WO2024011647A1 - Deep learning-based thalamus individualized map drawing method guided by group prior knowledge - Google Patents
Deep learning-based thalamus individualized map drawing method guided by group prior knowledge Download PDFInfo
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Definitions
- the invention belongs to the field of brain mapping of magnetic resonance imaging, and specifically relates to a method, system and equipment for individualized mapping of the thalamus based on deep learning guided by group priori.
- the thalamus is a relay nucleus in the brain that participates in brain functional circuits such as hearing, vision, movement, somatosensory, emotion, memory and learning.
- the thalamus as the target of deep brain stimulation (DBS)
- DBS deep brain stimulation
- neuropsychiatric diseases such as Parkinson's disease, epilepsy, multiple sclerosis, vegetative awakening, schizophrenia, and essential tremor. Therefore, the drawing of fine and accurate thalamic maps is the key to thalamic research.
- researchers use methods such as histological section staining and magnetic resonance imaging to characterize the structural or functional characteristics of the thalamus, and use this as the basis for thalamic division.
- histological section staining is regarded as the gold standard for thalamic partitioning, which can only be performed on isolated brain specimens, is not reproducible and relies on manual marking by anatomists.
- Rapidly developing magnetic resonance imaging can non-invasively characterize features within the thalamus, including local microstructure, anatomical connections, and functional connections. Based on this, the data-driven thalamic partitioning process has gradually become a research hotspot in thalamic partitioning.
- existing thalamic partitioning can be divided into different methods based on three modalities of structural, diffusion, and functional imaging data.
- the thalamic partitioning based on diffusion magnetic resonance is the closest to the anatomical structure of the thalamus.
- Diffusion magnetic resonance imaging can provide two types of diffusion information, namely fiber bundle connections and local diffusion characteristics.
- thalamic divisions based on fiber tract connections did not correspond well to the actual thalamic anatomy, while thalamic divisions based on local diffusion characteristics were basically consistent with the anatomical structure. Therefore, thalamic partitioning based on local diffusion characteristics is the most direct method to characterize the local microstructure of the thalamus.
- thalamic partitioning studies use a group of subjects. Based on the thalamic partitioning results in their individual spaces, the thalamic partitions of different subjects are mapped to the same space through manual marking or automatic registration methods, thereby constructing a group-level thalamus. Map. This method can objectively and unbiasedly reflect the intrinsic partitioning pattern of the thalamus, such as the number of subregions, and the consistent attributes at the group level, such as the structural and functional connectivity patterns of thalamic subnuclei and other brain regions.
- the first method relies on high-quality magnetic resonance imaging data and robust partitioning algorithms, including fiber projection method, spectral clustering method, edge detection method, region growing method, etc.; the second method directly registers group maps to the individual space, thus treating the group map as an individual map; the third method first constructs the group map and treats the group map as prior knowledge of individual partitions to assist subsequent individual partitions.
- the first partitioning method is suitable for nuclei with specific fiber tract projections, such as the subthalamic nucleus, medial globus pallidus, etc.
- the second method is suitable for subjects with severe brain damage or in whom diffusion magnetic resonance imaging is not possible, such as patients with brain tumors and patients with metal implants in the head.
- the third method is suitable for the cerebral cortex and nuclei with larger volumes and richer individual characteristics. Therefore, in order to accurately construct an individualized thalamic map, an individualized partitioning strategy guided by group prior can be used.
- HARDI High Angular Resolution Diffusion Imaging
- various existing q-space sampling methods support the construction of higher-order dispersion models. For example, diffusion kurtosis imaging, diffusion spectrum imaging, Q-ball imaging and its derived multi-spherical shell imaging, etc.
- multi-spherical shell multi-tissue restricted spherical deconvolution can directly estimate the diffusion direction distribution function (ODF) of brain tissue.
- ODF diffusion direction distribution function
- This method relies on multi-b-value HARDI and is currently the most suitable for extracting thalamus. method of local diffusion characteristics.
- deep learning has developed rapidly in the past decade, and its powerful data fitting and classification capabilities have made it brilliant in various fields including neuroscience. In this context, it is gradually becoming possible to build an automated individualized thalamic map drawing method based on deep learning models by combining local diffusion characteristics and group prior-guided individualized partitioning strategies.
- a group prior guided method for drawing an individualized thalamus map based on deep learning is proposed. The method includes:
- S400 combined with the second mask, calculate the coefficients of the 45-dimensional spherical harmonic function and the position coordinates of the 3-dimensional diffusion magnetic resonance space of each voxel in the group prior map, and merge the two into a 48-dimensional Feature vector, as an individual feature; input the individual features into the pre-built individualized classification model to obtain the predicted probability value vector of the voxels in each undefined area, and assign the largest sub-region label corresponding to the predicted probability value vector As the final sub-region label of the voxel, a map of the undefined area is generated; the individualized classification model is built based on a deep learning neural network;
- the construction method of the group thalamic probability map is:
- A100 obtain the structural MRI images and diffusion tensor MRI images of the individual brains of N subjects as input images; N is a positive integer;
- A200 sequentially perform HCP minimum preprocessing, ROI registration, and ROI postprocessing on the input image to obtain the final thalamus ROI of the subject's individual brain, and obtain the final thalamus ROI of the subject's individual brain through the ODF estimation algorithm.
- A300 combined with the local diffusion characteristics obtained by A200, calculates the similarity between voxels and performs clustering to obtain the clustering results of voxels within the final thalamic ROI of the subject's individual brain;
- A400 register the clustering results obtained by A300 to the standard space, and perform label remapping to obtain the sub-region label corresponding to each voxel in the final thalamic ROI of the individual subject's brain, that is, N individual subjects are obtained thalamic partitioning of the brain in standard space;
- A500 calculate the sub-region probability value corresponding to each voxel in the final thalamus ROI of the individual brain of the subject, remove the voxel points with the largest sub-region probability value lower than the first threshold, and then construct the remaining voxel points
- the thalamic probability map at the group level is the group thalamic probability map; the sub-region probability value is the ratio of the number of subjects in each sub-region to the total number of subjects.
- the input image is sequentially subjected to HCP minimum pre-processing, ROI registration, and ROI post-processing to obtain the final thalamus ROI of the subject's individual brain.
- the method is:
- the diffusion magnetic resonance space and the structural magnetic resonance space, the structural magnetic resonance space and the standard space are aligned through the ROI registration method.
- the ROI registration method obtain individual thalamus ROI;
- voxel points whose anisotropy fraction value is greater than the set anisotropy fraction threshold or whose cerebrospinal fluid probability value is greater than the set cerebrospinal fluid probability threshold are removed, and the remaining voxel points are used as the final individual thalamus ROI.
- the local diffusion characteristics of each voxel in the final thalamic ROI of the subject's individual brain are obtained by:
- the dhollander algorithm In the diffusion magnetic resonance space within the final thalamic ROI of the subject's individual brain, use the dhollander algorithm to calculate the response function of the brain tissue under different diffusion weighting factor b value parameters on the diffusion magnetic resonance data; combine the response of the brain tissue function, using the multi-tissue multi-spherical shell restricted spherical deconvolution method to calculate the 45-dimensional coefficients of the 8th order spherical harmonic function to quantify the local diffusion characteristics of each voxel.
- the similarity between voxels is calculated as follows:
- S(i,j) represents the similarity between two voxels
- E pos (i, j) represents the Euclidean distance between the three-dimensional coordinates of two voxels in the diffusion magnetic resonance space
- E odf (i, j) represents the Euclidean distance between the sampling coefficients of the 45-dimensional spherical harmonic function of two voxels
- w pos and w odf respectively represent the correspondence of E pos (i, j) and E odf (i, j) when calculating similarity.
- the clustering results of voxels in the final thalamic ROI of the subject's individual brain are obtained by:
- the spectral clustering method is used to reduce the dimensionality of the local diffusion characteristics of each voxel in the final thalamic ROI of the subject's individual brain and the similarity between voxels;
- K-means clustering is used to cluster each voxel into K categories, which is used as the clustering result of the voxels in the final thalamus ROI of the subject's individual brain.
- the sub-region label corresponding to each voxel in the final thalamus ROI of the subject's individual brain is obtained by:
- the clustering results of the voxels in the final thalamic ROI of each subject's individual brain are relabeled according to the spatial maximum overlap method, thereby obtaining the final thalamic ROI of each subject's individual brain.
- the N-dimensional label vector of each voxel point on N subjects is calculated, that is, the sub-region label corresponding to the voxel point of each subject is extracted, and one sub-region is extracted for each N subjects. labels, forming an N-dimensional label vector.
- the training method of the individualized classification model is:
- the loss value is obtained through the mean square error loss function, and the model parameters of the individualized classification model are updated;
- the second aspect of the present invention proposes a group prior guided thalamic individualized map drawing system based on deep learning, including: a thalamic ROI acquisition module, a group prior map acquisition module, a elimination processing module, and an individualized classification Modules, personalized map generation modules;
- the thalamic ROI acquisition module is configured to acquire the group thalamic probability map under a first threshold and perform binarization to obtain a mask of the group thalamic probability map as the first mask; convert the first mask Register to the diffusion magnetic resonance space of the subject's individual brain to obtain the thalamus ROI of the subject's individual brain;
- the group prior map acquisition module is configured to obtain the group thalamic probability map under the second threshold, and register it to the diffusion magnetic resonance space of the subject's individual brain to obtain the group's individual brain.
- Group prior map ;
- the elimination processing module is configured to eliminate the group prior map in the thalamus ROI in the diffusion magnetic resonance space of the subject's individual brain, and obtain a mask of the undefined thalamus region as the second mask. ;
- the individualized classification module is configured to calculate the coefficients of the 45-dimensional spherical harmonic function and the position coordinates of the 3-dimensional diffusion magnetic resonance space of each voxel in the group prior map in combination with the second mask, and combine the two or merged into a 48-dimensional feature vector as individual features; input the individual features into the pre-built individualized classification model to obtain the predicted probability value vector of voxels in each undefined area, and add the predicted probability value vector to The corresponding largest sub-region label is used as the final sub-region label of the voxel, and then a map of the undefined area is generated; the individualized classification model is built based on a deep learning neural network;
- the individualized map generation module is configured to merge the group prior map and the map of the undefined area to generate a subject's individualized thalamic map;
- the construction method of the group thalamic probability map is:
- A100 obtain the structural MRI images and diffusion tensor MRI images of the individual brains of N subjects as input images; N is a positive integer;
- A200 sequentially perform HCP minimum preprocessing, ROI registration, and ROI postprocessing on the input image to obtain the final thalamus ROI of the subject's individual brain, and obtain the final thalamus ROI of the subject's individual brain through the ODF estimation algorithm.
- A300 combined with the local diffusion characteristics obtained by A200, calculates the similarity between voxels and performs clustering to obtain the clustering results of voxels within the final thalamic ROI of the subject's individual brain;
- A400 register the clustering results obtained by A300 to the standard space, and perform label remapping to obtain the sub-region label corresponding to each voxel in the final thalamus ROI of the individual subject's brain, that is, N individual subjects are obtained thalamic partitioning of the brain in standard space;
- A500 calculate the sub-region probability value corresponding to each voxel in the final thalamus ROI of the individual brain of the subject, remove the voxel points with the largest sub-region probability value lower than the first threshold, and then construct the remaining voxel points
- the thalamic probability map at the group level is the group thalamic probability map; the sub-region probability value is the ratio of the number of subjects in each sub-region to the total number of subjects.
- a third aspect of the present invention provides an electronic device, including: at least one processor; and a memory communicatively connected to at least one of the processors; wherein the memory stores instructions that can be executed by the processor. , the instructions are configured to be executed by the processor to implement the above-mentioned group prior guided deep learning-based individualized map drawing method of the thalamus.
- a fourth aspect of the present invention provides a computer-readable storage medium that stores computer instructions, and the computer instructions are used to be executed by the computer to implement the above-mentioned group a priori guidance.
- the present invention uses high-confidence group a priori to guide individualized thalamic partitioning and map drawing, thereby improving the accuracy, robustness and repeatability of the drawn individualized thalamic map.
- the present invention draws an individualized thalamic atlas based on high-confidence group-level thalamic atlas and single subject data, which not only integrates the group consistency of the thalamic partitioning pattern, but also reflects the specificity of the individual partitioning pattern.
- the results show that this method is more effective than single-subject clustering and group atlas registration on the HCP-3T and HCP-7T data. High partitioning accuracy.
- the results show that this method has high inter-scan partitioning pattern consistency on Test-retest data.
- the results show that the method is robust to different numbers of subregions, and has higher partitioning at the finer number of 12 subregions. accuracy.
- the present invention partitions the thalamus at the group level based on high-order diffusion characteristics and spatial location, and discovers a more refined thalamic partitioning pattern; and shows higher intra-subject partitioning consistency on the more refined thalamic atlas, It can support the drawing of more fine-grained individualized thalamic maps; it is robust under different magnetic field scanning intensities, and higher magnetic field scanning intensities can provide higher intra-subject partition consistency gains; in the same subject's Repeatability across different scan batches.
- Figure 1 is a schematic flowchart of a method for drawing an individualized map of the thalamus based on deep learning guided by group priori according to an embodiment of the present invention
- Figure 2 is a schematic framework diagram of a group prior-guided deep learning-based individualized map drawing system for the thalamus according to an embodiment of the present invention
- Figure 3 is a schematic flow chart of the final thalamic ROI acquisition process of an individual subject's brain according to an embodiment of the present invention
- Figure 4 is a schematic flow chart of ODF estimation according to an embodiment of the present invention.
- Figure 5 is a schematic flowchart of the construction process of a group thalamic probability map according to an embodiment of the present invention
- Figure 6 is a schematic flowchart of the construction process of a personalized thalamic map according to an embodiment of the present invention.
- the group prior-guided deep learning-based personalized map drawing method of the thalamus of the present invention includes the following steps:
- S400 combined with the second mask, calculate the coefficients of the 45-dimensional spherical harmonic function and the position coordinates of the 3-dimensional diffusion magnetic resonance space of each voxel in the group prior map, and merge the two into a 48-dimensional Feature vector, as an individual feature; input the individual features into the pre-built individualized classification model to obtain the predicted probability value vector of the voxels in each undefined area, and assign the largest sub-region label corresponding to the predicted probability value vector As the final sub-region label of the voxel, a map of the undefined area is generated; the individualized classification model is built based on a deep learning neural network;
- the construction method of the group thalamic probability map is:
- A100 obtain the structural MRI images and diffusion tensor MRI images of the individual brains of N subjects as input images; N is a positive integer;
- A200 sequentially perform HCP minimum preprocessing, ROI registration, and ROI postprocessing on the input image to obtain the final thalamus ROI of the subject's individual brain, and obtain the final thalamus ROI of the subject's individual brain through the ODF estimation algorithm.
- A300 combined with the local diffusion characteristics obtained by A200, calculates the similarity between voxels and performs clustering to obtain the clustering results of voxels within the final thalamic ROI of the subject's individual brain;
- A400 register the clustering results obtained by A300 to the standard space, and perform label remapping to obtain the sub-region label corresponding to each voxel in the final thalamus ROI of the individual subject's brain, that is, N individual subjects are obtained thalamic partitioning of the brain in standard space;
- A500 calculate the sub-region probability value corresponding to each voxel in the final thalamus ROI of the individual brain of the subject, remove the voxel points with the largest sub-region probability value lower than the first threshold, and then construct the remaining voxel points
- the thalamic probability map at the group level is the group thalamic probability map; the sub-region probability value is the ratio of the number of subjects in each sub-region to the total number of subjects.
- the group prior guided deep learning-based individualized map drawing method of the thalamus described in the present invention is divided into two main steps: the construction of the group probability map of the thalamus and the construction of the individualized thalamus map.
- the construction stage of the thalamic group probability map first based on a set of high-quality data, the direction distribution function and individual diffusion magnetic resonance space of each voxel in the thalamic region of interest (Region of Interest, ROI) are extracted in diffusion magnetic resonance imaging.
- map areas with high probability values at the group level of the thalamus are regarded as group priors, and are registered to the individual diffusion magnetic resonance space as high-confidence group priors for individual maps.
- the maximum The template of the probability map was registered to the individual diffusion magnetic resonance space as the ROI of the individual thalamic map.
- the 45-dimensional coefficients of the 8th order spherical harmonic function in the ROI are extracted through Multi-Shell Multi-Tissue Constrained Spherical Deconvolution (MSMT-CSD) as ODF features, while calculating 3-dimensional individual diffusion magnetic resonance spatial coordinates as spatial position features, thereby constructing 48-dimensional individual features for voxels in each ROI.
- MSMT-CSD Multi-Shell Multi-Tissue Constrained Spherical Deconvolution
- the construction process of the group thalamic probability map is first described in detail, and then the process of generating the individualized map based on a group prior-guided deep learning-based individualized map drawing method of the thalamus is described in detail. narrate.
- A100 obtain the structural MRI images and diffusion tensor MRI images of the individual brains of N subjects as input images; N is a positive integer;
- a group that is, N
- structural MRI images and diffusion tensor MRI images of the brains of individual subjects are first obtained.
- A200 sequentially perform HCP minimum preprocessing, ROI registration, and ROI postprocessing on the input image to obtain the final thalamus ROI of the subject's individual brain, and obtain the final thalamus ROI of the subject's individual brain through the ODF estimation algorithm.
- minimum preprocessing of HCP data i.e., HCP minimum preprocessing
- T1 and DWI diffusion tensor NMR image
- DWI diffusion Weighted Imaging
- the diffusion magnetic resonance space (B0, referred to as diffusion space) of the subject's individual brain is , as shown in Figure 3) and the structural magnetic resonance space (T1, referred to as the structural space, as shown in Figure 3) are linearly registered, and the structural magnetic resonance space (T1) and the standard space (Montreal Neurological Institute, MNI) are Nonlinear registration, and then combine the two registration matrices to generate a registration matrix from the diffusion magnetic resonance space (B0) of the subject's individual brain to the standard space (MNI) and transpose it to obtain the standard space to the individual diffusion space. registration matrix. Based on this registration matrix, the classic Morel thalamic atlas was registered to the individual diffusion magnetic resonance space, which was used as the individual thalamic ROI. As shown in (a) in Figure 3.
- ROI post-processing is performed, as shown in (b) in Figure 3: specifically: using FSL to calculate the FA map (i.e., the anisotropy distribution corresponding to each voxel point) in the diffusion magnetic resonance space of the individual brain of the subject.
