Vertical Splitting Method and Device of the Sub-branch of the Cuneocerebellar Tract

Abstract

The present invention provides a method and device for segmenting sub-branches of the vertical occipital fasciculus. The method includes: obtaining a magnetic resonance image, determining a whole-brain fiber streamline and an anatomical brain region segmentation map based on the magnetic resonance image, determining a vertical occipital fasciculus fiber streamline based on the whole-brain fiber streamline, and determining a region of interest for sub-branch division based on the anatomical brain region segmentation map; determining a voxel mask matrix corresponding to each region of interest for sub-branch division and the first endpoint coordinate and the second endpoint coordinate of the vertical occipital fasciculus fiber streamline, and determining the nearest neighbor region of interest of the vertical occipital fasciculus fiber streamline based on each voxel mask matrix, the first endpoint coordinate and the second endpoint coordinate; and determining the sub-branch to which the vertical occipital fasciculus fiber streamline belongs based on the nearest neighbor region of interest of the vertical occipital fasciculus fiber streamline. The present application can achieve more detailed sub-branch segmentation of the vertical occipital fasciculus.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetic resonance imaging, and in particular to a method and device for segmenting sub-branches of the vertical occipital fasciculus. Background Art

[0002] Diffusion magnetic resonance technology generates a non-uniform linear magnetic field through pulsed gradients, causing the diffusion of water molecules along the gradient direction to result in a certain phase difference in the microscopic magnetization vector, obtaining signal intensity related to the degree of water molecule diffusion, thereby measuring the water molecule diffusion intensity in this gradient direction and obtaining a set of diffusion-weighted image data. After modeling, the diffusion-weighted image can be represented as a tensor model or a direction distribution function. The long axis or peak direction of the model represents the direction in which the diffusion of the voxel is the strongest, that is, the tissue structure has less hindrance along this direction; therefore, it can non-invasively depict the orientation of the living tissue structure and has an important position in brain research. The special myelin sheath structure in white matter makes the water molecules therein show restricted anisotropic diffusion. By using diffusion magnetic resonance technology, the diffusion direction in white matter can be obtained, and the directions indicated by each voxel are smoothly connected to obtain white matter fiber streamlines; by dividing the whole brain fibers into different clusters according to geometric shapes, anatomical features or functional features, etc., white matter fiber bundles can be obtained.

[0003] The vertical occipital fasciculus is a vertical fiber located in the occipital lobe and plays an important role in the visual pathway. It connects various cortical regions with different functions, integrates visual information related to object recognition, shape perception, color recognition, pattern recognition, visual object localization and motion perception, and is an essential fiber bundle for visual analysis. Currently, when performing visual analysis based on the vertical occipital fasciculus, only the vertical occipital fasciculus at the occipital lobe is regarded as a whole to screen vertical fibers from the whole brain fibers, determine the terminating cortex and remove arcuate fasciculus fibers, etc., and the vertical occipital fasciculus is not further segmented into sub-branches. Since the vertical occipital fasciculus connects multiple cortical regions with different functions, when part of the structure of the fiber bundle changes, the impact on the whole vertical occipital fasciculus may not be significant, and the information transmitted and processed by different regions of the vertical occipital fasciculus is not consistent. Therefore, some functions related to vision may be abnormal or changed; currently, when performing visual analysis based on the vertical occipital fasciculus, due to the inability to perform more detailed sub-branch segmentation of the vertical occipital fasciculus, the abnormality of some functions related to vision cannot be analyzed. Therefore, how to perform more detailed sub-branch segmentation of the vertical occipital fasciculus and then complete the abnormality analysis of some functions related to vision is a technical problem to be solved urgently. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a method and device for segmenting sub-branches of the vertical occipital fasciculus to eliminate or improve one or more defects existing in the prior art.

[0005] One aspect of the present invention provides a method for segmenting the vertical occipital fasciculus sub-branches, the method comprising:

[0006] Obtain a magnetic resonance image, determine the whole-brain fiber streamline and the anatomical brain region segmentation map based on the magnetic resonance image, determine the vertical occipital fasciculus fiber streamline based on the whole-brain fiber streamline, and determine the region of interest for sub-branch division based on the anatomical brain region segmentation map;

[0007] Determine the voxel mask matrix corresponding to each region of interest for sub-branch division and the first endpoint coordinates and the second endpoint coordinates of the vertical occipital fasciculus fiber streamline, and determine the nearest neighbor region of interest of the vertical occipital fasciculus fiber streamline based on each voxel mask matrix, the first endpoint coordinates and the second endpoint coordinates;

[0008] Determine the sub-branch to which the vertical occipital fasciculus fiber streamline belongs based on the nearest neighbor region of interest of the vertical occipital fasciculus fiber streamline.

[0009] In some embodiments of the present invention, determining the nearest neighbor region of interest of the vertical occipital fasciculus fiber streamline based on each voxel mask matrix, the first endpoint coordinates and the second endpoint coordinates includes:

[0010] Determine the central point coordinates of each region of interest for sub-branch division based on each voxel mask matrix;

[0011] In some embodiments of the present invention, determining the nearest neighbor region of interest of the vertical occipital fasciculus fiber streamline by the K-nearest neighbor algorithm based on each voxel mask matrix, the first endpoint coordinates and the second endpoint coordinates includes:

[0012] Calculate the first distances between the first endpoint coordinates and each region of interest for sub-branch division based on the first endpoint coordinates and the central point coordinates;

[0013] Calculate the second distances between the second endpoint coordinates and each region of interest for sub-branch division based on the second endpoint coordinates and the central point coordinates;

[0014] Determine the nearest neighbor region of interest of the vertical occipital fasciculus fiber streamline based on each first distance and each second distance.

