A magnetic resonance pulse generation method and a magnetic resonance imaging method

Abstract

The present invention discloses a magnetic resonance pulse generation method and a magnetic resonance imaging method. The magnetic resonance pulse generation method includes: acquiring a slice of a target object, wherein the slice includes multiple single layers arranged along a preset slice selection direction; dividing the single layer into multiple sublayers according to the preset slice selection direction, wherein each sublayer has a positive or negative pulse excitation direction; and generating a sub-excitation pulse signal corresponding to each sublayer based on the parameters of each sublayer and the pulse excitation direction of each sublayer. The present invention solves the technical problem that the existing 90-degree effect elimination solution cannot effectively eliminate the 90-degree effect.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic resonance imaging, and in particular to a magnetic resonance pulse generation method, a magnetic resonance imaging method, a device, an electronic device and a storage medium. Background Art

[0002] Conventional magnetic resonance imaging generally requires radio frequency pulse excitation, gradient layer selection and positioning, and then spatial encoding to obtain the final image. In the case of gradient and radio frequency effects, radio frequency pulses are generally split into three effects, 0 degrees, 90 degrees, and 180 degrees, of which the 90-degree effect corresponds to the FID signal. In some imaging, the pulse needs to play a 180-degree role, and the introduction of 90-degree components is undesirable, such as FSE (fast spin echo) imaging. In the existing technology, it is difficult to achieve pure 180-degree excitation by the pulse itself without introducing a 90-degree effect. On the one hand, it is difficult to achieve very precise voltage correction, resulting in a few degrees of deviation in radio frequency. On the other hand, there is always a transition zone in the layer selection direction, and the pulses felt by the components in the transition zone must be a transition of 0-180 degrees. Discrete excitation is impossible under realistic conditions. Therefore, in order to eliminate the 90-degree effect (FID (free induction decay) signal component), the traditional approach requires the introduction of gradient destruction, such as Figure 1 As shown, RF represents the axis corresponding to the radio frequency pulse, G represents the axis corresponding to the gradient pulse, α represents the flip angle, and the gradient pulse below introduces a pair of damaging pulses in the front and back.

[0003] Although the gradient destruction method can effectively eliminate the FID signal generated by the 90-degree component, it also introduces a diffusion effect and, to a certain extent, introduces diffusion weighting, which causes a certain change in contrast. In addition, relatively large gradients can stimulate the organism and produce peripheral nerve stimulation. At the same time, the application of additional gradients will also lengthen the TE time of the sequence.

[0004] In summary, the 90-degree effect elimination solution in the prior art cannot effectively eliminate the 90-degree effect, has poor elimination effect, and has significant side effects. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned technical deficiencies and provide a magnetic resonance pulse generation method, a magnetic resonance imaging method, an apparatus, an electronic device and a storage medium to solve the technical problem that the 90-degree effect elimination scheme in the prior art cannot effectively eliminate the 90-degree effect.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0007] In one aspect, the present invention provides a method for generating a magnetic resonance pulse, comprising the following steps:

[0008] Acquire a slice of the target object, wherein the slice includes a plurality of single layers arranged along a preset slice selection direction;

[0009] Splitting the single layer into a plurality of sublayers according to the preset layer selection direction, wherein each sublayer has a positive or negative pulse excitation direction, and within the same single layer, the number of sublayers with positive pulse excitation directions and the number of sublayers with negative pulse excitation directions are the same;

[0010] According to the parameters of each sub-layer and the pulse excitation direction of each sub-layer, a sub-excitation pulse signal corresponding to each sub-layer is generated.

[0011] In some embodiments, the parameters of the sub-layer include at least the location of the sub-layer and the thickness of the sub-layer.

[0012] In some embodiments, an initial phase difference between the sub-excitation pulse signal of the sub-layer with the positive pulse excitation direction and the initial phase difference between the sub-excitation pulse signal of the sub-layer with the negative pulse excitation direction is 180 degrees.

[0013] In some embodiments, the magnetic resonance pulse generation method further comprises:

[0014] The sub-excitation pulse signals of each sub-layer of the same single layer are summed to obtain the magnetic resonance pulse signal of each single layer.

[0015] In some embodiments, summing the sub-excitation pulse signals of each sub-layer of the same single layer includes:

[0016] Based on the sub-excitation pulse signals of each sub-layer of the single layer and the positional relationship between the sub-layers, the sub-excitation pulse signals of each sub-layer of the same single layer are summed.