- FA map i.e., the anisotropy distribution corresponding to each voxel point
- ODF estimation is performed, as shown in Figure 4: specifically: in MRtrix3, the dhollander algorithm is used to first calculate the response function of the brain tissue under different diffusion weighting factor b value parameters on the diffusion magnetic resonance data, and then combine the response functions of the brain tissue
- the response function uses the multi-tissue multi-spherical shell restricted spherical deconvolution method (i.e., the abbreviated multi-tissue multi-spherical shell restricted deconvolution in Figure 4) to calculate the 45-dimensional coefficients of the 8th order spherical harmonic function (i.e., the multi-tissue multi-spherical shell restricted deconvolution in Figure 4).
- Spherical harmonic coefficient matrix to represent the local diffusion characteristics of each voxel in the thalamus (that is, taking the 8th order spherical harmonic function as the sampling base, calculating the 45-dimensional spherical harmonic function coefficient of each voxel in the thalamus ROI to construct its ODF model, thus obtaining Spherical harmonic function coefficient matrix within the thalamus ROI).
- A300 combined with the local diffusion characteristics obtained by A200, calculates the similarity between voxels and performs clustering to obtain the clustering results of voxels within the final thalamic ROI of the subject's individual brain;
- the similarity between voxels is first calculated based on the diffusion characteristics and spatial position characteristics of the voxels, and a similarity matrix is constructed.
- the specific calculation method of the similarity between voxels is as shown in formula (1):
- S(i,j) represents the similarity between two voxels
- E pos (i, j) represents the Euclidean distance between the three-dimensional coordinates of two voxels in the diffusion magnetic resonance space
- E odf (i, j) represents the Euclidean distance between the sampling coefficients of the 45-dimensional spherical harmonic function of two voxels
- w pos and w odf respectively represent the correspondence of E pos (i, j) and E odf (i, j) when calculating similarity.
- Weighting coefficient In the present invention, w pos and w odf are preferably set to 0.5.
- the 45-dimensional spherical harmonic function coefficient is multiplied by a scaling factor and then the Euclidean distance between ODFs is calculated.
- the scaling factor is 89 (3T data) and 98 (7T data). ).
- clustering is performed, specifically: using the spectral clustering method to reduce the dimensionality of the local diffusion characteristics of each voxel in the final thalamic ROI of the subject's individual brain and the similarity between voxels; based on the dimensionality reduction Based on the local diffusion characteristics and the similarity between voxels, K-means clustering is used to cluster each voxel into K categories, which is used as the clustering result of the voxels within the final thalamus ROI of the subject's individual brain.
- the value of K ranges from 2 to 28.
- A400 register the clustering results obtained by A300 to the standard space, and perform label remapping to obtain the sub-region label corresponding to each voxel in the final thalamic ROI of the individual subject's brain, that is, N individual subjects are obtained thalamic partitioning of the brain in standard space;
- label remapping is performed first, specifically:
- Label remapping After registering the clustering results in the individual subject space to the MNI space, the sub-region labels between the initial partitions of the individual subject cannot correspond to the same.
- the corresponding sub-region labels are extracted from each of the N subjects to form an N-dimensional label vector).
- all voxel points within the final thalamus ROI of the subject's individual brain are clustered according to the similarity of their label vectors, and the clustering result is a group-level partition label.
- the clustering results of each subject are re-labeled according to the spatial maximum overlap method, so as to obtain the sub-region label corresponding to each voxel in the final thalamus ROI of the subject's individual brain, that is, N
- the thalamic partitions of the individual subject's brains in standard space are used to obtain consistent labels across individuals.
- A500 calculate the sub-region probability value corresponding to each voxel in the final thalamus ROI of the individual brain of the subject, remove the voxel points with the largest sub-region probability value lower than the first threshold, and then construct the remaining voxel points
- the thalamic probability map at the group level is the group thalamic probability map; the sub-region probability value is the ratio of the number of subjects in each sub-region to the total number of subjects.
- the sub-region probability value of each voxel in the final thalamic ROI of the individual subject's brain is calculated, that is, the subject belonging to a certain sub-region is calculated.
- the voxel point After calculating the sub-region probability values of all voxels, take a certain threshold (0.25) and remove the voxel points whose maximum sub-region probability value is lower than the threshold (that is, obtain the maximum sub-region probability corresponding to each voxel point, If the maximum sub-region probability is lower than the set first threshold, the voxel point is removed), and a group-level thalamic probability map is constructed based on the remaining voxel points, that is, the group thalamic probability map, that is, in Figure 5 Group map. Binarize the probability map to obtain the ROI (mask) of the group probability map. According to the winner-take-all principle, the sub-region label of each voxel in the probability map is set to the label corresponding to the maximum probability value, thereby constructing the maximum probability map.
- post-A500 also includes verification of the optimal number of partitions: based on the maximum probability map generated above, calculate the partition consistency between individuals and groups and the topological consistency between cerebral hemispheres to determine the optimal number of thalamic sub-regions.
- the consistency of partitions between individuals and groups is verified using the overlap rate Dice value of individual partitions and group partitions. The closer the Dice value is to 1, the higher the consistency of partitioning between individuals and groups, and the more consistent the number of thalamic partitions here is with the internal partitioning pattern of the thalamus.
- the individual partitioned subjects and the group partitioned subject sets were divided, and the Dice average value of the consistency of individual and group partitions was calculated for 100 times.
- topological consistency index between cerebral hemispheres is verified on the group map using topological distance TpD (Topological Distance, TpD).
- TpD Topological Distance
- Topological distance first calculates the number of adjacent voxels between each sub-region and other sub-regions in a single hemisphere, and generates a K ⁇ K-dimensional matrix. After unfolding this matrix, the similarity of this matrix between the two cerebral hemispheres is calculated, that is, the topological distance within the partition.
- the Dice indicator appears as a local maximum when the number of clusters is 7 and 12, and the TpD value under these two cluster numbers is basically 0, indicating that the number of partitions is 7 and 12. Partitioning patterns within the thalamus.
- the anterior thalamic nucleus, ventroanterior nucleus, dorsomedial nucleus, dorsolateral-posterolateral nucleus, lateral pulvinar nucleus, ventrolateral-ventroposterior nucleus and medial pulvinar nucleus can be complete according to the number of subregions. Split it out. There is strong homology between the left and right hemispheres of the thalamus. Each subregion of the thalamus shows strong structural homogeneity.
- the number of subdivisions is: anterior thalamic nucleus, ventroanterior nucleus, dorsomedial nucleus, posteromedial nucleus, ventrolateral nucleus, ventroposterior nucleus, anterior pulvinar nucleus, lateral pulvinar nucleus, medial pulvinar nucleus
- the nucleus, dorsoanterior dorsomedial nucleus, dorsal dorsomedial nucleus, and ventral dorsomedial nucleus can be completely segmented.
- Each subregion of the thalamus shows strong structural homogeneity. Compared with the zoning pattern of 7 subregions, the thalamic map of 12 subregions is more refined.
- the group thalamic probability map constructed above (ie, the group map in Figure 6(a) and (b)) is taken as a first threshold (preferably set to 0.25 in the present invention) and binarized Generate a mask mask for the group thalamic probability map, that is, the maximum probability mask in (a) in Figure 6.
- the maximum probability mask is registered to the diffusion magnetic resonance space of the subject's individual brain to obtain the thalamus ROI of the subject's individual brain (ie, the individual mask in (a) in Figure 6).
- the group thalamic probability map constructed above is set to a second threshold (preferably set to >0.75 in the present invention) to generate a high-probability thalamic map (ie, the high-confidence group in (b) in Figure 6 group map), and register it to the individual diffusion magnetic resonance space as a group prior map (i.e., individual prior map) of the subject's individual brain, as shown in (b) in Figure 6 .
- the first threshold and the second threshold are used to remove the voxel points with the largest sub-region probability value lower than the threshold (i.e. the first threshold or the second threshold), and then construct the group thalamic probability map (specifically, as shown in A500 Show).
- the group prior map in the thalamus ROI is eliminated to obtain a mask of the undefined thalamus region as the second mask, as shown in (c) of Figure 6 .
- S400 combined with the second mask, calculate the coefficients of the 45-dimensional spherical harmonic function and the position coordinates of the 3-dimensional diffusion magnetic resonance space of each voxel in the group prior map, and merge the two into a 48-dimensional Feature vector, as an individual feature; input the individual features into the pre-built individualized classification model to obtain the predicted probability value vector of the voxels in each undefined area, and assign the largest sub-region label corresponding to the predicted probability value vector As the final sub-region label of the voxel, a map of the undefined area is generated; the individualized classification model is built based on a deep learning neural network;
- the group is first calculated.
- the coefficients of the 45-dimensional spherical harmonic function and the position coordinates of the 3-dimensional diffusion magnetic resonance space of each voxel in the prior map are combined, and the individual characteristics are obtained by merging the two. Input the individual characteristics (i.e.
- the pre-built individualized classification model 48 dimensions into the pre-built individualized classification model to obtain the predicted probability value vector of the voxels in each undefined area, and use the sub-region label with the largest predicted probability value vector as the voxel's
- the final sub-region label is generated, and a map of the undefined area is generated; the individualized classification model is built based on a deep learning neural network (ie, the deep learning model in (e) in Figure 6).
- the individualized classification model is built based on the deep learning neural network, and its training process is as follows, as shown in (d) in Figure 6:
- the loss value is obtained through the mean square error loss function, and the model parameters of the individualized classification model are updated; the individualized classification model is trained in a loop until the Trained individualized classification model.
- S500 Merge the group prior map and the map of the undefined area to generate a subject's individualized thalamus map. As shown in (f) in Figure 6.
- the Euclidean distance of the 45-dimensional spherical harmonic function coefficients is used as the distance metric.
- the gain index uses the Silhouette value of the individualized thalamic map clustered by a single subject as the denominator, and the difference between the Silhouette value of the individualized thalamic map guided by group prior guidance or group registration and its numerator as the numerator.
- a positive gain means that the accuracy of a certain individualized map drawing method is higher than that of single-subject clustering, and the greater the gain, the greater the accuracy improvement.
- a negative number means that it is lower than single-subject clustering.
- the verification indicators were calculated when the number of partitions was 7 and 12, respectively.
- the results show that on the four data sets, the three individuation methods of group a priori guidance, group registration and single-subject clustering show similar consistency of within-subject partitioning patterns, but the group a priori guidance of individuals The thalamus atlas had higher within-subject consistency than the other two methods.
- the gain index of the intra-subject partition consistency of the individualized map is the gain comparison of the intra-subject partition consistency on the HCP 3T and HCP 7T data, and the gain comparison of the intra-subject partition consistency on the HCP Test and HCP Retest data. .
- the within-subject partition consistency of the individualized thalamic atlas drawn by the group registration method is worse than that of single-subject clustering.
- the group-prior guided individualized thalamic atlas has stronger intra-subject partition consistency than single-subject clustering.
- the gains of 3T and 7T data are the same.
- the gain of 7T data is higher than that of 3T data.
- the gains of Test and Retest are basically the same.
- the group prior-guided individualized thalamic atlas has a higher gain when the number of partitions is 12 than when the number of partitions is 7.
- a group prior-guided deep learning-based personalized map drawing system of the thalamus includes: a thalamus ROI acquisition module 100, a group prior map acquisition module 200, and elimination Processing module 300, individualized classification module 400, individualized map generation module 500;
- the thalamic ROI acquisition module 100 is configured to acquire the group thalamic probability map under a first threshold and perform binarization to obtain a mask of the group thalamic probability map as the first mask;
- the membrane is registered to the diffusion magnetic resonance space of the subject's individual brain, and the thalamus ROI of the subject's individual brain is obtained;
- the group prior map acquisition module 200 is configured to obtain the group thalamic probability map under the second threshold, and register it to the diffusion magnetic resonance space of the subject's individual brain to obtain the subject's individual brain.
- the elimination processing module 300 is configured to eliminate the group prior map in the thalamus ROI in the diffusion magnetic resonance space of the subject's individual brain to obtain a mask of the undefined thalamus region as the second mask. membrane;
- the individualized classification module 400 is configured to calculate the coefficients of the 45-dimensional spherical harmonic function and the position coordinates of the 3-dimensional diffusion magnetic resonance space of each voxel in the group prior map, and merge the two to obtain individual characteristics; Input the individual characteristics into the pre-built individualized classification model to obtain the predicted probability value vector of the voxel in each undefined area, and use the sub-region label with the largest predicted probability value vector as the final sub-region label of the voxel, And generate a map of undefined areas; the individualized classification model is built based on a deep learning neural network;
- the personalized map generation module 500 is configured to merge the group prior map and the map of the undefined area to generate a subject's individualized thalamic map;
- the construction method of the group thalamic probability map is:
- A100 obtain the structural MRI images and diffusion tensor MRI images of the individual brains of N subjects as input images; N is a positive integer;
- A200 sequentially perform HCP minimum preprocessing, ROI registration, and ROI postprocessing on the input image to obtain the final thalamus ROI of the subject's individual brain, and obtain the final thalamus ROI of the subject's individual brain through the ODF estimation algorithm.
- A300 combined with the local diffusion characteristics obtained by A200, calculates the similarity between voxels and performs clustering to obtain the clustering results of voxels within the final thalamic ROI of the subject's individual brain;
- A400 register the clustering results obtained by A300 to the standard space, and perform label remapping to obtain the sub-region label corresponding to each voxel in the final thalamus ROI of the individual subject's brain, that is, N individual subjects are obtained thalamic partitioning of the brain in standard space;
- A500 calculate the sub-region probability value corresponding to each voxel in the final thalamus ROI of the individual brain of the subject, remove the voxel points with the largest sub-region probability value lower than the first threshold, and then construct the remaining voxel points
- the thalamic probability map at the group level is the group thalamic probability map; the sub-region probability value is the ratio of the number of subjects in each sub-region to the total number of subjects.
- the group a priori-guided deep learning-based personalized map drawing system of the thalamus provided in the above embodiments is only illustrated by the division of each functional module mentioned above. In practical applications, the above mentioned functions can be used as needed. Function allocation is completed by different functional modules, that is, the modules or steps in the embodiment of the present invention are decomposed or combined. For example, the modules in the above embodiment can be combined into one module, or further divided into multiple sub-modules to complete All or part of the functions described above.
- the names of the modules and steps involved in the embodiments of the present invention are only used to distinguish each module or step and are not regarded as improper limitations of the present invention.
- An electronic device includes: at least one processor; and a memory communicatively connected to at least one of the processors; wherein the memory stores instructions that can be executed by the processor, so The instructions are used to be executed by the processor to implement the above-mentioned group prior-guided deep learning-based individualized map drawing method of the thalamus.
- a computer-readable storage medium stores computer instructions, and the computer instructions are used to be executed by the computer to implement the above-mentioned group a priori guidance based on depth.
- a device for drawing individualized maps of the thalamus based on deep learning guided by group prior guidance in the fifth embodiment of the present invention includes: a magnetic resonance image acquisition device and a central processing device,
- the magnetic resonance image acquisition equipment includes magnetic resonance imaging equipment and a superconducting magnetic resonance instrument, and is configured to acquire structural MRI images and diffusion tensor MRI images of the subject's individual brain;
- the central processing device includes a GPU and is configured to obtain a group thalamic probability map under a first threshold and perform binarization to obtain a mask of the group thalamic probability map as a first mask; converting the first mask
- the membrane is registered to the diffusion magnetic resonance space of the subject's individual brain, and the thalamus ROI of the subject's individual brain is obtained;
- the group thalamic probability map under the second threshold and register it to the diffusion magnetic resonance space of the subject's individual brain to obtain the group prior map of the subject's individual brain; in the subject's individual brain In the diffusion magnetic resonance space, the group prior map in the thalamus ROI is eliminated to obtain a mask of the undefined thalamus area as the second mask;
- the construction method of the group thalamic probability map is:
- A100 obtain the structural MRI images and diffusion tensor MRI images of the individual brains of N subjects as input images; N is a positive integer;
- A200 sequentially perform HCP minimum preprocessing, ROI registration, and ROI postprocessing on the input image to obtain the final thalamus ROI of the subject's individual brain, and obtain the final thalamus ROI of the subject's individual brain through the ODF estimation algorithm.
- A300 combined with the local diffusion characteristics obtained by A200, calculates the similarity between voxels and performs clustering to obtain the clustering results of voxels within the final thalamic ROI of the subject's individual brain;
- A400 register the clustering results obtained by A300 to the standard space, and perform label remapping to obtain the sub-region label corresponding to each voxel in the final thalamus ROI of the individual subject's brain, that is, N individual subjects are obtained thalamic partitioning of the brain in standard space;
- A500 calculate the sub-region probability value corresponding to each voxel in the final thalamus ROI of the individual brain of the subject, remove the voxel points with the largest sub-region probability value lower than the first threshold, and then construct the remaining voxel points
- the thalamic probability map at the group level is the group thalamic probability map; the sub-region probability value is the ratio of the number of subjects in each sub-region to the total number of subjects.
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Abstract
The present invention belongs to the field of brain map drawing using magnetic resonance imaging, and particularly relates to a deep learning-based thalamus individualized map drawing method and system guided by group prior knowledge, and a device, which are aimed at solving the problems in the prior art of the accuracy, robustness and repeatability of a drawn individualized thalamus map being relatively poor. The present method comprises: acquiring thalamus ROIs of individual brains of subjects; acquiring a group prior map of the individual brains of the subjects; eliminating the group prior map from the thalamus ROIs; acquiring an individual feature, inputting same into an individualized classification model, so as to obtain a prediction probability value vector of a voxel in each undefined region, and then generating a map of the undefined region; and combining the group prior map and maps of undefined regions, so as to generate individualized thalamus maps of the subjects. In the present invention, individualized thalamus parcellation and map drawing are guided by using high-credibility group prior knowledge, such that the accuracy, robustness and repeatability of drawn individualized thalamus maps are improved.
Description
本发明属于磁共振成像的脑图谱绘制领域,具体涉及一种群组先验引导的基于深度学习的丘脑个体化图谱绘制方法、系统、设备。The invention belongs to the field of brain mapping of magnetic resonance imaging, and specifically relates to a method, system and equipment for individualized mapping of the thalamus based on deep learning guided by group priori.
