Magnetic resonance scanning method and scanning control method of magnetic resonance system

Abstract

The invention relates to a magnetic resonance scanning method and a scanning control method of a magnetic resonance system. The method comprises the following steps: based on physique information, body position information and a to-be-scanned part of a detected object, searching a target PNS limit value model adaptive to the detected object from a plurality of groups of PNS limit value models; the multiple groups of PNS limit value models are obtained by performing gradient pulse testing on a plurality of prior test objects with different physiques at different body positions and different scanning parts; determining a PNS limit value corresponding to the sequence to be scanned based on the target PNS limit value model; in response to the fact that the PNS predicted value of the sequence to be scanned is not matched with the corresponding PNS limit value, optimizing at least one parameter of the sequence to be scanned; and scanning the to-be-scanned part of the detected object by adopting the optimized scanning sequence. By adopting the method, the gradient performance of the magnetic resonance system can be brought into full play, and the scanning result of magnetic resonance can be improved.

Description

Technical Field

[0001] This application relates to the field of magnetic resonance scanning technology, and in particular to a magnetic resonance scanning method and a scanning control method for a magnetic resonance system. Background Art

[0002] During magnetic resonance scanning, an induced electric field will be generated in the human body in a changing magnetic field. An action potential will be generated in the nerve membrane in the human body under the action of this induced electric field. When the action potential is greater than a certain threshold, peripheral nerve stimulation (PNS) will occur. Once the PNS detection value exceeds the limit, there will be certain potential safety hazards to the human body.

[0003] In related technologies, during magnetic resonance scanning, the PNS limit value of the most sensitive part of the human body is mainly applied to all scanning parts of the human body to ensure the safety of the magnetic resonance scanning process. However, this method will limit the performance of the gradient of the magnetic resonance system and affect the scanning results of magnetic resonance. Summary of the Invention

[0004] Based on this, it is necessary to provide a magnetic resonance scanning method and a scanning control method for a magnetic resonance system in view of the above technical problems, which can give full play to the gradient performance of the magnetic resonance system and help improve the scanning results of magnetic resonance.

[0005] In a first aspect, this application provides a magnetic resonance scanning method, including:

[0006] Based on the physical constitution information, body position information, and part to be scanned of the detection object, find a target PNS limit model adapted to the detection object from multiple groups of PNS limit models; the multiple groups of PNS limit models are obtained by performing gradient pulse tests on multiple prior test objects with different physical constitutions in different body positions and different scanning parts;

[0007] Based on the target PNS limit model, determine the PNS limit value corresponding to the sequence to be scanned;

[0008] In response to the PNS prediction value of the sequence to be scanned not matching the corresponding PNS limit value, optimize at least one parameter of the sequence to be scanned;

[0009] Scan the part to be scanned of the detection object using the optimized scan sequence.

[0010] In one embodiment, based on the target PNS limit model, determining the PNS limit value corresponding to the sequence to be scanned includes:

[0011] Obtain the effective stimulation duration of at least one time sequence segment in the sequence to be scanned;

[0012] Determine the PNS limit of the sequence to be scanned based on the effective stimulation duration of at least one temporal segment and the target PNS limit model.

[0013] In one embodiment, in response to the PNS prediction value of the sequence to be scanned not matching the corresponding PNS limit, optimize at least one parameter of the sequence to be scanned, including:

[0014] Obtain the target temporal segment corresponding to the mismatched PNS prediction value;

[0015] Optimize the parameters in the target temporal segment.

[0016] In one embodiment, the target PNS limit model represents a curve of the PNS limit varying with time.

[0017] In one embodiment, the at least one parameter includes phase encoding resolution, readout encoding resolution, phase direction FOV, readout direction FOV, and slice thickness.

[0018] In one embodiment, the construction process of multiple groups of PNS limit models includes:

[0019] Perform gradient pulse tests on prior test subjects with different constitutions at different body positions and different scanning sites, and fit the PNS limits corresponding to the effective stimulation durations obtained from each test to obtain multiple groups of PNS limit models.

[0020] In one embodiment, the method further includes:

[0021] During the process of scanning the part to be scanned of the detection object using the optimized scanning sequence, obtain the PNS detection value corresponding to the current temporal segment of the scanning sequence;

[0022] Determine the magnetic resonance scanning state of the part to be scanned according to the PNS detection value corresponding to the current temporal segment and the corresponding PNS limit.

[0023] In one embodiment, determining the magnetic resonance scanning state of the part to be scanned according to the PNS detection value corresponding to the current temporal segment and the corresponding PNS limit includes:

[0024] When the PNS detection value corresponding to the current temporal segment is greater than the corresponding PNS limit, control the magnetic resonance scanning state to be in a stopped scanning state.

[0025] In a second aspect, the present application further provides a scanning control method for a magnetic resonance system, the method including:

[0026] Obtain the constitution information and body position information of the detection object, where the detection object includes a first part to be scanned and a second part to be scanned;

[0027] Search for a candidate PNS limit model adapted to the detection object from the database based on the physical constitution information and body position information; the database includes multiple groups of PNS limit models;

[0028] Control the first part to be scanned of the detection object to move to the imaging field of view of the magnetic resonance system;

[0029] Scan the first part to be scanned using the target scan sequence;

[0030] Control the second part to be scanned of the detection object to move to the imaging field of view of the magnetic resonance system, and select a second target PNS limit model that matches the second part to be scanned from the candidate PNS limit models;

[0031] Based on the second target PNS limit model, determine the PNS limit corresponding to scanning the second part to be scanned with the target scan sequence;

[0032] In response to the PNS predicted value not matching the corresponding PNS limit, optimize at least one parameter of the second scan sequence to be scanned based on the PNS detection value of the first part to be scanned, and obtain an optimized target scan sequence;

[0033] Scan the second part to be scanned using the optimized target scan sequence, determine the second PNS detection value corresponding to the second scan sequence to be scanned based on the second target PNS limit model during the scanning process, and stop scanning the second part to be scanned after the second PNS detection value exceeds the corresponding second PNS limit.