[0017] In another aspect, the present invention further provides a magnetic resonance imaging method comprising the following steps:

[0018] Applying a layer selection gradient along a preset layer selection direction to the target object to divide the target object into multiple single layers along the preset layer selection direction;

[0019] Exciting each single layer using a radio frequency pulse generated by the magnetic resonance pulse generation method described above to obtain a magnetic resonance signal corresponding to each single layer;

[0020] applying phase encoding and frequency encoding to the magnetic resonance signal respectively to obtain encoding data of the magnetic resonance signal;

[0021] Filling the encoded data into the K space;

[0022] The K space is reconstructed to obtain a magnetic resonance image of the target object.

[0023] In another aspect, the present invention further provides a magnetic resonance pulse generating device, comprising:

[0024] a slice acquisition module, configured to acquire a slice of a target object, wherein the slice includes a plurality of single layers arranged along a preset slice selection direction;

[0025] a single-layer segmentation module, configured to segment the single layer into a plurality of sub-layers according to the preset layer selection direction, wherein each sub-layer has a positive or negative pulse excitation direction, and within the same single layer, the number of sub-layers with positive pulse excitation directions and the number of sub-layers with negative pulse directions are equal;

[0026] The sub-excitation pulse generating module is used to generate a sub-excitation pulse signal corresponding to each sub-layer according to the parameters of each sub-layer and the pulse excitation direction of each sub-layer.

[0027] In yet another aspect, the present invention further provides a magnetic resonance imaging system, comprising the magnetic resonance pulse generating device and an imaging device as described above, wherein the imaging device comprises:

[0028] A layering module is used to apply a layer selection gradient along a preset layer selection direction to the target object, dividing the target object into multiple single layers along the preset layer selection direction;

[0029] an excitation module, configured to excite each single layer using the radio frequency pulses generated by the magnetic resonance pulse generating device to obtain magnetic resonance signals corresponding to each single layer;

[0030] an encoding module, configured to apply phase encoding and frequency encoding to the magnetic resonance signal to obtain encoded data of the magnetic resonance signal;

[0031] A data filling module, used for filling the encoded data into the K space;

[0032] The reconstruction module is used to reconstruct the K space to obtain a magnetic resonance image of the target object.

[0033] In another aspect, the present invention further provides an electronic device, comprising: a processor and a memory;

[0034] The memory stores a computer-readable program executable by the processor;

[0035] When the processor executes the computer-readable program, the steps in the magnetic resonance pulse generating method or the magnetic resonance imaging method described above are implemented.

[0036] On the other hand, the present invention also provides a computer-readable storage medium, which stores one or more programs, and the one or more programs can be executed by one or more processors to implement the steps in the above-mentioned abnormal magnetic resonance pulse generation or the above-mentioned magnetic resonance imaging method.

[0037] Compared with the prior art, the magnetic resonance pulse generation method, magnetic resonance imaging method, device, electronic device, and storage medium provided by the present invention first obtain a slice of the target object, then divide each single layer of the slice into multiple sublayers according to a preset slice selection direction, and make each sublayer have a positive or negative pulse excitation direction. Then, based on the parameters of each sublayer and the pulse excitation direction, a sub-excitation pulse signal corresponding to the sublayer is generated, and the sum of the positive and negative sub-excitation pulse signals in the same single layer is ensured to be the same, that is, a pulse excitation signal for each sublayer is obtained, and the pulse excitation signal can be used to achieve excitation of each single layer. The present invention uses a bidirectional excitation method, adopting positive and negative excitation directions for different positions of the slice, so that the 90-degree components of the signal within the two slices are exactly opposite and cancel each other, while the 180-degree components are unaffected, thereby effectively suppressing the 90-degree effect after pulse excitation. For pulses mainly used for refocusing, the damage gradient at both ends of the pulse can be removed, thereby effectively eliminating the 90-degree effect while eliminating the diffusion effect caused by the damage gradient, the physiological stimulation caused by the gradient switching, the time consumption, and other side effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of a pulse sequence that introduces a gradient destruction method in the prior art;

[0039] Figure 2 is a flow chart of an embodiment of a method for generating a magnetic resonance pulse provided by the present invention;

[0040] Figure 3 is a schematic diagram of an embodiment of stratifying a single layer in the magnetic resonance pulse generation method provided by the present invention;

[0041] Figure 4 1 is a schematic diagram of a sequence of sub-excitation pulse signals generated in the magnetic resonance pulse generation method provided by the present invention;

[0042] Figure 5 is a flow chart of an embodiment of a magnetic resonance imaging method provided by the present invention;

[0043] Figure 6 is a schematic diagram of an embodiment of a magnetic resonance pulse generating device provided by the present invention;

[0044] Figure 7is a schematic diagram of an embodiment of an imaging device in a magnetic resonance imaging system provided by the present invention;

[0045] Figure 8 FIG. 1 is a schematic diagram of an operating environment of a computer program according to an embodiment of the present invention. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention 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 invention and are not intended to limit the present invention.

