Multi-modal parameter determination method and device, magnetic resonance equipment and storage medium

Abstract

The invention relates to a multi-modal parameter determination method and device, magnetic resonance equipment and a storage medium. An imaging sequence is applied to an imaging area to obtain a target magnetic resonance image, the target magnetic resonance image comprises a plurality of amplitude images and a plurality of groups of phase images, displacement parameters and temperature parameters of the imaging area are obtained based on the phase images, and hemodynamic parameters of the imaging area are obtained based on the amplitude images. In the embodiment of the invention, the space-time coding technology, the MR-ARFI and the blood oxygen level dependent functional magnetic resonance imaging technology BOLD are combined, a staggered acquisition mode is adopted, acquisition of various modal parameters is completed in one imaging sequence, and multi-dimensional information complementation can be realized by fusing the various modal parameters; the limitation of a single modal parameter is broken through, accurate positioning, real-time monitoring and comprehensive evaluation are realized in a complex physiological environment, and the accuracy of therapeutic effect evaluation after nerve regulation and control is improved.

Description

Technical Field

[0001] The present application relates to the field of medical technology, and in particular to a multimodal parameter determination method, device, magnetic resonance equipment, and storage medium. Background Art

[0002] Functional brain diseases are clinically difficult to treat, often imaging neurological disorders with high prevalence and recurrence rates. Neuromodulation and functional brain diseases are closely linked. With the continuous advancement of neuromodulation technology, electrical, optical, and ultrasonic methods have been used to inhibit or modulate the nervous system, thereby improving patients' neurological function and enabling guided treatment of the nervous system. For example, this approach is used to treat functional brain diseases such as epilepsy, Parkinson's disease, and anxiety disorders.

[0003] In actual clinical applications, how to accurately locate the diseased area or the affected brain functional area and evaluate the therapeutic effect after neuromodulation based on displacement parameters is a technical problem that needs to be solved urgently in this field.

[0004] Currently, Magnetic Resonance Acoustic Radiation Force Imaging (MR-ARFI) technology is mainly used to scan tissues to determine displacement parameters and evaluate the therapeutic effect after nerve regulation based on the displacement parameters.

[0005] However, the above-mentioned method of using displacement parameters to evaluate the therapeutic effect after nerve regulation has the problem of incomplete evaluation. Summary of the Invention

[0006] Based on this, it is necessary to provide a multi-modal parameter determination method, device, magnetic resonance equipment and storage medium that can obtain multiple modal parameters and improve evaluation accuracy in response to the above technical problems.

[0007] In a first aspect, the present application provides a multimodal parameter determination method, comprising:

[0008] An imaging sequence is applied to an imaging region to obtain a target magnetic resonance image; the imaging sequence includes a focused ultrasound pulse, a spatial coding excitation unit, and an acquisition unit; the spatial coding excitation unit is disposed before the focused ultrasound pulse and the acquisition unit, and the spatial coding gradient pulses in the spatial coding excitation unit and the acquisition gradient pulses in the acquisition unit satisfy a preset relationship so that the spatial coding gradient pulses applied to the imaging region cover the imaging region; the target magnetic resonance image includes a plurality of amplitude maps and a plurality of phase maps;

[0009] Based on each of the phase images, obtaining a displacement parameter and a temperature parameter of the imaging area;

[0010] Based on each of the amplitude maps, the hemodynamic parameters of the imaging area are acquired; the multimodal parameters include the displacement parameter, the temperature parameter and the hemodynamic parameter.

[0011] In one embodiment, the imaging sequence also includes a refocusing pulse unit and a first motion encoding gradient pulse; the spatial encoding excitation unit, the first motion encoding gradient pulse, the focused ultrasound pulse, the refocusing pulse unit, the acquisition unit, the spatial encoding excitation unit, the refocusing pulse unit, the acquisition unit, the spatial encoding excitation unit and the acquisition unit are applied in sequence; the spatial encoding excitation unit also includes a swept frequency excitation pulse; the refocusing pulse unit includes a refocusing pulse and a layer selection gradient pulse, and the acquisition unit also includes a readout gradient pulse.

[0012] In one embodiment, the imaging sequence further includes a second motion encoding gradient pulse, and the second motion encoding gradient pulse and the focused ultrasound pulse are sequentially applied between the spatial encoding excitation unit and the refocusing pulse unit; the polarity of the second motion encoding gradient pulse is opposite to that of the first motion encoding gradient pulse.

[0013] In one embodiment, the first motion coding gradient pulse includes a first sub-motion coding gradient pulse, a second sub-motion coding gradient pulse and a third sub-motion coding gradient pulse, the first sub-motion coding gradient pulse and the second sub-motion coding gradient pulse have the same polarity, and the first sub-motion coding gradient pulse and the third sub-motion coding gradient pulse have opposite polarities.

[0014] In one embodiment, the first modulus of the zero-order gradient moment of the first sub-motion coding gradient pulse is equal to the second modulus of the zero-order gradient moment of the second sub-motion coding gradient pulse, and the third modulus of the zero-order gradient moment of the third sub-motion coding gradient pulse is equal to the sum of the first modulus and the second modulus.

