WO2019232688A1 - Method, apparatus, and computing device for segmenting veins in magnetic susceptibility weighted image - Google Patents

Method, apparatus, and computing device for segmenting veins in magnetic susceptibility weighted image Download PDF

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WO2019232688A1
WO2019232688A1 PCT/CN2018/089899 CN2018089899W WO2019232688A1 WO 2019232688 A1 WO2019232688 A1 WO 2019232688A1 CN 2018089899 W CN2018089899 W CN 2018089899W WO 2019232688 A1 WO2019232688 A1 WO 2019232688A1
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image block
brain
swi
convolution
neural network
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PCT/CN2018/089899
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French (fr)
Chinese (zh)
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张晓东
张轶群
胡庆茂
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中国科学院深圳先进技术研究院
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Publication of WO2019232688A1 publication Critical patent/WO2019232688A1/en

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    • G06COMPUTING; CALCULATING OR COUNTING
    • G06TIMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00Image analysis

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  • the invention belongs to the field of image processing, and particularly relates to a method, a device, and a computing device for segmenting a venous blood vessel in a magnetically sensitive weighted image.
  • Acute ischemic stroke has high morbidity, high mortality, and high recurrence rate.
  • SWI magnetically sensitive weighted images
  • DWI magnetic resonance diffusion weighted images
  • SWI veins are smaller. There is only 1 to 2 voxels in the radius of the narrow area; 2) there is a very large difference in the apparent appearance of the SWI vein signal, which makes it difficult for experts to mark; And gray level changes are various.
  • the prior art generally uses shallow features to classify voxels in a brain computed tomography image (CTA) or magnetic resonance imaging (MRA) image to achieve cerebral arterial segmentation.
  • CTA brain computed tomography image
  • MRA magnetic resonance imaging
  • the region-based active contour method can utilize both grayscale and shape information, and iteratively optimizes through level set to achieve blood vessel segmentation.
  • this method uses shallow features such as grayscale and shape, it has limited recognition ability and low segmentation accuracy.
  • An object of the present invention is to provide a method, a device, and a computing device for segmenting a venous blood vessel in a magnetically sensitive weighted image to accurately segment a venous blood vessel in a magnetically sensitive weighted image.
  • a first aspect of the present invention provides a method for segmenting a venous blood vessel in a magnetically sensitive weighted image.
  • the method includes:
  • a set of first image blocks and second image blocks with coincident centers are extracted centering on any one sampling point defined by m voxels per interval m in the standardized brain SWI.
  • the area of the first image block includes M 1 * A voxel arranged in a M 1 order matrix
  • the region of the second image block includes a voxel arranged in a M 2 * M 2 order matrix
  • the n, m, M 1 and M 2 are natural numbers, and M 2 > M 1 >m;
  • the trained convolutional neural network is trained on the convolutional neural network through a supervised learning method, and the area of the third image block includes m * m-order matrix arranged voxels;
  • a device for segmenting a venous blood vessel in a magnetically sensitive weighted image includes:
  • a normalization module for extracting and normalizing brain regions in the original brain magnetically sensitive weighted image SWI to obtain a standardized brain SWI;
  • An image block extraction module for extracting a set of first image blocks and second image blocks with coincident centers centered on any one sampling point defined by every voxel in the standardized brain SWI
  • the region of contains the voxels arranged in a M 1 * M 1 order matrix
  • the region of the second image block contains the voxels arranged in a M 2 * M 2 order matrix, where m, M 1 and M 2 are Natural number, and M 2 > M 1 >m;
  • a labeling module configured to input n groups of first image blocks and second image blocks to a trained convolutional neural network, and the trained convolutional neural network
  • the venous vessels are labeled to obtain two sets of n third image blocks labeled with venous vessels.
  • the trained convolutional neural network is trained by a convolutional neural network in a supervised learning manner, and the area of the third image block includes Voxels arranged in an m * m order matrix, where n is the number of the sampling points;
  • a mapping module configured to map the venous blood vessel marks of the n sets of two third image blocks back to the original brain magnetically sensitive weighted image SWI to obtain a venous blood vessel segmentation result.