[0047] The magnetic resonance pulse generation method, magnetic resonance imaging method, apparatus, device, or computer-readable storage medium of the present invention can be used in magnetic resonance imaging systems in the medical field. The method, apparatus, device, or computer-readable storage medium of the present invention can be integrated with the above-mentioned systems or can be independent of each other.

[0048] This embodiment provides a method for generating magnetic resonance pulses, which can be executed by a medical imaging system, which can be a magnetic resonance imaging system, and can be specifically executed by one or more processors of the system. Figure 2 , the magnetic resonance pulse generation method includes:

[0049] S110, obtaining a slice of the target object, where the slice includes a plurality of single layers arranged along a preset layer selection direction;

[0050] S120, dividing the single layer into multiple sublayers according to a preset layer selection direction, wherein each sublayer has a positive or negative pulse excitation direction, and within the same single layer, the number of sublayers with positive pulse excitation directions and the number of sublayers with negative pulse excitation directions are equal;

[0051] S130 , generating a sub-excitation pulse signal corresponding to each sub-layer according to the parameters of each sub-layer and the pulse excitation direction of each sub-layer.

[0052] In this embodiment, a slice of the target object is first acquired. The slice can be acquired using a slice selection gradient. Each single layer of the slice is then divided into multiple sublayers according to a preset slice selection direction, and each sublayer is given a positive or negative pulse excitation direction. Then, based on the parameters of each sublayer and the pulse excitation direction, a sub-excitation pulse signal corresponding to the sublayer is generated, and the sum of the positive and negative sub-excitation pulse signals within the same single layer is ensured to be the same. In other words, a pulse excitation signal for each sublayer is obtained, and each single layer can be excited using this pulse excitation signal. The present invention uses a bidirectional excitation method, employing positive and negative excitation directions at different locations within a single layer, so that the 90-degree components of the signal within the layer are exactly opposite and cancel each other out, while the 180-degree components are unaffected. This effectively suppresses the 90-degree effect after pulse excitation. For pulses primarily used for refocusing, the damage gradients at both ends of the pulse can be removed, thereby effectively eliminating the 90-degree effect while also eliminating side effects such as the diffusion effect caused by the damage gradient, the physiological stimulation caused by gradient switching, and time consumption.

[0053] In some embodiments, in step S110, the target object refers to a part that needs to be scanned by magnetic resonance imaging, which may include but is not limited to the human body, human tissues and organs, animals, non-living things, etc. The slices of the target object are acquired by layer selection gradient excitation. The parameters of the layer selection gradient may include the direction of gradient application, gradient field strength, gradient application time, and gradient pulse duration, etc. The imaged target object can be gradient segmented by layer selection gradient to extract the part that needs to be collected currently. The obtained 2D scanning data is a layer of data. The layer selection gradient can segment the target object according to a preset layer selection direction, wherein the preset layer selection direction can be a left-right direction, an up-down direction, or a front-back direction. In the embodiment of the present invention, layer selection is preferably performed in the left-right direction, and the left-right gradient field is applied to achieve layer selection of the target object along the left-right direction.

[0054] In some embodiments, in step S120, in order to achieve the cancellation of the 90-degree component of the signal within a single layer, the single layer is further subdivided into multiple sublayers according to the preset layer selection direction, and each sublayer has a positive or negative pulse excitation direction. The pulse excitation direction is to set the initial phase of the excitation pulse. In the embodiment of the present invention, the pulse excitation direction of each sublayer is set to positive or negative, so that there are multiple sublayers with opposite pulse excitation directions within the single layer. The 90-degree components of the excitation pulses applied thereto will be opposite and canceled, while the 180-degree components will not be affected. In a specific embodiment, as Figure 3As shown, according to the preset layer selection direction, the single layer is further subdivided into two layers, namely the upper half and the lower half, wherein the pulse excitation direction of the upper half is positive and the pulse excitation direction of the lower half is negative, so that the 90-degree components of the upper half and the lower half are opposite, thereby canceling out the 90-degree component, while the 180-degree component will not be affected.