[0015] In some embodiments of the present invention, determining the nearest neighbor region of interest of the vertical occipital fasciculus fiber streamline based on each first distance and each second distance includes:

[0016]

[0017] ​Determine a first region of interest corresponding to a first minimum distance and a second region of interest corresponding to a second minimum distance;

[0018] When the first region of interest and the second region of interest are each only one sub-branch divided region of interest, the first region of interest and the second region of interest are the nearest neighbor regions of interest of the vertical occipital fasciculus fiber streamline.

[0019] In some embodiments of the present invention, the method further includes:

[0020] When the first region of interest and / or the second region of interest includes at least two regions of interest with the same distance, calculate respective third distances between the corresponding endpoint coordinates and each voxel point of each of the regions of interest with the same distance based on the voxel mask matrix corresponding to the regions of interest with the same distance, determine an average third distance corresponding to each of the regions of interest with the same distance based on the respective third distances, and determine a final region of interest corresponding to the endpoint coordinates based on the minimum average third distance. The final region of interest corresponding to the endpoint coordinates is the nearest neighbor region of interest of the vertical occipital fasciculus fiber streamline.

[0021] In some embodiments of the present invention, determining the sub-branch to which the vertical occipital fasciculus fiber streamline belongs based on the nearest neighbor region of interest of the vertical occipital fasciculus fiber streamline includes:

[0022] Judge whether the first region of interest and the second region of interest belong to the same functional sub-branch. When they belong to the same functional sub-branch, the functional sub-branch corresponding to the first region of interest and the second region of interest is the sub-branch to which the vertical occipital fasciculus fiber streamline belongs.

[0023] In some embodiments of the present invention, the sub-branch divided regions of interest include: the ventral and dorsal regions of the first visual cortex V1, the ventral and dorsal regions of the second visual cortex V2, the ventral and dorsal regions of the third visual cortex V3, the suboccipital sulcus region, the inferior occipital gyrus region, the transverse occipital sulcus region, the posterior transverse collateral sulcus region, the anterior occipital sulcus region, the collateral sulcus region, the posterior occipitotemporal sulcus region, and the posterior parietal sulcus region;

[0024] The sub-branch is an early visual information encoding sub-bundle, a spatial feature selection sub-bundle, a motion information processing sub-bundle, or a spatial attention sub-bundle;

[0025] The sub-branch divided regions of interest of the early visual information encoding sub-bundle include the ventral and dorsal regions of the first visual cortex V1, the ventral and dorsal regions of the second visual cortex V2, and the ventral and dorsal regions of the third visual cortex V3. The sub-branch divided regions of interest of the spatial feature selection sub-bundle include the suboccipital sulcus region, the inferior occipital gyrus region, and the transverse occipital sulcus region. The sub-branch divided regions of interest of the motion information processing sub-bundle include the transverse occipital sulcus region, the posterior transverse collateral sulcus region, and the anterior occipital sulcus region. The sub-branch divided regions of interest of the spatial attention sub-bundle include the collateral sulcus region, the posterior occipitotemporal sulcus region, and the posterior parietal sulcus region.

[0026] In some embodiments of the present invention, the method further includes:

[0027] Determining the central streamline of the vertical occipital fasciculus fibers corresponding to each sub-branch based on all the vertical occipital fasciculus fiber streamlines within each sub-branch;

[0028] Calculating the distances between each vertical occipital fasciculus fiber streamline within each sub-branch and the corresponding central streamline of the vertical occipital fasciculus fibers;

[0029] Determining the outlier fibers within each sub-branch based on the distances between each vertical occipital fasciculus fiber streamline within each sub-branch and the corresponding central streamline of the vertical occipital fasciculus fibers;

[0030] Deleting the outlier fibers from the corresponding sub-branch.

[0031] According to another aspect of the present invention, a vertical occipital fasciculus sub-branch segmentation device is also disclosed. The device includes a processor, a memory, and a computer program stored on the memory. The processor is used to execute the computer program, and when the computer program is executed, the device implements the steps of the method described in any of the above embodiments.

[0032] According to still another aspect of the present invention, a computer-readable storage medium is also disclosed, on which a computer program is stored. When the computer program is executed by a processor, it implements the steps of the method described in any of the above embodiments.

[0033] The vertical occipital fasciculus sub-branch segmentation method and device disclosed in the above embodiments of the present application further determine the nearest neighbor region of interest of the vertical occipital fasciculus fiber streamline based on the voxel mask matrix of the region of interest divided by each sub-branch, the first endpoint coordinate and the second endpoint coordinate of the vertical occipital fasciculus fiber streamline, and determine the sub-branch to which the vertical occipital fasciculus fiber streamline belongs according to the nearest neighbor region of interest of the vertical occipital fasciculus fiber streamline. This method combines the functional characteristics of the brain regions connected by the vertical occipital fasciculus, divides multiple vertical occipital fasciculus fiber streamlines in the occipital lobe into sub-bundles with different functions, thereby realizing a more detailed sub-branch segmentation of the vertical occipital fasciculus, and further completing the abnormal analysis of some functions related to vision.

[0034] Additional advantages, objects, and features of the present invention will be partly set forth in the description which follows, and will partly become apparent to those of ordinary skill in the art upon examination of the following, or may be learned by practice of the present invention. The objects and other advantages of the present invention may be realized and obtained by the structure particularly pointed out in the specification and the drawings.