  • a third aspect of the present invention provides a computing device, including a memory, a processor, and a computer program stored in the memory and executable on the processor.
  • the processor executes the computer program, the following method is implemented: step:
  • a set of first image blocks and second image blocks with coincident centers are extracted centering on any one sampling point defined by m voxels per interval m in the standardized brain SWI.
  • the area of the first image block includes M 1 * A voxel arranged in a matrix of order M 1
  • the region of the second image block includes a voxel arranged in a matrix of order M 2 * M 2
  • the m, M 1 and M 2 are natural numbers, and M 2 > M 1 >m;
  • Input n sets of first image blocks and second image blocks to a trained convolutional neural network and the trained convolutional neural network marks the venous blood vessels in the n sets of first image blocks and second image blocks
  • the n groups of two third image blocks labeled with venous blood vessels are obtained, and the trained convolutional neural network is trained on the convolutional neural network through a supervised learning method.
  • the region of the third image block includes m * m orders. Voxels arranged in a matrix, where n is the number of sampling points;
  • a fourth aspect of the present invention provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the following method are implemented:
  • a set of first image blocks and second image blocks with coincident centers are extracted centering on any one sampling point defined by m voxels per interval m in the standardized brain SWI.
  • the area of the first image block includes M 1 * A voxel arranged in a matrix of order M 1
  • the region of the second image block includes a voxel arranged in a matrix of order M 2 * M 2
  • the m, M 1 and M 2 are natural numbers, and M 2 > M 1 >m;
  • Input n sets of first image blocks and second image blocks to a trained convolutional neural network and the trained convolutional neural network marks the venous blood vessels in the n sets of first image blocks and second image blocks
  • the n groups of two third image blocks labeled with venous blood vessels are obtained, and the trained convolutional neural network is trained on the convolutional neural network through a supervised learning method.
  • the region of the third image block includes m * m orders. Voxels arranged in a matrix, where n is the number of sampling points;
  • the trained convolutional neural network is trained on the convolutional neural network through a supervised learning method
  • the supervised learning automatically learns prior knowledge from existing data and extracts deep features, thereby being able to Accurately identifying the venous blood vessels in the brain SWI, compared with the prior art, the accuracy of venous blood vessel segmentation in the brain SWI is improved.
  • FIG. 1 is a schematic flowchart of an implementation method of a method for segmenting a venous blood vessel in a magnetically sensitive weighted image according to an embodiment of the present invention
  • FIG. 2 is a schematic diagram of a voxel and its sampling points in a standardized brain SWI according to an embodiment of the present invention
  • FIG. 3 is a schematic structural diagram of a convolutional neural network according to an embodiment of the present invention.
  • FIG. 4 is a schematic structural diagram of a device for segmenting a venous blood vessel in a magnetically sensitive weighted image according to an embodiment of the present invention
  • FIG. 5 is a schematic structural diagram of a device for segmenting a vein and a blood vessel in a magnetically sensitive weighted image according to another embodiment of the present invention.
  • FIG. 6 is a schematic structural diagram of a computing device according to an embodiment of the present invention.
  • FIG. 1 is a schematic flowchart of an implementation method of a method for segmenting a venous blood vessel in a magnetically sensitive weighted image according to an embodiment of the present invention, which mainly includes the following steps S101 to S104, which are described in detail below:
  • S101 Extract and normalize a brain region in the original brain magnetically sensitive weighted image SWI to obtain a standardized brain SWI.
  • the brain region in the original brain magnetically sensitive weighted image SWI is extracted in order to exclude the interference of the skull and other non-brain tissues; the extracted brain region in the SWI, that is, the brain mask image belongs to the pre- Process.
  • extracting and normalizing the brain region in the original brain magnetically sensitive weighted image SWI, and obtaining a standardized brain SWI includes the following implementation process: using a threshold method to extract all background voxels whose gray value in the original brain SWI is less than 50, And extract the largest connected region; after inverting the largest connected region, use a 3 * 3 * 3 size structural element to perform morphological closing operation to restore the threshold segmentation of the lost vein voxels; calculate the brain region in the original brain SWI Voxel mean and standard deviation, the mean value of each voxel of the brain region in the original brain SWI is subtracted from the mean and divided by the standard deviation to obtain a standardized brain SWI.