[0055] In some embodiments, the initial phase difference between the sub-excitation pulse signal of the sub-layer with a positive pulse excitation direction and the initial phase difference between the sub-excitation pulse signal of the sub-layer with a negative pulse excitation direction is 180 degrees. In this embodiment, since the pulse excitation direction is used to set the initial phase of the excitation pulse, in order to avoid affecting the 180-degree component, the initial phase difference between the sub-excitation pulse signals of the positive and negative sub-layers is set to 180 degrees in this embodiment, so that the 90-degree components with positive and negative pulse directions can be offset from each other without affecting the 180-degree component. The addition of the damage gradient is omitted, thereby avoiding the side effects of introducing the damage gradient.

[0056] In some embodiments, step S130 is to generate sub-excitation pulse signals for each sub-layer, wherein the sub-excitation pulse signals include free induction decay sequences, spin echo sequences, fast spin echo sequences, hybrid sequences, and the like. Individual pulse design can be achieved using the parameters of each sub-layer and the pulse excitation direction of each sub-layer. The sub-layer parameters include at least the sub-layer location and thickness. The sub-excitation pulse signal parameters can be designed using the sub-layer parameters. The sub-excitation pulse signal parameters include at least the pulse amplitude, center frequency, and initial phase. Specifically, the sub-excitation pulse signal center frequency can be calculated based on the sub-layer location, the sub-excitation pulse signal bandwidth can be designed based on the sub-layer thickness, and the sub-excitation pulse signal amplitude can be obtained. The sub-excitation pulse signal initial phase can be designed based on the sub-layer pulse excitation direction. The sub-excitation pulse signal can be obtained based on these three parameters. The specific pulse design method is based on the Bloch equation, and specifically, methods such as SLR (Shinnar-Le Roux, a pulse design algorithm commonly used in the industry) and SINC function can be used to design the waveform or shape profile.

[0057] It should be noted that in this embodiment, in the same single layer, the sum of the sub-excitation pulse signals of the sub-layer with the positive pulse excitation direction is the same as the sum of the sub-excitation pulse signals of the sub-layer with the negative pulse excitation direction. Therefore, it is just possible to ensure that the 90-degree components of the signals in the positive and negative pulse excitation directions are exactly opposite and cancel each other out, while the 180-degree components are not affected. Thus, while eliminating the 90-degree effect, the side effects such as the diffusion effect caused by the damage gradient, the physiological stimulation caused by the gradient switching, and the time consumption are eliminated. In a specific implementation, since the thickness of the sub-layer affects the bandwidth of the pulse, the total layer thickness of the sub-layer with the positive pulse excitation direction and the total layer thickness of the sub-layer with the negative pulse excitation direction can be kept consistent, so that the sum of the sub-excitation pulse signals of the positive and negative sub-layers are the same.

[0058] In a specific embodiment, Figure 3 and Figure 4 As shown in the figure, according to the preset layer selection direction, the single layer is further subdivided into two layers: the upper layer A and the lower layer B. The pulse excitation direction of the upper layer is positive X, and the pulse excitation direction of the lower layer is negative -X. RF represents the axis corresponding to the radio frequency pulse, G represents the axis corresponding to the gradient pulse, and α represents the flip angle. The layer thickness of both the upper and lower layers is half that of the original single layer. Because the layer thickness of the upper and lower halves is the same, when designing the sub-excitation pulse signal, the upper and lower halves use the same pulse waveform RF_ori, but with opposite initial phases. The pulse waveform RF_ori can excite the upper or lower halves independently.

[0059] In some embodiments, step S130 further includes:

[0060] S140 , summing the sub-excitation pulse signals of each sub-layer of the same single layer to obtain a magnetic resonance pulse signal of each single layer.

[0061] In this embodiment, the sub-excitation pulse signals of multiple sub-layers are combined, and the sub-excitation pulse signals of each sub-layer are summed to obtain the magnetic resonance pulse signal of a single layer. This makes it easier and faster to excite the single layer and facilitates waveform design. Of course, the embodiments of the present invention are not limited to the use of a combined approach for pulse excitation. The sub-excitation pulse signals of each sub-layer can be directly used to excite the sub-layers individually, or the sub-excitation pulse signals of each sub-layer can be combined to excite the single layer. As long as the 90-degree effect is eliminated and the damage gradient is omitted, any method can be applied to the technical solution of the present invention.