[0035] Those skilled in the art will understand that the objects and advantages that can be achieved by the present invention are not limited to those specifically described above, and the above and other objects that the present invention can achieve will be more clearly understood from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings described herein are used to provide a further understanding of the present invention, form a part of this application, and do not limit the present invention. The components in the drawings are not drawn to scale, but are only for showing the principles of the present invention. For the convenience of showing and describing some parts of the present invention, the corresponding parts in the drawings may be enlarged, that is, may become larger relative to other components in the exemplary device actually manufactured according to the present invention. In the drawings:

[0037] Figure 1 It is a schematic flow chart of a method for dividing the vertical occipital fasciculus sub-branch according to an embodiment of the present application.

[0038] Figure 2 It is a schematic flow chart of a method for dividing the vertical occipital fasciculus sub-branch according to another embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] To make the objects, technical solutions, and advantages of the present invention more clear and understandable, the present invention will be further described in detail below in conjunction with the embodiments and the drawings. Herein, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but do not limit the present invention.

[0040] Herein, it should also be noted that in order to avoid obscuring the present invention due to unnecessary details, only the structures and / or processing steps closely related to the solution of the present invention are shown in the drawings, and other details less related to the present invention are omitted.

[0041] It should be emphasized that the term "comprising / including" when used herein refers to the presence of features, elements, steps, or components, but does not exclude the presence or addition of one or more other features, elements, steps, or components.

[0042] Herein, it should also be noted that if not otherwise specified, the term "connection" in this article can not only refer to direct connection, but also represent indirect connection with an intermediate, not only can represent wired connection, but also can be wireless connection, and can be specifically changed based on the actual application scenario.

[0043] The following are the noun explanations related to the technical solution:

[0044] K-nearest neighbor algorithm: A supervised learning algorithm based on instances, commonly used to solve classification and regression problems. The algorithm determines the class or output value of a sample by finding the K nearest known samples in the feature space and making a decision based on the classes or values of these samples.

[0045] Vertical occipital fasciculus: An important fiber bundle in the visual pathway, closely related to visual function. The action potential of the retina reaches the lateral geniculate body of the thalamus through the optic nerve, optic chiasm, and optic tract, and then reaches the primary visual cortex of the occipital lobe through the optic radiation. Visual information is initially encoded by the cognitive processing process within the primary visual cortex and then divided into the ventral stream and dorsal stream, reaching the temporal lobe and parietal lobe respectively; the ventral stream provides information about shape, color, and size to help identify and select targets, while the dorsal stream mediates information about spatial perception and goal-directed actions; the vertical occipital fasciculus is the main connecting bundle between these two branches, facilitating their close cooperation in various tasks.

[0046] Fiber tracking: The process of reconstructing the white matter fibers of the brain from diffusion magnetic resonance images. This process is based on the characteristics of diffusion magnetic resonance imaging, which can detect the degree and direction of anisotropic diffusion of water molecules in tissues in vivo, estimate the fiber orientation distribution in each voxel of the image, and further select the most likely orientation based on the connection probability between the selected seed voxel and other voxels, thereby obtaining the fiber connections of the whole brain.

[0047] Anatomical brain atlas: A brain partition map used to analyze structural T1-weighted magnetic resonance images. Brain regions are often partitioned according to structure, function, etc., and different brain atlases have different partitioning rules; among commonly used brain atlases, the Desikan-Killiany atlas contains 68 cortical partitions, retaining the anatomical positions of the macroscopic brain sulci and gyri; the 2009 version of the Destrieux brain region template contains 74 cortical partitions in each of the left and right brains (a total of 148 partitions), providing a more detailed partition for cortical research.

[0048] Currently, when analyzing visual function based on magnetic resonance images in the prior art, only the vertical occipital fasciculus is segmented from the whole-brain fiber streamlines according to the position and shape of the fiber bundle, that is, all the vertical occipital fasciculi in the occipital lobe are regarded as a whole, and no more detailed sub-branch segmentation of the vertical occipital fasciculus is performed based on the sub-functional characteristics of visual function, thus ignoring the abnormalities and changes brought by the fiber streamlines of each vertical occipital fasciculus to the sub-functional characteristics in visual function, thereby affecting the accuracy of the visual analysis results. To address the above problems existing in the prior art, the present application proposes a method and device for sub-branch segmentation of the vertical occipital fasciculus to further divide the fiber streamlines of multiple vertical occipital fasciculi into multiple sub-bundles with different functions based on the sub-branches they connect, thereby achieving a more detailed sub-branch segmentation of the vertical occipital fasciculus.

[0049] In healthy adults, the terminal of the ventral vertical occipital fasciculus converges on the inferior occipital gyrus (IOG), inferior occipital sulcus (IOS), and posterior transverse collateral sulcus (ptCoS); in addition, part of the fasciculus extends to the midpoint of the mid-fusiform sulcus (MFS) and anterior occipital sulcus (aOS); the dorsal part of the vertical occipital fasciculus mainly lies within the transverse occipital sulcus (TOS) and posterior intraparietal sulcus (pIPS). Among the ventral cortices it connects, the inferior occipital gyrus and inferior occipital sulcus are located upstream of the ventral pathway, with functions of spatial and face feature selection, and at the same time provide the neural basis for the interaction of features and positions in perception; the posterior transverse collateral sulcus is part of the fourth visual cortex V4, usually serving as an intermediate stage of pattern recognition and being related to shape processing; the anterior occipital sulcus, as the middle temporal visual area, is responsible for extracting depth information from motion perception and performing multimodal motion processing. In addition, the V4 region is also related to motion processing and coordinates with the dorsal-related regions to jointly affect motion perception. The mid-fusiform sulcus consists of the collateral sulcus (CoS) and posterior occipitotemporal sulcus (pOTS); the collateral sulcus is located on the outer edge of the parahippocampal gyrus, where the visual information of object recognition from the occipitotemporal lobe and the spatial context information from the parietal lobe intersect, which is the convergence area of the dorsal stream and ventral stream and is responsible for controlling the complex mechanism of spatial memory; the posterior occipitotemporal sulcus is usually called the visual word form area and plays an important role in the cognitive process of shape processing.

