scanning, the computer device can send a pre-scanning instruction to the magnetic resonance device, and after receiving the pre-scanning instruction, the magnetic resonance device pre-scans the patient to obtain the amplitude and phase of each transmission channel during the pre-scanning process. The amplitude and phase of each transmission channel are used as radio frequency shimming parameters in the subsequent scanning process.

[0079] S302, searching the sensitivity distribution matrix of the patient and the radio frequency coil port parameters of the magnetic resonance device from a parameter database according to the physiological characteristic information of the patient and the radio frequency shimming parameters.

[0080] Among them, the physiological characteristic information can be the patient's height, weight, age, etc. Various types of human body sensitivity distribution matrices and radio frequency coil port parameters of magnetic resonance equipment are stored in the parameter database. Various types of human body sensitivity distribution matrices can be obtained by simulating human body models of different heights and weights, or they can be sensitivity distribution matrices of historical scanned patients. The radio frequency coil port parameters of the magnetic resonance equipment can be obtained by simulating the electromagnetic field of the magnetic resonance equipment, or they can be multiple radio frequency coil port parameters in the historical scanning process. The embodiment of the present application does not limit the source of the sensitivity distribution matrix and radio frequency coil port parameters stored in the parameter database.

[0081] In an embodiment of the present application, the computer device can match the patient's physiological characteristic information with multiple physiological characteristic information in the parameter database, and use the successfully matched physiological characteristic information as candidate physiological characteristic information. Then, the radio frequency shim parameters in the pre-scan process are matched with the radio frequency shim parameters corresponding to the candidate physiological characteristic information, and information identical or similar to the radio frequency shim parameters is searched from the parameter database. The identical or similar information is used as the sensitivity distribution matrix of the patient and the radio frequency coil port parameters of the magnetic resonance device.

[0082] In the above-mentioned method for determining the specific absorption rate, the radio frequency shimming parameters of the patient during the pre-scan process are obtained; according to the patient's physiological characteristics and the radio frequency shimming parameters, the sensitivity distribution matrix of the patient and the radio frequency coil port parameters of the magnetic resonance device are searched from the parameter database. This method can accurately determine the transmission mode during the magnetic resonance scanning process through the radio frequency shimming parameters of the pre-scan process. Based on the radio frequency shimming parameters and the patient's physiological characteristics, the sensitivity distribution matrix and radio frequency coil port parameters of the patient can be accurately searched from the parameter database.

[0083] Next, the construction process of the above parameter data is introduced through an embodiment, as shown in FIG4 , the construction process has the following steps:

[0084] S401, constructing a radio frequency coil model of multiple radio frequency coils on a magnetic resonance device.

[0085] In an embodiment of the present application, a computer device may obtain parameter information of a radio frequency coil on a magnetic resonance device, and construct a radio frequency coil model of the magnetic resonance device based on the parameter information of the radio frequency coil. For example, when the magnetic resonance device includes radio frequency coils of 8 channels, the corresponding radio frequency coil model also includes radio frequency coils of 8 channels.

[0086] S402, performing three-dimensional electromagnetic field simulation on multiple human body models using a radio frequency coil model to obtain sensitivity distribution matrices of the multiple human body models and radio frequency coil port parameters of the magnetic resonance device.

[0087] In the embodiment of the present application, the computer device can predict multiple human models of different heights and weights, and use the constructed radio frequency coil model to perform three-dimensional electromagnetic field simulation on multiple human models, that is, simulate the magnetic resonance scanning process of multiple human models to obtain simulation results. And according to the simulation results, the sensitivity distribution matrix of each human model and the radio frequency coil port parameters of the magnetic resonance device are determined.

[0088] Based on the calculation formula of the sensitivity distribution matrix, the specific absorption rate (SAR) at point r in the space using the RF shim parameters during the simulation process can be expressed as:

[0089]

[0090] Among them, the Q(r) matrix is ​​an n×n positive definite matrix, which is defined as the sensitivity matrix; σ(r) represents the conductivity of human tissue at point r; ρ(r) represents the density of human tissue at point r; ω represents the RF uniform field parameter; E(r) represents the electric field complex vector of all coil channels at point r; E i (r) represents the E field of the i-th channel coil at point r; represents the E field complex vector generated by the unit excitation of each channel; H represents the conjugate transpose. Based on the above formula, the simulation results can be integrated in different volumes V to obtain the sensitivity matrix of different regions. For example, integrating within the patient's head can obtain the head sensitivity matrix; integrating within the whole body can obtain the whole body sensitivity matrix; integrating within the exposed area of ​​the body can obtain the partial body sensitivity matrix; integrating within 10g of tissue can obtain the local sensitivity matrix within 10g of tissue.

[0091] S403: Store the sensitivity distribution matrices of the multiple human body models and the radio frequency coil port parameters of the magnetic resonance device into a parameter database.