[0062] In some embodiments, summing the sub-excitation pulse signals of each sub-layer of the same single layer includes:

[0063] Based on the sub-excitation pulse signals of each sub-layer of the single layer and the positional relationship between the sub-layers, the sub-excitation pulse signals of each sub-layer of the same single layer are summed.

[0064] In a specific embodiment, Figure 3 As shown in the figure, if the upper and lower halves use the same pulse waveform RF_ori, the slice selection gradient is doubled, and the magnetic resonance pulse signal of a single layer becomes in The difference in center frequency is caused by the position difference between the two layers, which is caused by the upper and lower position offset of the upper and lower halves. R_renew is the newly designed single-layer magnetic resonance pulse signal that can excite the entire single layer.

[0065] The embodiment of the present invention uses a bidirectional excitation method, adopting positive and negative excitation directions for different positions of the layer, so that the 90-degree components of the signal within the layer are exactly opposite and cancel each other out, while the 180-degree components are not affected. In this way, the damage gradient can be omitted, thereby eliminating the side effects brought by the damage gradient.

[0066] Based on the above-mentioned magnetic resonance pulse generation method, an embodiment of the present invention also provides a magnetic resonance imaging method. The magnetic resonance imaging method can be applied to a magnetic resonance device or scanner, and can be specifically executed by one or more processors of the magnetic resonance imaging device or scanner. Figure 5 , MRI methods include:

[0067] S210, applying a layer selection gradient along a preset layer selection direction to the target object, dividing the target object into multiple single layers along the preset layer selection direction;

[0068] S220, exciting each single layer using a radio frequency pulse generated by a magnetic resonance pulse generation method to obtain a magnetic resonance signal corresponding to each single layer;

[0069] S230, applying phase encoding and frequency encoding to the magnetic resonance signal respectively to obtain encoded data of the magnetic resonance signal;

[0070] S240, filling the encoded data into the K space;

[0071] S250 : Reconstruct the K space to obtain a magnetic resonance image of the target object.

[0072] The magnetic resonance pulse generating method is the magnetic resonance pulse generating method described in the above embodiments. Since the magnetic resonance pulse generating method has been described in detail above, it will not be repeated here.

[0073] In this embodiment, during 3D magnetic resonance imaging, a slice selection gradient along a preset slice selection direction is first applied to the target object. This divides the target object into multiple layers along the preset slice selection direction. RF pulses are then used to excite the multiple layers, causing the nuclei in the multiple layers to spin due to the RF pulses. This allows magnetic resonance signals corresponding to the multiple layers to be acquired. Subsequently, the magnetic resonance signals are encoded and K-space is reconstructed to obtain a magnetic resonance image of the target object. This embodiment utilizes a magnetic resonance pulse generation method to generate RF pulses, effectively avoiding the 90-degree effect and eliminating the side effects of the lossy gradient.

[0074] In a preferred embodiment, in step S210, the preset slice selection direction may be the left-right direction. In step S230, the magnetic resonance signals may be phase-encoded using a gradient field in the front-to-back direction, and the magnetic resonance signals may be frequency-encoded using a gradient field in the top-to-bottom direction. Of course, in other embodiments, the preset slice selection direction may be the front-to-back direction, and the corresponding phase encoding direction may be the left-to-right direction. This is not limited in the present embodiment.

[0075] Once the encoding is complete, the encoded data corresponding to the magnetic resonance signal is populated into K-space. K-space, also known as Fourier space, is a space filled with encoded data containing spatially coded information. Each magnetic resonance image has its own corresponding K-space data matrix. Performing a Fourier transform on the data in K-space yields digital magnetic resonance signals of varying frequencies, phases, and amplitudes corresponding to the encoded data. Assigning these digital magnetic resonance signals to corresponding pixels yields the resulting magnetic resonance image.

[0076] Based on the above magnetic resonance pulse generation method, the embodiment of the present invention also provides a magnetic resonance pulse generation device 300. Figure 6 The magnetic resonance pulse generating device 400 includes a slice acquisition module 310 , a single-layer segmentation module 320 and a sub-excitation pulse generating module 330 .

[0077] The slice acquisition module 310 is used to acquire slices of the target object, where the slices include multiple single layers arranged along a preset slice selection direction;

[0078] The single layer segmentation module 320 is used to segment a single layer into multiple sub-layers according to a preset layer selection direction, wherein each sub-layer has a positive or negative pulse excitation direction, and within the same single layer, the number of sub-layers with positive pulse excitation directions and the number of sub-layers with negative pulse excitation directions are equal;

[0079] The sub-excitation pulse generating module 330 is configured to generate a sub-excitation pulse signal corresponding to each sub-layer according to the parameters of each sub-layer and the pulse excitation direction of each sub-layer.