[0034] In a third aspect, the present application also provides a scanning control method for a magnetic resonance system, and the method includes:

[0035] Obtain the part to be scanned, physical constitution information, and body position information of the detection object;

[0036] Determine an initial scan protocol from the scan protocol database based on the part to be scanned;

[0037] Search for a candidate PNS limit model adapted to the detection object from the database based on the physical constitution information and body position information; the database includes multiple groups of PNS limit models;

[0038] And select a target PNS limit model that matches the part to be scanned from the candidate PNS limit models;

[0039] Based on the target PNS limit model, determine the PNS limit corresponding to the initial scan protocol;

[0040] In response to the PNS predicted value of the scan sequence to be scanned not matching the corresponding PNS limit, optimize at least one parameter of the scan sequence to be scanned to obtain a target scan sequence;

[0041] The to-be-scanned part of the detection object is scanned using a target scanning sequence.

[0042] In a fourth aspect, the present application further provides a magnetic resonance scanning device, including:

[0043] An acquisition module, configured to find a target PNS limit model adapted to the detection object from multiple groups of PNS limit models based on the physical constitution information, body position information, and to-be-scanned part of the detection object; the multiple groups of PNS limit models are obtained by performing gradient pulse tests on multiple prior test objects with different physical constitutions in different body positions and different scanning parts;

[0044] A determination module, configured to determine the PNS limit corresponding to the to-be-scanned sequence based on the target PNS limit model;

[0045] An optimization module, configured to optimize at least one parameter of the to-be-scanned sequence in response to the PNS predicted value of the to-be-scanned sequence not matching the corresponding PNS limit;

[0046] A scanning module, configured to scan the to-be-scanned part of the detection object using the optimized scanning sequence.

[0047] In a fifth aspect, the present application further provides a computer device, including a memory and a processor, where the memory stores a computer program, and when the processor executes the computer program, it implements the content of any one of the embodiments of the magnetic resonance scanning method in the first aspect, and the content of the scanning control method of the magnetic resonance system in the second and third aspects.

[0048] In a sixth aspect, the present application further provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, it implements the content of any one of the embodiments of the magnetic resonance scanning method in the first aspect, and the content of the scanning control method of the magnetic resonance system in the second and third aspects.

[0049] In a seventh aspect, the present application further provides a computer program product, including a computer program, and when the computer program is executed by a processor, it implements the content of any one of the embodiments of the magnetic resonance scanning method in the first aspect, and the content of the scanning control method of the magnetic resonance system in the second and third aspects.

[0050] The above-mentioned magnetic resonance scanning method and the scanning control method of the magnetic resonance system are based on the physical constitution information, body position information, and the part to be scanned of the detection object, and search for a target PNS limit model adapted to the detection object from multiple groups of PNS limit models; the multiple groups of PNS limit models are obtained by performing gradient pulse tests on multiple prior test objects with different physical constitutions at different body positions and different scanning parts; based on the target PNS limit model, determine the PNS limit corresponding to the sequence to be scanned; in response to the mismatch between the PNS prediction value of the sequence to be scanned and the corresponding PNS limit, optimize at least one parameter of the sequence to be scanned; use the optimized scanning sequence to scan the part to be scanned of the detection object. By fully considering the physical constitution information, body position information, and the part to be scanned of the detection object, this method searches for a suitable target model from multiple groups of PNS limit models, making the determined target PNS limit model more in line with the actual situation of the part to be scanned of the detection object. Further, determine the PNS limit of the sequence to be scanned from the target PNS limit model, and when the PNS prediction value of the sequence to be scanned does not match the corresponding PNS limit, optimize the parameters of the sequence to be scanned. The optimized parameters can guide the actual magnetic resonance scanning process, maximize the gradient performance of the magnetic resonance system while ensuring the safety of the detection object, and at the same time, can also improve the scanning result of the magnetic resonance and the quality of the magnetic resonance image. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments of the present application or related technologies. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0052] Figure 1 It is an application environment diagram of the magnetic resonance scanning method in an embodiment;

[0053] Figure 2 It is a flowchart of the magnetic resonance scanning method in an embodiment;

[0054] Figure 3 It is a schematic diagram of multiple groups of PNS limit models in an embodiment;

[0055] Figure 4 It is a schematic diagram of the PNS limit model in an embodiment;

[0056] Figure 5 It is a flowchart of the magnetic resonance scanning method in an embodiment;

[0057] Figure 6Schematic diagram of the scanning sequence and effective stimulation duration in an embodiment;

[0058] Figure 7 Flow schematic diagram of a magnetic resonance scanning method in an embodiment;

[0059] Figure 8 Flow schematic diagram of a magnetic resonance scanning method in an embodiment;

[0060] Figure 9 Flow schematic diagram of a magnetic resonance scanning method in an embodiment;

[0061] Figure 10 Flow schematic diagram of a magnetic resonance scanning method in an embodiment;

[0062] Figure 11 Schematic diagram of the readout gradient of the EPI sequence in an embodiment;

[0063] Figure 12 Flow schematic diagram of a magnetic resonance scanning method in an embodiment;

[0064] Figure 13 Structural block diagram of a magnetic resonance scanning device in an embodiment. Detailed implementation manners

[0065] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to 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.

[0066] Before introducing the technical solutions of the present application in detail, the background technology of the present application will be briefly introduced.

[0067] During magnetic resonance scanning, an induced electric field will be generated in the human body in a changing magnetic field. An action potential will be generated in the nerve membrane in the human body under the action of this induced electric field. When the action potential is greater than a certain threshold, a PNS detection value will be detected. Once the PNS detection value exceeds the limit, there will be certain potential safety hazards to the human body. Therefore, it is necessary to set reasonable safety limits to ensure the safety during human body scanning.