[0092] In an embodiment of the present application, after obtaining the sensitivity distribution matrices of multiple human body models and the radio frequency coil port parameters of the magnetic resonance device, the multiple sensitivity distribution matrices and the radio frequency coil port parameters are stored in a parameter database. For example, the data stored in the parameter database includes: scattering parameter S0, head sensitivity distribution matrix, whole body sensitivity distribution matrix, partial body sensitivity distribution matrix, and local sensitivity distribution matrix, etc. The parameter database may be a memory in the magnetic resonance device.

[0093] It is understandable that the computer device can also integrate the sensitivity distribution matrices of multiple human body models and the radio frequency coil port parameters of the magnetic resonance device into a lookup table. When it is necessary to find the sensitivity distribution matrix corresponding to the patient and the radio frequency coil port parameters of the magnetic resonance device, the sensitivity distribution matrix and radio frequency coil port parameters matching the patient can be directly queried in the lookup table.

[0094] In the above-mentioned method for determining the specific absorption rate, a radio frequency coil model of multiple radio frequency coils on a magnetic resonance device is constructed; a three-dimensional electromagnetic field simulation is performed on multiple human body models using the radio frequency coil model to obtain the sensitivity distribution matrix of the multiple human body models and the radio frequency coil port parameters of the magnetic resonance device; and the sensitivity distribution matrix of the multiple human body models and the radio frequency coil port parameters of the magnetic resonance device are stored in a parameter database. This method can simulate the magnetic resonance scanning process of multiple human body models by constructing a radio frequency coil model and performing a three-dimensional electromagnetic field simulation, so that the sensitivity distribution matrix and radio frequency coil port parameters of the multiple human body models can be accurately obtained, making the information in the parameter database richer.

[0095] Next, the specific content of obtaining the patient's absorbed power ratio based on the sensitivity distribution matrix and the radio frequency coil port parameters is introduced through an embodiment. As shown in FIG5 , the specific content includes the following steps:

[0096] S501, obtaining physiological characteristic information of the patient and radio frequency shimming parameters in the pre-scan process.

[0097] In an embodiment of the present application, the computer device may filter out the patient's physiological characteristic information based on the patient's registration information during the process of booking the magnetic resonance device. Alternatively, the computer device may also measure the patient's physiological characteristic information before the magnetic resonance scan. The embodiment of the present application does not limit the method of obtaining the patient's physiological characteristic information.

[0098] It is understandable that the computer device can search for relevant parameters identical to the identification information from the shimming parameter database according to the patient's identification information, and use the relevant parameters identical to the identification information as the RF shimming parameters of the patient during the pre-scan process. Alternatively, the computer device can send a pre-scan instruction to the magnetic resonance device, and after receiving the pre-scan instruction, the magnetic resonance device pre-scans the patient to obtain the amplitude and phase of each transmission channel during the pre-scan process. The amplitude and phase of each transmission channel are used as the RF shimming parameters during the pre-scan process.

[0099] S502, calculating the patient's absorbed power ratio based on the sensitivity distribution matrix, the radio frequency coil port parameters, the patient's scanning part, the patient's physiological characteristic information and the radio frequency shim parameters.

[0100] In the embodiment of the present application, the calculation formula of the patient's absorbed power ratio can be expressed as:

[0101]

[0102] The sensitivity distribution matrix includes a local sensitivity distribution matrix and a whole-body sensitivity distribution matrix. The computer device can obtain the whole-body sensitivity distribution matrix from the sensitivity distribution matrix, that is, the whole-body sensitivity distribution matrix. In addition, the patient mass is obtained from the patient's physiological characteristic information. Then, the whole-body sensitivity distribution matrix, the RF coil port parameters, the patient mass and the RF shim parameters are all brought into the above formula to calculate the patient's absorbed power ratio.

[0103] In the above-mentioned method for determining the specific absorption rate, the patient's physiological characteristics information and the radio frequency shimming parameters in the pre-scan process are obtained; based on the sensitivity distribution matrix, the radio frequency coil port parameters, the patient's scanning part, the patient's physiological characteristics information and the radio frequency shimming parameters, the patient's absorbed power ratio is calculated. This method can accurately calculate the ratio of the patient's absorbed power to the total absorbed power through multiple parameter information such as the sensitivity distribution matrix, the radio frequency coil port parameters, the patient's physiological characteristics information and the radio frequency shimming parameters, and the obtained patient's absorbed power ratio is more accurate.

[0104] The total absorbed power of the RF coil channels can be determined by measuring the voltage of the RF coil. In one embodiment, as shown in FIG6 , the method for calculating the total absorbed power of multiple RF coil channels on a magnetic resonance device comprises the following steps:

[0105] S601, measuring the forward voltage and reverse voltage of each radio frequency coil of the magnetic resonance device.