丘脑是大脑中的一个中继核团,参与了听觉、视觉、运动、躯体感觉、情绪、记忆和学习等大脑功能环路。在临床中,丘脑作为深部脑刺激(DBS)的作用靶点,参与了帕金森病、癫痫、多发性硬化、植物人促醒、精神分裂症和特发性震颤等神经精神系统疾病的调控治疗。因此,精细准确的丘脑图谱的绘制是丘脑研究的关键。在现有的研究中,研究者们通过组织学切片染色和磁共振成像等方法来刻画丘脑的结构或者功能特征,并以此作为丘脑分区的依据。在这些丘脑分区的方法中,组织学切片染色被视为丘脑分区的金标准,而其只能在离体脑标本中进行,不具备可重复性且依赖解剖学家的手工标记。发展迅速的磁共振成像可以无创地描述丘脑内的特征,包括局部微观结构、解剖连接和功能连接等。基于此,数据驱动的丘脑分区流程逐渐成为丘脑分区的研究热点。根据磁共振成像的模态,现有的丘脑分区可以分为基于结构、弥散和功能影像三种模态数据的不同方法。在基于这三种磁共振模态数据的丘脑分区方法中,基于弥散磁共振的丘脑分区是最接近丘脑的解剖学构筑的。弥散磁共振影像能提供两种弥散信息,即纤维束连接和局部弥散特征。在早期的研究中,研究者们发现基于纤维束连接的丘脑分区与实际的丘脑解剖构筑的对应性也不佳,而基于局部弥散特征的丘脑分区与 解剖构筑基本一致。因此,基于局部弥散特征的丘脑分区是最直接刻画丘脑的局部微观结构的方法。The thalamus is a relay nucleus in the brain that participates in brain functional circuits such as hearing, vision, movement, somatosensory, emotion, memory and learning. In clinical practice, the thalamus, as the target of deep brain stimulation (DBS), is involved in the regulation and treatment of neuropsychiatric diseases such as Parkinson's disease, epilepsy, multiple sclerosis, vegetative awakening, schizophrenia, and essential tremor. Therefore, the drawing of fine and accurate thalamic maps is the key to thalamic research. In existing studies, researchers use methods such as histological section staining and magnetic resonance imaging to characterize the structural or functional characteristics of the thalamus, and use this as the basis for thalamic division. Among these methods for thalamic partitioning, histological section staining is regarded as the gold standard for thalamic partitioning, which can only be performed on isolated brain specimens, is not reproducible and relies on manual marking by anatomists. Rapidly developing magnetic resonance imaging can non-invasively characterize features within the thalamus, including local microstructure, anatomical connections, and functional connections. Based on this, the data-driven thalamic partitioning process has gradually become a research hotspot in thalamic partitioning. According to the modality of magnetic resonance imaging, existing thalamic partitioning can be divided into different methods based on three modalities of structural, diffusion, and functional imaging data. Among the thalamic partitioning methods based on these three magnetic resonance modality data, the thalamic partitioning based on diffusion magnetic resonance is the closest to the anatomical structure of the thalamus. Diffusion magnetic resonance imaging can provide two types of diffusion information, namely fiber bundle connections and local diffusion characteristics. In early studies, researchers found that thalamic divisions based on fiber tract connections did not correspond well to the actual thalamic anatomy, while thalamic divisions based on local diffusion characteristics were basically consistent with the anatomical structure. Therefore, thalamic partitioning based on local diffusion characteristics is the most direct method to characterize the local microstructure of the thalamus.
上述的丘脑分区研究大多使用一组被试,基于其个体空间中的丘脑分区结果,通过手工标记或者自动配准的方法将不同被试的丘脑分区映射到同一空间,从而构建群组水平的丘脑图谱。该方法能客观无偏地反映丘脑的内在分区模式,如亚区数量,和群组水平的一致属性,如丘脑亚核团和其他脑区的结构连接模式和功能连接模式等。然而,随着研究的深入,研究者们发现不论是在大脑皮层还是皮下核团中,个体间的大脑分区模式存在明显差异,且个体特异性的脑分区比群组水平的脑分区更能反映个体特征,例如认知、发育、老化和疾病特征等。此外,在临床中,特别是精准医学等领域,被试特异性的脑图谱发挥着重要的作用,例如术前诊断、疗效预测、靶点定位等。因此,个体化脑图谱绘制的重要性也逐渐被研究者们所关注。一些个体化图谱绘制的方法也逐渐被开发出来,其大致分为三种,单被试的直接分区、群组图谱的个体配准和组先验引导的个体分区。第一种方法依赖高质量的磁共振成像数据和鲁棒的分区算法,大致有纤维投射法、谱聚类法、边缘检测法、区域增长法等;第二中方法将群组图谱直接配准到个体空间,从而将群组图谱视为个体图谱;第三种方法首先构建群组图谱,并将群组图谱视为个体分区的先验知识,从而辅助后续的个体分区。第一种分区方法适用于具有特定纤维束投射的核团,例如丘脑底核、内侧苍白球等。第二种方法适用于脑部严重损伤或者无法进行弥散磁共振成像的被试,例如脑肿瘤患者和头部有金属植入物的患者。第三种方法适用于大脑皮层,以及体积较大、个体特征较丰富的核团。因此,为了精准地构建个体化丘脑图谱,可以采用群组先验引导的个体化分区策略。Most of the above-mentioned thalamic partitioning studies use a group of subjects. Based on the thalamic partitioning results in their individual spaces, the thalamic partitions of different subjects are mapped to the same space through manual marking or automatic registration methods, thereby constructing a group-level thalamus. Map. This method can objectively and unbiasedly reflect the intrinsic partitioning pattern of the thalamus, such as the number of subregions, and the consistent attributes at the group level, such as the structural and functional connectivity patterns of thalamic subnuclei and other brain regions. However, with the deepening of research, researchers have found that there are obvious differences in brain partition patterns between individuals, whether in the cerebral cortex or subcortical nuclei, and that individual-specific brain partitions are better reflective than group-level brain partitions. Individual characteristics, such as cognitive, developmental, aging, and disease characteristics. In addition, in clinical practice, especially in fields such as precision medicine, subject-specific brain maps play an important role, such as preoperative diagnosis, efficacy prediction, target positioning, etc. Therefore, the importance of personalized brain mapping has gradually attracted the attention of researchers. Some individualized map drawing methods have also been gradually developed, which are roughly divided into three types: direct partitioning of single subjects, individual registration of group maps, and individual partitioning guided by group priors. The first method relies on high-quality magnetic resonance imaging data and robust partitioning algorithms, including fiber projection method, spectral clustering method, edge detection method, region growing method, etc.; the second method directly registers group maps to the individual space, thus treating the group map as an individual map; the third method first constructs the group map and treats the group map as prior knowledge of individual partitions to assist subsequent individual partitions. The first partitioning method is suitable for nuclei with specific fiber tract projections, such as the subthalamic nucleus, medial globus pallidus, etc. The second method is suitable for subjects with severe brain damage or in whom diffusion magnetic resonance imaging is not possible, such as patients with brain tumors and patients with metal implants in the head. The third method is suitable for the cerebral cortex and nuclei with larger volumes and richer individual characteristics. Therefore, in order to accurately construct an individualized thalamic map, an individualized partitioning strategy guided by group prior can be used.
随着磁共振成像的技术发展,多b值高角度分辨率弥散加权成像(High Angular Resolution Diffusion Imaging,HARDI)极大地提升了 局部弥散方向的建模和估计的效率和准确度。不论是在神经科学研究还是在临床扫描中,多b值高角度分辨率弥散磁共振成像逐渐成为一种趋势。同时,在局部弥散方向估计的方法性研究中,区别于经典的弥散张量模型,现存的多种q空间采样方法支持更高阶的弥散模型的构建。例如弥散峰度成像、弥散谱成像、Q-ball成像及其衍生的多球壳成像等。在这类方法中,多球壳多组织限制性球面反卷积(MSMT-CSD)能直接估计大脑组织的弥散方向分布函数(ODF),该方法依赖多b值HARDI,是目前最适合提取丘脑的局部弥散特征的方法。此外,深度学习在近十年中迅猛发展,强大的数据拟合和分类能力使其在包括神经科学内的各个领域大方异彩。在此种背景下,结合局部弥散特征和群组先验引导的个体化分区策略,基于深度学习模型构建一套自动化的个体化丘脑图谱绘制方法逐渐成为可能。With the development of magnetic resonance imaging technology, multi-b-value High Angular Resolution Diffusion Imaging (HARDI) has greatly improved the efficiency and accuracy of modeling and estimation of local diffusion directions. Whether in neuroscience research or clinical scanning, multi-b-value high-angle resolution diffusion magnetic resonance imaging has gradually become a trend. At the same time, in the methodological research on local dispersion direction estimation, different from the classic dispersion tensor model, various existing q-space sampling methods support the construction of higher-order dispersion models. For example, diffusion kurtosis imaging, diffusion spectrum imaging, Q-ball imaging and its derived multi-spherical shell imaging, etc. Among such methods, multi-spherical shell multi-tissue restricted spherical deconvolution (MSMT-CSD) can directly estimate the diffusion direction distribution function (ODF) of brain tissue. This method relies on multi-b-value HARDI and is currently the most suitable for extracting thalamus. method of local diffusion characteristics. In addition, deep learning has developed rapidly in the past decade, and its powerful data fitting and classification capabilities have made it brilliant in various fields including neuroscience. In this context, it is gradually becoming possible to build an automated individualized thalamic map drawing method based on deep learning models by combining local diffusion characteristics and group prior-guided individualized partitioning strategies.
发明内容Contents of the invention
为了解决现有技术中的上述问题,即为了解决现有的丘脑个体化图谱绘制方法无法构建高可信度的群组先验、无法利用群组先验引导个体化的丘脑图谱的绘制,造成绘制的个体化的丘脑图谱的准确性、鲁棒性以及可重复性较差的问题,本发明第一方面,提出了一种群组先验引导的基于深度学习的丘脑个体化图谱绘制方法,该方法包括:In order to solve the above-mentioned problems in the existing technology, that is, to solve the problem that the existing individualized thalamus map drawing method cannot construct a high-confidence group prior and cannot use the group prior to guide the drawing of the individualized thalamus map, resulting in The problem of poor accuracy, robustness and repeatability of the drawn individualized thalamus map. In the first aspect of the present invention, a group prior guided method for drawing an individualized thalamus map based on deep learning is proposed. The method includes:
S100,获取在第一阈值下的群组丘脑概率图谱并进行二值化,得到群组丘脑概率图谱的掩膜,作为第一掩膜;将所述第一掩膜配准到受试者个体脑部的弥散磁共振空间,得到受试者个体脑部的丘脑ROI;S100, obtain the group thalamic probability map under the first threshold and perform binarization to obtain the mask of the group thalamic probability map as the first mask; register the first mask to the individual subject The diffusion magnetic resonance space of the brain is used to obtain the thalamus ROI of the subject's individual brain;
S200,获取在第二阈值下的群组丘脑概率图谱,并配准到受试者个体脑部的弥散磁共振空间,得到受试者个体脑部的群组先验图谱;S200, obtain the group thalamic probability map under the second threshold, and register it to the diffusion magnetic resonance space of the subject's individual brain to obtain the group prior map of the subject's individual brain;
S300,在受试者个体脑部的弥散磁共振空间中,剔除所述丘脑ROI中的群组先验图谱,得到未定义的丘脑区域的掩膜,作为第二掩膜;S300, in the diffusion magnetic resonance space of the subject's individual brain, eliminate the group prior map in the thalamus ROI and obtain a mask of the undefined thalamus area as the second mask;
S400,结合所述第二掩膜,计算所述群组先验图谱中每个体素的45维球面调和函数的系数和3维弥散磁共振空间的位置坐标,将两者合并为一个48维的特征向量,作为个体特征;将所述个体特征输入预构建的个体化分类模型,得到每个未定义区域内的体素的预测概率值向量,并将预测概率值向量对应的最大的亚区标签作为体素的最终亚区标签,进而生成未定义区域的图谱;所述个体化分类模型基于深度学习神经网络构建;S400, combined with the second mask, calculate the coefficients of the 45-dimensional spherical harmonic function and the position coordinates of the 3-dimensional diffusion magnetic resonance space of each voxel in the group prior map, and merge the two into a 48-dimensional Feature vector, as an individual feature; input the individual features into the pre-built individualized classification model to obtain the predicted probability value vector of the voxels in each undefined area, and assign the largest sub-region label corresponding to the predicted probability value vector As the final sub-region label of the voxel, a map of the undefined area is generated; the individualized classification model is built based on a deep learning neural network;
S500,将所述群组先验图谱和所述未定义区域的图谱进行合并,生成受试者个体化的丘脑图谱;S500, merge the group prior map and the map of the undefined area to generate a subject's individualized thalamus map;
其中,所述群组丘脑概率图谱其构建方法为:Wherein, the construction method of the group thalamic probability map is:
A100,获取N个受试者个体脑部的结构核磁共振图像、弥散张量核磁共振图像,作为输入图像;N为正整数;A100, obtain the structural MRI images and diffusion tensor MRI images of the individual brains of N subjects as input images; N is a positive integer;
A200,对所述输入图像依次进行HCP最小预处理、ROI配准、ROI后处理,得到受试者个体脑部最终的丘脑ROI,并通过ODF估计算法,得到受试者个体脑部最终的丘脑ROI内每个体素的局部弥散特征;A200, sequentially perform HCP minimum preprocessing, ROI registration, and ROI postprocessing on the input image to obtain the final thalamus ROI of the subject's individual brain, and obtain the final thalamus ROI of the subject's individual brain through the ODF estimation algorithm. Local diffusion characteristics of each voxel within the ROI;
A300,结合A200获取的局部弥散特征,计算体素之间的相似度,并进行聚类,得到受试者个体脑部最终的丘脑ROI内体素的聚类结果;A300, combined with the local diffusion characteristics obtained by A200, calculates the similarity between voxels and performs clustering to obtain the clustering results of voxels within the final thalamic ROI of the subject's individual brain;
A400,将A300获取的聚类结果配准至标准空间,并进行标签重映射,得到受试者个体脑部最终的丘脑ROI内每个体素对应的亚区标签,即得到N个受试者个体脑部在标准空间中的丘脑分区;A400, register the clustering results obtained by A300 to the standard space, and perform label remapping to obtain the sub-region label corresponding to each voxel in the final thalamic ROI of the individual subject's brain, that is, N individual subjects are obtained thalamic partitioning of the brain in standard space;
A500,计算受试者个体脑部最终的丘脑ROI内每个体素对应的亚区概率值,并去掉最大的亚区概率值低于第一阈值的体素点,然后将剩余的体素点构建群组水平的丘脑概率图谱,即群组丘脑概率图谱;所述亚区概率值为各亚区的受试者人数与总受试者人数的比值。A500, calculate the sub-region probability value corresponding to each voxel in the final thalamus ROI of the individual brain of the subject, remove the voxel points with the largest sub-region probability value lower than the first threshold, and then construct the remaining voxel points The thalamic probability map at the group level is the group thalamic probability map; the sub-region probability value is the ratio of the number of subjects in each sub-region to the total number of subjects.
在一些优选的实施方式中,对所述输入图像依次进行HCP最小预处理、ROI配准、ROI后处理,得到受试者个体脑部最终的丘脑ROI,其方法为:In some preferred embodiments, the input image is sequentially subjected to HCP minimum pre-processing, ROI registration, and ROI post-processing to obtain the final thalamus ROI of the subject's individual brain. The method is:
对受试者个体脑部的结构核磁共振图像、弥散张量核磁共振图像进行HCP最小预处理,得到预处理的结构核磁共振图像、预处理的弥散张量核磁共振图像;Perform HCP minimal preprocessing on the structural MRI images and diffusion tensor MRI images of the subject's individual brain to obtain preprocessed structural MRI images and preprocessed diffusion tensor MRI images;
基于所述预处理的结构核磁共振图像、所述预处理的弥散张量核磁共振图像,通过ROI配准方法将弥散磁共振空间与结构磁共振空间、结构磁共振空间和标准空间之间进行配准,得到个体的丘脑ROI;Based on the preprocessed structural magnetic resonance image and the preprocessed diffusion tensor nuclear magnetic resonance image, the diffusion magnetic resonance space and the structural magnetic resonance space, the structural magnetic resonance space and the standard space are aligned through the ROI registration method. Accurately, obtain individual thalamus ROI;
在受试者个体脑部的弥散磁共振空间使用FSL计算每个体素点对应的各向异性分数值;Use FSL to calculate the anisotropy fraction corresponding to each voxel point in the diffusion magnetic resonance space of the subject's individual brain;
在受试者个体脑部的结构磁共振空间使用SPM计算每个体素点对应的脑脊液概率值;Use SPM to calculate the cerebrospinal fluid probability value corresponding to each voxel point in the structural magnetic resonance space of the subject's individual brain;
在个体的丘脑ROI中去除掉各向异性分数值大于设定各向异性分数阈值或脑脊液概率值大于设定脑脊液概率阈值的体素点,将剩余的体素点作为最终的个体丘脑ROI。In the individual thalamus ROI, voxel points whose anisotropy fraction value is greater than the set anisotropy fraction threshold or whose cerebrospinal fluid probability value is greater than the set cerebrospinal fluid probability threshold are removed, and the remaining voxel points are used as the final individual thalamus ROI.
在一些优选的实施方式中,所述受试者个体脑部最终的丘脑ROI内每个体素的局部弥散特征,其获取方法为:In some preferred embodiments, the local diffusion characteristics of each voxel in the final thalamic ROI of the subject's individual brain are obtained by:
在受试者个体脑部最终的丘脑ROI内的弥散磁共振空间中,使用dhollander算法在弥散磁共振数据上计算不同弥散加权因子b值参数下大脑组织的响应函数;结合所述大脑组织的响应函数,使用多组织多球壳限制性球面反卷积方法计算8阶球面调和函数的45维系数,量化每个体素的局部弥散特征。In the diffusion magnetic resonance space within the final thalamic ROI of the subject's individual brain, use the dhollander algorithm to calculate the response function of the brain tissue under different diffusion weighting factor b value parameters on the diffusion magnetic resonance data; combine the response of the brain tissue function, using the multi-tissue multi-spherical shell restricted spherical deconvolution method to calculate the 45-dimensional coefficients of the 8th order spherical harmonic function to quantify the local diffusion characteristics of each voxel.
在一些优选的实施方式中,计算体素之间的相似度,其方法为:In some preferred implementations, the similarity between voxels is calculated as follows:
其中,S(i,j)表示两个体素之间的相似度,E
pos(i,j)表示两个体素在弥散磁共振空间中的3维坐标之间的欧式距离,E
odf(i,j)表示两个体素的45维球面调和函数的采样系数之间的欧式距离,w
pos和w
odf分别表示E
pos(i,j)、E
odf(i,j)在计算相似度时的对应加权系数。
Among them, S(i,j) represents the similarity between two voxels, E pos (i, j) represents the Euclidean distance between the three-dimensional coordinates of two voxels in the diffusion magnetic resonance space, E odf (i, j) represents the Euclidean distance between the sampling coefficients of the 45-dimensional spherical harmonic function of two voxels, w pos and w odf respectively represent the correspondence of E pos (i, j) and E odf (i, j) when calculating similarity. Weighting coefficient.
