A method for transcranial magnetic stimulation of deep brain regions based on diffusion tensor imaging

Abstract

The present invention discloses a method for realizing transcranial magnetic stimulation of deep brain regions based on diffusion tensor imaging, which comprises the following steps: obtaining brain structural image information and diffusion tensor imaging information of a subject to be subjected to transcranial magnetic stimulation; determining the coordinates of the deep brain regions of the subject to be subjected to transcranial magnetic stimulation based on the diffusion tensor imaging technology; constructing the white matter structure connection characteristics of the deep brain regions and the whole brain of the subject to be subjected to transcranial magnetic stimulation based on the diffusion tensor imaging information, and extracting the cortical brain regions with white matter structure connections to the deep brain regions; determining the optimal cortical position coordinates of the subject to be subjected to transcranial magnetic stimulation based on the cortical brain regions with white matter structure connections to the deep brain regions; with the help of a navigation and positioning system, using the optimal cortical position coordinates as the direct intervention site of a conventional stimulation coil, and guiding the placement direction of the stimulation coil based on the white matter fiber connection direction in the white matter structure connection characteristics, so as to realize the precise and individualized intervention of the transcranial magnetic stimulation coil on the deep brain regions.

Description

Technical Field

[0001] The present invention relates to a method for implementing transcranial magnetic stimulation on deep brain regions, and in particular to a method for implementing individualized and precise transcranial magnetic stimulation on deep brain regions based on diffusion tensor imaging. Background Art

[0002] Transcranial magnetic stimulation is a non-invasive extracranial neuromodulation technology. By applying an electromagnetic field outside the skull, the magnetic field penetrates the skull to generate an induced electric field in the cerebral cortex, which can cause neuronal depolarization, have an excitatory or inhibitory effect, and change the plasticity of the local brain. In 1985, Barker and his collaborators developed the first modern transcranial magnetic stimulation instrument in Sheffield, England. After that, transcranial magnetic stimulation technology was first applied to basic research and cognitive research on brain function localization. It was subsequently discovered that the effect of a specific pattern of transcranial magnetic stimulation on brain activity still exists for a certain period of time after the end of stimulation. The therapeutic effect of transcranial magnetic stimulation has attracted public attention and has been approved for clinical treatment of depressive disorders. There is also a large amount of clinical research evidence in mental and neurological diseases such as schizophrenia, Parkinson's disease, and pain. Transcranial magnetic stimulation technology has the advantages of being non-invasive, safe, and having few side effects, and has important clinical value and demand.

[0003] The intervention position of transcranial magnetic stimulation is a key parameter that affects the effect of magnetic stimulation and clinical efficacy. At present, conventional magnetic stimulation coils (taking the figure eight coil as an example) can reach 2-3cm below the coil, and the latest H-type magnetic stimulation coil can reach 4-6cm at its deepest. The effective site of magnetic stimulation is still mainly located in the cortex. Therefore, the existing magnetic stimulation coils have a bottleneck that cannot effectively act on the deep part of the brain. The subcortical structures deep in the brain, such as the cingulate, hippocampus, amygdala, striatum, etc., are key positions in the emotional and cognitive neural pathways, and are closely related to the pathogenesis of a variety of mental and neurological diseases. The existing transcranial magnetic stimulation technology cannot achieve effective intervention in the deep structures of the brain, which limits the scope of brain plasticity research, restricts the efficacy of this technology in clinical treatment, and limits clinical application and promotion. Summary of the invention

[0004] In view of the problems and shortcomings of the prior art, the present invention provides a method for realizing transcranial magnetic stimulation of deep brain regions based on diffusion tensor imaging. The method uses diffusion tensor imaging technology to construct a cortical position with the strongest white matter structure connection to a deep intervention target as the intervention position of a conventional magnetic stimulation coil; the placement direction of the stimulation coil is guided based on the direction of the white matter fiber bundles, thereby realizing precise and individualized intervention of deep brain regions.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] The present invention provides a method for realizing transcranial magnetic stimulation of deep brain regions based on diffusion tensor imaging, which is characterized in that it comprises the following steps:

[0007] S1. Obtaining brain structural image information and diffusion tensor imaging information of the subject to be subjected to transcranial magnetic stimulation;

[0008] S2. Determine the coordinates of the deep brain regions of the subjects to be treated with transcranial magnetic stimulation based on diffusion tensor imaging technology;

[0009] S3. Construct the white matter structural connection features of the deep brain regions and the whole brain of the subjects to be subjected to transcranial magnetic stimulation based on diffusion tensor imaging information, and extract the cortical brain regions that have white matter structural connections with the deep brain regions;

[0010] S4, determining the optimal cortical position coordinates of the subject to receive transcranial magnetic stimulation based on the cortical brain area that has white matter structure connections with the deep brain area;

[0011] S5. With the help of the navigation and positioning system, the optimal cortical position coordinates are used as the direct intervention site of the conventional stimulation coil, and the white matter fiber connection direction in the white matter structure connection characteristics is used to guide the placement direction of the stimulation coil, so as to achieve precise and individualized intervention of the transcranial magnetic stimulation coil on deep brain areas.

[0012] Preferably, in step S1, the brain structural image information includes a single voxel or multiple voxels, and the brain structural image information is derived from a magnetic resonance structural image of a subject to receive transcranial magnetic stimulation or a public standard structural image.

[0013] Preferably, step S2 comprises the following steps:

[0014] S21. Establish the mapping and transformation relationship between the acquired brain structural image information and diffusion tensor imaging information;

[0015] S22. Determine the coordinates of the deep brain regions of the subject to be subjected to transcranial magnetic stimulation on the diffusion tensor imaging image.

[0016] Preferably, step S3 includes the following steps:

[0017] S31, according to the deep brain region coordinates determined on the diffusion tensor imaging image, using a white matter fiber tracking algorithm, which may be but not limited to a deterministic tracking algorithm or a probabilistic tracking algorithm, to calculate the white matter structure connection characteristic values ​​between the deep brain region coordinates and all voxels in the whole brain;

[0018] S32. Extract cortical brain areas that have white matter structural connections with deep brain areas as candidate stimulation locations for transcranial magnetic stimulation.

[0019] On the basis of being in accordance with the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0020] The positive and progressive effects of the present invention are:

[0021] 1) In view of the defect that existing magnetic stimulation intervention cannot act on deep brain areas, this technical solution can achieve magnetic stimulation intervention on deep brain areas based on diffusion tensor imaging, expanding and extending the effective intervention range of magnetic stimulation on the brain.

[0022] 2) Compared with existing neuronavigation positioning methods, this technical solution not only provides precise cortical intervention sites, but also determines the intervention direction of transcranial magnetic stimulation based on the direction of individual white matter fibers, further improving the accuracy of positioning.

[0023] 3) This method can be implemented with the help of conventional transcranial magnetic stimulation coils and is compatible with existing hardware. It will greatly improve the effectiveness and application scope of the equipment and benefit basic research and clinical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The present invention is a flowchart of a method for implementing transcranial magnetic stimulation of deep brain regions based on diffusion tensor imaging according to a preferred embodiment of the present invention.

[0025] Figure 2 This is a flow chart of implementing magnetic stimulation to deep brain regions (hippocampus) based on diffusion tensor imaging according to a preferred embodiment of the present invention.

[0026] Figure 3 This is a diagram showing the effect of magnetic stimulation of deep brain regions (hippocampus) based on diffusion tensor imaging according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0028] like Figure 1 As shown, this embodiment provides a method for implementing transcranial magnetic stimulation of deep brain regions based on diffusion tensor imaging, which includes the following steps:

[0029] Step 1: Obtain brain structural image information and diffusion tensor imaging information of the subject to be treated with transcranial magnetic stimulation.