[0015] In one embodiment, the preset relationship is that a first product result corresponding to the acquisition gradient pulse is equal to a second product result corresponding to the spatial encoding gradient pulse; the first product result is the product result of the amplitude of the acquisition gradient pulse and the duration of the acquisition gradient pulse, and the second product result is the product result of the amplitude of the spatial encoding gradient pulse and the duration of the spatial encoding gradient pulse.

[0016] In a second aspect, the present application further provides a multimodal parameter determination device, comprising:

[0017] an application module, configured to apply an imaging sequence to an imaging region to obtain a target magnetic resonance image; the imaging sequence includes a focused ultrasound pulse, a spatial coding excitation unit, and an acquisition unit; the spatial coding excitation unit is disposed before the focused ultrasound pulse and the acquisition unit, and the spatial coding gradient pulses in the spatial coding excitation unit and the acquisition gradient pulses in the acquisition unit satisfy a preset relationship so that the spatial coding gradient pulses applied to the imaging region cover the imaging region; the target magnetic resonance image includes a plurality of amplitude maps and a plurality of phase maps;

[0018] A first acquisition module, configured to acquire a displacement parameter and a temperature parameter of the imaging area based on each of the phase images;

[0019] A second acquisition module is configured to acquire hemodynamic parameters of the imaging region based on each of the amplitude maps; the multimodal parameters include the displacement parameter, the temperature parameter, and the hemodynamic parameter. In a third aspect, the present application further provides a magnetic resonance imaging device comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method steps provided in the first aspect are implemented.

[0020] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, which implements the method steps provided in the first aspect when the computer program is executed by a processor.

[0021] In a fifth aspect, the present application also provides a computer program product, comprising a computer program, which implements the method steps provided in the first aspect when executed by a processor.

[0022] The above-mentioned multimodal parameter determination method, device, magnetic resonance equipment and storage medium obtain a target magnetic resonance image by applying an imaging sequence to the imaging area, obtain the displacement parameters and temperature parameters of the imaging area based on each phase map, and obtain the hemodynamic parameters of the imaging area based on each amplitude map; the imaging sequence includes a focused ultrasound pulse, a spatial coding excitation unit and an acquisition unit; the spatial coding excitation unit is arranged before the focused ultrasound pulse and the acquisition unit, and the spatial coding gradient pulse in the spatial coding excitation unit and the acquisition gradient pulse in the acquisition unit satisfy a preset relationship so that the spatial coding gradient pulse applied to the imaging area covers the imaging area, the multimodal parameters include displacement parameters, temperature parameters and hemodynamic parameters, and the target magnetic resonance image includes multiple amplitude maps and multiple groups of phase maps. In an embodiment of the present application, the embodiment of the present application combines spatiotemporal coding technology with MR-ARFI and blood oxygen level-dependent functional magnetic resonance imaging technology BOLD, adopts an interleaved acquisition mode, and completes the acquisition of multiple modal parameters in one imaging sequence. The fusion of multiple modal parameters can achieve multi-dimensional information complementarity, break through the limitations of a single modal parameter, and achieve precise positioning, real-time monitoring and comprehensive evaluation in a complex physiological environment, thereby improving the accuracy of the evaluation of therapeutic effects after neuromodulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments of the present application or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying any creative work.

[0024] Figure 1 FIG. 1 is a diagram illustrating an application environment of a multimodal parameter determination method according to an embodiment;

[0025] Figure 2 1 is a flow chart of a method for determining multimodal parameters in one embodiment;

[0026] Figure 3 is a schematic diagram of an imaging sequence in one embodiment;

[0027] Figure 4 FIG. 1 is a structural block diagram of a multimodal parameter determination apparatus in one embodiment. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0029] The multimodal parameter determination method provided in the embodiment of the present application can be applied to Figure 1 The application environment shown in FIG. The application environment includes a magnetic resonance device, which includes a computer device and a scanning device, wherein the computer device 11 communicates with the scanning device 12. The data storage system can store data that the computer device 11 needs to process. The data storage system can be integrated with the computer device 11, or placed on the cloud or other network servers. The computer device can be a terminal, and its internal structure can be as shown in FIG. Figure 1 As shown. The computer device includes a processor, memory, an input / output interface, a communication interface, a display unit, and an input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are connected to the system bus via the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with external terminals via wired or wireless means, and the wireless means can be implemented via Wi-Fi, a mobile cellular network, near field communication (NFC), or other technologies. When executed by the processor, the computer program implements a multimodal parameter determination method. The display unit of the computer device is used to form a visually visible image, and can be a display screen, a projection device, or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the computer device casing, or an external keyboard, touchpad or mouse.

[0030] Those skilled in the art will understand that Figure 1 The structure shown in the figure is merely a block diagram of a portion of the structure related to the present application scheme, and does not constitute a limitation on the magnetic resonance device to which the present application scheme is applied. The specific magnetic resonance device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0031] In an exemplary embodiment, Figure 2 As shown, a multimodal parameter determination method is provided, which is applied to Figure 1 The magnetic resonance device in the embodiment is used as an example to illustrate the method, which includes the following S201 to S203.