[0106] FIG7 is a block diagram of the principle of multiple radio frequency coils of a magnetic resonance device. The radio frequency transmission signal of each channel is amplified by a radio frequency power amplifier (RFPA). The forward voltage (UF n ) and reverse voltage (UR n ) is collected and fed into the RF transmitting coil for exciting the magnetic resonance signal. The collected signal is converted into a digital signal through A / D analog-to-digital conversion, and the power or specific absorption rate is monitored after data processing. Among them, the multi-channel transmission system provides more free adjustment variables for the ultra-high field magnetic resonance system, that is, the transmission complex signal of each transmission channel: A1( 1 ), A2( 2), …A n ( n ) controls the B1 fields of the coil units of each channel to be combined into a more uniform synthetic B1 field in the target imaging area, where A1, A2, …, An represent the amplitudes of the transmission signals of each transmission channel, respectively. 1, 2,…, n Respectively represent the phase of the transmission signal of each transmission channel.

[0107] S602: Determine the total absorbed power of multiple radio frequency coil channels on the magnetic resonance device according to each forward voltage and each reverse voltage.

[0108] In an embodiment of the present application, the computer device may bring multiple forward voltages and corresponding reverse voltages into a calculation formula for total absorbed power, and obtain the total absorbed power of multiple radio frequency coil channels on the magnetic resonance device through calculation using the formula.

[0109] In the above method for determining the specific absorption rate, the forward voltage and the reverse voltage of each radio frequency coil of the magnetic resonance device are measured; and the total absorbed power of multiple radio frequency coil channels on the magnetic resonance device is determined based on each forward voltage and each reverse voltage. In this method, both the forward voltage and the reverse voltage are measured, and based on the measured forward voltage and the reverse voltage, the total absorbed power of multiple radio frequency coil channels on the magnetic resonance device can be accurately calculated.

[0110] In one embodiment, as shown in FIG8 , determining the total absorbed power of multiple radio frequency coil channels on the magnetic resonance device according to each forward voltage and each reverse voltage includes:

[0111] S701, calculating the sum of square differences between forward voltages and reverse voltages of multiple radio frequency coil channels on a magnetic resonance device.

[0112] In the embodiment of the present application, the calculation formula for the total absorbed power of multiple radio frequency coil channels of the magnetic resonance device can be expressed as:

[0113]

[0114] Among them, Ptotal represents the total absorbed power; Z0 represents the characteristic impedance of the RF coil. Generally, Z0=50 ohms, which is the impedance of the RF coil; UF i represents the forward voltage of the i-th RF coil; UR i represents the reverse voltage of the i-th RF coil.

[0115] Therefore, in the embodiment of the present application, for any RF coil channel on the magnetic resonance device, the computer device can calculate the square difference between the forward voltage and the reverse voltage on the RF coil channel, and then add the square differences of all RF coil channels to obtain the sum of the square differences of multiple RF coil channels on the magnetic resonance device.

[0116] S702 , taking the ratio of the sum of the square differences to the impedance of the radio frequency coil as the total absorbed power of the radio frequency coil channel.

[0117] In an embodiment of the present application, after obtaining the sum of square differences of multiple radio frequency coil channels on the magnetic resonance device, the computer device calculates the ratio of the sum of square differences to the radio frequency coil impedance, and uses the ratio as the total absorbed power of the radio frequency coil channel.

[0118] In the above method for determining the specific absorption rate, for any RF coil channel, the sum of the square differences between the forward voltage and the reverse voltage of the RF coil channel is calculated; and the ratio of the sum of the square differences to the RF coil impedance is used as the total absorbed power of the RF coil channel. This method can accurately calculate the total absorbed power by calculating the ratio of the square difference to the RF coil impedance using the calculation formula for the total absorbed power.

[0119] During the MRI scan, the patient can be scanned on the whole body, part (for example, any 10g of tissue), head, or part of the body (for example, the abdomen, stomach, etc.). It should be noted that the part here does not refer to the part of the patient's body, but refers to the local specific absorption rate. Next, the scanning process of the whole body, part, head, and part of the body of the patient will be introduced one by one.

[0120] First, the process of calculating the whole-body specific absorption rate of a patient is described in detail through an embodiment. As shown in FIG9 , the specific absorption rate of the patient includes the whole-body specific absorption rate. The specific calculation process of determining the specific absorption rate of the patient based on the ratio of the total absorbed power to the absorbed power of the patient may include:

[0121] S801, calculating the product of the total absorbed power and the absorbed power ratio of the patient.

[0122] In the embodiment of the present application, the calculation formula of the whole body specific absorption rate can be expressed as:

[0123]

[0124] Therefore, the computer device may multiply the total absorbed power Ptotal by the absorbed power ratio of the patient to obtain the product of the total absorbed power and the absorbed power ratio of the patient.

[0125] S802, taking the ratio of the product to the patient's mass as the patient's whole body specific absorption rate.