[0030] In step 1, the brain structural image information includes a single voxel or multiple voxels, and the brain structural image information is derived from a magnetic resonance structural image of a subject to receive transcranial magnetic stimulation or a public standard structural image.

[0031] Step 2: Determine the coordinates of the deep brain areas of the subjects to be treated with transcranial magnetic stimulation based on diffusion tensor imaging technology.

[0032] Step 2.1: Establish the mapping and transformation relationship between the acquired brain structural image information and diffusion tensor imaging information.

[0033] Step 2.2: Determine the coordinates of the deep brain regions of the subject to be treated with transcranial magnetic stimulation on the diffusion tensor imaging image.

[0034] Step 3: Based on the diffusion tensor imaging information, construct the white matter structure connection characteristics of the deep brain regions and the whole brain of the subjects to be treated with transcranial magnetic stimulation, and extract the cortical brain regions that have white matter structure connections with the deep brain regions.

[0035] Step 31: Based on the deep brain region coordinates determined on the diffusion tensor imaging image, a white matter fiber tracking algorithm is used, which may include but is not limited to a deterministic tracking algorithm or a probabilistic tracking algorithm, to calculate the white matter structure connection characteristic values ​​between the deep brain region coordinates and all voxels in the whole brain.

[0036] Step 32: Extract cortical brain regions that have white matter structural connections with deep brain regions as candidate stimulation locations for transcranial magnetic stimulation.

[0037] Step 4: Determine the optimal cortical position coordinates of the subject to receive transcranial magnetic stimulation based on the cortical brain area that has white matter structural connections with the deep brain area.

[0038] Step 5: With the help of the navigation and positioning system, the optimal cortical position coordinates are used as the direct intervention site of the conventional stimulation coil, and the white matter fiber connection direction in the white matter structure connection characteristics is used to guide the placement direction of the stimulation coil, so as to achieve precise and individualized intervention of the transcranial magnetic stimulation coil on deep brain areas.

[0039] Based on the principle of the above-mentioned method for realizing transcranial magnetic stimulation of deep brain regions based on diffusion tensor imaging, a specific example is given below to illustrate the present invention so that those skilled in the art can better understand the technical solution of the present invention:

[0040] This embodiment takes the deep brain region hippocampus as an example, and the specific implementation steps are as follows: Figure 2 As shown, including:

[0041] Step 1: Acquire structural magnetic resonance imaging (sMRI) and diffusion tensor imaging (DTI) images of the subject to be treated with transcranial magnetic stimulation.

[0042] Step 2.1: After conventional preprocessing, the sMRI and DTI images are registered to generate mapping and conversion information between the sMRI and DTI spaces.

[0043] Step 2.2: Based on the sMRI images of the subject to be subjected to transcranial magnetic stimulation, determine the location of the deep brain area to be stimulated as the region of interest (ROI). ROI selection can be based on actual needs, and single-voxel or multi-voxel ROI can be used. In this embodiment, the ROI selects the left hippocampus located in the deep subcortical structure, which contains multiple voxels. The method for generating the left hippocampus template is to extract it from the Harvard-Oxford template, such as Figure 3 As shown in (a) in .

[0044] Step 2.3: Generate a ROI template in DTI space. Perform the conversion according to the space where the ROI template is located (individual sMRI space or standard template space). In this embodiment, the left hippocampus template is taken from the standard space, and the conversion from the standard space to the individual DTI space needs to be completed to generate the ROI template in the individual DTI space, such as Figure 3 As shown in (b) in .

[0045] Step 3: Using the ROI template in the DTI space and the white matter fiber tracking algorithm, obtain the white matter structure connection map between the region of interest and the whole brain. In this embodiment, the left hippocampus template in the DTI space of the subject is used as the seed point to obtain the white matter structure connection map between the left hippocampus and the whole brain, as shown in FIG. Figure 3 As shown in (c) in .