[0032] S201, applying an imaging sequence to an imaging area to obtain a target magnetic resonance image; the imaging sequence includes a focused ultrasound pulse, a spatial coding excitation unit, and an acquisition unit; the spatial coding excitation unit is arranged before the focused ultrasound pulse and the acquisition unit, and the spatial coding gradient pulse in the spatial coding excitation unit and the acquisition gradient pulse in the acquisition unit satisfy a preset relationship so that the spatial coding gradient pulse applied to the imaging area covers the imaging area; the target magnetic resonance image includes multiple amplitude maps and multiple sets of phase maps.

[0033] In which, the spatial coding gradient pulse in the spatial coding excitation unit and the acquisition gradient pulse in the acquisition unit satisfy a preset relationship. The preset relationship can be that a first product result corresponding to the acquisition gradient pulse is equal to a second product result corresponding to the spatial coding gradient pulse; the first product result is the product result of the amplitude of the acquisition gradient pulse and the duration of the acquisition gradient pulse, and the second product result is the product result of the amplitude of the spatial coding gradient pulse and the duration of the spatial coding gradient pulse.

[0034] The preset relationship may also be that the difference between the first product result corresponding to the acquisition gradient pulse and the second product result corresponding to the spatial encoding gradient pulse is smaller than a preset threshold, so that the spatial encoding gradient pulse applied to the imaging area covers the imaging area.

[0035] In an embodiment of the present application, the imaging sequence includes multiple basic units, each basic unit includes a focused ultrasound pulse, a spatially coded excitation unit, and an acquisition unit. By applying focused ultrasound pulses, spatially coded excitation units, and acquisition units to the imaging area through multiple basic units, corresponding multiple amplitude maps and multiple sets of phase maps can be obtained.

[0036] Taking a basic unit as an example, a spatial encoding excitation unit, a first motion encoding gradient pulse, a focused ultrasound pulse, a refocusing pulse unit, and an acquisition unit are sequentially applied to the imaging region to generate a first magnetic resonance signal, and a first phase map generated based on the first magnetic resonance signal is obtained. A spatial encoding excitation unit, a refocusing pulse unit, and an acquisition unit are applied to the imaging region to generate a second magnetic resonance signal, and a second phase map generated based on the second magnetic resonance signal is obtained. A spatial encoding excitation unit and an acquisition unit are also applied to the imaging region to generate a third magnetic resonance signal, and an amplitude map generated based on the third magnetic resonance signal is obtained. Optionally, the spatial encoding excitation unit includes a sweep excitation pulse and a spatial encoding gradient pulse, the refocusing pulse unit includes a refocusing pulse and a layer selection gradient pulse, and the acquisition unit includes a readout gradient pulse and an acquisition gradient pulse.

[0037] In a possible implementation, a crushing gradient pulse may be applied to the imaging region when the focusing pulse unit is applied to the imaging region.

[0038] An image reconstruction algorithm is used to reconstruct the first magnetic resonance signal to obtain a first phase map, the second magnetic resonance signal to obtain a second phase map, and the third magnetic resonance signal to obtain an amplitude map. Image reconstruction methods include, but are not limited to, inverse Fourier transform and super-resolution reconstruction.

[0039] The spatially encoded excitation unit and the acquisition unit can be used as blood oxygen level dependent functional MRI (BOLD-fMRI). The BOLD-fMRI obtained by combining the spatially encoded excitation unit and the acquisition unit in the embodiment of the present application is different from the BOLD-fMRI obtained by combining traditional radio frequency pulses and slice-selective gradient pulses. The BOLD-fMRI in the embodiment of the present application can reduce the scanning time and is not easily affected by metal components such as external ultrasonic transducers, thereby having higher robustness to magnetic field inhomogeneity, magnetic susceptibility distortion and chemical shift artifacts.

[0040] Optionally, the order of the acquisition module corresponding to the blood oxygen level-dependent functional magnetic resonance imaging technology and the acquisition modules composed of the spatiotemporal encoding imaging technology and MR-ARFI is not restricted. That is, the amplitude image can be acquired first, followed by the first phase image and the second phase image. In other words, the order of applying the imaging sequence is: spatial encoding excitation unit, acquisition unit, spatial encoding excitation unit, first motion encoding gradient pulse, focused ultrasound pulse, refocusing pulse unit, acquisition unit, spatial encoding excitation unit, refocusing pulse unit, and acquisition unit.

[0041] Among them, the spatial coding excitation unit, the refocusing pulse unit and the acquisition unit can be used as space-time coding imaging technology, and the first motion coding gradient pulse and the focused ultrasound pulse can be used as MR-ARFI, that is, the present application combines space-time coding imaging technology and MR-ARFI for imaging.

[0042] Optionally, the emission timing of the high-intensity focused ultrasound pulses is controlled by a sequence trigger module in a computer device.

[0043] Optionally, the amplitude and shape of the spatial encoding gradient pulse Ge can be defined according to actual application conditions.

[0044] S202 : Acquire displacement parameters and temperature parameters of the imaging area based on each phase image.

[0045] In this embodiment of the present application, the same slice is acquired twice. The polarity of the first motion encoding gradient pulse in the first acquisition is opposite to the polarity of the second motion encoding gradient pulse in the second acquisition, or no second motion encoding gradient pulse is applied in the second acquisition. This results in a set of phase maps, namely, a first phase map and a second phase map. Each second phase map is subtracted from the corresponding first phase map, thereby obtaining displacement parameters and temperature parameters of the imaging region caused by the high-intensity focused ultrasound pulse.