[0126] In the embodiment of the present application, after obtaining the product, the computer device calculates the ratio of the product to the patient's mass, and uses the obtained ratio as the patient's whole body specific absorption rate. It should be noted that the whole body specific absorption rate of patients with different masses is different.

[0127] In the above-mentioned method for determining the specific absorption rate, the product of the total absorbed power and the patient's absorbed power ratio is calculated; and the ratio of the product to the patient's physiological characteristic information is used as the patient's whole-body specific absorption rate. This method can accurately calculate the patient's whole-body specific absorption rate through the calculation formula of the whole-body specific absorption rate, the total absorbed power, the absorbed power ratio, and the patient's mass and other parameter information.

[0128] Next, another embodiment is used to introduce in detail the process of calculating the local specific absorption rate of the patient. As shown in FIG10 , the specific absorption rate of the patient also includes the local specific absorption rate. The above-mentioned determination of the specific absorption rate of the patient based on the ratio of the total absorbed power to the absorbed power of the patient includes:

[0129] S901, obtaining a ratio of a local sensitivity distribution matrix to a whole body sensitivity distribution matrix of the patient.

[0130] In the embodiment of the present application, the calculation formula of the local specific absorption rate can be expressed as:

[0131]

[0132] in, Indicates the normalized RF shimming parameters. The RF shimming parameters of each RF coil channel can be normalized by the RF shimming parameters of the first RF coil channel. The RF shimming parameters are expressed as: .in, Indicates the phase of the transmit signal of each transmit channel.

[0133] Furthermore, the ratio of the local specific absorption rate to the whole-body specific absorption rate can be calculated according to the fitted data through a series of different patient information (such as height, weight) and the patient's position relative to the RF transmitting coil.

[0134] S902: The product of the ratio and the systemic specific absorption rate of the patient is taken as the local specific absorption rate of the patient.

[0135] In an embodiment of the present application, after obtaining the ratio of the local sensitivity distribution matrix to the whole-body sensitivity distribution matrix, the computer device may multiply the ratio by the whole-body specific absorption rate of the patient, and use the obtained product as the local specific absorption rate of the patient.

[0136] In the above-mentioned method for determining the specific absorption rate, the ratio of the patient's local sensitivity distribution matrix to the whole-body sensitivity distribution matrix is ​​obtained; and the product of the ratio and the patient's whole-body specific absorption rate is taken as the patient's local specific absorption rate. This method can accurately calculate the patient's local specific absorption rate through the calculation formula of the local specific absorption rate, the whole-body specific absorption rate, the sensitivity distribution matrix and other parameter information.

[0137] Another embodiment is used to introduce in detail the process of calculating the head specific absorption rate of the patient. As shown in FIG11 , the specific absorption rate of the patient also includes the head specific absorption rate. The above-mentioned determination of the specific absorption rate of the patient based on the ratio of the total absorbed power to the absorbed power of the patient includes:

[0138] S1001, obtaining a ratio of a patient's head sensitivity distribution matrix to a whole body sensitivity distribution matrix.

[0139] In the embodiment of the present application, when the local scan of the patient is a head scan, the calculation formula of the specific absorption rate of the head can be expressed as:

[0140]

[0141] Furthermore, the ratio of the head specific absorption rate to the whole body specific absorption rate can be calculated according to the fitted data through a series of different patient information (such as height, weight) and the position of the patient relative to the RF transmitting coil.

[0142] S1002, taking the product of the ratio and the patient's whole body specific absorption rate as the patient's head specific absorption rate.

[0143] In an embodiment of the present application, after obtaining the ratio of the head sensitivity distribution matrix to the whole body sensitivity distribution matrix, the computer device can multiply the ratio by the patient's whole body absorption power and use the product as the patient's head specific absorption rate.

[0144] In the above-mentioned method for determining the specific absorption rate, the ratio of the patient's head sensitivity distribution matrix to the whole body sensitivity distribution matrix is ​​obtained; and the product of the ratio and the patient's whole body specific absorption rate is taken as the patient's head specific absorption rate. This method can accurately calculate the patient's head specific absorption rate through the calculation formula of the head specific absorption rate, the whole body specific absorption rate, the sensitivity distribution matrix and other parameter information.

[0145] Finally, another embodiment is used to introduce in detail the process of calculating the specific absorption rate of a part of the patient's body. As shown in FIG12 , the specific absorption rate of the patient also includes the specific absorption rate of the part of the body. The above-mentioned determination of the specific absorption rate of the patient based on the ratio of the total absorbed power to the absorbed power of the patient includes:

[0146] S1101, obtaining a ratio of a partial body sensitivity distribution matrix to a whole body sensitivity distribution matrix of a patient.

[0147] In the embodiment of the present application, when the local scan of the patient is a partial body scan, the calculation formula of the specific absorption rate of the partial body can be expressed as:

[0148]

[0149] Furthermore, the ratio of the partial specific absorption rate to the whole body specific absorption rate can be calculated according to the fitted data through a series of different patient information (such as height, weight) and the position of the patient relative to the RF transmitting coil.