[0068] The magnitude of the PNS detection value is related to the design of the gradient coil, the position of the human body in the coil, the height, weight and body mass index (BMI) of the human body, etc. When performing magnetic resonance scanning on the human body, due to different scanning parts, the body areas of the human body exposed to the gradient field are different, and the detected PNS detection values are also different. That is to say, the position of the human body in the coil is affected by the scanning part.

[0069] In the related art, during magnetic resonance scanning, the PNS limit value of the most sensitive part of the human body is mainly applied to all scanning parts of the human body to ensure the safety of the magnetic resonance scanning process.

[0070] When the effective stimulation duration is the same, if the PNS limit value of the most sensitive part is applied to the whole body, the PNS limit values of other non-sensitive parts will be underestimated, which limits the performance of the system gradient during scanning of non-sensitive parts. When it is necessary to increase the ramp rate of the gradient pulse to improve the image resolution or reduce the slice thickness, it is easy to cause PNS overrun, making the scanning process unable to continue. Especially when using a magnetic resonance system for a specific part, this phenomenon is particularly obvious. In addition, differences in individual human information will also cause different PNS magnitudes felt by patients.

[0071] Based on the above problems, the present application provides a magnetic resonance scanning method and a scanning control method for a magnetic resonance system, which can fully utilize the gradient performance of the magnetic resonance system and help improve the scanning results of magnetic resonance. Of course, the technical solutions provided in the embodiments of the present application are not limited to only solving the above problems, and there are other technical effects, which can be specifically seen in the following embodiments. Next, the technical solutions of the present application will be introduced in detail.

[0072] The magnetic resonance scanning method provided in the embodiments of the present application can be applied to an Figure 1 application environment as shown. This application environment includes a magnetic resonance device 101, which has a processing function, that is, a processor is included in the magnetic resonance device 101. Before using the magnetic resonance device 101 for scanning, the processor can search for a target PNS limit model adapted to the detection object from multiple groups of PNS limit models based on the physical information, body position information, and part to be scanned of the detection object, and determine the PNS limit value corresponding to the sequence to be scanned based on the target PNS limit model; in response to the PNS predicted value of the sequence to be scanned not matching the corresponding PNS limit value, optimize at least one parameter of the sequence to be scanned to determine the optimized scanning sequence. The magnetic resonance device 101 can scan the part to be scanned of the detection object according to the optimized scanning sequence.

[0073] In an exemplary embodiment, as Figure 2 shown, a magnetic resonance scanning method is provided. Taking the magnetic resonance device in Figure 1 as an example, it includes the following steps 101 to 104. Among them:

[0074] S101. Based on the physical condition information, body position information, and the part to be scanned of the detection object, find a target PNS limit model adapted to the detection object from multiple groups of PNS limit models; the multiple groups of PNS limit models are obtained by performing gradient pulse tests on multiple prior test objects with different physical conditions in different body positions and at different scanning parts.

[0075] Among them, the physical condition information refers to information such as the height, weight, and body fat percentage of the detection object. The body position information can be the supine position, prone position, and the order of entering the magnetic resonance system (for example, head first or feet first). The part to be scanned can be parts such as the head, neck, or abdomen. In addition to the physical condition information, body position information, and the part to be scanned, factors such as the gender and age of the detection object can also be referred to during the search process.

[0076] In the embodiment of the present application, after obtaining the physical condition information, body position information, and the part to be scanned of the detection object, the magnetic resonance device can analyze the similarity between the relevant information of the detection object and the multiple information in the multiple groups of PNS limit models, screen out the model with the highest similarity from the multiple groups of PNS limit models, and use the model with the highest similarity as the target PNS limit model adapted to the detection object.

[0077] Or, the magnetic resonance device can also find all the PNS limit models of the part to be scanned from the multiple groups of PNS limit models based on the part to be scanned of the detection object. Then, based on the body position information of the detection object, find all the PNS limit models of the body position information from all the PNS limit models of the part to be scanned. After that, based on the body position information of the detection object, find the PNS limit model of the body position information from all the PNS limit models of the body position information. And use the PNS limit model of the body position information as the target PNS limit model adapted to the detection object.

[0078] Taking the PNS limit model as a hyperbolic model as an example, Figure 3 As a schematic diagram of multiple groups of PNS limit models, it can be seen from the figure that there are n types of physical condition information of the prior test object, and each physical condition information includes k scanning parts. Then, the corresponding number of hyperbolic models is nk.

[0079] S102. Based on the target PNS limit model, determine the PNS limit corresponding to the scanning sequence to be performed.

[0080] In the embodiment of the present application, for each scanning part, the scanning part includes a combination scan of multiple different scanning sequences, and the PNS limits corresponding to different scanning sequences are different.

[0081] Figure 4It is a schematic diagram of the PNS limit model. In the figure, the abscissa represents time, and the ordinate represents the gradient climb intensity. The three curves in the figure respectively represent the schematic diagrams of the PNS limits of different parts (scan part 1, scan part 2, and scan part 3) changing with time. There are different sequences during the scanning process. The figure includes sequence A, sequence B, and sequence C. It can be seen from the figure that the PNS limits corresponding to the same scan part are different for different sequences, and the PNS limits corresponding to different scan parts are different for the same sequence.

[0082] In one embodiment, the target PNS limit model represents a curve of the PNS limit changing with time. Taking the sequence as a time segment as an example, after obtaining the target PNS limit model adapted to the detection object, the magnetic resonance device can obtain the effective stimulation duration of at least one time segment in the sequence to be scanned. Then, based on the target PNS limit model and the effective stimulation duration of at least one time segment, the PNS limit corresponding to at least one time segment is determined.