[0046] Theoretically, after subtracting the first and second phase images, the phase in the non-focal area should be equal to zero. However, considering that magnetic field inhomogeneity may cause the phases of the two phase images in the non-focal area to be non-zero, phase correction can be performed. For example, two additional phase images without focused ultrasound can be collected, and phase correction can be performed on the corresponding first and second phase images.

[0047] Furthermore, tissue displacement is obtained through displacement parameters to achieve precise positioning of the imaging area. In addition, temperature imaging can be performed synchronously based on the phase changes captured by motion encoding. The temperature of the focal area is monitored in real time in combination with temperature parameters to prevent tissue damage caused by temperature increase due to excessive treatment.

[0048] S203 , based on each amplitude map, obtaining hemodynamic parameters of the imaging area; the multimodal parameters include displacement parameters, temperature parameters and hemodynamic parameters.

[0049] In an embodiment of the present application, after obtaining each amplitude map through an imaging sequence, the mean value of the pixels in the focal area corresponding to each amplitude map is obtained. Based on each mean value, a response function regarding hemodynamics, that is, a hemodynamic parameter, can be obtained. The blood flow changes in the imaging area are monitored in combination with the hemodynamic parameters. The hemodynamic parameters can be used to evaluate whether the expected functional changes or metabolic changes occur in the neural regulatory brain area.

[0050] Furthermore, by combining focused ultrasound pulses, spatially coded excitation units and acquisition units, real-time linkage of displacement parameters, temperature parameters and hemodynamic parameters is achieved, and an integrated neuroregulatory platform of "positioning-regulation-evaluation and verification" is constructed, which not only improves the accuracy and real-time performance of treatment, but also provides auxiliary decision-making basis for individualized treatment.

[0051] In the above-mentioned multimodal parameter determination method, an imaging sequence is applied to the imaging region to obtain a target magnetic resonance image, and displacement parameters and temperature parameters of the imaging region are obtained based on each phase map, and hemodynamic parameters of the imaging region are obtained based on each amplitude map. The imaging sequence includes a focused ultrasound pulse, a spatial coding excitation unit, and an acquisition unit. The spatial coding excitation unit is arranged before the focused ultrasound pulse and the acquisition unit, and the spatial coding gradient pulse in the spatial coding excitation unit and the acquisition gradient pulse in the acquisition unit satisfy a preset relationship so that the spatial coding gradient pulse applied to the imaging region covers the imaging region. The multimodal parameters include displacement parameters, temperature parameters, and hemodynamic parameters, and the target magnetic resonance image includes multiple amplitude maps and multiple sets of phase maps. In an embodiment of the present application, the embodiment of the present application combines spatiotemporal coding technology with MR-ARFI and blood oxygen level-dependent functional magnetic resonance imaging technology BOLD, adopts an interleaved acquisition mode, and completes the acquisition of multiple modal parameters in one imaging sequence. The fusion of multiple modal parameters can achieve multi-dimensional information complementarity, break through the limitations of a single modal parameter, and achieve precise positioning, real-time monitoring, and comprehensive evaluation in complex physiological environments, thereby improving the accuracy of the evaluation of the therapeutic effect after neuromodulation.

[0052] In one embodiment, the imaging sequence also includes a refocusing pulse unit and a first motion encoding gradient pulse; the spatial encoding excitation unit, the first motion encoding gradient pulse, the focused ultrasound pulse, the refocusing pulse unit, the acquisition unit, the spatial encoding excitation unit, the refocusing pulse unit, the acquisition unit, the spatial encoding excitation unit and the acquisition unit are applied in sequence; the spatial encoding excitation unit also includes a swept frequency excitation pulse; the refocusing pulse unit includes a refocusing pulse and a layer selection gradient pulse, and the acquisition unit also includes a readout gradient pulse.

[0053] In the embodiments of this application, Figure 3 As shown, Figure 3 Figure 1 is a schematic diagram of an imaging sequence in one embodiment. A swept excitation pulse (90° Chirp) with a flip angle of 90° and a spatial encoding gradient pulse Ge are simultaneously applied to the imaging area. Under the action of the spatial encoding gradient pulse Ge, hydrogen protons in the human body spin along the spatial encoding direction. The duration of the spatial encoding gradient pulse is T Ge At the end of the swept excitation pulse, the accumulated spin phase of the hydrogen protons is a quadratic function of the different positions in the matrix spatial encoding direction, showing a quadratic parabola. Spin-based spatial encoding gradient pulses are used in the spatial encoding axis, replacing traditional phase encoding gradient pulses. Quadratic phase technology is used to increase the bandwidth in the spatial encoding direction.

[0054] After applying the spatial encoding excitation unit, the first motion encoding gradient pulse (MEG) and focused ultrasound pulse in the imaging sequence are applied to the imaging area. The focused ultrasound pulse causes tissue displacement in the imaging area. The first motion encoding gradient pulse MEG1 is used to encode the tiny displacement (micrometer level) caused by the focused ultrasound pulse inside the tissue in the imaging area, accurately locating the focus of the focused ultrasound pulse neural regulation.