[0150] S1102, taking the product of the ratio and the whole body specific absorption rate of the patient as the partial body specific absorption rate of the patient.

[0151] In an embodiment of the present application, after obtaining the ratio of the partial body sensitivity distribution matrix to the whole body sensitivity distribution matrix, the computer device can multiply the ratio by the patient's whole body absorption power and use the product as the patient's partial body specific absorption rate.

[0152] In the above-mentioned method for determining the specific absorption rate, the ratio of the partial body sensitivity distribution matrix of the patient to the whole body sensitivity distribution matrix is ​​obtained; and the product of the ratio and the whole body specific absorption rate of the patient is taken as the partial body specific absorption rate of the patient. This method can accurately calculate the partial body specific absorption rate of the patient through the calculation formula of the partial body specific absorption rate, the whole body specific absorption rate and the sensitivity distribution matrix and other parameter information.

[0153] When the specific absorption rate of the patient is determined, the magnetic resonance scanning process can be managed according to the specific absorption rate of the patient. In one embodiment, the above method may also include:

[0154] The patient's magnetic resonance scanning process is managed based on the patient's specific absorption rate.

[0155] In an embodiment of the present application, after obtaining the specific absorption rate of the patient, in one case, the computer device can analyze the specific absorption rate of the patient to determine whether the scanning conditions are met. If the scanning conditions are met, the subsequent process of performing a magnetic resonance scan on the patient is performed. If the scanning conditions are not met, the specific absorption rate of the patient needs to be recalculated.

[0156] In another case, the computer device can calculate the specific absorption rate of the patient during the scanning process according to the measured forward voltage and reverse voltage during the scanning process, and determine whether the patient meets the scanning conditions during the scanning process according to the specific absorption rate. Once it is found that the specific absorption rate of the patient during the scanning process does not meet the scanning conditions, the magnetic resonance scanning is stopped.

[0157] In the above-mentioned method for determining the specific absorption rate, the patient's magnetic resonance scanning process is managed according to the patient's specific absorption rate. Since the total absorbed power is calculated from the measured voltage, the patient's specific absorption rate calculated by the total absorbed power will also be more accurate, so that the patient's magnetic resonance scanning process can be managed more accurately.

[0158] The management of the MRI scanning process is divided into two situations, one is the management before the MRI scanning, and the other is the management during the MRI scanning process. Next, the management process before the MRI scanning is introduced through an embodiment. As shown in FIG13 , the specific content of the management of the MRI scanning process of the patient according to the specific absorption rate of the patient includes:

[0159] S1201, verify the patient's specific absorption rate.

[0160] In the embodiment of the present application, the computer device can compare the specific absorption rate of the patient with a preset threshold value. If the specific absorption rate of the patient is greater than or equal to the preset threshold value, it means that the specific absorption rate of the patient is large and is not suitable for magnetic resonance scanning, that is, the verification fails. If the specific absorption rate of the patient is less than the preset threshold value, it means that the specific absorption rate of the patient is small and magnetic resonance scanning can be performed, that is, the verification passes.

[0161] S1202: If the patient's specific absorption rate is verified to be passed, a magnetic resonance scan is performed on the patient using a magnetic resonance device.

[0162] In the embodiment of the present application, when the patient's specific absorption rate is verified to be passed, the computer device can send a scanning instruction to the magnetic resonance device. After receiving the scanning instruction, the magnetic resonance device performs a magnetic resonance scan on the patient based on the scanning instruction.

[0163] In the above-mentioned specific absorption rate determination method, the specific absorption rate of the patient is verified; if the specific absorption rate of the patient passes the verification, the patient is subjected to an MRI scan by means of an MRI device. This method analyzes the specific absorption rate of the patient by means of verification to accurately determine whether an MRI scan can be performed on the patient, thereby improving the safety of the MRI scanning process.

[0164] In one embodiment, as shown in FIG. 14 , the specific content of managing the patient's magnetic resonance scanning process according to the patient's specific absorption rate includes:

[0165] S1301, obtaining measured voltages of multiple radio frequency coil channels during scanning of a patient using a magnetic resonance device.

[0166] In the embodiment of the present application, when the magnetic resonance device is scanning a patient, each radio frequency coil on the magnetic resonance device will emit a radio frequency field. In this case, a forward voltage and a reverse voltage will be generated on the directional coupler of each radio frequency coil. The computer device can measure the forward voltage and the reverse voltage on each radio frequency coil through a voltage detection device to obtain the measured voltages of multiple radio frequency coil channels.

[0167] S1302: Determine a current specific absorption rate of the patient based on measured voltages of a plurality of radio frequency coil channels.