在一些优选的实施方式中,所述受试者个体脑部最终的丘脑ROI内体素的聚类结果,其获取方法为:In some preferred embodiments, the clustering results of voxels in the final thalamic ROI of the subject's individual brain are obtained by:
通过谱聚类方法对受试者个体脑部最终的丘脑ROI内每个体素的局部弥散特征以及体素之间的相似度进行降维;The spectral clustering method is used to reduce the dimensionality of the local diffusion characteristics of each voxel in the final thalamic ROI of the subject's individual brain and the similarity between voxels;
基于降维后的局部弥散特征以及体素之间的相似度,使用K-means聚类将各体素聚为K类,作为受试者个体脑部最终的丘脑ROI内体素的聚类结果。Based on the local diffusion characteristics after dimensionality reduction and the similarity between voxels, K-means clustering is used to cluster each voxel into K categories, which is used as the clustering result of the voxels in the final thalamus ROI of the subject's individual brain. .
在一些优选的实施方式中,所述受试者个体脑部最终的丘脑ROI内每个体素对应的亚区标签,其获取方法为:In some preferred embodiments, the sub-region label corresponding to each voxel in the final thalamus ROI of the subject's individual brain is obtained by:
计算每个体素点在N个受试者上的N维标签向量,然后对受试者个体脑部最终的丘脑ROI内的所有体素点按照其标签向量的相似度进行聚类,聚类结果作为分区标签;Calculate the N-dimensional label vector of each voxel point on N subjects, and then cluster all voxel points in the final thalamus ROI of the subject's individual brain according to the similarity of their label vectors, and the clustering results as partition label;
基于所述分区标签,按照空间最大重叠的方法将每个受试者个体脑部最终的丘脑ROI内体素的聚类结果进行重新标记,从而得到受试者个体脑部最终的丘脑ROI内每个体素对应的亚区标签;Based on the partition labels, the clustering results of the voxels in the final thalamic ROI of each subject's individual brain are relabeled according to the spatial maximum overlap method, thereby obtaining the final thalamic ROI of each subject's individual brain. The subregion label corresponding to the voxel;
其中,计算每个体素点在N个受试者上的N维标签向量,即提取每个受试者在该体素点上对应的亚区标签,对N个受试者分别提取一个亚区标签,组成N维标签向量。Among them, the N-dimensional label vector of each voxel point on N subjects is calculated, that is, the sub-region label corresponding to the voxel point of each subject is extracted, and one sub-region is extracted for each N subjects. labels, forming an N-dimensional label vector.
在一些优选的实施方式中,所述个体化分类模型,其训练方法为:In some preferred embodiments, the training method of the individualized classification model is:
通过S100-S400的方法,获取个体特征,并将个体特征输入预构建的个体化分类模型,得到每个未定义区域内的体素的预测概率值向量;Through the methods of S100-S400, obtain individual features and input the individual features into the pre-built individualized classification model to obtain the predicted probability value vector of voxels in each undefined area;
基于所述预测概率值向量,结合群组先验图谱对应的亚区类别,通过均方误差损失函数得到损失值,更新个体化分类模型的模型参数;Based on the predicted probability value vector, combined with the sub-region category corresponding to the group prior map, the loss value is obtained through the mean square error loss function, and the model parameters of the individualized classification model are updated;
循环上述步骤,直至得到训练好的个体化分类模型。Repeat the above steps until the trained individualized classification model is obtained.
本发明的第二方面,提出了一种群组先验引导的基于深度学习的丘脑个体化图谱绘制系统,包括:丘脑ROI获取模块、群组先验图谱获取模块、剔除处理模块、个体化分类模块、个体化图谱生成模块;The second aspect of the present invention proposes a group prior guided thalamic individualized map drawing system based on deep learning, including: a thalamic ROI acquisition module, a group prior map acquisition module, a elimination processing module, and an individualized classification Modules, personalized map generation modules;
所述丘脑ROI获取模块,配置为获取在第一阈值下的群组丘脑概率图谱并进行二值化,得到群组丘脑概率图谱的掩膜,作为第一掩膜;将所述第一掩膜配准到受试者个体脑部的弥散磁共振空间,得到受试者个体脑部的丘脑ROI;The thalamic ROI acquisition module is configured to acquire the group thalamic probability map under a first threshold and perform binarization to obtain a mask of the group thalamic probability map as the first mask; convert the first mask Register to the diffusion magnetic resonance space of the subject's individual brain to obtain the thalamus ROI of the subject's individual brain;
所述群组先验图谱获取模块,配置为获取在第二阈值下的群组丘脑概率图谱,并配准到受试者个体脑部的弥散磁共振空间,得到受试者个体脑部的群组先验图谱;The group prior map acquisition module is configured to obtain the group thalamic probability map under the second threshold, and register it to the diffusion magnetic resonance space of the subject's individual brain to obtain the group's individual brain. Group prior map;
所述剔除处理模块,配置为在受试者个体脑部的弥散磁共振空间中,剔除所述丘脑ROI中的群组先验图谱,得到未定义的丘脑区域的掩膜,作为第二掩膜;The elimination processing module is configured to eliminate the group prior map in the thalamus ROI in the diffusion magnetic resonance space of the subject's individual brain, and obtain a mask of the undefined thalamus region as the second mask. ;
所述个体化分类模块,配置为结合所述第二掩膜,计算所述群组先验图谱中每个体素的45维球面调和函数的系数和3维弥散磁共振空间的位置坐标,将两者合并为一个48维的特征向量,作为个体特征;将所述个体特征输入预构建的个体化分类模型,得到每个未定义区域内的体素的预测概率值向量,并将预测概率值向量对应的最大的亚区标签 作为体素的最终亚区标签,进而生成未定义区域的图谱;所述个体化分类模型基于深度学习神经网络构建;The individualized classification module is configured to calculate the coefficients of the 45-dimensional spherical harmonic function and the position coordinates of the 3-dimensional diffusion magnetic resonance space of each voxel in the group prior map in combination with the second mask, and combine the two or merged into a 48-dimensional feature vector as individual features; input the individual features into the pre-built individualized classification model to obtain the predicted probability value vector of voxels in each undefined area, and add the predicted probability value vector to The corresponding largest sub-region label is used as the final sub-region label of the voxel, and then a map of the undefined area is generated; the individualized classification model is built based on a deep learning neural network;
所述个体化图谱生成模块,配置为将所述群组先验图谱和所述未定义区域的图谱进行合并,生成受试者个体化的丘脑图谱;The individualized map generation module is configured to merge the group prior map and the map of the undefined area to generate a subject's individualized thalamic map;
其中,所述群组丘脑概率图谱其构建方法为:Wherein, the construction method of the group thalamic probability map is:
A100,获取N个受试者个体脑部的结构核磁共振图像、弥散张量核磁共振图像,作为输入图像;N为正整数;A100, obtain the structural MRI images and diffusion tensor MRI images of the individual brains of N subjects as input images; N is a positive integer;
A200,对所述输入图像依次进行HCP最小预处理、ROI配准、ROI后处理,得到受试者个体脑部最终的丘脑ROI,并通过ODF估计算法,得到受试者个体脑部最终的丘脑ROI内每个体素的局部弥散特征;A200, sequentially perform HCP minimum preprocessing, ROI registration, and ROI postprocessing on the input image to obtain the final thalamus ROI of the subject's individual brain, and obtain the final thalamus ROI of the subject's individual brain through the ODF estimation algorithm. Local diffusion characteristics of each voxel within the ROI;
A300,结合A200获取的局部弥散特征,计算体素之间的相似度,并进行聚类,得到受试者个体脑部最终的丘脑ROI内体素的聚类结果;A300, combined with the local diffusion characteristics obtained by A200, calculates the similarity between voxels and performs clustering to obtain the clustering results of voxels within the final thalamic ROI of the subject's individual brain;
A400,将A300获取的聚类结果配准至标准空间,并进行标签重映射,得到受试者个体脑部最终的丘脑ROI内每个体素对应的亚区标签,即得到N个受试者个体脑部在标准空间中的丘脑分区;A400, register the clustering results obtained by A300 to the standard space, and perform label remapping to obtain the sub-region label corresponding to each voxel in the final thalamus ROI of the individual subject's brain, that is, N individual subjects are obtained thalamic partitioning of the brain in standard space;
A500,计算受试者个体脑部最终的丘脑ROI内每个体素对应的亚区概率值,并去掉最大的亚区概率值低于第一阈值的体素点,然后将剩余的体素点构建群组水平的丘脑概率图谱,即群组丘脑概率图谱;所述亚区概率值为各亚区的受试者人数与总受试者人数的比值。A500, calculate the sub-region probability value corresponding to each voxel in the final thalamus ROI of the individual brain of the subject, remove the voxel points with the largest sub-region probability value lower than the first threshold, and then construct the remaining voxel points The thalamic probability map at the group level is the group thalamic probability map; the sub-region probability value is the ratio of the number of subjects in each sub-region to the total number of subjects.
本发明的第三方面,提出了一种电子设备,包括:至少一个处理器;以及与至少一个所述处理器通信连接的存储器;其中,所述存储器存储有可被所述处理器执行的指令,所述指令用于被所述处理器执行以实现上述的群组先验引导的基于深度学习的丘脑个体化图谱绘制方法。A third aspect of the present invention provides an electronic device, including: at least one processor; and a memory communicatively connected to at least one of the processors; wherein the memory stores instructions that can be executed by the processor. , the instructions are configured to be executed by the processor to implement the above-mentioned group prior guided deep learning-based individualized map drawing method of the thalamus.
本发明的第四方面,提出了一种计算机可读存储介质,所述计算机可读存储介质存储有计算机指令,所述计算机指令用于被所述计算机执行以实现上述的群组先验引导的基于深度学习的丘脑个体化图谱绘制方法。A fourth aspect of the present invention provides a computer-readable storage medium that stores computer instructions, and the computer instructions are used to be executed by the computer to implement the above-mentioned group a priori guidance. A method for drawing individualized maps of the thalamus based on deep learning.
本发明的有益效果:Beneficial effects of the present invention:
本发明利用高可信度群组先验引导个体化丘脑分区以及图谱绘制,提升了绘制的个体化的丘脑图谱的准确性、鲁棒性以及可重复性。The present invention uses high-confidence group a priori to guide individualized thalamic partitioning and map drawing, thereby improving the accuracy, robustness and repeatability of the drawn individualized thalamic map.
1)本发明基于高可信度组水平丘脑图谱和单个被试的数据绘制个体化丘脑图谱,既融合了丘脑分区模式的群组一致性,又体现出个体分区模式的特异性。使用被试内分区模式一致性指标来量化该个体化丘脑图谱的分区准确性时,结果表明该方法在HCP-3T和HCP-7T数据上比单个被试聚类和群组图谱配准有更高的分区准确度。使用Test-retest数据测试该个体化方法进行可重复性测试时,结果表明该方法在Test-retest数据上有较高的扫描间分区模式一致性。使用7和12作为丘脑的分区数量进行可重复测试时,结果表明该方法在不同亚区数目上均有较强的鲁棒性,且在更精细的12个亚区数量上有更高的分区准确性。1) The present invention draws an individualized thalamic atlas based on high-confidence group-level thalamic atlas and single subject data, which not only integrates the group consistency of the thalamic partitioning pattern, but also reflects the specificity of the individual partitioning pattern. When using the within-subject partitioning pattern consistency index to quantify the partitioning accuracy of this individualized thalamic atlas, the results show that this method is more effective than single-subject clustering and group atlas registration on the HCP-3T and HCP-7T data. High partitioning accuracy. When testing the reproducibility of this individualized method using Test-retest data, the results show that this method has high inter-scan partitioning pattern consistency on Test-retest data. When reproducibly tested using 7 and 12 as the number of subregions of the thalamus, the results show that the method is robust to different numbers of subregions, and has higher partitioning at the finer number of 12 subregions. accuracy.
2)本发明基于高阶弥散特征和空间位置对丘脑进行群组水平的分区,发现了更加精细的丘脑分区模式;而且在更精细的丘脑图谱上表现出更高的被试内分区一致性,能支持更细粒度的个体化丘脑图谱的绘制;在不同的磁场扫描强度下具有鲁棒性,且更高的磁场扫描强度能提供更高的被试内分区一致性增益;在同一被试的不同扫描批次下具有可重复性。2) The present invention partitions the thalamus at the group level based on high-order diffusion characteristics and spatial location, and discovers a more refined thalamic partitioning pattern; and shows higher intra-subject partitioning consistency on the more refined thalamic atlas, It can support the drawing of more fine-grained individualized thalamic maps; it is robust under different magnetic field scanning intensities, and higher magnetic field scanning intensities can provide higher intra-subject partition consistency gains; in the same subject's Repeatability across different scan batches.
通过阅读参照以下附图所做的对非限制性实施例所做的详细描述,本申请的其他特征、目的和优点将会变得更明显。Other features, objects and advantages of the present application will become more apparent upon reading the detailed description of non-limiting embodiments taken with reference to the following drawings.
图1是本发明一种实施例的群组先验引导的基于深度学习的丘脑个体化图谱绘制方法的流程示意图;Figure 1 is a schematic flowchart of a method for drawing an individualized map of the thalamus based on deep learning guided by group priori according to an embodiment of the present invention;
图2是本发明一种实施例的群组先验引导的基于深度学习的丘脑个体化图谱绘制系统的框架示意图;Figure 2 is a schematic framework diagram of a group prior-guided deep learning-based individualized map drawing system for the thalamus according to an embodiment of the present invention;
图3是本发明一种实施例的受试者个体脑部最终的丘脑ROI获取过程的流程示意图;Figure 3 is a schematic flow chart of the final thalamic ROI acquisition process of an individual subject's brain according to an embodiment of the present invention;
图4是本发明一种实施例的ODF估计的流程示意图;Figure 4 is a schematic flow chart of ODF estimation according to an embodiment of the present invention;
图5是本发明一种实施例的群组丘脑概率图谱的构建流程示意图;Figure 5 is a schematic flowchart of the construction process of a group thalamic probability map according to an embodiment of the present invention;
图6是本发明一种实施例的个体化丘脑图谱的构建流程示意图。Figure 6 is a schematic flowchart of the construction process of a personalized thalamic map according to an embodiment of the present invention.
为使本发明的目的、技术方案和优点更加清楚,下面将结合附图对本发明实施例中的技术方案进行清楚、完整地描述,显然,所描述的实施例是本发明一部分实施例,而不是全部的实施例。基于本发明中的实施例,本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例,都属于本发明保护的范围。In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not All examples. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.
下面结合附图和实施例对本申请作进一步的详细说明。可以理解的是,此处所描述的具体实施例仅用于解释相关发明,而非对该发明的限定。另外还需要说明的是,为了便于描述,附图中仅示出了与有关发明相关的部分。The present application will be further described in detail below in conjunction with the accompanying drawings and examples. It can be understood that the specific embodiments described here are only used to explain the relevant invention, but not to limit the invention. It should also be noted that, for convenience of description, only the parts related to the invention are shown in the drawings.
需要说明的是,在不冲突的情况下,本申请中的实施例及实施例中的特征可以相互组合。It should be noted that, as long as there is no conflict, the embodiments and features in the embodiments of this application can be combined with each other.
本发明的群组先验引导的基于深度学习的丘脑个体化图谱绘制方法,如图1所示,包括以下步骤:The group prior-guided deep learning-based personalized map drawing method of the thalamus of the present invention, as shown in Figure 1, includes the following steps:
S100,获取在第一阈值下的群组丘脑概率图谱并进行二值化,得到群组丘脑概率图谱的掩膜,作为第一掩膜;将所述第一掩膜配准到受试者个体脑部的弥散磁共振空间,得到受试者个体脑部的丘脑ROI;S100, obtain the group thalamic probability map under the first threshold and perform binarization to obtain the mask of the group thalamic probability map as the first mask; register the first mask to the individual subject The diffusion magnetic resonance space of the brain is used to obtain the thalamus ROI of the subject's individual brain;
S200,获取在第二阈值下的群组丘脑概率图谱,并配准到受试者个体脑部的弥散磁共振空间,得到受试者个体脑部的群组先验图谱;S200, obtain the group thalamic probability map under the second threshold, and register it to the diffusion magnetic resonance space of the subject's individual brain to obtain the group prior map of the subject's individual brain;
S300,在受试者个体脑部的弥散磁共振空间中,剔除所述丘脑ROI中的群组先验图谱,得到未定义的丘脑区域的掩膜,作为第二掩膜;S300, in the diffusion magnetic resonance space of the subject's individual brain, eliminate the group prior map in the thalamus ROI and obtain a mask of the undefined thalamus area as the second mask;
S400,结合所述第二掩膜,计算所述群组先验图谱中每个体素的45维球面调和函数的系数和3维弥散磁共振空间的位置坐标,将两者合并为一个48维的特征向量,作为个体特征;将所述个体特征输入预构建的个体化分类模型,得到每个未定义区域内的体素的预测概率值向量,并将预测概率值向量对应的最大的亚区标签作为体素的最终亚区标签,进而生成未定义区域的图谱;所述个体化分类模型基于深度学习神经网络构建;S400, combined with the second mask, calculate the coefficients of the 45-dimensional spherical harmonic function and the position coordinates of the 3-dimensional diffusion magnetic resonance space of each voxel in the group prior map, and merge the two into a 48-dimensional Feature vector, as an individual feature; input the individual features into the pre-built individualized classification model to obtain the predicted probability value vector of the voxels in each undefined area, and assign the largest sub-region label corresponding to the predicted probability value vector As the final sub-region label of the voxel, a map of the undefined area is generated; the individualized classification model is built based on a deep learning neural network;
S500,将所述群组先验图谱和所述未定义区域的图谱进行合并,生成受试者个体化的丘脑图谱;S500, merge the group prior map and the map of the undefined area to generate a subject's individualized thalamus map;
其中,所述群组丘脑概率图谱其构建方法为:Wherein, the construction method of the group thalamic probability map is:
A100,获取N个受试者个体脑部的结构核磁共振图像、弥散张量核磁共振图像,作为输入图像;N为正整数;A100, obtain the structural MRI images and diffusion tensor MRI images of the individual brains of N subjects as input images; N is a positive integer;
A200,对所述输入图像依次进行HCP最小预处理、ROI配准、ROI后处理,得到受试者个体脑部最终的丘脑ROI,并通过ODF估计算法,得到受试者个体脑部最终的丘脑ROI内每个体素的局部弥散特征;A200, sequentially perform HCP minimum preprocessing, ROI registration, and ROI postprocessing on the input image to obtain the final thalamus ROI of the subject's individual brain, and obtain the final thalamus ROI of the subject's individual brain through the ODF estimation algorithm. Local diffusion characteristics of each voxel within the ROI;
A300,结合A200获取的局部弥散特征,计算体素之间的相似度,并进行聚类,得到受试者个体脑部最终的丘脑ROI内体素的聚类结果;A300, combined with the local diffusion characteristics obtained by A200, calculates the similarity between voxels and performs clustering to obtain the clustering results of voxels within the final thalamic ROI of the subject's individual brain;
A400,将A300获取的聚类结果配准至标准空间,并进行标签重映射,得到受试者个体脑部最终的丘脑ROI内每个体素对应的亚区标签,即得到N个受试者个体脑部在标准空间中的丘脑分区;A400, register the clustering results obtained by A300 to the standard space, and perform label remapping to obtain the sub-region label corresponding to each voxel in the final thalamus ROI of the individual subject's brain, that is, N individual subjects are obtained thalamic partitioning of the brain in standard space;
A500,计算受试者个体脑部最终的丘脑ROI内每个体素对应的亚区概率值,并去掉最大的亚区概率值低于第一阈值的体素点,然后将剩余的体素点构建群组水平的丘脑概率图谱,即群组丘脑概率图谱;所述亚区概率值为各亚区的受试者人数与总受试者人数的比值。A500, calculate the sub-region probability value corresponding to each voxel in the final thalamus ROI of the individual brain of the subject, remove the voxel points with the largest sub-region probability value lower than the first threshold, and then construct the remaining voxel points The thalamic probability map at the group level is the group thalamic probability map; the sub-region probability value is the ratio of the number of subjects in each sub-region to the total number of subjects.