[0055] After applying the spatial encoding excitation unit, the first motion encoding gradient pulse, and the focused ultrasound pulse, the imaging sequence's refocusing pulse and slice selection gradient pulse Gss are applied to the imaging area. The refocusing pulse is used to refocus the de-phased hydrogen protons, bringing them back into phase. The slice selection gradient pulse Gss is used to select a specific layer for imaging. By applying a linearly varying magnetic field in a certain direction, the frequency of hydrogen protons in the human body changes linearly along that direction, enabling precise selection of a specific layer. TE1 is the echo time in the first image acquisition sequence.

[0056] After applying the focusing pulse unit, an acquisition gradient pulse Gacq is applied to the tissue on the spatial encoding axis, and a readout gradient pulse Gro is applied on the readout axis. The acquisition gradient pulse Gacq is mainly used to spatially locate the signal before imaging to ensure that the received signal can accurately correspond to a specific position within the imaging area. The readout gradient pulse Gro is used to read the acquired signal from the imaging area and convert it into an electrical signal. The readout gradient pulse Gro is used in conjunction with the acquisition gradient pulse Gacq to complete the imaging process. After applying the acquisition gradient pulse Gacq, the hydrogen protons within the imaging area will generate signals of different frequencies. The function of the readout gradient pulse Gro is to separate these signals of different frequencies, arrange them in a certain order, and then convert them into electrical signals through the receiving coil. In this way, a set of first magnetic resonance signals representing the tissue structure information within the imaging area can be obtained.

[0057] Based on the above approach, a spatial encoding excitation unit, a refocusing pulse unit, and an acquisition unit are sequentially applied to the imaging area to obtain a second magnetic resonance signal, and a second phase map is obtained based on the second magnetic resonance signal. Alternatively, a spatial encoding excitation unit, a second motion encoding gradient pulse, a focused ultrasound pulse, a refocusing pulse unit, and an acquisition unit are sequentially applied to the imaging area to obtain a second magnetic resonance signal, and a second phase map is obtained based on the second magnetic resonance signal. The second motion encoding gradient pulse is applied to the same target logical axis as the first motion encoding gradient pulse, and the second motion encoding gradient pulse has an opposite polarity to the first motion encoding gradient pulse.

[0058] A sweep excitation pulse and a spatial encoding gradient pulse Ge are applied to the imaging area. After the spatial encoding excitation unit is applied, an acquisition gradient pulse Gacq and a readout gradient pulse Gro are applied to the imaging area to generate a third magnetic resonance signal, and an amplitude map generated based on the third magnetic resonance signal is obtained.

[0059] Optionally, the focused ultrasound pulse can be emitted simultaneously with the first motion encoding gradient pulse MEG1, and the starting point of the focused ultrasound pulse can also be separated from the starting point of the first motion encoding gradient pulse MEG1 by a preset duration Tdelay, which is less than the duration of the first motion encoding gradient pulse.

[0060] The target logical axis applied by the first motion encoding gradient pulse MEG1 can be any one of a readout axis (RO), a spatial encoding axis (SP), or a slice selection axis (SS). The target logical axis applied by the first motion encoding gradient pulse MEG1 can be determined based on the propagation direction of the focused ultrasound pulse and / or a preset displacement measurement direction. For example, if the propagation direction of the focused ultrasound pulse is the readout axis, the target logical axis applied by the first motion encoding gradient pulse MEG1 is the readout axis; alternatively, if the preset displacement measurement direction is the spatial encoding axis, the target logical axis applied by the first motion encoding gradient pulse MEG1 is the spatial encoding axis.

[0061] Optionally, the RF pulse type can be a hard pulse, a soft pulse, an adiabatic pulse, or the like. That is, the swept excitation pulse and the subsequent focusing pulse can be a hard pulse, a soft pulse, an adiabatic pulse, or the like. The flip angle of the swept excitation pulse can be 90° or other angles, and the amplitude of the swept excitation pulse is not limited.

[0062] Optionally, the amplitude and duration of the first motion encoding gradient pulse MEG1, and the amplitude, duration, and flip angle of the refocusing pulse can be defined based on actual application conditions. The first motion encoding gradient pulse MEG1 can be a bipolar repetitive displacement encoding gradient pulse, a unipolar motion encoding gradient pulse, an inverted bipolar motion encoding gradient pulse, or other possible displacement encoding gradient pulses, which can also improve the signal-to-noise ratio of the first phase image.

[0063] Optionally, the readout gradient pulse Gro can adopt non-Cartesian acquisition (based on spiral readout or radial readout) or Cartesian acquisition. Acquisition methods including but not limited to echo planar imaging (EPI), gradient echo (GRE), and spin echo (SE) can also be adopted.

[0064] Optionally, the frequency, duration and Tdelay time of the focused ultrasound pulse are different for different test parts and treatment purposes. The focused ultrasound pulse is controlled by a sequence trigger module and can be applied to any axis, that is, the target logical axis to which the first motion encoding gradient pulse is applied; by transforming the target logical axis to which the first motion encoding gradient pulse is applied, three first phase images can be obtained, thereby obtaining a three-dimensional displacement distribution map based on the corresponding second phase image.