[0083] Alternatively, during the construction process of the target PNS limit model, it is obtained by applying multiple different time segments. The magnetic resonance device can search the database for the PNS limits corresponding to at least one time segment during the construction process of the target PNS limit model, and use the PNS limits corresponding to at least one time segment during the construction process as the PNS limits corresponding to the sequence to be scanned. The embodiments of the present application do not limit the method for determining the PNS limits corresponding to the sequence to be scanned based on the target PNS limit model.

[0084] S103, in response to the PNS prediction value of the sequence to be scanned not matching the corresponding PNS limit, optimize at least one parameter of the sequence to be scanned.

[0085] Among them, the PNS prediction value of the sequence to be scanned can be determined based on the PNS detection value in the historical scanning process, or the PNS simulation value obtained by using the simulated scanning method can be used as the PNS prediction value.

[0086] In the embodiments of the present application, after obtaining the PNS prediction value of the sequence to be scanned, for the prediction value of any sequence, the magnetic resonance device can compare the prediction value of the sequence with the corresponding PNS limit to determine whether the PNS prediction value matches the corresponding PNS limit. Specifically, the situation where the PNS prediction value of the sequence to be scanned matches the corresponding PNS limit includes: the PNS prediction value of at least one time segment in the sequence to be scanned approaches the corresponding PNS limit, but does not exceed the corresponding PNS limit.

[0087] The situation where the PNS prediction value of the sequence to be scanned does not match the corresponding PNS limit includes: the PNS prediction value of at least one sequence in the sequence to be scanned does not match the corresponding PNS limit.

[0088] For any one sequence in the sequence to be scanned, the situation where the PNS prediction value of the sequence does not match the corresponding PNS limit includes any of the following situations:

[0089] The PNS prediction value of the sequence is less than the corresponding PNS limit, and the absolute value of the difference between the PNS prediction value and the corresponding PNS limit is greater than a preset threshold;

[0090] The PNS prediction value of the sequence is greater than or equal to the corresponding PNS limit.

[0091] In the embodiment of the present application, when it is determined that the PNS prediction value of the sequence to be scanned does not match the corresponding PNS limit, the magnetic resonance device can optimize at least one parameter in the sequence to be scanned, and the optimized sequence to be scanned is more suitable for scanning the scanned part of the detection object.

[0092] In one embodiment, at least one parameter includes phase encoding resolution, readout encoding resolution, phase direction FOV, readout direction FOV, and slice thickness.

[0093] S104, scan the part to be scanned of the detection object using the optimized scan sequence.

[0094] In the embodiment of the present application, when the optimized scan sequence is obtained, the magnetic resonance device can apply the optimized scan sequence at the sequence application time of the effective stimulation duration during the scanning process of the part to be scanned of the detection object. After the scanning is completed, the quality of the obtained magnetic resonance image is higher.

[0095] In the above magnetic resonance scanning method, based on the physical constitution information, body position information, and the part to be scanned of the detection object, a target PNS limit model adapted to the detection object is searched from multiple groups of PNS limit models; the multiple groups of PNS limit models are obtained by performing gradient pulse tests on prior test objects with different physical constitutions in different body positions and different scanning parts; based on the target PNS limit model, the PNS limit corresponding to the sequence to be scanned is determined; in response to the PNS prediction value of the sequence to be scanned not matching the corresponding PNS limit, at least one parameter of the sequence to be scanned is optimized; the part to be scanned of the detection object is scanned using the optimized scanning sequence. By fully considering the physical constitution information, body position information, and the part to be scanned of the detection object, this method searches for an adapted target model from multiple groups of PNS limit models, making the determined target PNS limit model more in line with the actual situation of the part to be scanned of the detection object. Further, the PNS limit of the sequence to be scanned is determined from the target PNS limit model, and when the PNS prediction value of the sequence to be scanned does not match the corresponding PNS limit, the parameters of the sequence to be scanned are optimized. The optimized parameters can guide the actual magnetic resonance scanning process, maximize the gradient performance of the magnetic resonance system on the premise of ensuring the safety of the detection object, and at the same time, can also improve the magnetic resonance scanning result and the quality of the magnetic resonance image.

[0096] Next, a specific example is used to illustrate the specific content of determining the PNS limit corresponding to the sequence to be scanned based on the target PNS limit model, as Figure 5 shown, the specific content includes:

[0097] S201, obtain the effective stimulation duration of at least one time-sequence segment in the sequence to be scanned.

[0098] Among them, the sequence to be scanned usually consists of five parts, which are radio frequency pulse, slice selection gradient field, phase encoding gradient field, frequency encoding gradient field, and the signal of atomic nuclei in the magnetic field in magnetic resonance (MR) phenomenon. The above five parts are arranged in sequence in time and in terms of action time from left to right. The sequence to be scanned can be divided into time-sequence segments according to the action time (such as repetition time, echo time).

[0099] In the embodiment of the present application, the magnetic resonance device can obtain the action time of each time-sequence segment in the sequence to be scanned, and use the action time of each time-sequence segment as the effective stimulation duration of the time-sequence segment.

[0100] S202, based on the effective stimulation duration of at least one time-sequence segment and the target PNS limit model, determine the PNS limit of the sequence to be scanned.

[0101] In an embodiment of the present application, after obtaining the effective stimulation duration of at least one time sequence segment, the magnetic resonance device looks up the PNS limit corresponding to the effective stimulation duration of each time sequence segment in the target PNS limit model, and calculates the average value of the PNS limits corresponding to the multiple time sequence segments as the PNS limit of the sequence to be scanned. Alternatively, the minimum PNS limit among the PNS limits corresponding to the multiple time sequence segments can also be used as the PNS limit of the sequence to be scanned. Or, the median value of the PNS limits corresponding to the multiple time sequence segments can be used as the PNS limit of the sequence to be scanned.