[0080] In this embodiment, a slice of the target object is first acquired. Each single layer of the slice is then divided into multiple sublayers according to a preset layer selection direction, and each sublayer is given a positive or negative pulse excitation direction. Then, based on the parameters of each sublayer and the pulse excitation direction, a sub-excitation pulse signal corresponding to the sublayer is generated, and the sum of the positive and negative sub-excitation pulse signals within the same single layer is ensured to be the same, thus obtaining a pulse excitation signal for each sublayer, which can be used to excite each single layer. The present invention uses a bidirectional excitation method, adopting positive and negative excitation directions for different positions within a single layer, so that the 90-degree components of the signal within the layer are exactly opposite and cancel each other out, while the 180-degree components are unaffected, thereby effectively suppressing the 90-degree effect after pulse excitation. For pulses mainly used for refocusing, the damage gradient at both ends of the pulse can be removed, thereby effectively eliminating the 90-degree effect while eliminating the side effects such as the diffusion effect caused by the damage gradient, the physiological stimulation caused by the gradient switching, and the time consumption caused by the gradient switching.

[0081] In some embodiments, the parameters of the sub-layer include at least the location of the sub-layer and the thickness of the sub-layer.

[0082] In some embodiments, the initial phase difference between the sub-excitation pulse signal for the sub-layer with a positive pulse excitation direction and the initial phase difference between the sub-excitation pulse signal for the sub-layer with a negative pulse excitation direction is 180 degrees.

[0083] In some embodiments, the magnetic resonance pulse generating device 300 further includes a single-layer pulse generating module 340 for summing the sub-excitation pulse signals of each sub-layer of the same single layer to obtain the magnetic resonance pulse signals of each single layer.

[0084] In some embodiments, the single layer pulse generation module 340 is specifically configured to sum the sub-excitation pulse signals of each sub-layer of the same single layer based on the sub-excitation pulse signals of each sub-layer of the single layer and the positional relationship between the sub-layers.

[0085] Based on the above-mentioned magnetic resonance imaging method and magnetic resonance pulse generating device 300, an embodiment of the present invention further provides a magnetic resonance imaging system, including the magnetic resonance pulse generating device 300 and the imaging device 400 as described in the above-mentioned embodiments. Figure 7 The imaging device 400 includes a layering module 410 , an excitation module 420 , an encoding module 430 , a data filling module 440 and a reconstruction module 450 .

[0086] The layering module 410 is used to apply a layer selection gradient along a preset layer selection direction to the target object, and divide the target object into multiple single layers along the preset layer selection direction.

[0087] The excitation module 420 is used to excite each single layer using the radio frequency pulse generated by the magnetic resonance pulse generating device 300 to obtain the magnetic resonance signal corresponding to each single layer;

[0088] The encoding module 430 is configured to apply phase encoding and frequency encoding to the magnetic resonance signal to obtain encoding data of the magnetic resonance signal.

[0089] The data filling module 440 is used to fill the encoded data into the K space.

[0090] The reconstruction module 450 is used to reconstruct the K space to obtain a magnetic resonance image of the target object.

[0091] Since the magnetic resonance imaging method and the magnetic resonance pulse generating device 300 have been described in detail above, the technical effects of the magnetic resonance imaging method and the magnetic resonance pulse generating device are also possessed by the magnetic resonance imaging system and will not be described in detail here.

[0092] like Figure 8 As shown, based on the above-mentioned magnetic resonance pulse generation method, the present invention also provides an electronic device, which can be a computing device such as a mobile terminal, a desktop computer, a notebook, a palmtop computer, and a server. The electronic device includes a processor 10, a memory 20, and a display 30. Figure 5 Only some of the components of the electronic device are shown, but it should be understood that it is not required to implement all of the shown components, and more or fewer components may be implemented instead.

[0093] In some embodiments, the memory 20 may be an internal storage unit of the electronic device, such as a hard disk or memory of the electronic device. In other embodiments, the memory 20 may also be an external storage device of the electronic device, such as a plug-in hard disk equipped on the electronic device, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. Furthermore, the memory 20 may also include both an internal storage unit of the electronic device and an external storage device. The memory 20 is used to store application software and various types of data installed in the electronic device, such as program codes installed in the electronic device. The memory 20 may also be used to temporarily store data that has been output or is to be output. In one embodiment, a computer program 40 is stored on the memory 20, and the computer program 40 can be executed by the processor 10, thereby realizing the magnetic resonance pulse generation method or the magnetic resonance imaging method of each embodiment of the present application.