为了更清晰地对本发明群组先验引导的基于深度学习的丘脑个体化图谱绘制方法进行说明,下面结合附图对本发明方法一种实施例中各步骤进行展开详述。In order to more clearly explain the group a priori-guided deep learning-based personalized map drawing method of the thalamus of the present invention, each step in one embodiment of the method of the present invention will be described in detail below with reference to the accompanying drawings.
本发明所阐述的群组先验引导的基于深度学习的丘脑个体化图谱绘制方法分为两个主要步骤:丘脑群组概率图谱的构建和丘脑个体化图谱的构建。在丘脑群组概率图谱构建阶段,首先基于一组高质量数据,在弥散磁共振成像中提取丘脑感兴趣区域(Region of Interest,ROI)内的每个体素的方向分布函数和个体弥散磁共振空间坐标,以此作为特征构建体素之间的相似度矩阵,利用谱聚类算法初步绘制个体的初始分区,并将其配准到MNI标准空间来建立群组水平的丘脑概率图谱和最大概率图谱。在个体化图谱绘制阶段,将丘脑的组水平高概率值的图谱区域视为群组先验,将其配准至个体弥散磁共振空间作为个体图谱的高可信度组先验,同时将最大概率图谱的模板配准至个体弥散磁共振空间作为个体丘脑图谱的ROI。接下来,在个体弥散磁共振数据上通过多球壳多组织限制球面反卷积(Multi-Shell Multi-Tissue Constrained Spherical Deconvolution,MSMT-CSD)提取ROI内的8阶球面调和函数的45维系 数作为ODF特征,同时计算3维个体弥散磁共振空间坐标作为空间位置特征,从而为每个ROI内的体素构建出48维个体特征。以ROI内体素的亚区类别作为标签,将组先验图谱作为训练数据,ROI内未标记区域作为测试数据,基于深度学习的方法构建个体化分类模型。最后,将高可信度组先验图谱和预测的未标记图谱结合,从而生成个体化的丘脑图谱。The group prior guided deep learning-based individualized map drawing method of the thalamus described in the present invention is divided into two main steps: the construction of the group probability map of the thalamus and the construction of the individualized thalamus map. In the construction stage of the thalamic group probability map, first based on a set of high-quality data, the direction distribution function and individual diffusion magnetic resonance space of each voxel in the thalamic region of interest (Region of Interest, ROI) are extracted in diffusion magnetic resonance imaging. coordinates, using this as a feature to construct a similarity matrix between voxels, using the spectral clustering algorithm to initially draw the initial partition of the individual, and register it to the MNI standard space to establish a group-level thalamic probability map and maximum probability map . In the individualized map drawing stage, map areas with high probability values at the group level of the thalamus are regarded as group priors, and are registered to the individual diffusion magnetic resonance space as high-confidence group priors for individual maps. At the same time, the maximum The template of the probability map was registered to the individual diffusion magnetic resonance space as the ROI of the individual thalamic map. Next, on the individual diffusion magnetic resonance data, the 45-dimensional coefficients of the 8th order spherical harmonic function in the ROI are extracted through Multi-Shell Multi-Tissue Constrained Spherical Deconvolution (MSMT-CSD) as ODF features, while calculating 3-dimensional individual diffusion magnetic resonance spatial coordinates as spatial position features, thereby constructing 48-dimensional individual features for voxels in each ROI. Using the sub-region categories of voxels within the ROI as labels, the group prior map as training data, and the unlabeled areas within the ROI as test data, an individualized classification model is constructed based on deep learning methods. Finally, the high-confidence group prior map and the predicted unlabeled map are combined to generate an individualized thalamic map.
在下述实施例中,先对群组丘脑概率图谱的构建过程进行详述,再对基于一种群组先验引导的基于深度学习的丘脑个体化图谱绘制方法进行个体化图谱生成的过程进行详述。In the following embodiments, the construction process of the group thalamic probability map is first described in detail, and then the process of generating the individualized map based on a group prior-guided deep learning-based individualized map drawing method of the thalamus is described in detail. narrate.
1、群组丘脑概率图谱的构建过程1. Construction process of group thalamic probability map
A100,获取N个受试者个体脑部的结构核磁共振图像、弥散张量核磁共振图像,作为输入图像;N为正整数;A100, obtain the structural MRI images and diffusion tensor MRI images of the individual brains of N subjects as input images; N is a positive integer;
在本实施例中,先获取一组(即N个)受试者个体脑部的结构核磁共振图像、弥散张量核磁共振图像。In this embodiment, a group (that is, N) structural MRI images and diffusion tensor MRI images of the brains of individual subjects are first obtained.
A200,对所述输入图像依次进行HCP最小预处理、ROI配准、ROI后处理,得到受试者个体脑部最终的丘脑ROI,并通过ODF估计算法,得到受试者个体脑部最终的丘脑ROI内每个体素的局部弥散特征;A200, sequentially perform HCP minimum preprocessing, ROI registration, and ROI postprocessing on the input image to obtain the final thalamus ROI of the subject's individual brain, and obtain the final thalamus ROI of the subject's individual brain through the ODF estimation algorithm. Local diffusion characteristics of each voxel within the ROI;
在本实施例中,先使用HCP数据的最小预处理(即HCP最小预处理)对结构核磁共振图像(T1)和弥散张量核磁共振图像(Diffusion Weighted Imaging,DWI)数据分别进行最小预处理,得到预处理的结构核磁共振图像、预处理的弥散张量核磁共振图像。In this embodiment, minimum preprocessing of HCP data (i.e., HCP minimum preprocessing) is first used to perform minimum preprocessing on the structural NMR image (T1) and diffusion tensor NMR image (Diffusion Weighted Imaging, DWI) data respectively. The preprocessed structural NMR image and the preprocessed diffusion tensor NMR image are obtained.
基于所述预处理的结构核磁共振图像、所述预处理的弥散张量核磁共振图像,在FMRIB's Software Library(FSL)中,将受试者个体脑部的弥散磁共振空间(B0,简称弥散空间,如图3所示)与结构磁共振空间(T1,简称为结构空间,如图3所示)进行线性配准,将结构磁共振空间(T1)和标准空间(Montreal Neurological Institute,MNI)进行非线性配准,然后结合这两次配准矩阵生成受试者个体脑部的弥散磁共振空 间(B0)到标准空间(MNI)的配准矩阵并进行转置,得到标准空间到个体弥散空间的配准矩阵。基于该配准矩阵,将经典的Morel丘脑图谱配准至个体弥散磁共振空间,将其作为个体的丘脑ROI。如图3中的(a)所示。Based on the preprocessed structural MRI image and the preprocessed diffusion tensor MRI image, in FMRIB's Software Library (FSL), the diffusion magnetic resonance space (B0, referred to as diffusion space) of the subject's individual brain is , as shown in Figure 3) and the structural magnetic resonance space (T1, referred to as the structural space, as shown in Figure 3) are linearly registered, and the structural magnetic resonance space (T1) and the standard space (Montreal Neurological Institute, MNI) are Nonlinear registration, and then combine the two registration matrices to generate a registration matrix from the diffusion magnetic resonance space (B0) of the subject's individual brain to the standard space (MNI) and transpose it to obtain the standard space to the individual diffusion space. registration matrix. Based on this registration matrix, the classic Morel thalamic atlas was registered to the individual diffusion magnetic resonance space, which was used as the individual thalamic ROI. As shown in (a) in Figure 3.
然后,进行ROI后处理,如图3中的(b)所示:具体为:在受试者个体脑部的弥散磁共振空间使用FSL计算FA图(即每个体素点对应的各向异性分数值);在受试者个体脑部的结构磁共振空间使用SPM计算CSF概率图(即每个体素点对应的脑脊液概率值);在个体的丘脑ROI中去除掉各向异性分数(FA,Fractional Anisotropy)值大于设定各向异性分数FA阈值(本发明优选设置为0.6)或脑脊液(CSF,Cerebrospinal Fluid)概率值大于设定脑脊液概率阈值(本发明优选设置为0.05)的体素点,将剩余的体素点作为最终的个体丘脑ROI(即图3中的个体弥散空间中的ROI)。Then, ROI post-processing is performed, as shown in (b) in Figure 3: specifically: using FSL to calculate the FA map (i.e., the anisotropy distribution corresponding to each voxel point) in the diffusion magnetic resonance space of the individual brain of the subject. value); use SPM to calculate the CSF probability map (that is, the cerebrospinal fluid probability value corresponding to each voxel point) in the structural magnetic resonance space of the individual brain of the subject; remove the anisotropy fraction (FA, Fractional) in the individual thalamus ROI Anisotropy) value is greater than the set anisotropy fraction FA threshold (the present invention is preferably set to 0.6) or the cerebrospinal fluid (CSF, Cerebrospinal Fluid) probability value is greater than the set cerebrospinal fluid probability threshold (the present invention is preferably set to 0.05) voxel points, the The remaining voxel points serve as the final individual thalamic ROI (i.e., the ROI in the individual diffusion space in Figure 3).
最后进行ODF估计,如图4所示:具体为:在MRtrix3中,使用dhollander算法在弥散磁共振数据上先计算不同弥散加权因子b值参数下大脑组织的响应函数,然后结合所述大脑组织的响应函数,使用多组织多球壳限制性球面反卷积方法(即图4中简写的多组织多球壳限制性反卷积)计算8阶球面调和函数的45维系数(即图4中的球谐系数矩阵),来表示丘脑内每个体素的局部弥散特征(即取8阶球面调和函数作为采样基,计算丘脑ROI内每个体素的45维球面调和函数系数构建其ODF模型,从而得到丘脑ROI内球面调和函数系数矩阵)。Finally, ODF estimation is performed, as shown in Figure 4: specifically: in MRtrix3, the dhollander algorithm is used to first calculate the response function of the brain tissue under different diffusion weighting factor b value parameters on the diffusion magnetic resonance data, and then combine the response functions of the brain tissue The response function uses the multi-tissue multi-spherical shell restricted spherical deconvolution method (i.e., the abbreviated multi-tissue multi-spherical shell restricted deconvolution in Figure 4) to calculate the 45-dimensional coefficients of the 8th order spherical harmonic function (i.e., the multi-tissue multi-spherical shell restricted deconvolution in Figure 4). Spherical harmonic coefficient matrix) to represent the local diffusion characteristics of each voxel in the thalamus (that is, taking the 8th order spherical harmonic function as the sampling base, calculating the 45-dimensional spherical harmonic function coefficient of each voxel in the thalamus ROI to construct its ODF model, thus obtaining Spherical harmonic function coefficient matrix within the thalamus ROI).
A300,结合A200获取的局部弥散特征,计算体素之间的相似度,并进行聚类,得到受试者个体脑部最终的丘脑ROI内体素的聚类结果;A300, combined with the local diffusion characteristics obtained by A200, calculates the similarity between voxels and performs clustering to obtain the clustering results of voxels within the final thalamic ROI of the subject's individual brain;
在本实施例中,先结合体素的弥散特征和空间位置特征计算体素之间的相似度,构建相似度矩阵。体素之间的相似度具体计算方法如公式(1)所示:In this embodiment, the similarity between voxels is first calculated based on the diffusion characteristics and spatial position characteristics of the voxels, and a similarity matrix is constructed. The specific calculation method of the similarity between voxels is as shown in formula (1):
其中,S(i,j)表示两个体素之间的相似度,E
pos(i,j)表示两个体素在弥散磁共振空间中的3维坐标之间的欧式距离,E
odf(i,j)表示两个体素的45维球面调和函数的采样系数之间的欧式距离,w
pos和w
odf分别表示E
pos(i,j)、E
odf(i,j)在计算相似度时的对应加权系数。在本发明中,w
pos和w
odf优选设置为0.5。另外,为了平衡聚类过程中的距离偏差,对45维球面调和函数系数乘以一个放缩因子后再计算ODF之间的欧式距离,该放缩因子为89(3T数据)和98(7T数据)。其中,图5中的(Indi1……Indi100,表示本发明优选的100个被试者对应的丘脑ROI)
Among them, S(i,j) represents the similarity between two voxels, E pos (i, j) represents the Euclidean distance between the three-dimensional coordinates of two voxels in the diffusion magnetic resonance space, E odf (i, j) represents the Euclidean distance between the sampling coefficients of the 45-dimensional spherical harmonic function of two voxels, w pos and w odf respectively represent the correspondence of E pos (i, j) and E odf (i, j) when calculating similarity. Weighting coefficient. In the present invention, w pos and w odf are preferably set to 0.5. In addition, in order to balance the distance bias in the clustering process, the 45-dimensional spherical harmonic function coefficient is multiplied by a scaling factor and then the Euclidean distance between ODFs is calculated. The scaling factor is 89 (3T data) and 98 (7T data). ). Among them, (Indi1...Indi100 in Figure 5 represents the thalamic ROI corresponding to the 100 subjects preferred by the present invention)
然后,进行聚类,具体为:通过谱聚类方法对受试者个体脑部最终的丘脑ROI内每个体素的局部弥散特征以及体素之间的相似度进行降维;基于降维后的局部弥散特征以及体素之间的相似度,使用K-means聚类将各体素聚为K类,作为受试者个体脑部最终的丘脑ROI内体素的聚类结果。在本发明中,为了测试最优的丘脑分区数目,K的取值为2到28。Then, clustering is performed, specifically: using the spectral clustering method to reduce the dimensionality of the local diffusion characteristics of each voxel in the final thalamic ROI of the subject's individual brain and the similarity between voxels; based on the dimensionality reduction Based on the local diffusion characteristics and the similarity between voxels, K-means clustering is used to cluster each voxel into K categories, which is used as the clustering result of the voxels within the final thalamus ROI of the subject's individual brain. In the present invention, in order to test the optimal number of thalamic partitions, the value of K ranges from 2 to 28.
A400,将A300获取的聚类结果配准至标准空间,并进行标签重映射,得到受试者个体脑部最终的丘脑ROI内每个体素对应的亚区标签,即得到N个受试者个体脑部在标准空间中的丘脑分区;A400, register the clustering results obtained by A300 to the standard space, and perform label remapping to obtain the sub-region label corresponding to each voxel in the final thalamic ROI of the individual subject's brain, that is, N individual subjects are obtained thalamic partitioning of the brain in standard space;
在本实施例中,先进行标签重映射,具体为:In this embodiment, label remapping is performed first, specifically:
将受试者个体空间内的聚类结果配准至MNI空间后,受试者个体初始分区之间的亚区标签无法同一对应。标签重映射首先计算每个体素点在N(本发明中优选设置为N=100)个被试(即受试者)上的N维标签向量(即提取每个受试者在该体素点上对应的亚区标签,对N个受试者分别提取一个亚区标签,组成N维标签向量)。接下来,并对受试者个体脑部最终的丘脑ROI内的所有体素点按照其标签向量的相似度进行聚类,聚类结果为群组水平的分区标签。基于所述分区标签,按照 空间最大重叠的方法将每个被试的聚类结果进行重新标记,从而得到受试者个体脑部最终的丘脑ROI内每个体素对应的亚区标签,即得到N个受试者个体脑部在标准空间中的丘脑分区,从而得到个体间一致的标签。After registering the clustering results in the individual subject space to the MNI space, the sub-region labels between the initial partitions of the individual subject cannot correspond to the same. Label remapping first calculates the N-dimensional label vector of each voxel point on N (preferably set to N=100 in the present invention) subjects (i.e., subjects) (i.e., extracts the N-dimensional label vector of each subject at the voxel point). The corresponding sub-region labels are extracted from each of the N subjects to form an N-dimensional label vector). Next, all voxel points within the final thalamus ROI of the subject's individual brain are clustered according to the similarity of their label vectors, and the clustering result is a group-level partition label. Based on the partition labels, the clustering results of each subject are re-labeled according to the spatial maximum overlap method, so as to obtain the sub-region label corresponding to each voxel in the final thalamus ROI of the subject's individual brain, that is, N The thalamic partitions of the individual subject's brains in standard space are used to obtain consistent labels across individuals.
A500,计算受试者个体脑部最终的丘脑ROI内每个体素对应的亚区概率值,并去掉最大的亚区概率值低于第一阈值的体素点,然后将剩余的体素点构建群组水平的丘脑概率图谱,即群组丘脑概率图谱;所述亚区概率值为各亚区的受试者人数与总受试者人数的比值。A500, calculate the sub-region probability value corresponding to each voxel in the final thalamus ROI of the individual brain of the subject, remove the voxel points with the largest sub-region probability value lower than the first threshold, and then construct the remaining voxel points The thalamic probability map at the group level is the group thalamic probability map; the sub-region probability value is the ratio of the number of subjects in each sub-region to the total number of subjects.