[0046] Step 4: Determine the best site for direct intervention with the conventional magnetic stimulation coil based on the location and the functional connection strength with the ROI. In this embodiment, in the functional connection map between the left hippocampus and the whole brain white matter obtained in step 3, the best intervention site is the left parietal lobe, such as Figure 3 The cross coordinates in (d) are shown.

[0047] Step 5: With the help of the navigation and positioning system, the cortical site is used as the direct intervention site of the conventional stimulation coil. The direction of the white matter fiber connection guides the placement direction of the stimulation coil, so as to achieve precise and individualized intervention of the conventional magnetic stimulation coil on the deep brain area.

[0048] The present invention constructs a white matter structure connection map between the deep brain structure (>5cm) and the superficial cortex (2-3cm) based on diffusion tensor imaging; the magnetic stimulation coil directly acts on the superficial cortical site to achieve the effect of indirectly acting on the deep structure.

[0049] This method not only accurately locates the position of the superficial direct intervention site, but also can precisely control the placement direction of the magnetic stimulation coil according to the direction of the white matter fibers, thereby achieving precise and individualized magnetic stimulation intervention.

[0050] Although the specific embodiments of the present invention are described above, those skilled in the art should understand that these are only examples, and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A method for localizing the intervention position of deep brain regions by transcranial magnetic stimulation based on diffusion tensor imaging, characterized in that: It includes the following steps: S1. Obtaining brain structural image information and diffusion tensor imaging information of the subject to be subjected to transcranial magnetic stimulation; S2. Determine the coordinates of the deep brain regions of the subjects to be treated with transcranial magnetic stimulation based on diffusion tensor imaging technology; Step S2 includes the following steps: S21, establishing a mapping and conversion relationship between the acquired brain structural image information and the diffusion tensor imaging information; S22, determining the position of the deep brain region to be stimulated as the region of interest based on the brain structural image information of the subject to be subjected to transcranial magnetic stimulation; S23, completing the conversion of the region of interest from the brain structural image information to the diffusion tensor imaging information, generating a region of interest template on the diffusion tensor imaging image, and determining the coordinates of the deep brain region of the subject to be subjected to transcranial magnetic stimulation by using the region of interest template on the diffusion tensor imaging image; S3. Construct the white matter structural connection features of the deep brain regions and the whole brain of the subjects to be subjected to transcranial magnetic stimulation based on diffusion tensor imaging information, and extract the cortical brain regions that have white matter structural connections with the deep brain regions; Step S3 includes the following steps: S31, according to the coordinates of the deep brain area determined on the diffusion tensor imaging image, using the white matter fiber tracking algorithm, calculating the white matter structure connection characteristic values ​​of the deep brain area coordinates and all voxels in the whole brain; S32, extracting the cortical brain area that has white matter structure connection with the deep brain area as the candidate stimulation position of transcranial magnetic stimulation; S4, determining the optimal cortical position coordinates of the subject to receive transcranial magnetic stimulation based on the location of the cortical brain area that has white matter structure connections with the deep brain area and the strength of the white matter structure connection; S5. With the help of the navigation and positioning system, the optimal cortical position coordinates are used as the direct intervention site of the conventional stimulation coil, and the placement direction of the stimulation coil is guided by the white matter fiber connection direction in the white matter structure connection characteristics.

2. The method for locating the intervention position of deep brain regions by transcranial magnetic stimulation based on diffusion tensor imaging according to claim 1, characterized in that: In step S1, the brain structural image information includes a single voxel or multiple voxels, and the brain structural image information is derived from a magnetic resonance structural image of a subject to receive transcranial magnetic stimulation or a public standard structural image.

3. The method for locating the intervention position of deep brain regions by transcranial magnetic stimulation based on diffusion tensor imaging according to claim 1, characterized in that: The white matter fiber tracking algorithm adopts a deterministic tracking algorithm or a probabilistic tracking algorithm.

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