[0102] It can be understood that the PNS limit of the sequence to be scanned can also include multiple values, that is, the PNS limit corresponding to each time sequence segment is used as the PNS limit of the sequence to be scanned.

[0103] Figure 6 FIG. is a schematic diagram of the scanning sequence and the effective stimulation duration. In the figure, G represents the magnetic field gradient, with the unit of T / m; G max is the maximum gradient; dB / dt is the time change rate of the gradient, with the unit of T / m / s; (dB / dt) max is the maximum value of the time change rate of the gradient.

[0104] In the above magnetic resonance scanning method, the effective stimulation duration of at least one time sequence segment in the sequence to be scanned is obtained; based on the effective stimulation duration of at least one time sequence segment and the target PNS limit model, the PNS limit of the sequence to be scanned is determined. Through the effective stimulation duration of at least one time sequence segment, this method can accurately locate the PNS limit corresponding to at least one time sequence segment from the target PNS limit model. That is to say, not only starting from the comprehensive information of the detection object, the target PNS limit model most suitable for the part to be scanned is determined, but it can also be further refined to at least one time sequence segment. In this way, based on the PNS limit of at least one time sequence segment, support can be provided for the subsequent scanning optimization process.

[0105] In one embodiment, as Figure 7 shown, for the above-mentioned optimizing at least one parameter of the sequence to be scanned in response to the mismatch between the PNS prediction value of the sequence to be scanned and the corresponding PNS limit, the specific content includes:

[0106] S301, obtain the target time sequence segment corresponding to the PNS prediction value that does not match the corresponding PNS limit.

[0107] In an embodiment of the present application, when it is determined that one or several PNS prediction values in the sequence to be scanned do not match the corresponding PNS limit values, the target time sequence segment in the sequence to be scanned can be determined based on the mismatched PNS prediction values. Specifically, the target time sequence segment can be the time sequence segment in the sequence to be scanned that exceeds the PNS limit value, or the time sequence segment with a large difference from the PNS limit value.

[0108] S302. Optimize the parameters in the target time sequence segment.

[0109] In an embodiment of the present application, for different time sequence segments, the magnetic resonance device can determine the parameters corresponding to the target time sequence segment based on the target time sequence segment, and perform optimization processing on the parameters in the target time sequence segment, so that the PNS prediction value of the optimized target time sequence segment matches the corresponding PNS limit value.

[0110] Specifically, assuming that the PNS prediction value of the target time sequence segment is quite different from the PNS limit value, then, through parameter optimization, the PNS prediction value of the optimized target time sequence segment is made to approach the PNS limit value. Assuming that the PNS prediction value of the target time sequence segment exceeds the PNS limit value, then, through parameter optimization, the PNS prediction value of the optimized target time sequence segment is reduced to below the PNS limit value.

[0111] In the above magnetic resonance scanning method, the target time sequence segment corresponding to the PNS prediction value that does not match the corresponding PNS limit value is obtained; the parameters in the target time sequence segment are optimized. By obtaining the mismatched target time sequence segment, this method can quickly and accurately lock the problematic time sequence segment in the sequence to be scanned, avoiding non-discriminatory adjustment of all time sequence segments in the sequence to be scanned, and significantly improving the optimization efficiency.

[0112] The above multiple groups of PNS limit value models are obtained by performing gradient pulse tests on multiple prior test objects with different physiques at different body positions and different scanning parts. In one embodiment, the construction process of the multiple groups of PNS limit value models is described in detail, and the method further includes:

[0113] Perform gradient pulse tests on multiple prior test objects with different physiques at different body positions and different scanning parts, and fit the PNS limit values corresponding to the effective stimulation duration obtained from each test to obtain multiple groups of PNS limit value models.

[0114] In an embodiment of the present application, the multiple prior test objects with different physiques can be test objects with different heights, different weights, and different ages.

[0115] In the embodiments of the present application, for any prior test object, the magnetic resonance device can perform gradient pulse tests on different scanning parts of the prior test object in different body positions, and obtain the effective stimulation duration and the corresponding PNS limit values of multiple time series segments for each test. For each test, the magnetic resonance device can perform curve fitting on the effective stimulation durations and the corresponding PNS limit values of all the time series segments obtained from the test, and obtain a set of PNS limit models corresponding to the test. By fitting the PNS limit values corresponding to the effective stimulation durations of each test process in this way, multiple sets of PNS limit models are obtained.

[0116] Further, based on each set of PNS limit models, the base intensity and the chronaxie of each gradient pulse test can be determined through corresponding formulas. The corresponding formulas can be expressed as:

[0117]

[0118]

[0119] where L12 and L01 are the PNS limit values in the first-level controlled mode and the normal mode respectively; is the effective stimulation duration; is the base intensity; is the chronaxie. It should be noted that the first-level controlled mode means that when the working parameters reach a certain value, it will cause discomfort reactions in the human body. The normal mode means that any electromagnetic output is safe.

[0120] In the above magnetic resonance scanning method, gradient pulse tests are performed on prior test objects with different constitutions in different body positions and different scanning parts, and the PNS limit values corresponding to the effective stimulation durations obtained from each test are fitted to obtain multiple sets of PNS limit models. By combining different body positions and scanning parts for testing, this method takes into account the response differences of different parts of the human body to magnetic field stimulation, and obtains more abundant PNS limit values corresponding to the effective stimulation durations. Through the fitting method, more abundant PNS limit models can be obtained.

[0121] The PNS limit values can not only be used to optimize at least one parameter of the to-be-scanned sequence, but also be used to guide the actual scanning process. Then, in one embodiment, as Figure 8 shown, the method further includes:

[0122] S401, during the process of scanning the to-be-scanned part of the detection object using the optimized scanning sequence, obtain the PNS detection value corresponding to the current time series segment of the scanning sequence.