在本实施例中,基于N个受试者个体的MNI空间中的丘脑分区,计算受试者个体脑部最终的丘脑ROI内每个体素的亚区概率值,即属于某一个亚区的受试者人数与总受试者人数的比值。计算完所有体素的亚区概率值后,取一定的阈值(0.25)并去掉最大的亚区概率值低于该阈值的体素点(即获取各体素点对应的最大的亚区概率,若最大的亚区概率低于设定的第一阈值,则去掉该体素点),基于剩余的体素点构建群组水平的丘脑概率图谱,即群组丘脑概率图谱,即图5中的群组图谱。将概率图谱二值化,得到群组概率图谱的ROI(mask)。按照赢家通吃的原则,将概率图谱内每个体素的亚区标签设置为最大概率值对应的标签,从而构建最大概率图谱。In this embodiment, based on the thalamic partitions in the MNI space of N subject individuals, the sub-region probability value of each voxel in the final thalamic ROI of the individual subject's brain is calculated, that is, the subject belonging to a certain sub-region is calculated. The ratio of the number of subjects to the total number of subjects. After calculating the sub-region probability values of all voxels, take a certain threshold (0.25) and remove the voxel points whose maximum sub-region probability value is lower than the threshold (that is, obtain the maximum sub-region probability corresponding to each voxel point, If the maximum sub-region probability is lower than the set first threshold, the voxel point is removed), and a group-level thalamic probability map is constructed based on the remaining voxel points, that is, the group thalamic probability map, that is, in Figure 5 Group map. Binarize the probability map to obtain the ROI (mask) of the group probability map. According to the winner-take-all principle, the sub-region label of each voxel in the probability map is set to the label corresponding to the maximum probability value, thereby constructing the maximum probability map.
另外,A500后还包括验证最优分区数:基于上述生成的最大概率图谱,计算个体和群组之间的分区一致性和大脑半球间的拓扑一致性,来确定最优的丘脑亚区数目。个体和群组之间的分区一致性使用个体分区和群组分区的重叠率Dice值进行验证。Dice值越接近1,表示个体和群体的分区一致性越高,此处的丘脑分区数目越符合丘脑内部的分区模式。基于留一法划分个体分区被试和群组分区被试集,计算在100次个体和群组分区一致性上的Dice平均值。大脑半球间拓扑一致性指标使用拓扑距离TpD(Topological Distance,TpD)在群组图谱上进行验证。TpD值越接近0,表示大脑左右半球间的同源程度越高,此处的丘脑分区 数目越符合丘脑内部的分区模式。拓扑距离首先计算单个半球内各亚区与其他亚区之间相邻的体素个数,并生成K×K维的矩阵。将该矩阵展开后,计算两个大脑半球间该矩阵的相似度,即分区内部的拓扑距离。In addition, post-A500 also includes verification of the optimal number of partitions: based on the maximum probability map generated above, calculate the partition consistency between individuals and groups and the topological consistency between cerebral hemispheres to determine the optimal number of thalamic sub-regions. The consistency of partitions between individuals and groups is verified using the overlap rate Dice value of individual partitions and group partitions. The closer the Dice value is to 1, the higher the consistency of partitioning between individuals and groups, and the more consistent the number of thalamic partitions here is with the internal partitioning pattern of the thalamus. Based on the leave-one-out method, the individual partitioned subjects and the group partitioned subject sets were divided, and the Dice average value of the consistency of individual and group partitions was calculated for 100 times. The topological consistency index between cerebral hemispheres is verified on the group map using topological distance TpD (Topological Distance, TpD). The closer the TpD value is to 0, the higher the degree of homology between the left and right hemispheres of the brain, and the number of thalamic divisions here is more consistent with the internal division pattern of the thalamus. Topological distance first calculates the number of adjacent voxels between each sub-region and other sub-regions in a single hemisphere, and generates a K×K-dimensional matrix. After unfolding this matrix, the similarity of this matrix between the two cerebral hemispheres is calculated, that is, the topological distance within the partition.
其中,群组最大概率图谱在验证时,Dice指标在聚类数目为7和12时出现局部极大值,且此两种聚类数目下TpD值基本为0,表示分区数目为7和12符合丘脑内部的分区模式。Among them, when the group maximum probability map is verified, the Dice indicator appears as a local maximum when the number of clusters is 7 and 12, and the TpD value under these two cluster numbers is basically 0, indicating that the number of partitions is 7 and 12. Partitioning patterns within the thalamus.
当丘脑分7个亚区时,该分区数目下,丘脑前核、腹前核、背内侧核、背外侧-后外侧核、外侧枕核、腹外侧-腹后侧核以及内侧枕核能完整的分割出来。丘脑的左右半球间表现出极强的同源性。丘脑各亚区内表现出极强的结构同质性。When the thalamus is divided into 7 subregions, the anterior thalamic nucleus, ventroanterior nucleus, dorsomedial nucleus, dorsolateral-posterolateral nucleus, lateral pulvinar nucleus, ventrolateral-ventroposterior nucleus and medial pulvinar nucleus can be complete according to the number of subregions. Split it out. There is strong homology between the left and right hemispheres of the thalamus. Each subregion of the thalamus shows strong structural homogeneity.
当丘脑分12个亚区时,该分区数目下,丘脑前核、腹前核、背内侧核、后内侧核、腹外侧核、腹后侧核、前侧枕核、外侧枕核、内侧枕核、背前侧背内侧核、背后侧背内侧核以及腹侧背内侧核能完整的分割出来。丘脑的左右半球间表现出极强的同源性。丘脑各亚区内表现出极强的结构同质性。相比7个亚区的分区模式,12个亚区的丘脑图谱更加精细。When the thalamus is divided into 12 subregions, the number of subdivisions is: anterior thalamic nucleus, ventroanterior nucleus, dorsomedial nucleus, posteromedial nucleus, ventrolateral nucleus, ventroposterior nucleus, anterior pulvinar nucleus, lateral pulvinar nucleus, medial pulvinar nucleus The nucleus, dorsoanterior dorsomedial nucleus, dorsal dorsomedial nucleus, and ventral dorsomedial nucleus can be completely segmented. There is strong homology between the left and right hemispheres of the thalamus. Each subregion of the thalamus shows strong structural homogeneity. Compared with the zoning pattern of 7 subregions, the thalamic map of 12 subregions is more refined.
2、群组先验引导的基于深度学习的丘脑个体化图谱绘制方法,如图6所示2. Group prior guided thalamus individualized map drawing method based on deep learning, as shown in Figure 6
S100,获取在第一阈值下的群组丘脑概率图谱并进行二值化,得到群组丘脑概率图谱的掩膜,作为第一掩膜;将所述第一掩膜配准到受试者个体脑部的弥散磁共振空间,得到受试者个体脑部的丘脑ROI;S100, obtain the group thalamic probability map under the first threshold and perform binarization to obtain the mask of the group thalamic probability map as the first mask; register the first mask to the individual subject The diffusion magnetic resonance space of the brain is used to obtain the thalamus ROI of the subject's individual brain;
在本实施例中,将上述构建的群组丘脑概率图谱(即图6(a)、(b)中的群组图谱)取第一阈值(本发明中优选设置为0.25),并二值化生成群组丘脑概率图谱的掩膜mask,即图6中的(a)中的最大概率掩膜。将最大概率掩膜配准到受试者个体脑部的弥散磁共振空间,得到受试者个体脑部的丘脑ROI(即图6中的(a)中的个体掩膜)。In this embodiment, the group thalamic probability map constructed above (ie, the group map in Figure 6(a) and (b)) is taken as a first threshold (preferably set to 0.25 in the present invention) and binarized Generate a mask mask for the group thalamic probability map, that is, the maximum probability mask in (a) in Figure 6. The maximum probability mask is registered to the diffusion magnetic resonance space of the subject's individual brain to obtain the thalamus ROI of the subject's individual brain (ie, the individual mask in (a) in Figure 6).
S200,获取在第二阈值下的群组丘脑概率图谱,并配准到受试者个体脑部的弥散磁共振空间,得到受试者个体脑部的群组先验图谱;S200, obtain the group thalamic probability map under the second threshold, and register it to the diffusion magnetic resonance space of the subject's individual brain to obtain the group prior map of the subject's individual brain;
在本实施例中,将上述构建的群组丘脑概率图谱取第二阈值(本发明优选设置为>0.75)生成高概率的丘脑图谱(即图6中的(b)中的高可信度群组图谱),并将其配准到个体弥散磁共振空间,作为受试者个体脑部的群组先验图谱(即个体先验图谱),如图6中的(b)所示。其中,第一阈值、第二阈值,用于去掉最大的亚区概率值低于该阈值(即第一阈值或第二阈值)的体素点,进而构建群组丘脑概率图谱(具体如A500所示)。In this embodiment, the group thalamic probability map constructed above is set to a second threshold (preferably set to >0.75 in the present invention) to generate a high-probability thalamic map (ie, the high-confidence group in (b) in Figure 6 group map), and register it to the individual diffusion magnetic resonance space as a group prior map (i.e., individual prior map) of the subject's individual brain, as shown in (b) in Figure 6 . Among them, the first threshold and the second threshold are used to remove the voxel points with the largest sub-region probability value lower than the threshold (i.e. the first threshold or the second threshold), and then construct the group thalamic probability map (specifically, as shown in A500 Show).
S300,在受试者个体脑部的弥散磁共振空间中,剔除所述丘脑ROI中的群组先验图谱,得到未定义的丘脑区域的掩膜,作为第二掩膜;S300, in the diffusion magnetic resonance space of the subject's individual brain, eliminate the group prior map in the thalamus ROI and obtain a mask of the undefined thalamus area as the second mask;
在本实施例中,剔除所述丘脑ROI中的群组先验图谱,得到未定义的丘脑区域的掩膜,作为第二掩膜,如图6中的(c)所示。In this embodiment, the group prior map in the thalamus ROI is eliminated to obtain a mask of the undefined thalamus region as the second mask, as shown in (c) of Figure 6 .
S400,结合所述第二掩膜,计算所述群组先验图谱中每个体素的45维球面调和函数的系数和3维弥散磁共振空间的位置坐标,将两者合并为一个48维的特征向量,作为个体特征;将所述个体特征输入预构建的个体化分类模型,得到每个未定义区域内的体素的预测概率值向量,并将预测概率值向量对应的最大的亚区标签作为体素的最终亚区标签,进而生成未定义区域的图谱;所述个体化分类模型基于深度学习神经网络构建;S400, combined with the second mask, calculate the coefficients of the 45-dimensional spherical harmonic function and the position coordinates of the 3-dimensional diffusion magnetic resonance space of each voxel in the group prior map, and merge the two into a 48-dimensional Feature vector, as an individual feature; input the individual features into the pre-built individualized classification model to obtain the predicted probability value vector of the voxels in each undefined area, and assign the largest sub-region label corresponding to the predicted probability value vector As the final sub-region label of the voxel, a map of the undefined area is generated; the individualized classification model is built based on a deep learning neural network;
在本实施例中,结合所述第二掩膜(在个体化分类模型训练时,用第二掩膜内的区域,在验证时,使用第二掩膜外的区域),先计算所述群组先验图谱中每个体素的45维球面调和函数的系数和3维弥散磁共振空间的位置坐标,将两者合并,得到个体特征。将所述个体特征(即48维)输入预构建的个体化分类模型,得到每个未定义区域内的体素的预测概率值向量,并将预测概率值向量最大的亚区标签作为体素的 最终亚区标签,并生成未定义区域的图谱;所述个体化分类模型基于深度学习神经网络(即图6中的(e)中的深度学习模型)构建。In this embodiment, combined with the second mask (during individualized classification model training, the area within the second mask is used, and during verification, the area outside the second mask is used), the group is first calculated. The coefficients of the 45-dimensional spherical harmonic function and the position coordinates of the 3-dimensional diffusion magnetic resonance space of each voxel in the prior map are combined, and the individual characteristics are obtained by merging the two. Input the individual characteristics (i.e. 48 dimensions) into the pre-built individualized classification model to obtain the predicted probability value vector of the voxels in each undefined area, and use the sub-region label with the largest predicted probability value vector as the voxel's The final sub-region label is generated, and a map of the undefined area is generated; the individualized classification model is built based on a deep learning neural network (ie, the deep learning model in (e) in Figure 6).
其中,个体化分类模型基于深度学习神经网络构建,其训练过程如下,如图6中的(d)所示:Among them, the individualized classification model is built based on the deep learning neural network, and its training process is as follows, as shown in (d) in Figure 6:
通过S100-S400的方法,获取个体特征,并将个体特征输入预构建的个体化分类模型,得到每个未定义区域内的体素的K(K个亚区数目)维预测概率值向量;Through the methods of S100-S400, obtain individual characteristics and input the individual characteristics into the pre-built individualized classification model to obtain the K (number of K sub-regions) dimensional predicted probability value vector of voxels in each undefined area;
基于所述预测概率值向量,结合群组先验图谱对应的亚区类别,通过均方误差损失函数得到损失值,更新个体化分类模型的模型参数;循环对个体化分类模型进行训练,直至得到训练好的个体化分类模型。Based on the predicted probability value vector, combined with the sub-region category corresponding to the group prior map, the loss value is obtained through the mean square error loss function, and the model parameters of the individualized classification model are updated; the individualized classification model is trained in a loop until the Trained individualized classification model.
S500,将所述群组先验图谱和所述未定义区域的图谱进行合并,生成受试者个体化的丘脑图谱。如图6中的(f)所示。S500: Merge the group prior map and the map of the undefined area to generate a subject's individualized thalamus map. As shown in (f) in Figure 6.
最后,使用改进的轮廓系数Silhouette值对个体化的丘脑图谱进行验证,具体为:Finally, the improved silhouette coefficient Silhouette value is used to verify the individualized thalamic atlas, specifically:
使用45维球面调和函数系数的欧式距离作为距离度量。使用Silhouette的提升比例作为增益指标对群组先验引导、群组配准和单被试聚类三种个体化方法进行定量比较。增益指标以单被试聚类的个体化丘脑图谱的Silhouette值作为分母,以群组先验引导或者群组配准的个体化丘脑图谱的Silhouette值与其的差值作为分子。增益为正数表示某种个体化图谱绘制方法准确度高于单被试聚类,且增益越大准确度提高越多,为负数则表示低于单被试聚类。使用HCP 3T,HCP 7T,HCP Test和HCP Retest四个数据集,分别验证该个体化丘脑图谱的绘制方案在不同磁场强度和不同扫描批次下的鲁棒性和可重复性。使用不同的分区数量7和12,验证该个体化丘脑图谱的绘制方案在不同丘脑亚区数量下的鲁棒性。The Euclidean distance of the 45-dimensional spherical harmonic function coefficients is used as the distance metric. A quantitative comparison of three individuation methods, group prior guidance, group registration, and single-subject clustering, was performed using Silhouette's improvement ratio as the gain index. The gain index uses the Silhouette value of the individualized thalamic map clustered by a single subject as the denominator, and the difference between the Silhouette value of the individualized thalamic map guided by group prior guidance or group registration and its numerator as the numerator. A positive gain means that the accuracy of a certain individualized map drawing method is higher than that of single-subject clustering, and the greater the gain, the greater the accuracy improvement. A negative number means that it is lower than single-subject clustering. Four data sets, HCP 3T, HCP 7T, HCP Test and HCP Retest, were used to verify the robustness and repeatability of the personalized thalamus map drawing scheme under different magnetic field strengths and different scanning batches. Different partition numbers of 7 and 12 were used to verify the robustness of the personalized thalamic atlas drawing scheme under different numbers of thalamic subregions.
HCP四个数据集上的个体化丘脑图谱的被试内分区模式一致性指标,分别是HCP 3T(N=100)、HCP 7T(N=100)、HCP Test(N=30)和HCP Retest(N=30)数据集上的验证指标。在四个数据集上,分别计算了分区数目为7和12时的验证指标。结果表明,四个数据集上,群组先验引导、群组配准和单被试聚类三种个体化方法表现出类似的被试内分区模式一致性,但是群组先验引导的个体化丘脑图谱与其他两种方法相比有更高的被试内一致性。The intra-subject partition pattern consistency indicators of the individualized thalamic atlas on the four HCP data sets are HCP 3T (N=100), HCP 7T (N=100), HCP Test (N=30) and HCP Retest ( Validation metrics on N=30) data set. On the four data sets, the verification indicators were calculated when the number of partitions was 7 and 12, respectively. The results show that on the four data sets, the three individuation methods of group a priori guidance, group registration and single-subject clustering show similar consistency of within-subject partitioning patterns, but the group a priori guidance of individuals The thalamus atlas had higher within-subject consistency than the other two methods.
个体化图谱的被试内分区一致性的增益指标,即在HCP 3T和HCP 7T数据上被试内分区一致性的增益对比、在HCP Test和HCP Retest数据上被试内分区一致性的增益对比。群组配准的方法绘制的个体化丘脑图谱的被试内分区一致性比单被试聚类差。而群组先验引导的个体化丘脑图谱比单被试聚类的被试内分区一致性强。分区数目为7时,3T和7T数据的增益一致。分区数目为12时,7T数据的增益高于3T数据。分区数目为7和12时,Test和Retest的增益基本一致。在四个数据集上,群组先验引导的个体化丘脑图谱在分区数目为12时比分区数目为7时有更高的增益。The gain index of the intra-subject partition consistency of the individualized map is the gain comparison of the intra-subject partition consistency on the HCP 3T and HCP 7T data, and the gain comparison of the intra-subject partition consistency on the HCP Test and HCP Retest data. . The within-subject partition consistency of the individualized thalamic atlas drawn by the group registration method is worse than that of single-subject clustering. However, the group-prior guided individualized thalamic atlas has stronger intra-subject partition consistency than single-subject clustering. When the number of partitions is 7, the gains of 3T and 7T data are the same. When the number of partitions is 12, the gain of 7T data is higher than that of 3T data. When the number of partitions is 7 and 12, the gains of Test and Retest are basically the same. On the four data sets, the group prior-guided individualized thalamic atlas has a higher gain when the number of partitions is 12 than when the number of partitions is 7.
群组先验引导的个体化丘脑图谱在HCP Test和HCP Retest上进行一致性验证时,,在分区数目为7和12,群组先验引导的个体化丘脑图谱表现出稳定可靠的扫描批次间一致性。When the group a priori guided individualized thalamic atlas was verified for consistency on HCP Test and HCP Retest, when the number of partitions was 7 and 12, the group a priori guided individualized thalamic atlas showed stable and reliable scanning batches inter-consistency.