  • a set of first and second image blocks with coincident centers is extracted centered on any one sampling point defined by every voxel in the normalized brain SWI.
  • the area of the first image block includes M 1 *
  • the voxels are arranged in M 1 order matrix.
  • the area of the second image block includes voxels arranged in M 2 * M 2 order matrix, m, M 1 and M 2 are natural numbers, and M 2 > M 1 > m.
  • FIG. 2 An example of the standardized brain SWI obtained in step S101 is shown in FIG. 2.
  • the small white circles and small black circles represent the voxels of the standardized brain SWI.
  • the small white circles labeled 1, 2, 3, and 4 Represents a sampling point. Obviously, these sampling points are also voxels, and are spaced apart by 9 voxels.
  • the technical solution of the present invention is to use these sampling points as the center to extract a set of first image blocks and second image blocks with coincident centers.
  • extracting a set of first and second image blocks with coincident centers is an extraction region containing voxels arranged in a 25 * 25 order matrix.
  • the image blocks and regions contain image blocks of voxels arranged in a 57 * 57 order matrix. These two image blocks are a group, and the centers of the image blocks are centered on the sampling point labeled 1.
  • extracting a set of first and second image blocks with coincident centers is an extraction region containing a 25 * 25 order matrix.
  • the image block and region of the voxel contain image blocks of voxels arranged in a 57 * 57 order matrix. These two image blocks are a group, and the centers of the image blocks are centered on the sampling point labeled 2. .
  • the trained convolutional neural network performs venous blood vessels in the n sets of first image blocks and second image blocks.
  • two sets of three third image blocks labeled with venous blood vessels can be obtained, where the region of the third image block contains voxels arranged in a matrix of order m * m.
  • m 9
  • the third image The area of the block contains voxels arranged in a 9 * 9 order matrix.
  • the trained convolutional neural network is trained on the convolutional neural network through a supervised learning method, which can be extracted and standardized from the brain region in the original brain SWI to obtain a standardized brain SWI. That is, before the brain region in the original brain SWI is extracted and standardized to obtain a standardized brain SWI, steps S1031 to S1033 of the following method are further included:
  • S1031 Extract a training image block pair and a vein segmentation gold standard image block corresponding to the training image block pair from the brain SWI for training, where the training image block pair is composed of a first training image block and a second training image block.
  • the extracted training image block pair and the vein segmentation gold standard image block corresponding to the training image block pair are used to train a convolutional neural network, wherein the vein segmentation gold standard image block is based on artificial (generally (Experts) Experience
  • the image blocks obtained by labeling the venous low signal in the training image are all randomly collected the same number of sample voxels from the venous region and the background region of the brain SWI used for training. Extracted as the center.
  • the sizes of the first training image block and the second training image block are respectively a set of center coincident with a set of centers extracted from any one of the sampling points defined in the normalized brain SWI in each interval m voxels.
  • One image block and the second image block are the same size, that is, the area of the first training image block contains voxels arranged in a M 1 * M 1 order matrix, and the area of the second training image block contains M 2 * M 2 Order voxels, and the size of the gold standard image block for vein segmentation is the same as the size of the third image block in the previous embodiment, that is, the area of the gold standard image block for vein segmentation includes the m * m order matrix. Voxels.
  • the area of the first image block in the foregoing embodiment contains voxels arranged in a 25 * 25 order matrix
  • the area of the second image block contains voxels arranged in a 57 * 57 order matrix
  • the area of the first training image block contains voxels arranged in a 25 * 25 order matrix
  • the area of the second training image block contains voxels arranged in a 57 * 57 order matrix
  • the third image block in the foregoing embodiment The region of contains the voxels arranged in a 9 * 9 order matrix
  • the area of the gold standard image block for vein segmentation contains the voxels arranged in a 9 * 9 order matrix.
  • a training image block pair is extracted from the brain SWI used for training and the vein segmentation gold corresponding to the training image block pair Before the standard image block, the SWI of the brain used for training is also symmetrically reversed along the X-axis and Y-axis of the two-dimensional coordinate system, and in order to enhance the robustness of the convolutional neural network to grayscale changes, After extracting a training image block pair from a brain SWI used for training and dividing a vein standard gold standard image block corresponding to the training image block pair, the method further includes a voxel grayscale for the first training image block and the second training image block.