[0123] In an embodiment of the present application, during the process of the magnetic resonance device scanning a part to be scanned of a detection object using an optimized scanning sequence, a sequence to be scanned needs to be applied. The sequence to be scanned may include multiple timing segments, and the PNS detection values corresponding to different timing segments are all different. After each application of a timing segment, the magnetic resonance device can calculate the PNS detection value corresponding to the current timing segment according to the changes in the electric field and magnetic field intensities.

[0124] S402. Determine the magnetic resonance scanning state of the part to be scanned according to the PNS detection value corresponding to the current timing segment and the corresponding PNS limit value.

[0125] Among them, the magnetic resonance scanning state includes a scanning state and a stop scanning state.

[0126] In an embodiment of the present application, after obtaining the PNS detection value corresponding to the current timing segment, the magnetic resonance device can determine whether the PNS detection value corresponding to the current timing segment exceeds the corresponding PNS limit value. If it does not exceed, it means that the detection object is in a safe scanning environment, and the scanning continues; if it exceeds, it means that there may be a safety hazard for the detection object, and the scanning is stopped.

[0127] In one embodiment, the specific content of determining the magnetic resonance scanning state of the part to be scanned according to the PNS detection value corresponding to the current timing segment and the corresponding PNS limit value includes:

[0128] When the PNS detection value corresponding to the current timing segment is greater than the corresponding PNS limit value, control the magnetic resonance scanning state to be in the stop scanning state.

[0129] In an embodiment of the present application, the magnetic resonance device can compare the PNS detection value corresponding to the current timing segment with the PNS limit value corresponding to the current timing segment, and determine the magnetic resonance scanning state of the part to be scanned according to the comparison result. Specifically, if the PNS detection value corresponding to the current timing segment is greater than or equal to the PNS limit value corresponding to the current timing segment, it means that there may be a safety hazard for the detection object, and control the magnetic resonance scanning state to be in the stop scanning state.

[0130] In the above magnetic resonance scanning method, during the process of scanning the part to be scanned of the detection object using the optimized scanning sequence, the PNS detection value corresponding to the current time sequence segment of the scanning sequence is obtained; according to the PNS detection value corresponding to the current time sequence segment and the corresponding PNS limit value, the magnetic resonance scanning state of the part to be scanned is determined. This method can accurately judge the actual state of the part to be scanned during magnetic resonance scanning by obtaining the PNS detection value corresponding to the current time sequence segment in the scanning sequence in real time and comparing it with the PNS limit value, so as to timely detect potential safety hazards during the scanning process and stop the scanning when a safety hazard occurs, effectively ensuring the safety of the detection object during the scanning process.

[0131] In a detailed embodiment, as Figure 9 shown, the magnetic resonance scanning method includes:

[0132] S501, based on the physical constitution information, body position information, and the part to be scanned of the detection object, search for the target PNS limit value model adapted to the detection object from multiple groups of PNS limit value models;

[0133] S502, obtain the effective stimulation duration of at least one time sequence segment in the sequence to be scanned;

[0134] S503, based on the effective stimulation duration of at least one time sequence segment and the target PNS limit value model, determine the PNS limit value of the sequence to be scanned;

[0135] S504, in response to the PNS prediction value of the sequence to be scanned not matching the corresponding PNS limit value, obtain the target time sequence segment corresponding to the PNS prediction value that does not match the corresponding PNS limit value;

[0136] S505, optimize the parameters in the target time sequence segment;

[0137] S506, scan the part to be scanned of the detection object using the optimized scanning sequence;

[0138] S507, during the process of scanning the part to be scanned of the detection object using the optimized scanning sequence, obtain the PNS detection value corresponding to the current time sequence segment of the scanning sequence;

[0139] S508, when the PNS detection value corresponding to the current time sequence segment is greater than the corresponding PNS limit value, control the magnetic resonance scanning state to be in the stop scanning state.

[0140] In an exemplary embodiment, as Figure 10 shown, a scanning control method for a magnetic resonance system is provided, including the following steps 601 to step 608. Among them:

[0141] S601. Obtain the physical constitution information and body position information of the detection object, where the detection object includes a first part to be scanned and a second part to be scanned;

[0142] S602. Search the database for a candidate PNS limit model adapted to the detection object based on the physical constitution information and body position information; the database includes multiple groups of PNS limit models;

[0143] S603. Control the first part to be scanned of the detection object to move to the imaging field of view of the magnetic resonance system;

[0144] S604. Scan the first part to be scanned using a target scan sequence;

[0145] S605. Control the second part to be scanned of the detection object to move to the imaging field of view of the magnetic resonance system, and select a second target PNS limit model that matches the second part to be scanned from the candidate PNS limit models;

[0146] S606. Determine the PNS limit corresponding to scanning the second part to be scanned based on the second target PNS limit model;

[0147] S607. In response to the PNS predicted value not matching the corresponding PNS limit, optimize at least one parameter of the second scan sequence based on the PNS detection value of the first part to be scanned to obtain a target scan sequence;

[0148] S608. Scan the second part to be scanned using the optimized target scan sequence, determine the second PNS detection value corresponding to the second scan sequence during the scanning process based on the second target PNS limit model, and stop scanning the second part to be scanned after the second PNS detection value exceeds the corresponding second PNS limit.

[0149] In the embodiments of the present application, the parts to be scanned of the detection object include two parts. Of course, it may not be limited to two parts. For two parts, the scanning process of the first part to be scanned is exactly the same as the content in S101 - S104, and will not be elaborated here. During the process of optimizing at least one parameter of the second scan sequence, it can be optimized based on the PNS detection value of the first part to be scanned. Exemplarily, when the scan sequence is an EPI sequence, the smaller the echo spacing, the higher the bandwidth in the corresponding phase encoding direction, and the smaller the deformation of the obtained EPI image, that is, the better the image quality. Therefore, after scanning the first scan part using the EPI sequence, when scanning the second scan part, since the PNS limit is increased compared to the first scan part at this time, the echo spacing is adjusted to be smaller when scanning the second scan part to obtain better image quality.