[0065] In the embodiment of the present application, a spatial coding excitation unit, a first motion coding gradient pulse, a focused ultrasound pulse, a refocusing pulse unit, an acquisition unit, a spatial coding excitation unit, a refocusing pulse unit, an acquisition unit, a spatial coding excitation unit, and an acquisition unit are applied in sequence; the spatial coding excitation unit also includes a frequency sweep excitation pulse; the refocusing pulse unit includes a refocusing pulse and a layer selection gradient pulse, and the acquisition unit also includes a readout gradient pulse. The embodiment of the present application combines spatiotemporal coding technology with MR-ARFI and blood oxygen level-dependent functional magnetic resonance imaging technology, and adopts an interleaved acquisition mode to speed up the scanning speed, achieve rapid image acquisition in a shorter time, and reduce heat deposition caused by the focused ultrasound pulse. It is also not easily affected by external devices containing metal parts. In neuromodulation applications, it has high robustness to magnetic field uniformity, magnetic susceptibility distortion, and chemical shift artifacts, reduces image distortion, and improves the signal-to-noise ratio of the image, laying an important foundation for precise positioning of nervous system regulation and subsequent regulatory treatment.

[0066] In one embodiment, the imaging sequence further includes a second motion encoding gradient pulse, and the second motion encoding gradient pulse and the focused ultrasound pulse are sequentially applied between the spatial encoding excitation unit and the refocusing pulse unit; the polarity of the second motion encoding gradient pulse is opposite to that of the first motion encoding gradient pulse.

[0067] In which, the first motion encoding gradient pulse and the second motion encoding gradient pulse are applied to the same target logical axis, and the target logical axis includes any one of the layer selection axis, the spatial encoding axis and the readout axis; the target logical axis is determined based on the propagation direction of the focused ultrasound pulse and / or the preset displacement measurement direction.

[0068] In an embodiment of the present application, a second motion encoding gradient pulse may be applied simultaneously with the application of the focused ultrasound pulse, or the starting time of applying the focused ultrasound pulse may be later than the starting time of applying the second motion encoding gradient pulse.

[0069] In the embodiment of the present application, the polarity of the second motion encoding gradient pulse is opposite to the polarity of the first motion encoding gradient pulse, which eliminates the phase artifacts caused by field inhomogeneity and improves the sensitivity of displacement, thereby improving the signal-to-noise ratio of the first phase image and the second phase image.

[0070] In one embodiment, the first motion coding gradient pulse includes a first sub-motion coding gradient pulse, a second sub-motion coding gradient pulse and a third sub-motion coding gradient pulse, the first sub-motion coding gradient pulse and the second sub-motion coding gradient pulse have the same polarity, and the first sub-motion coding gradient pulse and the third sub-motion coding gradient pulse have opposite polarities.

[0071] In an embodiment of the present application, the first motion coding gradient pulse includes a three-petal motion coding gradient pulse, a first sub-motion coding gradient pulse, a second sub-motion coding gradient pulse, and a third sub-motion coding gradient pulse. The polarity of the first sub-motion coding gradient pulse and the second sub-motion coding gradient pulse is the same, and the polarity of the first sub-motion coding gradient pulse and the third sub-motion coding gradient pulse is opposite. Since the polarity of the first motion coding gradient pulse and the second motion coding gradient pulse is opposite, the second motion coding gradient pulse includes a fourth sub-motion coding gradient pulse and a fifth sub-motion coding gradient pulse with opposite polarity to the first sub-motion coding gradient pulse, and a sixth sub-motion coding gradient pulse with opposite polarity to the third sub-motion coding gradient pulse.

[0072] In an embodiment of the present application, the first motion encoding gradient pulse includes a first sub-motion encoding gradient pulse, a second sub-motion encoding gradient pulse and a third sub-motion encoding gradient pulse. The three-petal motion encoding gradient pulse has low sensitivity to the displacement caused by unrecovered tissue and high robustness to background phases such as residual motion, which is conducive to the measurement of instantaneous phase displacement and magnetic resonance elastography related parameters.

[0073] In one embodiment, the first modulus of the zero-order gradient moment of the first sub-motion encoding gradient pulse is equal to the second modulus of the zero-order gradient moment of the second sub-motion encoding gradient pulse, and the third modulus of the zero-order gradient moment of the third sub-motion encoding gradient pulse is equal to the sum of the first modulus and the second modulus.

[0074] In the embodiment of the present application, as mentioned above Figure 3 As shown, assuming that the first modulus of the zero-order gradient moment of the first sub-motion encoding gradient pulse is A1, the second modulus of the zero-order gradient moment of the second sub-motion encoding gradient pulse is A2, and the third modulus of the zero-order gradient moment of the third sub-motion encoding gradient pulse is A3. By setting A1 = A2 and A3 = A1 + A2, and combining the conditions that the polarity of the first sub-motion encoding gradient pulse is the same as that of the second sub-motion encoding gradient pulse, and the polarity of the first sub-motion encoding gradient pulse is opposite to that of the third sub-motion encoding gradient pulse, the total zero-order gradient is equal to zero, thereby eliminating the phase shift of stationary tissue, thereby improving image quality, reducing motion artifacts, and increasing the signal-to-noise ratio of the image.