  • I ' S I S + r * ⁇ c , where r is a random number sampled from a normal distribution N (0,1), and ⁇ c is the first training image block or the second training image block
  • the gray standard deviation, I ′ S is a gray value after transforming the gray I S in the first training image block or the second training image block.
  • constructing a convolutional neural network includes constructing a first convolution path, a second convolution path, a third convolution path, and a classifier, and the first convolution path, the second convolution path, A third convolution path is connected to the classifier, where the first convolution path is used to process the first training image block, the second convolution path is used to process the second training image block, and the first convolution path Or the second convolution path includes 8 convolution modules and 3 series layers, the second convolution path also includes a downsampling unit and an upsampling unit, and the third convolution path includes 3 convolution modules and 2 series Layer, the convolution modules 1 to 8 of the eight convolution modules are connected in series, and the outputs of convolution module 2 and convolution module 4 are connected to the input of layer 1 in series, and the output of layer 1 and convolution are connected in series.
  • the output of module 6 is connected to the input of serial layer 2 respectively, the output of serial layer 2 and the output of convolution module 8 are connected to the input of serial layer 3 respectively;
  • the input is connected to the output of the downsampling unit, and the second convolution
  • the output of serial layer 3 in the path is connected to the input of the upsampling unit.
  • the output of the upsampling unit and the output of serial layer 3 in the first convolution path are connected to the input of serial layer 1 in the third convolution path.
  • convolution module 1 in the third convolution path is connected in series with convolution module 2, the input end of convolution module 1 in the third convolution path is connected to the output end of series layer 1 in the third convolution path, and the third volume
  • the output of convolution module 2 in the convolution path and the output of series layer 1 in the third convolution path are connected to the input of series layer 2 in the third convolution path, and the output of series layer 2 in the third convolution path.
  • the input of the convolution module 3 in the third convolution path, and the output of the convolution module 3 in the third convolution path is connected to the classifier.
  • the structure of the entire convolutional neural network is shown in FIG. 3.
  • the first convolution path is used to process the first training image block
  • the second convolution path is used to process the second training image block.
  • the convolution nerve of the present invention illustrated in FIG. 3 The network is a multi-scale convolutional neural network. After the multi-scale convolutional neural network is trained, a multi-scale trained convolutional neural network is obtained.
  • the convolution modules of the first convolution path, the second convolution path, and the third convolution path all have the same structure, and each includes a batch standardized BN layer and a non-linear mapping PReLU layer.
  • conv layer Conv where the normalized BN layer solves the covariance shift problem in the neural network by normalizing the feature map of the incoming convolution layer, and the non-linear mapping PReLU layer implements the non-linear mapping of convolution features and avoids Conventional excitation functions, such as the disappearance of the gradient caused by saturation of the Sigmoid function, accelerate the convergence.
  • the conv layer Conv defines the convolution kernel (the size of the convolution kernel in the first and second convolution paths is 3x3, and the third convolution The size of the convolution kernel in the path is 1x1), and the convolution operation is implemented (the convolution step is 1):
  • [ ⁇ ] represents a tandem operation
  • x l represents a feature map of the output of the l-th convolution layer
  • the center part of the feature map x l-2 representing the output of the l-2 convolution layer is the same as x l .
  • An upsampling unit is added at the end of the second convolution path to achieve the output feature map size matching of the two convolution paths.
  • the feature maps sampled by the upsampling unit and the feature maps output from the third series layer of the first convolution path are connected in series and processed by the third convolution path.
  • the third convolution path also consists of a convolution module and a series layer. The difference is that the convolution kernels of the convolution layer in the convolution module of the third convolution path have a size of 1x1 and a step size of 1, so the third volume
  • the product path does not change the size of the output feature map.
  • the feature map processed by the output of the third convolution module in the third convolution path is processed by a classifier, such as a Softmax classifier, to obtain the input image block center m * m.
  • a classifier such as a Softmax classifier
  • the individual voxels belong to the vein or background. Probability and labeling.