[0150] Figure 11It is a schematic diagram of the readout gradient of the EPI sequence. The upper figure is the EPI sequence corresponding to the first scanning site, and the lower figure is the EPI sequence corresponding to the second scanning site. Comparing the two EPI sequences, the echo spacing 2 of the second scanning site is less than the echo spacing 1 of the first scanning site. Then, the quality of the magnetic resonance image of the second scanning site is higher than that of the first scanning site.

[0151] It should be noted that the scanning sequences used for the first scanning site and the second scanning site are the same sequence, which is the target scanning sequence.

[0152] In an exemplary embodiment, as Figure 12 shown, a scanning control method for a magnetic resonance system is provided, including the following steps 701 to 707. Among them:

[0153] S701, obtain the part to be scanned, physical fitness information and body position information of the detection object;

[0154] S702, determine the initial scanning protocol from the scanning protocol database based on the part to be scanned;

[0155] S703, search for a candidate PNS limit model adapted to the detection object from the database based on the physical fitness information and body position information; multiple groups of PNS limit models are included in the database;

[0156] S704, and select a target PNS limit model that matches the part to be scanned from the candidate PNS limit models;

[0157] S705, determine the PNS limit corresponding to the initial scanning protocol based on the target PNS limit model;

[0158] S706, in response to the PNS prediction value of the sequence to be scanned not matching the corresponding PNS limit, optimize at least one parameter of the sequence to be scanned to obtain the target scanning sequence;

[0159] S707, scan the part to be scanned of the detection object using the target scanning sequence.

[0160] In the embodiment of the present application, multiple groups of PNS limit models can be divided into multiple parts according to the scanning part and physical fitness information. For example, the PNS limit models of the same scanning part are grouped together, and multiple groups of PNS limit models with the same physical fitness information are classified into one category. Then, in the process of searching for the target PNS limit model that matches the part to be scanned from multiple groups of PNS limit models, it is necessary to search step by step according to the classification and grouping.

[0161] It should be understood that although the steps in the flowcharts involved in the above embodiments are sequentially shown according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, 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. These steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or steps or stages in other steps.

[0162] Based on the same inventive concept, an embodiment of the present application further provides a magnetic resonance scanning device for implementing the above-mentioned magnetic resonance scanning method. The solution provided by this device to solve the problem is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the magnetic resonance scanning device provided below can refer to the limitations on the magnetic resonance scanning method in the above text, and will not be repeated here.

[0163] In an exemplary embodiment, as Figure 13 shown, a magnetic resonance scanning device is provided, including: an acquisition module 11, a determination module 12, an optimization module 13, and a scanning module 14, where:

[0164] The acquisition module 11 is configured to search for a target PNS limit model adapted to the detection object from multiple groups of PNS limit models based on the physical constitution information, body position information, and part to be scanned of the detection object; the multiple groups of PNS limit models are obtained by performing gradient pulse tests on multiple prior test objects with different physical constitutions at different body positions and different scanning parts;

[0165] wherein, the target PNS limit model represents a curve of PNS limit changing with time;

[0166] The determination module 12 is configured to determine the PNS limit corresponding to the sequence to be scanned based on the target PNS limit model;

[0167] The optimization module 13 is configured to optimize at least one parameter of the sequence to be scanned in response to the PNS prediction value of the sequence to be scanned not matching the corresponding PNS limit;

[0168] wherein, the at least one parameter includes phase encoding resolution, readout encoding resolution, phase direction FOV, readout direction FOV, and slice thickness;

[0169] The scanning module 14 is configured to scan the part to be scanned of the detection object using the optimized scanning sequence.

[0170] In an exemplary embodiment, the above-mentioned determination module includes: a time acquisition unit and a determination unit, where:

[0171] The time acquisition unit is configured to acquire the effective stimulation duration of at least one timing segment in the sequence to be scanned;

[0172] The determination unit is configured to determine the PNS limit of the sequence to be scanned based on the effective stimulation duration of at least one timing segment and the target PNS limit model.

[0173] In an exemplary embodiment, the above-mentioned optimization module includes a segment acquisition unit and an optimization unit, where:

[0174] The segment acquisition unit is configured to acquire the target timing segment corresponding to the PNS prediction value that does not match the corresponding PNS limit;

[0175] The optimization unit is configured to optimize the parameters in the target timing segment.

[0176] In an exemplary embodiment, the above-mentioned magnetic resonance scanning device further includes a fitting module, where:

[0177] The fitting module is configured to perform gradient pulse tests on prior test objects with different constitutions in different body positions and different scanning parts, and fit the PNS limits corresponding to the effective stimulation duration obtained from each test to obtain multiple groups of PNS limit models.

[0178] In an exemplary embodiment, the above-mentioned magnetic resonance scanning device further includes: a detection value acquisition module and a state determination module, where:

[0179] The detection value acquisition module is configured to acquire the PNS detection value corresponding to the current timing segment of the scanning sequence during the process of scanning the part to be scanned of the detection object using the optimized scanning sequence;

[0180] The state determination module is configured to determine the magnetic resonance scanning state of the part to be scanned according to the PNS detection value corresponding to the current timing segment and the corresponding PNS limit.

[0181] In an exemplary embodiment, the above-mentioned state determination module includes a control unit, where:

[0182] The control unit is configured to control the magnetic resonance scanning state to be in a stopped scanning state when the PNS detection value corresponding to the current timing segment is greater than the corresponding PNS limit.