[0050] Among the dorsal cortices it connects, the area adjacent to the medial surface of the transverse occipital sulcus is a sub-region V3A (visual cortex 3A) of the third visual cortex, which is related to motion processing and spatial attention and is of great significance in scene processing. In addition, the posterior intraparietal sulcus also has multiple functions, including the management of spatial attention, the coordination of eye movements, and the facilitation of endogenous and exogenous orientation processes.

[0051] For better description of the technical solution of the present application, based on the above brain region functions, the present application divides the vertical occipital fasciculus into four functional sub-bundles (sub-branches), namely: (1) Vertical Occipital Fasciculus I (also known as the early visual information encoding sub-bundle): responsible for encoding early visual information, including vertical fibers connecting the ventral and dorsal regions of the first visual cortex V1 to the third visual cortex V3; (2) Vertical Occipital Fasciculus II (also known as the spatial feature selection sub-bundle): responsible for selecting spatial feature information, including vertical fibers connecting the suboccipital sulcus, inferior occipital gyrus, and transverse occipital sulcus; (3) Vertical Occipital Fasciculus III (also known as the motion information processing sub-bundle): responsible for processing motion-related information, including vertical fibers connecting the posterior transverse collateral sulcus, anterior occipital sulcus, and transverse occipital sulcus; (4) Vertical Occipital Fasciculus IV (also known as the spatial attention sub-bundle): spatial attention, including vertical fibers connecting the middle fusiform sulcus (lateral collateral sulcus and posterior occipitotemporal sulcus) and the posterior parietal sulcus. It should be understood that the number of the above-listed functional sub-bundles and the functions corresponding to each functional sub-bundle are only examples. In other embodiments, the vertical occipital fasciculus can also be divided into other numbers of functional sub-bundles, and the functions corresponding to each functional sub-bundle can also be other.

[0052] In the following, embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings, the same reference numerals represent the same or similar components, or the same or similar steps.

[0053] Figure 1 It is a schematic flow chart of a method for dividing the sub-branches of the vertical occipital fasciculus according to an embodiment of the present application. As Figure 1 shown, the method for dividing the sub-branches of the vertical occipital fasciculus at least includes steps S10 to S30.

[0054] Step S10: Obtain a magnetic resonance image, determine the whole-brain fiber streamline and the anatomical brain region segmentation map based on the magnetic resonance image, determine the vertical occipital fasciculus fiber streamline based on the whole-brain fiber streamline, and determine the region of interest for sub-branch division based on the anatomical brain region segmentation map.

[0055] This step is to trace the whole-brain fiber streamline from the diffusion magnetic resonance image, and segment the vertical occipital fasciculus fiber streamline located in the occipital lobe from the whole-brain fiber streamline to provide candidate fibers for subsequent sub-branch division; in addition, the anatomical brain region is segmented according to the magnetic resonance image to obtain the anatomical brain region segmentation map, which provides the region of interest for sub-branch division; for example, the anatomical brain region can be segmented based on the T1 structural magnetic resonance image.

[0056] When performing whole-brain fiber tracking on the magnetic resonance image, for example, the multi-shell multi-tissue constrained spherical deconvolution algorithm can be used to estimate the white matter fiber direction distribution function from the diffusion magnetic resonance images in different directions, place seed points in the white matter voxels, and use the probabilistic fiber tracking technology in the MRtrix3 neuroimaging visualization tool to generate the whole-brain fiber streamline.

[0057] When performing anatomical brain region segmentation, the T1 structural magnetic resonance image is registered to the Talairach space (also known as the Talairach space or Talairach coordinate system) by manually marking the anterior commissure (AC) and the posterior commissure (PC). The Freesurfer tool is used to perform automatic cortical segmentation of the T1 image based on the Destrieux brain atlas.

[0058] When segmenting the vertical occipital fasciculus from the whole-brain fiber streamlines, the fiber automatic quantification AFQ package of Matlab software can be used to read the whole-brain fiber streamline coordinates, and the traditional automatic fiber quantification analysis method (AFQ method) can be used to identify the arcuate fasciculus. The coordinates of the ventral occipitotemporal cortex (including the fusiform gyrus, inferior occipital gyrus, and inferior temporal gyrus) in the anatomical brain region segmentation are read, and all fibers terminating within 2 mm of the ventral occipitotemporal cortex are used as candidate fibers. Further, candidate fibers with an extension direction of the vertical direction are retained, and fibers mixed with the arcuate fasciculus are removed; the linear bundle estimation algorithm LiFE is used to evaluate the matching degree of each fiber relative to the diffusion direction of the corresponding voxel, and fibers with a probability less than 0 are removed to optimize the vertical occipital fasciculus segmentation result.

[0059] When performing environment configuration, development can be based on the Matlab programming language, and data processing and whole-brain fiber tracking rely on the ubuntu18.04 system; among them, the Freesurfer tool can be configured in the ubuntu system for anatomical brain region segmentation, and FSL and MRtrix3 can be configured for the processing of diffusion magnetic resonance data and whole-brain fiber tracking; the automatic fiber quantification package AFQ can be configured in Matlab software for vertical occipital fasciculus tracking.