[0168] In an embodiment of the present application, after obtaining the measured voltages of multiple radio frequency coil channels, the computer device can calculate the total absorbed power of multiple radio frequency coil channels of the magnetic resonance device according to the calculation formula of the total absorbed power, and calculate the patient's current specific absorption rate based on parameters such as the total absorbed power, patient mass, and sensitivity distribution matrix.

[0169] S1303: If the current specific absorption rate verification fails, the magnetic resonance device is controlled to stop scanning.

[0170] In the embodiment of the present application, the computer device may compare the current specific absorption rate with a preset threshold value.

[0171] If the current specific absorption rate is greater than or equal to the preset threshold, it is determined that the current specific absorption rate verification has failed; if the current specific absorption rate is less than the preset threshold, it is determined that the current specific absorption rate verification has succeeded. In the case of verification failure, it means that the subsequent magnetic resonance scanning process cannot be continued. At this time, the computer device can control the magnetic resonance device to stop scanning.

[0172] In the above-mentioned method for determining the specific absorption rate, during the process of scanning a patient using a magnetic resonance device, the measured voltages of multiple radio frequency coil channels are obtained; based on the measured voltages of multiple radio frequency coil channels, the current specific absorption rate of the patient is determined; if the current specific absorption rate verification fails, the magnetic resonance device is controlled to stop scanning. This method measures the voltage during the scanning process, and based on the measured voltage, the current specific absorption rate can be accurately calculated. Then, by means of verification, abnormalities can be discovered in time, and the magnetic resonance device can be controlled to stop scanning, thereby ensuring the scanning safety of the magnetic resonance device.

[0173] In a specific embodiment, as shown in FIG15 , the above-mentioned method for determining the specific absorption rate includes the following steps:

[0174] S1401, constructing a radio frequency coil model of multiple radio frequency coils on a magnetic resonance device;

[0175] S1402, performing three-dimensional electromagnetic field simulation on multiple human body models using the radio frequency coil model to obtain sensitivity distribution matrices of the multiple human body models and radio frequency coil port parameters of the magnetic resonance device;

[0176] S1403, storing the sensitivity distribution matrices of the multiple human body models and the radio frequency coil port parameters of the magnetic resonance device in a parameter database;

[0177] S1404, obtaining radio frequency shimming parameters of the patient during the pre-scan process;

[0178] S1405, searching the patient's sensitivity distribution matrix and the radio frequency coil port parameters of the magnetic resonance device from a parameter database according to the patient's physiological characteristic information and radio frequency shimming parameters;

[0179] S1406, obtaining the patient's physiological characteristic information and radio frequency shimming parameters during the pre-scan process;

[0180] S1407, calculating the patient's absorbed power ratio based on the sensitivity distribution matrix, the radio frequency coil port parameters, the patient's physiological characteristic information and the radio frequency shim parameters;

[0181] S1408, measuring the forward voltage and reverse voltage of each radio frequency coil of the magnetic resonance device;

[0182] S1409, calculating the sum of square differences between forward voltages and reverse voltages of multiple radio frequency coil channels on the magnetic resonance device;

[0183] S1410, taking the ratio of the sum of the square differences to the impedance of the radio frequency coil as the total absorbed power of the radio frequency coil channel;

[0184] S1411, calculating the product of the total absorbed power and the absorbed power ratio of the patient;

[0185] S1412, taking the ratio of the product to the patient's mass as the patient's systemic specific absorption rate;

[0186] S1413, calculating the local specific absorption rate according to the local sensitivity distribution matrix and the whole body specific absorption rate of the patient; and calculating the head specific absorption rate according to the head sensitivity distribution matrix and the whole body specific absorption rate of the patient; and calculating the partial body specific absorption rate according to the partial body sensitivity distribution matrix and the whole body specific absorption rate of the patient;

[0187] S1414, managing the patient's magnetic resonance scanning process according to the patient's specific absorption rate.

[0188] 16 is a flow chart of the method for determining the specific absorption rate, S1501, constructing a radio frequency coil model of a magnetic resonance device; S1502, obtaining multiple human body models; S1503, performing three-dimensional electromagnetic field simulation based on the radio frequency coil model and multiple human body models; S1504: storing the simulated radio frequency coil port parameters, head sensitivity distribution matrix, whole body sensitivity distribution matrix, partial body sensitivity distribution matrix and local sensitivity distribution matrix into a parameter database; S1505, based on patient information, patient relative coil position information and radio frequency uniform field parameters, searching the patient's sensitivity distribution matrix and radio frequency coil port parameters in a reference database, and calculating the patient's absorbed power ratio; S1506, calculating the patient's net absorbed power based on the patient's absorbed power ratio and total absorbed power; S1507, calculating the patient's specific absorption rate based on the patient's net absorbed power and the patient's weight.

[0189] It should be understood that, although the steps in the flowcharts involved in the above embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0190] Based on the same inventive concept, the embodiment of the present application also provides a device for determining a specific absorption rate for implementing the method for determining a specific absorption rate involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the method above, so the specific limitations in one or more embodiments of the device for determining a specific absorption rate provided below can refer to the limitations on the method for determining a specific absorption rate above, and will not be repeated here.