[0075] In one embodiment, the preset relationship is that a first product result corresponding to the acquisition gradient pulse is equal to a second product result corresponding to the spatial encoding gradient pulse; the first product result is the product result of the amplitude of the acquisition gradient pulse and the duration of the acquisition gradient pulse, and the second product result is the product result of the amplitude of the spatial encoding gradient pulse and the duration of the spatial encoding gradient pulse.

[0076] In the embodiment of the present application, the first product result is the amplitude A of the acquisition gradient pulse Gacq and the duration of the acquisition gradient pulse T Gacq The second product result is the amplitude A of the spatial encoding gradient pulse Ge and the duration of the spatial encoding gradient pulse T Ge The product result, that is, the preset relationship is |T Ge ×A Ge =T Gacq ×A Gacq |, which allows spatial encoding to cover the entire imaging area.

[0077] In one embodiment, the imaging sequence further includes a crushing gradient pulse and a destroying gradient pulse.

[0078] In the embodiment of the present application, as mentioned above Figure 3 As shown, the crushing gradient pulse includes a first crushing gradient pulse crush1 and a second crushing gradient pulse crush2, which are applied before and after the refocusing pulse. The first crushing gradient pulse crush1 and the second crushing gradient pulse crush2 are used to suppress interference signals, that is, to suppress unnecessary coherent spin signals.

[0079] After the acquisition unit is applied to the imaging area, a spoilage gradient pulse S can be added to the readout axis, the spatial encoding axis, and the slice selection axis to eliminate the residual phase in the remaining transverse plane to facilitate the next image acquisition.

[0080] Optionally, only the crushing gradient pulse or the destroying gradient pulse may be applied, or both the crushing gradient pulse and the destroying gradient pulse may be applied simultaneously.

[0081] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0082] Based on the same inventive concept, embodiments of the present application also provide a multimodal parameter determination device for implementing the multimodal parameter determination method involved above. The implementation solution provided by this device is similar to the implementation solution described in the above method. Therefore, the specific limitations of one or more multimodal parameter determination device embodiments provided below can be found in the above limitations of the multimodal parameter determination method and will not be repeated here.

[0083] In an exemplary embodiment, Figure 4 As shown, a multimodal parameter determination device is provided, comprising: an application module 51, a first acquisition module 52 and a second acquisition module 53, wherein:

[0084] An application module 51 is configured to apply an imaging sequence to an imaging region to obtain a target magnetic resonance image; the imaging sequence includes a focused ultrasound pulse, a spatially coded excitation unit, and an acquisition unit; the spatially coded excitation unit is disposed before the focused ultrasound pulse and the acquisition unit, and the spatially coded gradient pulses in the spatially coded excitation unit and the acquisition gradient pulses in the acquisition unit satisfy a preset relationship so that the spatially coded gradient pulses applied to the imaging region cover the imaging region; the target magnetic resonance image includes multiple amplitude maps and multiple sets of phase maps;

[0085] A first acquisition module 52 is used to acquire displacement parameters and temperature parameters of the imaging area based on each phase image;

[0086] The second acquisition module 53 is used to acquire the hemodynamic parameters of the imaging area based on each amplitude map; the multimodal parameters include displacement parameters, temperature parameters and hemodynamic parameters.

[0087] In one embodiment, the imaging sequence also includes a refocusing pulse unit and a first motion encoding gradient pulse; the spatial encoding excitation unit, the first motion encoding gradient pulse, the focused ultrasound pulse, the refocusing pulse unit, the acquisition unit, the spatial encoding excitation unit, the refocusing pulse unit, the acquisition unit, the spatial encoding excitation unit and the acquisition unit are applied in sequence; the spatial encoding excitation unit also includes a swept frequency excitation pulse; the refocusing pulse unit includes a refocusing pulse and a layer selection gradient pulse, and the acquisition unit also includes a readout gradient pulse.

[0088] In one embodiment, the imaging sequence further includes a second motion encoding gradient pulse, and the second motion encoding gradient pulse and the focused ultrasound pulse are sequentially applied between the spatial encoding excitation unit and the refocusing pulse unit; the polarity of the second motion encoding gradient pulse is opposite to that of the first motion encoding gradient pulse.

[0089] In one embodiment, the first motion coding gradient pulse includes a first sub-motion coding gradient pulse, a second sub-motion coding gradient pulse and a third sub-motion coding gradient pulse, the first sub-motion coding gradient pulse and the second sub-motion coding gradient pulse have the same polarity, and the first sub-motion coding gradient pulse and the third sub-motion coding gradient pulse have opposite polarities.

[0090] In one embodiment, the first modulus of the zero-order gradient moment of the first sub-motion encoding gradient pulse is equal to the second modulus of the zero-order gradient moment of the second sub-motion encoding gradient pulse, and the third modulus of the zero-order gradient moment of the third sub-motion encoding gradient pulse is equal to the sum of the first modulus and the second modulus.

[0091] In one embodiment, the preset relationship is that a first product result corresponding to the acquisition gradient pulse is equal to a second product result corresponding to the spatial encoding gradient pulse; the first product result is the product result of the amplitude of the acquisition gradient pulse and the duration of the acquisition gradient pulse, and the second product result is the product result of the amplitude of the spatial encoding gradient pulse and the duration of the spatial encoding gradient pulse.