[0060] In some embodiments of the present invention, the brain regions required for sub-branch segmentation are matched from the anatomical brain region segmentation map as the regions of interest for sub-branch division. The regions of interest for sub-branch division may include: the ventral and dorsal regions of the first visual cortex V1, the ventral and dorsal regions of the second visual cortex V2, the ventral and dorsal regions of the third visual cortex V3, the suboccipital sulcus region, the inferior occipital gyrus region, the transverse occipital sulcus region, the posterior transverse collateral sulcus region, the anterior occipital sulcus region, the collateral sulcus region, the posterior occipitotemporal sulcus region, and the posterior parietal sulcus region. The ventral and dorsal regions of the visual cortex V1-V3 are determined by Mona's human occipitotemporal visual cortex atlas, including 6 regions from the occipital pole to the transverse occipital sulcus, and there are 12 regions in total in the left and right brains; while other regions of interest are selected from the Destrieux brain atlas according to their positions and names as the brain regions required for sub-branch segmentation. If two or more regions of interest are in the same brain region, then this brain region is used as the region of interest for sub-branch segmentation. For example, the suboccipital sulcus and the inferior occipital gyrus are the same brain region in the atlas, and the brain region number in Freesurfer is 11102; if the naming of the brain atlas is inconsistent with the region of interest, then the corresponding brain region is selected in the brain atlas according to the position of the region of interest. The brain region numbers corresponding to the regions of interest are shown in the following table.

[0061]

[0062] Step S20: Determine the voxel mask matrix corresponding to the region of interest (ROI) divided by each sub-branch, as well as the first endpoint coordinates and the second endpoint coordinates of the vertical occipital fasciculus fiber streamline. Based on each voxel mask matrix, the first endpoint coordinates, and the second endpoint coordinates, determine the nearest neighbor ROI of the vertical occipital fasciculus fiber streamline.

[0063] In this step, map each sub-branch divided ROI from the surface into a voxel mask, and transform the ventral-dorsal visual region of the Mona atlas from the standard space to the individual space of the subject; determine the coordinate data of the vertical occipital fasciculus fiber streamline, and ensure that the vertical occipital fasciculus fiber streamline and the sub-branch divided ROI are in the same space.

[0064] Traverse the endpoint coordinates of all vertical occipital fasciculus fiber streamlines, and based on the voxel mask matrix corresponding to each sub-branch divided ROI, as well as the first endpoint coordinates and the second endpoint coordinates of each vertical occipital fasciculus fiber streamline, determine the nearest neighbor ROI of each vertical occipital fasciculus fiber streamline respectively.

[0065] Exemplarily, determining the nearest neighbor ROI of the vertical occipital fasciculus fiber streamline based on each voxel mask matrix, the first endpoint coordinates, and the second endpoint coordinates includes: determining the nearest neighbor ROI of the vertical occipital fasciculus fiber streamline through the K-nearest neighbor algorithm based on each voxel mask matrix, the first endpoint coordinates, and the second endpoint coordinates. Specifically, determining the nearest neighbor ROI of the vertical occipital fasciculus fiber streamline through the K-nearest neighbor algorithm based on each voxel mask matrix, the first endpoint coordinates, and the second endpoint coordinates specifically includes: determining the central point coordinates of each sub-branch divided ROI based on each voxel mask matrix; calculating each first distance between the first endpoint coordinates and each sub-branch divided ROI based on the first endpoint coordinates and each central point coordinate; calculating each second distance between the second endpoint coordinates and each sub-branch divided ROI based on the second endpoint coordinates and each central point coordinate; determining the nearest neighbor ROI of the vertical occipital fasciculus fiber streamline based on each first distance and each second distance. In this embodiment, calculate the distances between each endpoint of the vertical occipital fasciculus fiber streamline and each sub-branch divided ROI, and use the sub-branch divided ROI with the shortest distance to the vertical occipital fasciculus fiber streamline as its nearest neighbor ROI.

[0066] Furthermore, determining the nearest neighbor region of interest for the vertical occipital fasciculus fiber streamline based on each of the first distances and each of the second distances further includes the following steps: determining a first region of interest corresponding to the minimum value of the first distance and a second region of interest corresponding to the minimum value of the second distance; when each of the first region of interest and the second region of interest is only one sub-branch divided region of interest, the first region of interest and the second region of interest are the nearest neighbor regions of interest for the vertical occipital fasciculus fiber streamline. In this embodiment, both the first region of interest and the second region of interest have only one sub-branch divided region of interest, so at this time, the corresponding sub-branch divided region of interest is directly used as the nearest neighbor region of interest for the vertical occipital fasciculus fiber streamline.

[0067] In addition, if the first region of interest and / or the second region of interest includes at least two regions of interest with the same distance, calculate each third distance between the corresponding endpoint coordinates and each voxel point of each of the regions of interest with the same distance based on the voxel mask matrix corresponding to the regions of interest with the same distance, determine the average value of the third distances corresponding to each of the regions of interest with the same distance based on each of the third distances, and determine the final region of interest corresponding to the endpoint coordinates based on the minimum average value of the third distances. The final region of interest corresponding to the endpoint coordinates is the nearest neighbor region of interest for the vertical occipital fasciculus fiber streamline. In this embodiment, the distances between multiple sub-branch divided regions of interest and the endpoints of the vertical occipital fasciculus fiber streamline are equal. At this time, further calculate the distance between the other point coordinates (such as the coordinates of the region edge points) of the sub-branch divided region of interest except the center point coordinates and the endpoint coordinates of the vertical occipital fasciculus fiber streamline; for example, when the first region of interest includes two regions of interest with the same distance, further calculate the third distance between the first endpoint coordinates and each region of interest with the same distance. When calculating the third distance, the coordinates of the sub-branch divided region of interest used are other coordinates except the center point coordinates, such as the edge point coordinates, etc. At this time, the third distances corresponding to each region of interest with the same distance are multiple values. In order to determine the final distance between each region of interest with the same distance and the first endpoint, just average the multiple third distance values, and then use the region of interest with the same distance corresponding to the minimum average value of the third distances as the final region of interest for the first endpoint.