  • the first training image block and the second training image block are input to a convolutional neural network, and the convolutional neural network is trained according to the vein segmentation gold standard image block to obtain a trained convolutional neural network.
  • the first training image block and the second training image block are input to the convolutional neural network, and the convolutional neural network is trained according to the vein segmentation gold standard image block.
  • the trained convolutional neural network can be achieved through the following steps S1 and S2 :
  • the above loss function is a loss function defined by the Dice coefficient, where the predicted image block is the predicted output result after the first training image block and the second training image block are input to the convolutional neural network, and B is the process of training the convolutional neural network.
  • the number of training image block pairs processed at a time N is the number of voxels in the predicted image block, p ij is the probability that the jth voxel in the corresponding prediction image block of the i-th training image block belongs to the vein, and y ij
  • the i-th training image block is the true label of the j-th voxel in the corresponding vein segmentation gold standard image block, and the training image block pair is a combination of the first training image block and the second training image block mentioned in the foregoing embodiment. Pair of training image blocks.
  • the parameters of the convolutional neural network obtained at that time are the parameters of the trained convolutional neural network, which means that the convolutional neural network has been trained and can be used for data prediction, that is, to segment the vein blood vessels in the magnetically sensitive weighted image. Specifically, it will be extracted.
  • the first image block of each of the n groups of the first image block and the second image block is input to the first convolution path of the trained neural network, and the second image block of each group is input to the second volume of the trained neural network.
  • the trained convolutional neural network of the present invention is a multi-scale trained convolutional neural network
  • n sets of first image blocks and second image blocks are input to the trained convolutional neural network.
  • multi-scale trained convolutional neural network marks the venous blood vessels in the n sets of first image blocks and second image blocks
  • different sizes of first image blocks and second image blocks are used to obtain different ranges of context information
  • small image blocks mainly capture local information, while large image blocks focus more on global information.
  • the two kinds of information complement each other, thereby improving the performance of the convolutional neural network and the accuracy of vein segmentation.
  • n groups of two third image blocks labeled with venous vessels are obtained, and n groups of two third images are obtained.
  • the venous blood vessel label of each third image block of the block is mapped back to the original brain magnetically sensitive weighted image SWI to obtain the venous blood vessel segmentation result.
  • the specific mapping method is based on the space of the center of each third image block in the original image. Position, map a 9x9 size prediction marker around the center of the third image block to the original image. For example, the center coordinate of a third image block is (100, 100).
  • a 9x9 labeled area is obtained, and the label is mapped to [96: 104, 96: 104] to obtain the segmentation results of venous blood vessels.
  • the convolutional neural network provided by the present invention can extract deep features with stronger recognition capabilities. Compared with shallow features such as grayscale and shape, depth features have a better ability to identify problems such as uneven grayscale of veins and veins and background grayscale overlap.
  • the convolutional network provided by the present invention adds residual connections, and uses the loss function defined by the Dice coefficient to guide the training of the convolutional neural network, and the performance of the convolutional neural network is further improved. As shown in Table 1, the method provided by the present invention has the highest Dice coefficient in the segmentation result.
  • the single prediction type convolutional network adopts the same structure as the convolutional neural network provided by the present invention, but its input image block size is 17x17.
  • ischemic stroke is a recognized worldwide problem in the medical community, and its diagnosis process is quite complicated.
  • the technical solution of the present invention combines a convolutional neural network, it accurately segmentes the magnetically sensitive weighted images through image processing. Venous blood vessels, but this process is only used as a process to obtain an intermediate result, and the result is only used as an intermediate result. It cannot be directly used as a diagnosis of ischemic stroke. Obtain the health status of patients with ischemic stroke directly.
  • the trained convolutional neural network is trained on the convolutional neural network through a supervised learning method, the supervised learning is automatically used from the existing data. Learning prior knowledge and extracting deep features can accurately identify venous blood vessels in the brain SWI. Compared with the prior art, the accuracy of venous blood vessel segmentation in the brain SWI is improved.
  • FIG. 4 is a schematic diagram of a device for segmenting a venous blood vessel in a magnetically sensitive weighted image according to an embodiment of the present invention, which mainly includes a normalization module 401, an image block extraction module 402, a labeling module 403, and a mapping module 404.