本发明第二实施例的一种群组先验引导的基于深度学习的丘脑个体化图谱绘制系统,如图2所示,包括:丘脑ROI获取模块100、群组先验图谱获取模块200、剔除处理模块300、个体化分类模块400、个体化图谱生成模块500;A group prior-guided deep learning-based personalized map drawing system of the thalamus according to the second embodiment of the present invention, as shown in Figure 2, includes: a thalamus ROI acquisition module 100, a group prior map acquisition module 200, and elimination Processing module 300, individualized classification module 400, individualized map generation module 500;
所述丘脑ROI获取模块100,配置为获取在第一阈值下的群组丘脑概率图谱并进行二值化,得到群组丘脑概率图谱的掩膜,作为第一掩膜; 将所述第一掩膜配准到受试者个体脑部的弥散磁共振空间,得到受试者个体脑部的丘脑ROI;The thalamic ROI acquisition module 100 is configured to acquire the group thalamic probability map under a first threshold and perform binarization to obtain a mask of the group thalamic probability map as the first mask; The membrane is registered to the diffusion magnetic resonance space of the subject's individual brain, and the thalamus ROI of the subject's individual brain is obtained;
所述群组先验图谱获取模块200,配置为获取在第二阈值下的群组丘脑概率图谱,并配准到受试者个体脑部的弥散磁共振空间,得到受试者个体脑部的群组先验图谱;The group prior map acquisition module 200 is configured to obtain the group thalamic probability map under the second threshold, and register it to the diffusion magnetic resonance space of the subject's individual brain to obtain the subject's individual brain. Group prior map;
所述剔除处理模块300,配置为在受试者个体脑部的弥散磁共振空间中,剔除所述丘脑ROI中的群组先验图谱,得到未定义的丘脑区域的掩膜,作为第二掩膜;The elimination processing module 300 is configured to eliminate the group prior map in the thalamus ROI in the diffusion magnetic resonance space of the subject's individual brain to obtain a mask of the undefined thalamus region as the second mask. membrane;
所述个体化分类模块400,配置为计算所述群组先验图谱中每个体素的45维球面调和函数的系数和3维弥散磁共振空间的位置坐标,将两者合并,得到个体特征;将所述个体特征输入预构建的个体化分类模型,得到每个未定义区域内的体素的预测概率值向量,并将预测概率值向量最大的亚区标签作为体素的最终亚区标签,并生成未定义区域的图谱;所述个体化分类模型基于深度学习神经网络构建;The individualized classification module 400 is configured to calculate the coefficients of the 45-dimensional spherical harmonic function and the position coordinates of the 3-dimensional diffusion magnetic resonance space of each voxel in the group prior map, and merge the two to obtain individual characteristics; Input the individual characteristics into the pre-built individualized classification model to obtain the predicted probability value vector of the voxel in each undefined area, and use the sub-region label with the largest predicted probability value vector as the final sub-region label of the voxel, And generate a map of undefined areas; the individualized classification model is built based on a deep learning neural network;
所述个体化图谱生成模块500,配置为将所述群组先验图谱和所述未定义区域的图谱进行合并,生成受试者个体化的丘脑图谱;The personalized map generation module 500 is configured to merge the group prior map and the map of the undefined area to generate a subject's individualized thalamic map;
其中,所述群组丘脑概率图谱其构建方法为:Wherein, the construction method of the group thalamic probability map is:
A100,获取N个受试者个体脑部的结构核磁共振图像、弥散张量核磁共振图像,作为输入图像;N为正整数;A100, obtain the structural MRI images and diffusion tensor MRI images of the individual brains of N subjects as input images; N is a positive integer;
A200,对所述输入图像依次进行HCP最小预处理、ROI配准、ROI后处理,得到受试者个体脑部最终的丘脑ROI,并通过ODF估计算法,得到受试者个体脑部最终的丘脑ROI内每个体素的局部弥散特征;A200, sequentially perform HCP minimum preprocessing, ROI registration, and ROI postprocessing on the input image to obtain the final thalamus ROI of the subject's individual brain, and obtain the final thalamus ROI of the subject's individual brain through the ODF estimation algorithm. Local diffusion characteristics of each voxel within the ROI;
A300,结合A200获取的局部弥散特征,计算体素之间的相似度,并进行聚类,得到受试者个体脑部最终的丘脑ROI内体素的聚类结果;A300, combined with the local diffusion characteristics obtained by A200, calculates the similarity between voxels and performs clustering to obtain the clustering results of voxels within the final thalamic ROI of the subject's individual brain;
A400,将A300获取的聚类结果配准至标准空间,并进行标签重映射,得到受试者个体脑部最终的丘脑ROI内每个体素对应的亚区标签,即得到N个受试者个体脑部在标准空间中的丘脑分区;A400, register the clustering results obtained by A300 to the standard space, and perform label remapping to obtain the sub-region label corresponding to each voxel in the final thalamus ROI of the individual subject's brain, that is, N individual subjects are obtained thalamic partitioning of the brain in standard space;
A500,计算受试者个体脑部最终的丘脑ROI内每个体素对应的亚区概率值,并去掉最大的亚区概率值低于第一阈值的体素点,然后将剩余的体素点构建群组水平的丘脑概率图谱,即群组丘脑概率图谱;所述亚区概率值为各亚区的受试者人数与总受试者人数的比值。A500, calculate the sub-region probability value corresponding to each voxel in the final thalamus ROI of the individual brain of the subject, remove the voxel points with the largest sub-region probability value lower than the first threshold, and then construct the remaining voxel points The thalamic probability map at the group level is the group thalamic probability map; the sub-region probability value is the ratio of the number of subjects in each sub-region to the total number of subjects.
需要说明的是,上述实施例提供的群组先验引导的基于深度学习的丘脑个体化图谱绘制系统,仅以上述各功能模块的划分进行举例说明,在实际应用中,可以根据需要而将上述功能分配由不同的功能模块来完成,即将本发明实施例中的模块或者步骤再分解或者组合,例如,上述实施例的模块可以合并为一个模块,也可以进一步拆分成多个子模块,以完成以上描述的全部或者部分功能。对于本发明实施例中涉及的模块、步骤的名称,仅仅是为了区分各个模块或者步骤,不视为对本发明的不当限定。It should be noted that the group a priori-guided deep learning-based personalized map drawing system of the thalamus provided in the above embodiments is only illustrated by the division of each functional module mentioned above. In practical applications, the above mentioned functions can be used as needed. Function allocation is completed by different functional modules, that is, the modules or steps in the embodiment of the present invention are decomposed or combined. For example, the modules in the above embodiment can be combined into one module, or further divided into multiple sub-modules to complete All or part of the functions described above. The names of the modules and steps involved in the embodiments of the present invention are only used to distinguish each module or step and are not regarded as improper limitations of the present invention.
本发明第三实施例的一种电子设备,包括:至少一个处理器;以及与至少一个所述处理器通信连接的存储器;其中,所述存储器存储有可被所述处理器执行的指令,所述指令用于被所述处理器执行以实现上述的群组先验引导的基于深度学习的丘脑个体化图谱绘制方法。An electronic device according to a third embodiment of the present invention includes: at least one processor; and a memory communicatively connected to at least one of the processors; wherein the memory stores instructions that can be executed by the processor, so The instructions are used to be executed by the processor to implement the above-mentioned group prior-guided deep learning-based individualized map drawing method of the thalamus.
本发明第四实施例的一种计算机可读存储介质,所述计算机可读存储介质存储有计算机指令,所述计算机指令用于被所述计算机执行以实现上述的群组先验引导的基于深度学习的丘脑个体化图谱绘制方法。A computer-readable storage medium according to the fourth embodiment of the present invention, the computer-readable storage medium stores computer instructions, and the computer instructions are used to be executed by the computer to implement the above-mentioned group a priori guidance based on depth. A learning method for individualized mapping of the thalamus.
本发明第五实施例的一种群组先验引导的基于深度学习的丘脑个体化图谱绘制装置,包括:磁共振图像采集设备、中央处理设备,A device for drawing individualized maps of the thalamus based on deep learning guided by group prior guidance in the fifth embodiment of the present invention includes: a magnetic resonance image acquisition device and a central processing device,
所述磁共振图像采集设备包括磁共振成像设备、超导磁共振仪,配置为采集受试者个体脑部的结构核磁共振图像、弥散张量核磁共振图像;The magnetic resonance image acquisition equipment includes magnetic resonance imaging equipment and a superconducting magnetic resonance instrument, and is configured to acquire structural MRI images and diffusion tensor MRI images of the subject's individual brain;
所述中央处理设备包括GPU,配置为获取在第一阈值下的群组丘脑概率图谱并进行二值化,得到群组丘脑概率图谱的掩膜,作为第一掩膜;将所述第一掩膜配准到受试者个体脑部的弥散磁共振空间,得到受试者个体脑部的丘脑ROI;The central processing device includes a GPU and is configured to obtain a group thalamic probability map under a first threshold and perform binarization to obtain a mask of the group thalamic probability map as a first mask; converting the first mask The membrane is registered to the diffusion magnetic resonance space of the subject's individual brain, and the thalamus ROI of the subject's individual brain is obtained;
获取在第二阈值下的群组丘脑概率图谱,并配准到受试者个体脑部的弥散磁共振空间,得到受试者个体脑部的群组先验图谱;在受试者个体脑部的弥散磁共振空间中,剔除所述丘脑ROI中的群组先验图谱,得到未定义的丘脑区域的掩膜,作为第二掩膜;Obtain the group thalamic probability map under the second threshold, and register it to the diffusion magnetic resonance space of the subject's individual brain to obtain the group prior map of the subject's individual brain; in the subject's individual brain In the diffusion magnetic resonance space, the group prior map in the thalamus ROI is eliminated to obtain a mask of the undefined thalamus area as the second mask;
结合所述第二掩膜,计算所述群组先验图谱中每个体素的45维球面调和函数的系数和3维弥散磁共振空间的位置坐标,将两者合并为一个48维的特征向量,作为个体特征;将所述个体特征输入预构建的个体化分类模型,得到每个未定义区域内的体素的预测概率值向量,并将预测概率值向量对应的最大的亚区标签作为体素的最终亚区标签,进而生成未定义区域的图谱;所述个体化分类模型基于深度学习神经网络构建;将所述群组先验图谱和所述未定义区域的图谱进行合并,生成受试者个体化的丘脑图谱;Combined with the second mask, calculate the coefficients of the 45-dimensional spherical harmonic function and the position coordinates of the 3-dimensional diffusion magnetic resonance space of each voxel in the group prior map, and merge the two into a 48-dimensional feature vector , as individual features; input the individual features into the pre-built individualized classification model to obtain the predicted probability value vector of voxels in each undefined area, and use the largest sub-region label corresponding to the predicted probability value vector as the volume The final sub-region label of the element is then generated to generate a map of the undefined area; the individualized classification model is constructed based on a deep learning neural network; the group prior map and the map of the undefined area are merged to generate a subject individualized thalamus map;
其中,所述群组丘脑概率图谱其构建方法为:Wherein, the construction method of the group thalamic probability map is:
A100,获取N个受试者个体脑部的结构核磁共振图像、弥散张量核磁共振图像,作为输入图像;N为正整数;A100, obtain the structural MRI images and diffusion tensor MRI images of the individual brains of N subjects as input images; N is a positive integer;
A200,对所述输入图像依次进行HCP最小预处理、ROI配准、ROI后处理,得到受试者个体脑部最终的丘脑ROI,并通过ODF估计算法,得到受试者个体脑部最终的丘脑ROI内每个体素的局部弥散特征;A200, sequentially perform HCP minimum preprocessing, ROI registration, and ROI postprocessing on the input image to obtain the final thalamus ROI of the subject's individual brain, and obtain the final thalamus ROI of the subject's individual brain through the ODF estimation algorithm. Local diffusion characteristics of each voxel within the ROI;
A300,结合A200获取的局部弥散特征,计算体素之间的相似度,并进行聚类,得到受试者个体脑部最终的丘脑ROI内体素的聚类结果;A300, combined with the local diffusion characteristics obtained by A200, calculates the similarity between voxels and performs clustering to obtain the clustering results of voxels within the final thalamic ROI of the subject's individual brain;
A400,将A300获取的聚类结果配准至标准空间,并进行标签重映射,得到受试者个体脑部最终的丘脑ROI内每个体素对应的亚区标签,即得到N个受试者个体脑部在标准空间中的丘脑分区;A400, register the clustering results obtained by A300 to the standard space, and perform label remapping to obtain the sub-region label corresponding to each voxel in the final thalamus ROI of the individual subject's brain, that is, N individual subjects are obtained thalamic partitioning of the brain in standard space;
A500,计算受试者个体脑部最终的丘脑ROI内每个体素对应的亚区概率值,并去掉最大的亚区概率值低于第一阈值的体素点,然后将剩余的体素点构建群组水平的丘脑概率图谱,即群组丘脑概率图谱;所述亚区概率值为各亚区的受试者人数与总受试者人数的比值。A500, calculate the sub-region probability value corresponding to each voxel in the final thalamus ROI of the individual brain of the subject, remove the voxel points with the largest sub-region probability value lower than the first threshold, and then construct the remaining voxel points The thalamic probability map at the group level is the group thalamic probability map; the sub-region probability value is the ratio of the number of subjects in each sub-region to the total number of subjects.
所述技术领域的技术人员可以清楚的了解到,为描述的方便和简洁,上述描述的电子设备、计算机可读存储介质以及群组先验引导的基于深度学习的丘脑个体化图谱绘制装置的具体工作过程及有关说明,可以参考前述方法实例中的对应过程,在此不再赘述。Those skilled in the technical field can clearly understand that, for the convenience and simplicity of description, the specific details of the above-described electronic equipment, computer-readable storage media, and group prior-guided deep learning-based personalized map drawing device of the thalamus are For the working process and related instructions, please refer to the corresponding process in the foregoing method examples, and will not be repeated here.
本领域技术人员应该能够意识到,结合本文中所公开的实施例描述的各示例的模块、方法步骤,能够以电子硬件、计算机软件或者二者的结合来实现,软件模块、方法步骤对应的程序可以置于随机存储器(RAM)、内存、只读存储器(ROM)、电可编程ROM、电可擦除可编程ROM、寄存器、硬盘、可移动磁盘、CD-ROM、或技术领域内所公知的任意其它形式的存储介质中。为了清楚地说明电子硬件和软件的可互换性,在上述说明中已经按照功能一般性地描述了各示例的组成及步骤。这些功能究竟以电子硬件还是软件方式来执行,取决于技术方案的特定应用和设计约束条件。本领域技术人员可以对每个特定的应用来使用不同方法来实现所描述的功能,但是这种实现不应认为超出本发明的范围。Those skilled in the art should be able to realize that the modules and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented with electronic hardware, computer software, or a combination of both, and the programs corresponding to the software modules and method steps Can be placed in random access memory (RAM), memory, read only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, register, hard disk, removable disk, CD-ROM, or any other device known in the art. any other form of storage media. In order to clearly illustrate the interchangeability of electronic hardware and software, the composition and steps of each example have been generally described according to function in the above description. Whether these functions are performed as electronic hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementations should not be considered to be beyond the scope of the present invention.
术语“第一”、“第二”、“第三”等是用于区别类似的对象,而不是用于描述或表示特定的顺序或先后次序。The terms "first", "second", "third", etc. are used to distinguish similar objects, but are not used to describe or indicate a specific order or sequence.
至此,已经结合附图所示的优选实施方式描述了本发明的技术方案,但是,本领域技术人员容易理解的是,本发明的保护范围显然不局限于这些具体实施方式。在不偏离本发明的原理的前提下,本领域技术人员可以对相关技术特征做出等同的更改或替换,这些更改或替换之后的技术方案都将落入本发明的保护范围之内。So far, the technical solution of the present invention has been described with reference to the preferred embodiments shown in the drawings. However, those skilled in the art can easily understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or replacements to relevant technical features, and the technical solutions after these changes or replacements will fall within the protection scope of the present invention.