[0191] In an exemplary embodiment, as shown in FIG. 17 , a device for determining a specific absorption rate is provided, comprising: an acquisition module 11, a first determination module 12, and a second determination module 13, wherein:

[0192] An acquisition module 11 is used to acquire a sensitivity distribution matrix of a patient and radio frequency coil port parameters of a magnetic resonance device;

[0193] A first determination module 12 is used to obtain the patient's absorbed power ratio based on the sensitivity distribution matrix and the radio frequency coil port parameters;

[0194] The second determination module 13 is used to determine the specific absorption rate of the patient according to the ratio of the total absorbed power of the magnetic resonance device to the absorbed power of the patient.

[0195] In one embodiment, the acquisition module 11 includes: a first acquisition unit and a search unit, wherein:

[0196] A first acquisition unit, used for acquiring radio frequency shimming parameters of the patient during the pre-scan process;

[0197] The search unit is used to search the sensitivity distribution matrix of the patient and the radio frequency coil port parameters of the magnetic resonance device from the parameter database according to the physiological characteristic information of the patient and the radio frequency shim parameters.

[0198] In one embodiment, the above-mentioned specific absorption rate determination device further includes: a construction module, a simulation module and a storage module, wherein:

[0199] A construction module for constructing a radio frequency coil model of a plurality of radio frequency coils of a magnetic resonance device;

[0200] A simulation module, used to perform three-dimensional electromagnetic field simulation on multiple human body models using a radio frequency coil model, to obtain sensitivity distribution matrices of the multiple human body models and radio frequency coil port parameters of the magnetic resonance device;

[0201] The storage module is used to store the sensitivity distribution matrices of multiple human body models and the radio frequency coil port parameters of the magnetic resonance device in a parameter database.

[0202] In one embodiment, the first determination module 12 includes: a second acquisition unit and a first calculation unit, wherein:

[0203] A second acquisition unit is used to acquire the patient's physiological characteristic information and the radio frequency shimming parameters in the pre-scan process;

[0204] The first calculation unit is used to calculate the absorbed power ratio of the patient based on the sensitivity distribution matrix, the radio frequency coil port parameters, the scanning part of the patient, the physiological characteristic information of the patient and the radio frequency shim parameters.

[0205] In one embodiment, the above-mentioned specific absorption rate determination device further includes: a measurement module and a calculation module, wherein:

[0206] A measuring module, used for measuring a forward voltage and a reverse voltage of each radio frequency coil of a magnetic resonance device;

[0207] The calculation module is used to determine the total absorbed power of multiple radio frequency coil channels on the magnetic resonance device according to each forward voltage and each reverse voltage.

[0208] In one embodiment, the third determination module includes: a second calculation unit and a first determination unit, wherein:

[0209] A second calculation unit, configured to calculate, for any one radio frequency coil channel, a sum of square differences between a forward voltage and a reverse voltage of the radio frequency coil channel;

[0210] The first determining unit is configured to use the ratio of the sum of the square differences to the impedance of the radio frequency coil as the total absorbed power of the radio frequency coil channel.

[0211] In one embodiment, the second determination module includes: a third calculation unit and a second determination unit, wherein:

[0212] a third calculation unit, configured to calculate the product of the total absorbed power and the absorbed power ratio of the patient;

[0213] The second determination unit is used to use the ratio of the product to the patient's mass as the whole-body specific absorption rate of the patient.

[0214] In one embodiment, the second determination module further includes: a third acquisition unit and a third determination unit, wherein:

[0215] A third acquisition unit is used to acquire a ratio of a local sensitivity distribution matrix to a whole body sensitivity distribution matrix of the patient;

[0216] The third determination unit is configured to use the product of the ratio and the systemic specific absorption rate of the patient as the local specific absorption rate of the patient.

[0217] In one embodiment, the second determination module further includes: a fourth acquisition unit and a fourth determination unit, wherein:

[0218] a fourth acquisition unit, used to acquire a ratio of a head sensitivity distribution matrix to a whole body sensitivity distribution matrix of the patient;

[0219] The fourth determination unit is used to use the product of the ratio and the whole body specific absorption rate of the patient as the head specific absorption rate of the patient.

[0220] In one embodiment, the second determination module further includes: a fifth acquisition unit and a fifth determination unit, wherein:

[0221] In one embodiment, the second determination module further includes: a fifth acquisition unit and a fifth determination unit, wherein:

[0222] a fifth acquisition unit, configured to acquire a ratio of a partial body sensitivity distribution matrix to a whole body sensitivity distribution matrix of the patient;

[0223] A fifth determining unit is configured to use the product of the ratio and the whole-body specific absorption rate of the patient as the partial body specific absorption rate of the patient.