[0068] In a specific embodiment, a K-dimensional search tree can be constructed based on the coordinates of the regions of interest divided by each sub-branch, so as to search for the regions of interest closest to both ends of each vertical occipital fasciculus fiber streamline in the K-dimensional tree searcher, in order to split the fibers. That is, the voxel mask matrix corresponding to the regions of interest divided by each sub-branch is read based on the matlab code, and each region of interest divided by a sub-branch represents a category, and an initial input data set is constructed. In order to efficiently perform the nearest neighbor search, the built-in function KDTreeSearcher of matlab is used to organize the data into a K-dimensional tree searcher suitable for nearest neighbor search; the K-dimensional tree is a binary tree structure that divides the data space, and by recursively selecting dimensions and splitting points, the data is divided into different sub-spaces; the K-dimensional tree searcher can utilize the hierarchical structure of the tree to quickly narrow the search range, only accessing potential nearest neighbor candidate regions, and improving the search efficiency. When searching for the nearest neighbor region of interest of the vertical occipital fasciculus fiber streamline, the coordinate points of the vertical occipital fasciculus fiber streamline can be read, and the endpoint coordinates of all vertical occipital fasciculus fiber streamlines are traversed, and the nearest neighbor search of the K-dimensional tree is performed through the knnsearch function. Specifically, the Euclidean distance between all regions of interest divided by sub-branches and the endpoint coordinates of the vertical occipital fasciculus fiber streamline is calculated, and the region of interest divided by the sub-branch closest to the vertical occipital fasciculus fiber streamline is found based on the calculated distance value. The distance calculation formula is: , D represents the Euclidean distance between two points, is the coordinate value of the endpoint of the vertical occipital fasciculus fiber streamline i in the three-dimensional space, represents the point coordinates of the t-th region of interest divided by the sub-branch. Based on the above content, can represent the center point coordinates or other point coordinates (such as the edge point coordinates of the region) of the region of interest divided by the sub-branch.

[0069] In addition, after determining the nearest neighbor region of interest of each endpoint, it is further determined whether the distance between the endpoint and the nearest neighbor region of interest exceeds 4 cm. When the distance exceeds 4 cm, it is considered that the vertical occipital fasciculus fiber streamline does not belong to any sub-branch, and the vertical occipital fasciculus fiber streamline is deleted from the candidate fibers.

[0070] Obviously, the above embodiment uses the K-nearest neighbor algorithm to determine the nearest neighbor region of interest of the vertical occipital fasciculus fiber streamline, which is only some examples. In some other embodiments, other algorithms can also be used to determine the nearest neighbor region of interest of the vertical occipital fasciculus fiber streamline.

[0071] Step S30: Determine the sub-branch to which the vertical occipital fasciculus fiber streamline belongs based on the nearest neighbor region of interest of the vertical occipital fasciculus fiber streamline.

[0072] In this step, the sub-branch to which the vertical occipital fasciculus fiber streamline belongs is further determined based on the nearest neighbor regions of interest at both ends of the vertical occipital fasciculus fiber streamline. In some embodiments, the sub-branches can be divided based on the functions of brain regions. For example, according to the functions of brain regions, the ventral and dorsal brain regions are divided into four groups, and the vertical occipital fasciculus fiber streamlines connecting the brain regions within the connectome are divided into the corresponding functional groups to obtain the functional sub-bundles of each sub-branch. In this embodiment, the fibers connecting the brain regions in the functional sub-bundle are the pathways for transmitting the function-related information in the vertical occipital fasciculus. Specifically, the ends of each vertical occipital fasciculus fiber streamline will be assigned to two brain regions in the ventral and dorsal directions, and only when the ventral and dorsal brain regions of the fiber streamline belong to the same functional sub-bundle (or sub-branch), the fiber streamline is added to the corresponding sub-bundle. Exemplarily, the four sub-branches are specifically: the early visual information encoding sub-bundle, the spatial feature selection sub-bundle, the motion information processing sub-bundle, and the spatial attention sub-bundle.

[0073] The following table is a comparison table of the brain regions and functions connected by the sub-branches of the vertical occipital fasciculus:

[0074]