[0183] Each module in the above magnetic resonance scanning device can be implemented in whole or in part by software, hardware, or a combination thereof. Each of the above modules can be embedded in the processor of the computer device in hardware form or independent of it, or stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to each of the above modules.

[0184] In an exemplary embodiment, a computer device is provided, including a memory and a processor. A computer program is stored in the memory. When the processor executes the computer program, it implements the content of any one of the embodiments of the above magnetic resonance scanning method and the scanning control method of the magnetic resonance system.

[0185] In an embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by the processor, it implements the content of any one of the embodiments of the above magnetic resonance scanning method and the scanning control method of the magnetic resonance system.

[0186] In an embodiment, a computer program product is provided, including a computer program. When the computer program is executed by the processor, it implements the content of any one of the embodiments of the above magnetic resonance scanning method and the scanning control method of the magnetic resonance system.

[0187] 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 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 need to comply with relevant regulations.

[0188] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. 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 methods. Among them, any reference to a 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), magnetoresistive 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. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in the present application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in the present application can be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, data processing logics based on quantum computing, artificial intelligence (AI) processors, etc., without limitation.

[0189] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, 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, it should be considered to be within the scope recorded in the present application.

[0190] The above embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several variations and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A magnetic resonance scanning method, characterized in that, The method includes: Based on the physical constitution information, body position information, and the part to be scanned of the detection object, find a target PNS limit model adapted to the detection object from multiple groups of PNS limit models; the multiple groups of PNS limit models are obtained by performing gradient pulse tests on prior test objects with different physical constitutions in different body positions and at different scanning parts; Based on the target PNS limit model, determine the PNS limit corresponding to the sequence to be scanned; In response to the PNS prediction value of the sequence to be scanned not matching the corresponding PNS limit, optimize at least one parameter of the sequence to be scanned; Use the optimized scanning sequence to scan the part to be scanned of the detection object.

2. The method according to claim 1, wherein The determining the PNS limit corresponding to the sequence to be scanned based on the target PNS limit model includes: Obtain the effective stimulation duration of at least one time sequence segment in the sequence to be scanned; Based on the effective stimulation duration of the at least one time sequence segment and the target PNS limit model, determine the PNS limit of the sequence to be scanned.

3. The method according to claim 2, wherein The optimizing at least one parameter of the sequence to be scanned in response to the PNS prediction value of the sequence to be scanned not matching the corresponding PNS limit includes: Obtain the target time sequence segment corresponding to the PNS prediction value that does not match the corresponding PNS limit; Optimize the parameters in the target time sequence segment.

4. The method according to any one of claims 1-3, characterized in that, The target PNS limit model represents a curve of the PNS limit changing with time.

5. The method according to any one of claims 1 to 3, characterized in that, The at least one parameter includes phase encoding resolution, readout encoding resolution, phase direction FOV, readout direction FOV, and slice thickness.

6. The method according to any one of claims 1-3, characterized in that The construction process of the multiple groups of PNS limit models includes: Perform gradient pulse tests on the prior test objects with different physical constitutions in different body positions and at different scanning parts, and fit the PNS limits corresponding to the effective stimulation durations obtained from each test to obtain the multiple groups of PNS limit models.

7. The method according to any one of claims 1 to 3, characterized in that, The method further includes: During the process of scanning the part to be scanned of the detection object using the optimized scanning sequence, obtain the PNS detection value corresponding to the current time sequence segment of the scanning sequence; Based on the PNS detection value corresponding to the current time sequence segment and the corresponding PNS limit, determine the magnetic resonance scanning state of the part to be scanned.

8. The method according to claim 7, wherein The determining the magnetic resonance scanning state of the part to be scanned based on the PNS detection value corresponding to the current time sequence segment and the corresponding PNS limit includes: When the PNS detection value corresponding to the current time sequence segment is greater than the corresponding PNS limit, control the magnetic resonance scanning state to be in a stopped scanning state.

9. A scanning control method for a magnetic resonance system, characterized in that, The method includes: Obtain the physical constitution information and body position information of the detection object, where the detection object includes a first part to be scanned and a second part to be scanned; Based on the physical constitution information and body position information, find a candidate PNS limit model adapted to the detection object from a database; the database includes multiple groups of PNS limit models; Control the first part to be scanned of the detection object to move to the imaging field of the magnetic resonance system; Use the target scanning sequence to scan the first part to be scanned. Control the movement of the second part to be scanned of the detection object to the imaging field of view of the magnetic resonance system, and select a second target PNS limit model that matches the second part to be scanned from the candidate PNS limit models; Based on the second target PNS limit model, determine the PNS limit for scanning the second part to be scanned by the target scan sequence; In response to the PNS predicted value not matching the corresponding PNS limit, optimize at least one parameter of the second scan sequence to be scanned based on the PNS detection value of the first part to be scanned, and obtain the optimized target scan sequence; Use the optimized target scan sequence to scan the second part to be scanned. During the scanning process, based on the second target PNS limit model, determine the second PNS detection value corresponding to the second scan sequence to be scanned, and stop scanning the second part to be scanned after the second PNS detection value exceeds the corresponding second PNS limit.

10. A scanning control method for a magnetic resonance system, characterized in that, The method includes: Obtain the part to be scanned, physical fitness information, and body position information of the detection object; Determine an initial scan protocol from the scan protocol database based on the part to be scanned; Search for a candidate PNS limit model suitable for the detection object from the database based on the physical fitness information and the body position information; multiple groups of PNS limit models are included in the database; And select a target PNS limit model that matches the part to be scanned from the candidate PNS limit models; Based on the target PNS limit model, determine the PNS limit corresponding to the initial scan protocol; In response to the PNS predicted value of the scan sequence to be scanned not matching the corresponding PNS limit, optimize at least one parameter of the scan sequence to be scanned to obtain a target scan sequence; Use the target scan sequence to scan the part to be scanned of the detection object.

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