[0224] In one embodiment, the above-mentioned specific absorption rate determination device further includes: a management module, wherein:

[0225] The management module is used to manage the magnetic resonance scanning process of the patient according to the specific absorption rate of the patient.

[0226] In one embodiment, the management module includes: a verification unit and a scanning unit, wherein:

[0227] A calibration unit, used for calibrating the specific absorption rate of the patient;

[0228] The scanning unit is used to perform a magnetic resonance scan on the patient through a magnetic resonance device when the patient's specific absorption rate is verified to be passed.

[0229] In one embodiment, the management module includes: a sixth acquisition unit, a sixth determination unit and a control unit, wherein:

[0230] a sixth acquisition unit, configured to acquire measured voltages of a plurality of radio frequency coil channels during scanning of a patient using a magnetic resonance device;

[0231] a sixth determination unit, configured to determine a current specific absorption rate of the patient based on the measured voltages of the plurality of radio frequency coil channels;

[0232] The control unit is used to control the magnetic resonance device to stop scanning when the current specific absorption rate verification fails.

[0233] Each module in the above-mentioned specific absorption rate determination device can be implemented in whole or in part by software, hardware and a combination thereof. Each of the above-mentioned modules can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute the operations corresponding to each of the above modules.

[0234] In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the content of any one embodiment of the above-mentioned method for determining specific absorption rate is implemented.

[0235] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the content of any one embodiment of the above-mentioned method for determining specific absorption rate is implemented.

[0236] In one embodiment, a computer program product is provided, comprising a computer program, which implements the content of any one of the embodiments of the above-mentioned method for determining specific absorption rate when executed by a processor.

[0237] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0238] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0239] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0240] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for determining a specific absorption rate, characterized in that: The method comprises: Obtaining a sensitivity distribution matrix of a patient and radio frequency coil port parameters of a magnetic resonance device; Based on the sensitivity distribution matrix and the radio frequency coil port parameters, obtaining the absorbed power ratio of the patient; The specific absorption rate of the patient is determined based on the ratio of the total absorbed power of the magnetic resonance apparatus to the absorbed power of the patient.

2. The method according to claim 1, characterized in that The step of obtaining the sensitivity distribution matrix of the patient and the radio frequency coil port parameters of the magnetic resonance device includes: Acquiring radio frequency shimming parameters of the patient during a pre-scan process; According to the physiological characteristic information of the patient and the radio frequency shimming parameters, the sensitivity distribution matrix of the patient and the radio frequency coil port parameters of the magnetic resonance device are searched from a parameter database.

3. The method according to claim 2, characterized in that The method further comprises: Constructing radio frequency coil models for multiple radio frequency coils on a magnetic resonance device; Using the radio frequency coil model to perform three-dimensional electromagnetic field simulation on multiple human body models, to obtain sensitivity distribution matrices of the multiple human body models and radio frequency coil port parameters of the magnetic resonance device; The sensitivity distribution matrices of the multiple human body models and the radio frequency coil port parameters of the magnetic resonance device are stored in the parameter database.

4. The method according to any one of claims 1 to 3, characterized in that: The obtaining the absorbed power ratio of the patient based on the sensitivity distribution matrix and the radio frequency coil port parameters includes: Acquiring physiological characteristic information of the patient and radio frequency shimming parameters during the pre-scan process; The absorbed power ratio of the patient is calculated based on the sensitivity distribution matrix, the radio frequency coil port parameters, the scanning part of the patient, the physiological characteristic information of the patient and the radio frequency shim parameters.

5. The method according to any one of claims 1 to 3, characterized in that: The patient's specific absorption rate includes a systemic specific absorption rate; Determining the specific absorption rate of the patient according to the ratio of the total absorbed power to the absorbed power of the patient includes: calculating the product of the total absorbed power and the absorbed power ratio of the patient; The ratio of the product to the patient's mass is taken as the whole-body specific absorption rate of the patient.

6. The method according to claim 5, characterized in that The patient's specific absorption rate also includes a partial body specific absorption rate; Determining the specific absorption rate of the patient according to the ratio of the total absorbed power to the absorbed power of the patient includes: Obtaining a ratio of a partial body sensitivity distribution matrix to a whole body sensitivity distribution matrix of the patient; The product of the ratio and the whole body specific absorption rate of the patient is taken as the partial body specific absorption rate of the patient.

7. A device for determining a specific absorption rate, characterized in that: The device comprises: An acquisition module, used for acquiring a sensitivity distribution matrix of a patient and radio frequency coil port parameters of a magnetic resonance device; A first determination module, configured to obtain the absorbed power ratio of the patient based on the sensitivity distribution matrix and the radio frequency coil port parameters; The second determination module is used to determine the specific absorption rate of the patient according to the ratio of the total absorbed power of the magnetic resonance device to the absorbed power of the patient.

8. A computer 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 method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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