[0075] In one embodiment, determining the sub-branch to which the vertical occipital fasciculus fiber streamline belongs based on the nearest neighbor regions of interest of the vertical occipital fasciculus fiber streamline includes: determining whether the first region of interest and the second region of interest belong to the same functional sub-branch. When they belong to the same functional sub-branch, the functional sub-branch corresponding to the first region of interest and the second region of interest is the sub-branch to which the vertical occipital fasciculus fiber streamline belongs. For example, in the above table, the regions of interest for the sub-branch division of the early visual information encoding sub-bundle include the ventral and dorsal regions of the first visual cortex V1, the ventral and dorsal regions of the second visual cortex V2, and the ventral and dorsal regions of the third visual cortex V3. The regions of interest for the sub-branch division of the spatial feature selection sub-bundle include the suboccipital sulcus region, the inferior occipital gyrus region, and the transverse occipital sulcus region. The regions of interest for the sub-branch division of the motion information processing sub-bundle include the transverse occipital sulcus region, the posterior transverse collateral sulcus region, and the anterior occipital sulcus region. The regions of interest for the sub-branch division of the spatial attention sub-bundle include the collateral sulcus region, the posterior occipitotemporal sulcus region, and the posterior parietal sulcus region. Exemplarily, if the nearest neighbor regions of interest at both ends of a certain vertical occipital fasciculus fiber streamline are the inferior occipital gyrus region and the transverse occipital sulcus region respectively, then this vertical occipital fasciculus fiber streamline is divided into the spatial feature selection sub-bundle. If the nearest neighbor regions of interest at both ends of a certain vertical occipital fasciculus fiber streamline are the inferior occipital gyrus region and the posterior parietal sulcus region respectively, at this time, since the inferior occipital gyrus region and the posterior parietal sulcus region do not belong to the same functional sub-branch, then this vertical occipital fasciculus fiber streamline does not belong to any sub-branch and can be directly deleted from the vertical occipital fasciculus to be divided.

[0076] In some embodiments of the present invention, the method further includes: determining a vertical occipital fasciculus fiber center streamline corresponding to each sub-branch based on all vertical occipital fasciculus fiber streamlines within each sub-branch; calculating the distances between each vertical occipital fasciculus fiber streamline and the corresponding vertical occipital fasciculus fiber center streamline within each sub-branch; determining outlier fibers within each sub-branch based on the distances between each vertical occipital fasciculus fiber streamline and the corresponding vertical occipital fasciculus fiber center streamline within each sub-branch; and deleting the outlier fibers from the corresponding sub-branch. As Figure 2 shown, after the preliminary segmentation of the sub-branches, the structures of some sub-bundles are not regular and there are some outlier fibers; in order to optimize the structure of the sub-branches, the fiber streamlines deviating from the center of the sub-bundles in each sub-branch are further deleted, so as to obtain an optimized sub-branch segmentation result.

[0077] Specifically, first, linear interpolation resampling is performed on all vertical occipital fasciculus fiber streamlines in the sub-branch to unify the number of nodes of each fiber streamline to 100; the center point coordinates of each fiber streamline at the corresponding nodes are calculated to obtain the center line of the fiber bundle; the Euclidean distances between each node of each fiber streamline and the corresponding node of the center line are traversed and calculated, and the outlier fibers with an average distance from the center line exceeding 2 mm are removed.

[0078] It can be found through the above embodiments that the vertical occipital fasciculus, as a large fiber bundle connecting multiple brain regions, has rich functional characteristics in the brain regions it connects, resulting in different functional sub-branches; therefore, this application starts from the functions of the brain regions connected by the vertical occipital fasciculus and divides it into sub-bundles with different functions by using the distances from the fiber streamlines to each brain region, breaking through the limitation of the traditional method of only segmenting according to the position and shape of the fiber bundle, thereby realizing a detailed sub-branch segmentation of the vertical occipital fasciculus. This division method based on functional characteristics is more in line with the structural characteristics of the actual brain functional network and can support more in-depth brain function research. And based on this method, a detailed segmentation of the vertical occipital fasciculus is performed, avoiding analysis deviations caused by possible neglect of local fiber abnormalities or changes, and improving the accuracy and reliability of subsequent visual analysis or brain function research.

[0079] Correspondingly, the present invention also provides a vertical occipital fasciculus sub-branch segmentation device, which includes a processor, a memory, and a computer program stored on the memory. The processor is used to execute the computer program, and when the computer program is executed, the device realizes the steps of the method described in any one of the above embodiments.

[0080] An embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method described in any of the above embodiments are implemented. The computer-readable storage medium may be a tangible storage medium, such as a random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, floppy disks, hard disks, removable storage disks, CD-ROMs, or any other form of storage medium well-known in the art.

[0081] Those of ordinary skill in the art should understand that the various exemplary components, systems, and methods described in connection with the embodiments disclosed herein can be implemented in hardware, software, or a combination of both. Specifically, whether to implement in hardware or software depends on the specific application and design constraints of the technical solution. A professional technician can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention. When implemented in hardware, it can be, for example, an electronic circuit, an application-specific integrated circuit (ASIC), appropriate firmware, a plug-in, a functional card, etc. When implemented in software, the elements of the present invention are programs or code segments used to perform the required tasks. The programs or code segments can be stored in a machine-readable medium or transmitted through a data signal carried in a carrier wave on a transmission medium or a communication link.

[0082] It should be clear that the present invention is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order between steps after understanding the spirit of the present invention.

[0083] In the present invention, the features described and / or illustrated for one embodiment can be used in the same way or in a similar way in one or more other embodiments, and / or combined with the features of other embodiments or replace the features of other embodiments.

[0084] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, various changes and modifications can be made to the embodiments of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A vertical occipital fasciculus sub-branch segmentation method, characterized in that: The method comprises: Acquire a magnetic resonance image, determine a whole-brain fiber streamline and an anatomical brain region segmentation map based on the magnetic resonance image, determine a vertical occipital fasciculus fiber streamline based on the whole-brain fiber streamline, and determine a sub-branch division region of interest based on the anatomical brain region segmentation map; Determine the voxel mask matrix corresponding to each sub-branch divided region of interest and the first endpoint coordinates and the second endpoint coordinates of the vertical occipital fiber streamline, and determine the nearest neighbor region of interest of the vertical occipital fiber streamline based on each voxel mask matrix, the first endpoint coordinates and the second endpoint coordinates; Determine the sub-branch to which the vertical occipital fiber streamline belongs based on the nearest neighbor region of interest of the vertical occipital fiber streamline; the sub-branch is an early visual information encoding sub-bundle, a spatial feature selection sub-bundle, a motion information processing sub-bundle or a spatial attention sub-bundle; Among them, the end of each vertical occipital fiber streamline is divided into two ventral and dorsal brain regions, and only when the ventral and dorsal brain regions of the vertical occipital fiber streamline belong to the same sub-branch, the vertical occipital fiber streamline is added to the corresponding sub-bundle.