[0092] Each module in the multimodal parameter determination apparatus described above may be implemented in whole or in part via software, hardware, or a combination thereof. Each module may be embedded in or independent of a processor within the MRI device in hardware form, or may be stored in a memory within the MRI device in software form, so that the processor can call upon and execute the corresponding operations of each module.

[0093] In an exemplary embodiment, a magnetic resonance device is provided, including a memory and a processor. The memory stores a computer program, and the processor implements the method steps provided in any of the above embodiments when executing the computer program.

[0094] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the method steps provided in any of the above embodiments are implemented.

[0095] In one embodiment, a computer program product is provided, including a computer program, which implements the method steps provided in any of the above embodiments when executed by a processor.

[0096] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0097] Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the 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-mentioned methods. In particular, any reference to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the various embodiments provided herein may be, but are not limited to, general-purpose processors, central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), programmable logic devices (PLDs), quantum computing-based data processing logic devices, artificial intelligence (AI) processors, and the like.

[0098] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0099] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A multimodal parameter determination method, characterized in that: The method comprises: An imaging sequence is applied to an imaging region to obtain a target magnetic resonance image; the imaging sequence includes a focused ultrasound pulse, a spatial coding excitation unit, and an acquisition unit; the spatial coding excitation unit is disposed before the focused ultrasound pulse and the acquisition unit, and the spatial coding gradient pulses in the spatial coding excitation unit and the acquisition gradient pulses in the acquisition unit satisfy a preset relationship so that the spatial coding gradient pulses applied to the imaging region cover the imaging region; the target magnetic resonance image includes a plurality of amplitude maps and a plurality of phase maps; Based on each of the phase images, obtaining a displacement parameter and a temperature parameter of the imaging area; Based on each of the amplitude maps, the hemodynamic parameters of the imaging area are acquired; the multimodal parameters include the displacement parameter, the temperature parameter and the hemodynamic parameter.

2. The method according to claim 1, characterized in that The imaging sequence also includes a refocusing pulse unit and a first motion encoding gradient pulse; the spatial encoding excitation unit, the first motion encoding gradient pulse, the focused ultrasound pulse, the refocusing pulse unit, the acquisition unit, the spatial encoding excitation unit, the refocusing pulse unit, the acquisition unit, the spatial encoding excitation unit and the acquisition unit are applied in sequence; the spatial encoding excitation unit also includes a swept frequency excitation pulse; the refocusing pulse unit includes a refocusing pulse and a layer selection gradient pulse, and the acquisition unit also includes a readout gradient pulse.

3. The method according to claim 2, characterized in that The imaging sequence further includes a second motion encoding gradient pulse, wherein the second motion encoding gradient pulse and the focused ultrasound pulse are sequentially applied between the spatial encoding excitation unit and the refocusing pulse unit; The polarity of the second motion encoding gradient pulse is opposite to the polarity of the first motion encoding gradient pulse.

4. The method according to claim 3, characterized in that The first motion coding gradient pulse includes a first sub-motion coding gradient pulse, a second sub-motion coding gradient pulse and a third sub-motion coding gradient pulse. The polarity of the first sub-motion coding gradient pulse and the second sub-motion coding gradient pulse is the same, and the polarity of the first sub-motion coding gradient pulse and the third sub-motion coding gradient pulse is opposite.

5. The method according to claim 4, characterized in that The first modulus of the zero-order gradient moment of the first sub-motion coding gradient pulse is equal to the second modulus of the zero-order gradient moment of the second sub-motion coding gradient pulse, and the third modulus of the zero-order gradient moment of the third sub-motion coding gradient pulse is equal to the sum of the first modulus and the second modulus.

6. The method according to any one of claims 1 to 5, characterized in that The preset relationship is that a first product result corresponding to the acquisition gradient pulse is equal to a second product result corresponding to the spatial encoding gradient pulse; The first multiplication result is the product of the amplitude of the acquisition gradient pulse and the duration of the acquisition gradient pulse, and the second multiplication result is the product of the amplitude of the spatial encoding gradient pulse and the duration of the spatial encoding gradient pulse.

7. A multimodal parameter determination device, characterized in that: The device comprises: an application module, configured to apply an imaging sequence to an imaging region to obtain a target magnetic resonance image; the imaging sequence includes a focused ultrasound pulse, a spatial coding excitation unit, and an acquisition unit; the spatial coding excitation unit is disposed before the focused ultrasound pulse and the acquisition unit, and the spatial coding gradient pulses in the spatial coding excitation unit and the acquisition gradient pulses in the acquisition unit satisfy a preset relationship so that the spatial coding gradient pulses applied to the imaging region cover the imaging region; the target magnetic resonance image includes a plurality of amplitude maps and a plurality of phase maps; A first acquisition module, configured to acquire a displacement parameter and a temperature parameter of the imaging area based on each of the phase images; The second acquisition module is used to acquire the hemodynamic parameters of the imaging area based on each of the amplitude maps; the multimodal parameters include the displacement parameter, the temperature parameter and the hemodynamic parameter.

8. A magnetic resonance device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

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

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

Images