  • a normalization module 401 an image block extraction module 402
  • a labeling module 403 a labeling module 403
  • a mapping module 404 a mapping module
  • a normalization module 401 configured to extract and normalize brain regions in the original brain magnetically sensitive weighted image SWI to obtain a standardized brain SWI;
  • An image block extraction module 402 is used to extract a set of first image blocks and second image blocks with coincident centers around any one sampling point defined by m voxels per interval m in standardized brain SWI.
  • the region contains voxels arranged in a matrix of order M 1 * M 1
  • the region of the second image block contains voxels arranged in matrix of order M 2 * M 2
  • m, M 1 and M 2 are natural numbers, and M 2 > M 1 >m;
  • a labeling module 403 configured to input n sets of first image blocks and second image blocks to a trained convolutional neural network, and the trained convolutional neural network performs venous blood vessels in the n sets of first image blocks and second image blocks After labeling, two sets of third image blocks labeled with venous blood vessels are obtained.
  • the trained convolutional neural network is trained on the convolutional neural network through a supervised learning method.
  • the area of the third image block includes m * m orders. Voxels arranged in a matrix, n is the number of sampling points;
  • the mapping module 404 is configured to map the venous blood vessel marks of the n sets of two third image blocks back to the original brain magnetically sensitive weighted image SWI to obtain the venous blood vessel segmentation result.
  • the normalization module 401 illustrated in FIG. 4 may include an extraction unit 501, a negation unit 502, and a calculation unit 503, such as the device for segmenting a vein and blood vessel in a magnetically sensitive weighted image illustrated in FIG. 5, where:
  • An extraction unit 501 configured to extract all background voxels with a gray value less than 50 in the original brain SWI by using a threshold method, and extract a maximum connected region;
  • the inversion unit 502 is configured to perform a morphological closing operation using a 3 * 3 * 3 size structural element after inverting the largest connected region to restore the threshold segmentation of the lost vein voxels;
  • the calculation unit 503 is configured to calculate the mean and standard deviation of the voxels of the brain region in the original brain SWI, subtract the mean value of each voxel of the brain region in the original brain SWI, and divide by the standard deviation to obtain a standardized brain SWI.
  • the apparatus illustrated in FIG. 4 may further include a training image block extraction module, a construction module, and a training module, where:
  • a training image block extraction module is configured to extract a training image block pair from a brain SWI used for training and a vein standard gold standard image block corresponding to the training image block pair.
  • the training image block pair is composed of a first training image block.
  • a second training image block the region of the first training image block includes voxels arranged in a M 1 * M 1 order matrix, and the region of the second training image block includes a M 2 * M 2 order matrix Arranged voxels, the region of the vein-segmented gold standard image block including voxels arranged in an m * m order matrix;
  • a training module configured to input the first training image block and the second training image block into the convolutional neural network, and train the convolutional neural network according to the vein segmentation gold standard image block to obtain the trained Convolutional neural network.
  • the apparatus of the above embodiment further includes an inversion module and a transformation module, where:
  • Inversion module used for training image block extraction module to extract the training image block pair from the brain SWI used for training and before dividing the vein standard gold standard image block corresponding to the training image block pair to the training brain block SWI performs symmetrical inversions along the X and Y axes of the two-dimensional coordinate system, respectively;
  • a transformation module for training image block extraction module to extract a training image block pair from a brain SWI used for training and a vein segmentation gold standard image block corresponding to the training image block pair, and then to the first training image block and
  • the construction module of the above embodiment is specifically configured to construct a first convolution path, a second convolution path, a third convolution path, and a classifier, and perform the first convolution path, the second convolution path, and the third convolution.