Claims (10)
- 一种群组先验引导的基于深度学习的丘脑个体化图谱绘制方法,其特征在于,该方法包括以下步骤:A group prior-guided deep learning-based personalized map drawing method for the thalamus, which is characterized in that the method includes the following steps:S100,获取在第一阈值下的群组丘脑概率图谱并进行二值化,得到群组丘脑概率图谱的掩膜,作为第一掩膜;将所述第一掩膜配准到受试者个体脑部的弥散磁共振空间,得到受试者个体脑部的丘脑ROI;S100, obtain the group thalamic probability map under the first threshold and perform binarization to obtain the mask of the group thalamic probability map as the first mask; register the first mask to the individual subject The diffusion magnetic resonance space of the brain is used to obtain the thalamus ROI of the subject's individual brain;S200,获取在第二阈值下的群组丘脑概率图谱,并配准到受试者个体脑部的弥散磁共振空间,得到受试者个体脑部的群组先验图谱;S200, obtain the group thalamic probability map under the second threshold, and register it to the diffusion magnetic resonance space of the subject's individual brain to obtain the group prior map of the subject's individual brain;S300,在受试者个体脑部的弥散磁共振空间中,剔除所述丘脑ROI中的群组先验图谱,得到未定义的丘脑区域的掩膜,作为第二掩膜;S300, in the diffusion magnetic resonance space of the subject's individual brain, eliminate the group prior map in the thalamus ROI and obtain a mask of the undefined thalamus area as the second mask;S400,结合所述第二掩膜,计算所述群组先验图谱中每个体素的45维球面调和函数的系数和3维弥散磁共振空间的位置坐标,将两者合并为一个48维的特征向量,作为个体特征;将所述个体特征输入预构建的个体化分类模型,得到每个未定义区域内的体素的预测概率值向量,并将预测概率值向量对应的最大的亚区标签作为体素的最终亚区标签,进而生成未定义区域的图谱;所述个体化分类模型基于深度学习神经网络构建;S400, combined with the second mask, calculate the coefficients of the 45-dimensional spherical harmonic function and the position coordinates of the 3-dimensional diffusion magnetic resonance space of each voxel in the group prior map, and merge the two into a 48-dimensional Feature vector, as an individual feature; input the individual features into the pre-built individualized classification model to obtain the predicted probability value vector of the voxels in each undefined area, and assign the largest sub-region label corresponding to the predicted probability value vector As the final sub-region label of the voxel, a map of the undefined area is generated; the individualized classification model is built based on a deep learning neural network;S500,将所述群组先验图谱和所述未定义区域的图谱进行合并,生成受试者个体化的丘脑图谱;S500, merge the group prior map and the map of the undefined area to generate a subject's individualized thalamus map;其中,所述群组丘脑概率图谱其构建方法为:Wherein, the construction method of the group thalamic probability map is:A100,获取N个受试者个体脑部的结构核磁共振图像、弥散张量核磁共振图像,作为输入图像;N为正整数;A100, obtain the structural MRI images and diffusion tensor MRI images of the individual brains of N subjects as input images; N is a positive integer;A200,对所述输入图像依次进行HCP最小预处理、ROI配准、ROI后处理,得到受试者个体脑部最终的丘脑ROI,并通过ODF估计算法,得到受试者个体脑部最终的丘脑ROI内每个体素的局部弥散特征;A200, sequentially perform HCP minimum preprocessing, ROI registration, and ROI postprocessing on the input image to obtain the final thalamus ROI of the subject's individual brain, and obtain the final thalamus ROI of the subject's individual brain through the ODF estimation algorithm. Local diffusion characteristics of each voxel within the ROI;A300,结合A200获取的局部弥散特征,计算体素之间的相似度,并进行聚类,得到受试者个体脑部最终的丘脑ROI内体素的聚类结果;A300, combined with the local diffusion characteristics obtained by A200, calculates the similarity between voxels and performs clustering to obtain the clustering results of voxels within the final thalamic ROI of the subject's individual brain;A400,将A300获取的聚类结果配准至标准空间,并进行标签重映射,得到受试者个体脑部最终的丘脑ROI内每个体素对应的亚区标签,即得到N个受试者个体脑部在标准空间中的丘脑分区;A400, register the clustering results obtained by A300 to the standard space, and perform label remapping to obtain the sub-region label corresponding to each voxel in the final thalamus ROI of the individual subject's brain, that is, N individual subjects are obtained thalamic partitioning of the brain in standard space;A500,计算受试者个体脑部最终的丘脑ROI内每个体素对应的亚区概率值,并去掉最大的亚区概率值低于第一阈值的体素点,然后将剩余的体素点构建群组水平的丘脑概率图谱,即群组丘脑概率图谱;所述亚区概率值为各亚区的受试者人数与总受试者人数的比值。A500, calculate the sub-region probability value corresponding to each voxel in the final thalamus ROI of the individual brain of the subject, remove the voxel points with the largest sub-region probability value lower than the first threshold, and then construct the remaining voxel points The thalamic probability map at the group level is the group thalamic probability map; the sub-region probability value is the ratio of the number of subjects in each sub-region to the total number of subjects.
- 根据权利要求1所述的群组先验引导的基于深度学习的丘脑个体化图谱绘制方法,其特征在于,对所述输入图像依次进行HCP最小预处理、ROI配准、ROI后处理,得到受试者个体脑部最终的丘脑ROI,其方法为:The group a priori-guided deep learning-based personalized map drawing method of the thalamus according to claim 1, characterized in that the input image is sequentially subjected to HCP minimum pre-processing, ROI registration, and ROI post-processing to obtain the subject The final thalamus ROI of the individual brain of the subject is determined as follows:对受试者个体脑部的结构核磁共振图像、弥散张量核磁共振图像进行HCP最小预处理,得到预处理的结构核磁共振图像、预处理的弥散张量核磁共振图像;Perform HCP minimal preprocessing on the structural MRI images and diffusion tensor MRI images of the subject's individual brain to obtain preprocessed structural MRI images and preprocessed diffusion tensor MRI images;基于所述预处理的结构核磁共振图像、所述预处理的弥散张量核磁共振图像,通过ROI配准方法将弥散磁共振空间与结构磁共振空间、结构磁共振空间和标准空间之间进行配准,得到个体的丘脑ROI;Based on the preprocessed structural magnetic resonance image and the preprocessed diffusion tensor nuclear magnetic resonance image, the diffusion magnetic resonance space and the structural magnetic resonance space, the structural magnetic resonance space and the standard space are aligned through the ROI registration method. Accurately, obtain individual thalamus ROI;在受试者个体脑部的弥散磁共振空间使用FSL计算每个体素点对应的各向异性分数值;Use FSL to calculate the anisotropy fraction corresponding to each voxel point in the diffusion magnetic resonance space of the subject's individual brain;在受试者个体脑部的结构磁共振空间使用SPM计算每个体素点对应的脑脊液概率值;Use SPM to calculate the cerebrospinal fluid probability value corresponding to each voxel point in the structural magnetic resonance space of the subject's individual brain;在个体的丘脑ROI中去除掉各向异性分数值大于设定各向异性分数阈值或脑脊液概率值大于设定脑脊液概率阈值的体素点,将剩余的体素点作为最终的个体丘脑ROI。In the individual thalamus ROI, voxel points whose anisotropy fraction value is greater than the set anisotropy fraction threshold or whose cerebrospinal fluid probability value is greater than the set cerebrospinal fluid probability threshold are removed, and the remaining voxel points are used as the final individual thalamus ROI.
- 根据权利要求1所述的群组先验引导的基于深度学习的丘脑个体化图谱绘制方法,其特征在于,所述受试者个体脑部最终的丘脑ROI内每个体素的局部弥散特征,其获取方法为:The group a priori-guided deep learning-based personalized map drawing method of the thalamus according to claim 1, characterized in that the local diffusion characteristics of each voxel in the final thalamus ROI of the subject's individual brain, The acquisition method is:在受试者个体脑部最终的丘脑ROI内的弥散磁共振空间中,使用dhollander算法在弥散磁共振数据上计算不同弥散加权因子b值参数下大脑组织的响应函数;结合所述大脑组织的响应函数,使用多组织多球壳限制性球面反卷积方法计算8阶球面调和函数的45维系数,量化每个体素的局部弥散特征。In the diffusion magnetic resonance space within the final thalamic ROI of the subject's individual brain, use the dhollander algorithm to calculate the response function of the brain tissue under different diffusion weighting factor b value parameters on the diffusion magnetic resonance data; combine the response of the brain tissue function, using the multi-tissue multi-spherical shell restricted spherical deconvolution method to calculate the 45-dimensional coefficients of the 8th order spherical harmonic function to quantify the local diffusion characteristics of each voxel.
- 根据权利要求1所述的群组先验引导的基于深度学习的丘脑个体化图谱绘制方法,其特征在于,计算体素之间的相似度,其方法为:The group prior-guided deep learning-based personalized map drawing method of the thalamus according to claim 1, characterized in that the similarity between voxels is calculated by:其中,S(i,j)表示两个体素之间的相似度,E pos(i,j)表示两个体素在弥散磁共振空间中的3维坐标之间的欧式距离,E odf(i,j)表示两个体素的45维球面调和函数的采样系数之间的欧式距离,w pos和w odf分别表示E pos(i,j)、E odf(i,j)在计算相似度时的对应加权系数。 Among them, S(i,j) represents the similarity between two voxels, E pos (i, j) represents the Euclidean distance between the three-dimensional coordinates of two voxels in the diffusion magnetic resonance space, E odf (i, j) represents the Euclidean distance between the sampling coefficients of the 45-dimensional spherical harmonic function of two voxels, w pos and w odf respectively represent the correspondence of E pos (i, j) and E odf (i, j) when calculating similarity. Weighting coefficient.
- 根据权利要求4所述的群组先验引导的基于深度学习的丘脑个体化图谱绘制方法,其特征在于,所述受试者个体脑部最终的丘脑ROI内体素的聚类结果,其获取方法为:The group a priori-guided deep learning-based personalized map drawing method of the thalamus according to claim 4, characterized in that the clustering result of the voxels in the final thalamus ROI of the subject's individual brain is obtained. The method is:通过谱聚类方法对受试者个体脑部最终的丘脑ROI内每个体素的局部弥散特征以及体素之间的相似度进行降维;The spectral clustering method is used to reduce the dimensionality of the local diffusion characteristics of each voxel in the final thalamic ROI of the subject's individual brain and the similarity between voxels;基于降维后的局部弥散特征以及体素之间的相似度,使用K-means聚类将各体素聚为K类,作为受试者个体脑部最终的丘脑ROI内体素的聚类结果。Based on the local diffusion characteristics after dimensionality reduction and the similarity between voxels, K-means clustering is used to cluster each voxel into K categories, which is used as the clustering result of the voxels in the final thalamus ROI of the subject's individual brain. .
- 根据权利要求1所述的群组先验引导的基于深度学习的丘脑个体化图谱绘制方法,其特征在于,所述受试者个体脑部最终的丘脑ROI内每个体素对应的亚区标签,其获取方法为:The group a priori-guided deep learning-based personalized map drawing method of the thalamus according to claim 1, characterized in that the sub-region label corresponding to each voxel in the final thalamus ROI of the subject's individual brain, The acquisition method is:计算每个体素点在N个受试者上的N维标签向量,然后对受试者个体脑部最终的丘脑ROI内的所有体素点按照其标签向量的相似度进行聚类,聚类结果作为分区标签;Calculate the N-dimensional label vector of each voxel point on N subjects, and then cluster all voxel points in the final thalamus ROI of the subject's individual brain according to the similarity of their label vectors, and the clustering results as partition label;基于所述分区标签,按照空间最大重叠的方法将每个受试者个体脑部最终的丘脑ROI内体素的聚类结果进行重新标记,从而得到受试者个体脑部最终的丘脑ROI内每个体素对应的亚区标签;Based on the partition labels, the clustering results of the voxels in the final thalamic ROI of each subject's individual brain are relabeled according to the spatial maximum overlap method, thereby obtaining the final thalamic ROI of each subject's individual brain. The subregion label corresponding to the voxel;其中,计算每个体素点在N个受试者上的N维标签向量,即提取每个受试者在该体素点上对应的亚区标签,对N个受试者分别提取一个亚区标签,组成N维标签向量。Among them, the N-dimensional label vector of each voxel point on N subjects is calculated, that is, the sub-region label corresponding to the voxel point of each subject is extracted, and one sub-region is extracted for each N subjects. labels, forming an N-dimensional label vector.
- 根据权利要求6所述的群组先验引导的基于深度学习的丘脑个体化图谱绘制方法,其特征在于,所述个体化分类模型,其训练方法为:The group prior-guided deep learning-based individualized map drawing method of the thalamus according to claim 6, characterized in that the training method of the individualized classification model is:通过S100-S400的方法,获取个体特征,并将个体特征输入预构建的个体化分类模型,得到每个未定义区域内的体素的预测概率值向量;Through the methods of S100-S400, obtain individual features and input the individual features into the pre-built individualized classification model to obtain the predicted probability value vector of voxels in each undefined area;基于所述预测概率值向量,结合群组先验图谱对应的亚区类别,通过均方误差损失函数得到损失值,更新个体化分类模型的模型参数;Based on the predicted probability value vector, combined with the sub-region category corresponding to the group prior map, the loss value is obtained through the mean square error loss function, and the model parameters of the individualized classification model are updated;循环上述步骤,直至得到训练好的个体化分类模型。Repeat the above steps until the trained individualized classification model is obtained.
- 一种群组先验引导的基于深度学习的丘脑个体化图谱绘制系统,其特征在于,该系统包括:丘脑ROI获取模块、群组先验图谱获取模块、剔除处理模块、个体化分类模块、个体化图谱生成模块;A group prior guided thalamic individualized map drawing system based on deep learning, which is characterized in that the system includes: a thalamic ROI acquisition module, a group prior map acquisition module, a elimination processing module, an individualized classification module, and an individual Chemical map generation module;所述丘脑ROI获取模块,配置为获取在第一阈值下的群组丘脑概率图谱 并进行二值化,得到群组丘脑概率图谱的掩膜,作为第一掩膜;将所述第一掩膜配准到受试者个体脑部的弥散磁共振空间,得到受试者个体脑部的丘脑ROI;The thalamic ROI acquisition module is configured to acquire the group thalamic probability map under a first threshold and perform binarization to obtain a mask of the group thalamic probability map as the first mask; convert the first mask Register to the diffusion magnetic resonance space of the subject's individual brain to obtain the thalamus ROI of the subject's individual brain;所述群组先验图谱获取模块,配置为获取在第二阈值下的群组丘脑概率图谱,并配准到受试者个体脑部的弥散磁共振空间,得到受试者个体脑部的群组先验图谱;The group prior map acquisition module is configured to obtain the group thalamic probability map under the second threshold, and register it to the diffusion magnetic resonance space of the subject's individual brain to obtain the group's individual brain. Group prior map;所述剔除处理模块,配置为在受试者个体脑部的弥散磁共振空间中,剔除所述丘脑ROI中的群组先验图谱,得到未定义的丘脑区域的掩膜,作为第二掩膜,作为个体化模型的训练集;The elimination processing module is configured to eliminate the group prior map in the thalamus ROI in the diffusion magnetic resonance space of the subject's individual brain, and obtain a mask of the undefined thalamus region as the second mask. , as a training set for the individualized model;所述个体化分类模块,配置为结合所述第二掩膜,计算所述群组先验图谱中每个体素的45维球面调和函数的系数和3维弥散磁共振空间的位置坐标,将两者合并为一个48维的特征向量,作为个体特征;将所述个体特征输入预构建的个体化分类模型,得到每个未定义区域内的体素的预测概率值向量,并将预测概率值向量对应的最大的亚区标签作为体素的最终亚区标签,进而生成未定义区域的图谱;所述个体化分类模型基于深度学习神经网络构建;The individualized classification module is configured to calculate the coefficients of the 45-dimensional spherical harmonic function and the position coordinates of the 3-dimensional diffusion magnetic resonance space of each voxel in the group prior map in combination with the second mask, and combine the two or merged into a 48-dimensional feature vector as individual features; input the individual features into the pre-built individualized classification model to obtain the predicted probability value vector of voxels in each undefined area, and add the predicted probability value vector to The corresponding largest sub-region label is used as the final sub-region label of the voxel, and then a map of the undefined area is generated; the individualized classification model is built based on a deep learning neural network;所述个体化图谱生成模块,配置为将所述群组先验图谱和所述未定义区域的图谱进行合并,生成受试者个体化的丘脑图谱;The individualized map generation module is configured to merge the group prior map and the map of the undefined area to generate a subject's individualized thalamic map;其中,所述群组丘脑概率图谱其构建方法为:Wherein, the construction method of the group thalamic probability map is:A100,获取N个受试者个体脑部的结构核磁共振图像、弥散张量核磁共振图像,作为输入图像;N为正整数;A100, obtain the structural MRI images and diffusion tensor MRI images of the individual brains of N subjects as input images; N is a positive integer;A200,对所述输入图像依次进行HCP最小预处理、ROI配准、ROI后处理,得到受试者个体脑部最终的丘脑ROI,并通过ODF估计算法,得到受试者个体脑部最终的丘脑ROI内每个体素的局部弥散特征;A200, sequentially perform HCP minimum preprocessing, ROI registration, and ROI postprocessing on the input image to obtain the final thalamus ROI of the subject's individual brain, and obtain the final thalamus ROI of the subject's individual brain through the ODF estimation algorithm. Local diffusion characteristics of each voxel within the ROI;A300,结合A200获取的局部弥散特征,计算体素之间的相似度,并进行聚类,得到受试者个体脑部最终的丘脑ROI内体素的聚类结果;A300, combined with the local diffusion characteristics obtained by A200, calculates the similarity between voxels and performs clustering to obtain the clustering results of voxels within the final thalamic ROI of the subject's individual brain;A400,将A300获取的聚类结果配准至标准空间,并进行标签重映射,得到受试者个体脑部最终的丘脑ROI内每个体素对应的亚区标签,即得到N个受试者个体脑部在标准空间中的丘脑分区;A400, register the clustering results obtained by A300 to the standard space, and perform label remapping to obtain the sub-region label corresponding to each voxel in the final thalamus ROI of the individual subject's brain, that is, N individual subjects are obtained thalamic partitioning of the brain in standard space;A500,计算受试者个体脑部最终的丘脑ROI内每个体素对应的亚区概率值,并去掉最大的亚区概率值低于第一阈值的体素点,然后将剩余的体素点构建群组水平的丘脑概率图谱,即群组丘脑概率图谱;所述亚区概率值为各亚区的受试者人数与总受试者人数的比值。A500, calculate the sub-region probability value corresponding to each voxel in the final thalamus ROI of the individual brain of the subject, remove the voxel points with the largest sub-region probability value lower than the first threshold, and then construct the remaining voxel points The thalamic probability map at the group level is the group thalamic probability map; the sub-region probability value is the ratio of the number of subjects in each sub-region to the total number of subjects.
- 一种电子设备,其特征在于,包括:An electronic device, characterized by including:至少一个处理器;以及与至少一个所述处理器通信连接的存储器;at least one processor; and a memory communicatively connected to at least one processor;其中,所述存储器存储有可被所述处理器执行的指令,所述指令用于被所述处理器执行以实现权利要求1-7任一项所述的群组先验引导的基于深度学习的丘脑个体化图谱绘制方法。Wherein, the memory stores instructions that can be executed by the processor, and the instructions are used by the processor to implement the group a priori guided deep learning based on any one of claims 1-7. A method for drawing individualized maps of the thalamus.
- 一种计算机可读存储介质,其特征在于,所述计算机可读存储介质存储有计算机指令,所述计算机指令用于被所述计算机执行以实现权利要求1-7任一项所述的群组先验引导的基于深度学习的丘脑个体化图谱绘制方法。A computer-readable storage medium, characterized in that the computer-readable storage medium stores computer instructions, and the computer instructions are used to be executed by the computer to implement the group of any one of claims 1-7 A priori-guided deep learning-based personalized mapping method for the thalamus.
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CN113610808A (en) * | 2021-08-09 | 2021-11-05 | 中国科学院自动化研究所 | Individual brain atlas individualization method, system and equipment based on individual brain connection atlas |
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CN114376558A (en) * | 2022-03-24 | 2022-04-22 | 之江实验室 | Brain atlas individuation method and system based on magnetic resonance and twin map neural network |
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CN111081351A (en) * | 2019-12-02 | 2020-04-28 | 北京优脑银河科技有限公司 | Method and system for drawing brain function map |
US20220020154A1 (en) * | 2020-07-15 | 2022-01-20 | Siemens Healthcare Gmbh | Method and system for characterizing an impact of brain lesions on brain connectivity using mri |
CN113610808A (en) * | 2021-08-09 | 2021-11-05 | 中国科学院自动化研究所 | Individual brain atlas individualization method, system and equipment based on individual brain connection atlas |
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