[0094] In some embodiments, the processor 10 may be a central processing unit (CPU), a microprocessor, or other data processing chip, configured to execute program codes stored in the memory 20 or process data, such as executing a magnetic resonance pulse generation method or a magnetic resonance imaging method.

[0095] In some embodiments, the display 30 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, or an OLED (Organic Light-Emitting Diode) touchscreen. The display 30 is used to display information on the electronic device and to display a visual user interface. The components 10-30 of the electronic device communicate with each other via a system bus.

[0096] In one embodiment, when the processor 10 executes the computer program 40 in the memory 20, the following steps are implemented:

[0097] Acquire a slice of the target object, the slice comprising a plurality of single layers arranged along a preset layer selection direction;

[0098] Splitting the single layer into a plurality of sublayers according to the preset layer selection direction, wherein each sublayer has a positive or negative pulse excitation direction, and within the same single layer, the number of sublayers with positive pulse excitation directions and the number of sublayers with negative pulse excitation directions are the same;

[0099] According to the parameters of each sub-layer and the pulse excitation direction of each sub-layer, a sub-excitation pulse signal corresponding to each sub-layer is generated.

[0100] In some embodiments, the parameters of the sub-layer include at least the location of the sub-layer and the thickness of the sub-layer.

[0101] In some embodiments, the initial phase difference between the sub-excitation pulse signal for the sub-layer with a positive pulse excitation direction and the initial phase difference between the sub-excitation pulse signal for the sub-layer with a negative pulse excitation direction is 180 degrees.

[0102] In some embodiments, when the processor 10 executes the computer program 40 in the memory 20, the following steps are implemented:

[0103] The sub-excitation pulse signals of each sub-layer of the same single layer are summed to obtain the magnetic resonance pulse signal of each single layer.

[0104] In some embodiments, when the processor 10 executes the computer program 40 in the memory 20, the following steps are implemented:

[0105] Based on the sub-excitation pulse signals of each sub-layer of the single layer and the positional relationship between the sub-layers, the sub-excitation pulse signals of each sub-layer of the same single layer are summed.

[0106] In some embodiments, when the processor 10 executes the computer program 40 in the memory 20, the following steps are implemented:

[0107] Applying a layer selection gradient along a preset layer selection direction to the target object to divide the target object into multiple single layers along the preset layer selection direction;

[0108] Using a radio frequency pulse generated by a magnetic resonance pulse generation method to excite each single layer, and obtaining a magnetic resonance signal corresponding to each single layer;

[0109] applying phase encoding and frequency encoding to the magnetic resonance signal respectively to obtain encoding data of the magnetic resonance signal;

[0110] Fill the encoded data into the K space;

[0111] The K-space is reconstructed to obtain a magnetic resonance image of the target object.

[0112] In summary, the magnetic resonance pulse generation method, magnetic resonance imaging method, device, electronic device and storage medium provided by the present invention first obtain a slice of the target object, then divide each single layer of the slice into multiple sub-layers according to a preset layer selection direction, and make each sub-layer have a positive or negative pulse excitation direction, and then generate a sub-excitation pulse signal corresponding to the sub-layer according to the parameters of each sub-layer and the pulse excitation direction, and ensure that the sum of the positive and negative sub-excitation pulse signals in the same single layer is the same, that is, the pulse excitation signal of each sub-layer is obtained, and the excitation of each single layer can be achieved by the pulse excitation signal. The present invention uses a bidirectional excitation method, adopting positive and negative excitation directions for different positions of the slice, so that the 90-degree components of the signal within the two slices are exactly opposite and cancel each other, while the 180-degree components are not affected, thereby effectively suppressing the 90-degree effect after pulse excitation. For pulses mainly used for refocusing, the damage gradient at both ends of the pulse can be removed, thereby effectively eliminating the 90-degree effect while eliminating the diffusion effect caused by the damage gradient, the physiological stimulation caused by the gradient switching, the time consumption and other side effects.

[0113] Of course, those skilled in the art will appreciate that all or part of the processes in the above-described method embodiments can be implemented by instructing related hardware (such as a processor, controller, etc.) through a computer program. The program can be stored in a computer-readable storage medium, and when executed, the program can include the processes in the above-described method embodiments. The storage medium can be a memory, a magnetic disk, an optical disk, etc.