  • the path and the classifier are connected, the first convolution path is used to process the first training image block, the second convolution path is used to process the second training image block, and the first A convolution path or a second convolution path includes 8 convolution modules and 3 series layers, the second convolution path further includes a downsampling unit and an upsampling unit, and the third convolution path includes 3 Convolution modules and two series layers; after the first to eighth convolution modules of the eight convolution modules are connected in series, the output ends of the second and fourth convolution modules are respectively connected to the first The inputs of the two series layers are connected, the output of the first series layer and the output of the sixth convolution module are connected to the inputs of the second series layer, the output of the second series layer and the eighth The output end of the convolution
  • the output end of the upsampling unit and the output end of the third series layer in the first convolution path are respectively connected to the input end of the first series layer in the third convolution path; the third convolution The first convolution module in the path is connected in series with the second convolution module, and the input of the first convolution module in the third convolution path is connected to the output of the first series layer in the third convolution path. And the output end of the second convolution module in the third convolution path and the output end of the first series layer in the third convolution path are respectively connected to the second series layer in the third convolution path.
  • the input end of the third convolution path is connected to the output end of the second series layer in the third convolution path and the input end of the third convolution module in the third convolution path.
  • An output end of each convolution module is connected to the classifier.
  • the training module of the above embodiment further includes a function definition unit and a network training unit, where:
  • a function defining unit configured to define a loss function using a predicted image block and the vein segmentation gold standard image block
  • the predicted image block is a predicted output result after the first training image block and the second training image block are input to a convolutional neural network
  • B is the number of training image block pairs processed at one time during the training process of the convolutional neural network
  • N is the number of voxels in the predicted image block
  • p ij is the probability that the j-th voxel in the corresponding predicted image block belongs to the vein vein
  • y ij is the i-th training image block paired with the corresponding vein Segment the true label of the jth voxel in the gold standard image block
  • a network training unit is configured to use a first training image block and a second training image block as input features to train a convolutional neural network based on a batch gradient descent algorithm, and obtain parameters of the convolutional neural network while minimizing a loss function.
  • FIG. 6 is a schematic structural diagram of a computing device according to an embodiment of the present invention.
  • the computing device 6 of this embodiment includes a processor 60, a memory 61, and a computer program 62 stored in the memory 61 and executable on the processor 60, such as segmentation of a venous vessel in a magnetically sensitive weighted image Method of Procedure.
  • the processor 60 executes the computer program 62, the steps in the embodiment of the method for segmenting venous blood vessels in the magnetically sensitive weighted image described above are implemented, for example, steps S101 to S104 shown in FIG.
  • the processor 60 executes the computer program 62, the functions of the modules / units in the foregoing device embodiments are realized, such as the functions of the standardization module 401, image block extraction module 402, marking module 403, and mapping module 404 shown in FIG.
  • the computer program 62 of the method for segmenting venous blood vessels in a magnetically sensitive weighted image mainly includes: extracting and normalizing a brain region in the original brain magnetically sensitive weighted image SWI to obtain a standardized brain SWI; An arbitrary sampling point defined by an interval m voxels is taken as the center, and a set of first and second image blocks with coincident centers is extracted.
  • the area of the first image block includes voxels arranged in a M 1 * M 1 order matrix.
  • the region of the second image block contains voxels arranged in a M 2 * M 2 order matrix, m, M 1 and M 2 are natural numbers, and M 2 > M 1 >m; input n groups of the first image block and the second
  • the image block to the trained convolutional neural network, and the trained convolutional neural network marks the venous vessels in the n sets of first and second image blocks to obtain two sets of n labeled third venous vessels Image block, which has been trained by the trained convolutional neural network through supervised learning.
  • the area of the third image block contains voxels arranged in a matrix of order m * m, and n is the number of sampling points.
  • the computer program 62 may be divided into one or more modules / units, and the one or more modules / units are stored in the memory 61 and executed by the processor 60 to complete the present invention.
  • One or more modules / units may be a series of computer program instruction segments capable of performing a specific function, and the instruction segments are used to describe the execution process of the computer program 62 in the computing device 6.
  • the computer program 62 may be divided into functions (modules in a virtual device) of the normalization module 401, the image block extraction module 402, the marking module 403, and the mapping module 404.
  • each module The specific functions of each module are as follows: The brain region in the brain magnetically sensitive weighted image SWI is extracted and standardized to obtain a standardized brain SWI.
  • the image block extraction module 402 is used to center any one of the sampling points defined by m voxels in the standardized brain SWI as The first image block and the second image block coincide with the center of the group.