2. The vertical occipital fasciculus sub-branch segmentation method according to claim 1, characterized in that: Determining the nearest neighbor region of interest of the vertical occipital fiber streamline based on each of the voxel mask matrices, the first endpoint coordinates, and the second endpoint coordinates, comprises: The nearest neighbor region of interest of the vertical occipital fiber streamline is determined by a K-nearest neighbor algorithm based on each of the voxel mask matrices, the first endpoint coordinates, and the second endpoint coordinates.

3. The vertical occipital fasciculus sub-branch segmentation method according to claim 2, characterized in that: Determining the nearest neighbor region of interest of the vertical occipital fiber streamline by a K-nearest neighbor algorithm based on each of the voxel mask matrices, the first endpoint coordinates, and the second endpoint coordinates includes: Determine the center point coordinates of the regions of interest divided by each sub-branch based on each voxel mask matrix; Calculate each first distance between the first endpoint coordinate and each of the sub-branch divided regions of interest based on the first endpoint coordinate and each of the center point coordinates; Calculate each second distance between the second endpoint coordinate and each of the sub-branch divided regions of interest based on the second endpoint coordinate and each of the center point coordinates; The nearest neighbor region of interest of the vertical occipital fiber streamline is determined based on each of the first distances and each of the second distances.

4. The vertical occipital fasciculus sub-branch segmentation method according to claim 3, characterized in that: Determining the nearest neighbor region of interest of the vertical occipital fiber streamline based on each of the first distances and each of the second distances includes: Determine a first region of interest corresponding to the first minimum distance value and a second region of interest corresponding to the second minimum distance value; When the first region of interest and the second region of interest are divided into regions of interest for only one sub-branch respectively, the first region of interest and the second region of interest are the nearest neighbor regions of interest of the vertical occipital fiber streamline.

5. The vertical occipital fasciculus sub-branch segmentation method according to claim 4, characterized in that: The method further comprises: When the first region of interest and / or the second region of interest includes at least two regions of interest with the same distance, each third distance between the endpoint coordinates and each voxel point of each region of interest with the same distance is calculated based on the corresponding endpoint coordinates and the voxel mask matrix corresponding to the region of interest with the same distance, the third distance average value corresponding to each region of interest with the same distance is determined based on each of the third distances, and the final region of interest corresponding to the endpoint coordinates is determined based on the minimum third distance average value, and the final region of interest corresponding to the endpoint coordinates is the nearest neighbor region of interest of the vertical occipital fiber streamline.

6. The vertical occipital fasciculus sub-branch segmentation method according to claim 4, characterized in that: Determining the sub-branch to which the vertical occipital fascicle fiber streamline belongs based on the nearest neighbor region of interest of the vertical occipital fascicle fiber streamline, comprising: It is determined whether the first region of interest and the second region of interest belong to the same functional sub-branch. When they belong to the same functional sub-branch, the functional sub-branch corresponding to the first region of interest and the second region of interest is the sub-branch to which the vertical occipital fiber streamline belongs.

7. The vertical occipital fasciculus sub-branch segmentation method according to any one of claims 1 to 6, characterized in that: The sub-branch division areas of interest include: ventral and dorsal areas of the first visual cortex V1, ventral and dorsal areas of the second visual cortex V2, ventral and dorsal areas of the third visual cortex V3, the inferior occipital sulcus area, the inferior occipital gyrus area, the transverse occipital sulcus area, the posterior transverse collateral sulcus area, the anterior occipital sulcus area, the collateral sulcus area, the posterior occipitotemporal sulcus area, and the posterior parietal sulcus area; The sub-branch division areas of interest of the early visual information encoding sub-bundle include the ventral and dorsal areas of the first visual cortex V1, the ventral and dorsal areas of the second visual cortex V2, and the ventral and dorsal areas of the third visual cortex V3; the sub-branch division areas of interest of the spatial feature selection sub-bundle include the inferior occipital sulcus area, the inferior occipital gyrus area, and the transverse occipital sulcus area; the sub-branch division areas of interest of the motion information processing sub-bundle include the transverse occipital sulcus area, the posterior collateral transverse sulcus area, and the anterior occipital sulcus area; the sub-branch division areas of interest of the spatial attention sub-bundle include the collateral sulcus area, the posterior occipitotemporal sulcus area, and the posterior parietal sulcus area.

8. The vertical occipital fasciculus sub-branch segmentation method according to claim 7, characterized in that: The method further comprises: Based on all the vertical occipital fiber streamlines in each subbranch, the vertical occipital fiber center streamlines corresponding to each subbranch are determined; Calculate the distances between each vertical occipital fiber streamline in each subbranch and the corresponding vertical occipital fiber center streamline; Determine the outlier fibers in each subbranch based on the distances between each vertical occipital fiber streamline in each subbranch and the corresponding vertical occipital fiber center streamline; The stray fibers are deleted from the corresponding sub-branch.

9. A vertical occipital fasciculus subbranch segmentation device, the device comprising a processor, a memory, and a computer program stored in the memory, characterized in that: The processor is used to execute the computer program. When the computer program is executed, the device implements the steps of the method according to any one of claims 1 to 8.

10. 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 8 are implemented.

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