[0114] The specific embodiments of the present invention described above do not limit the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A method for generating a magnetic resonance pulse, characterized in that: The steps include: Acquire a slice of the target object, wherein the slice includes a plurality of single layers arranged along a preset slice selection direction; The single layer is divided into multiple sub-layers according to the preset layer selection direction, wherein each sub-layer has a positive or negative pulse excitation direction, and within the same single layer, the number of sub-layers with positive pulse excitation directions and the number of sub-layers with negative pulse directions are equal, and the 90-degree components of the signal within the layer are exactly opposite and cancel each other out, while the 180-degree components are not affected; According to the parameters of each sub-layer and the pulse excitation direction of each sub-layer, a sub-excitation pulse signal corresponding to each sub-layer is generated.

2. The magnetic resonance pulse generation method according to claim 1, wherein: The parameters of the sub-layer include at least the position of the sub-layer and the thickness of the sub-layer.

3. The magnetic resonance pulse generation method according to claim 1, wherein: The initial phase difference between the sub-excitation pulse signal of the sub-layer whose pulse excitation direction is positive and the initial phase difference between the sub-excitation pulse signal of the sub-layer whose pulse excitation direction is negative is 180 degrees.

4. The magnetic resonance pulse generation method according to claim 1, wherein: Also includes: The sub-excitation pulse signals of each sub-layer of the same single layer are summed to obtain the magnetic resonance pulse signal of each single layer.

5. The magnetic resonance pulse generation method according to claim 4, characterized in that: The summing of the sub-excitation pulse signals of each sub-layer of the same single layer includes: Based on the sub-excitation pulse signals of each sub-layer of the single layer and the positional relationship between the sub-layers, the sub-excitation pulse signals of each sub-layer of the same single layer are summed.

6. A magnetic resonance imaging method, characterized in that: The steps include: Applying a layer selection gradient along a preset layer selection direction to the target object to divide the target object into multiple single layers along the preset layer selection direction; Exciting each single layer using a radio frequency pulse generated by the magnetic resonance pulse generation method according to any one of claims 1 to 5 to obtain a magnetic resonance signal corresponding to each single layer; applying phase encoding and frequency encoding to the magnetic resonance signal respectively to obtain encoding data of the magnetic resonance signal; Filling the encoded data into the K space; The K space is reconstructed to obtain a magnetic resonance image of the target object.

7. A magnetic resonance pulse generating device, characterized in that: include: a slice acquisition module, configured to acquire a slice of a target object, wherein the slice includes a plurality of single layers arranged along a preset slice selection direction; a single-layer segmentation module, configured to segment the single layer into multiple sub-layers according to the preset layer selection direction, wherein each sub-layer has a positive or negative pulse excitation direction, and within the same single layer, the number of sub-layers with positive pulse excitation directions and the number of sub-layers with negative pulse directions are equal, the 90-degree components of the signal within the layer are exactly opposite and cancel each other out, and the 180-degree components are unaffected; The sub-excitation pulse generating module is used to generate a sub-excitation pulse signal corresponding to each sub-layer according to the parameters of each sub-layer and the pulse excitation direction of each sub-layer.

8. A magnetic resonance imaging system, characterized in that The method comprises the magnetic resonance pulse generating device and the imaging device according to claim 7, wherein the imaging device comprises: A layering module is used to apply a layer selection gradient along a preset layer selection direction to the target object, dividing the target object into multiple single layers along the preset layer selection direction; an excitation module, configured to excite each single layer using the radio frequency pulses generated by the magnetic resonance pulse generating device to obtain magnetic resonance signals corresponding to each single layer; an encoding module, configured to apply phase encoding and frequency encoding to the magnetic resonance signal to obtain encoded data of the magnetic resonance signal; A data filling module, used for filling the encoded data into the K space; The reconstruction module is used to reconstruct the K space to obtain a magnetic resonance image of the target object.

9. An electronic device, characterized in that: include: processor and memory; The memory stores a computer-readable program executable by the processor; When the processor executes the computer-readable program, the steps of the magnetic resonance pulse generating method according to any one of claims 1 to 5 or the magnetic resonance imaging method according to claim 6 are implemented.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores one or more programs, and the one or more programs can be executed by one or more processors to implement the steps in the magnetic resonance pulse generation method according to any one of claims 1 to 5 or the magnetic resonance imaging method according to claim 6.

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