  • the area of the first image block contains voxels arranged in a M 1 * M 1 order matrix, and the area of the second image block contains a M 2 * M 2 order matrix.
  • the arranged voxels, m, M 1 and M 2 are natural numbers, and M 2 > M 1 >m; the labeling module 403 is used to input n sets of first image blocks and second image blocks to the trained convolutional neural network , After training the convolutional neural network to label the venous blood vessels in the n groups of the first image block and the second image block, two sets of n third image blocks labeled with the venous blood vessel are obtained.
  • the trained convolutional neural network passes the supervision Learning style Product neural network training, the area of the third image block contains voxels arranged in a matrix of order m * m, n is the number of sampling points; the mapping module 404 is used to convert n groups of two third image blocks into Vein vein markers are mapped back to the original brain magnetically sensitive weighted image SWI to obtain the segmentation results of vein veins.
  • the computing device 6 may include, but is not limited to, a processor 60 and a memory 61. Those skilled in the art can understand that FIG. 6 is only an example of the computing device 6 and does not constitute a limitation on the computing device 6. It may include more or fewer components than shown in the figure, or combine some components or different components. For example, computing devices may also include input and output devices, network access devices, and buses.
  • the so-called processor 60 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), Ready-made programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.
  • a general-purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
  • the memory 61 may be an internal storage unit of the computing device 6, such as a hard disk or a memory of the computing device 6.
  • the memory 61 may also be an external storage device of the computing device 6, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) card, and a flash memory card (Flash) provided on the computing device 6. Card) and so on.
  • the memory 61 may also include both an internal storage unit of the computing device 6 and an external storage device.
  • the memory 61 is used to store computer programs and other programs and data required by the computing device.
  • the memory 61 may also be used to temporarily store data that has been output or is to be output.
  • the disclosed apparatus / computing device and method may be implemented in other ways.
  • the device / computing device embodiments described above are only schematic.
  • the division of modules or units is only a logical function division.
  • there may be another division manner, such as multiple units or components. Can be combined or integrated into another system, or some features can be ignored or not implemented.
  • the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, which may be electrical, mechanical or other forms.
  • the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, may be located in one place, or may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objective of the solution of this embodiment.
  • each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist separately physically, or two or more units may be integrated into one unit.
  • the above integrated unit may be implemented in the form of hardware or in the form of software functional unit.
  • integrated modules / units When integrated modules / units are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the method of the above embodiment, and can also be performed by a computer program instructing related hardware.
  • the computer program of the method for segmenting a vein in a magnetically sensitive weighted image can be stored in a computer In a readable storage medium, when the computer program is executed by a processor, it can implement the steps of the above method embodiments, that is, extract and normalize the brain region in the original brain magnetically sensitive weighted image SWI to obtain a standardized brain SWI ; Extracting a set of first and second image blocks that coincide with each other at the center of any sampling point defined by every voxel in the normalized brain SWI.
  • the area of the first image block includes M 1 * M 1 order Voxels arranged in a matrix
  • the region of the second image block includes voxels arranged in a matrix of order M 2 * M 2
  • m, M 1 and M 2 are natural numbers, and M 2 > M 1 >m
  • input n groups The first image block and the second image block to the trained convolutional neural network, and the trained convolutional neural network marks the venous vessels in the n groups of the first image block and the second image block to obtain a label
  • the n groups of two third image blocks of the venous blood vessels are trained by the trained convolutional neural network to train the convolutional neural network through a supervised learning method.
  • the region of the third image block contains voxels arranged in a m * m order matrix.
  • N is the number of sampling points; map the venous blood vessel marks of the two third image blocks of the n groups back to the original brain magnetic sensitive weighted image SWI to obtain the venous blood vessel segmentation result.
  • the computer program includes computer program code, and the computer program code may be in a source code form, an object code form, an executable file, or some intermediate form.
  • the computer-readable medium may include: any entity or device capable of carrying computer program code, a recording medium, a USB flash drive, a mobile hard disk, a magnetic disk, an optical disc, a computer memory, a read-only memory (ROM, Read-Only Memory), random access Memory (RAM, Random Access Memory), electric carrier signals, telecommunication signals, and software distribution media.
  • ROM Read-Only Memory
  • RAM random access Memory
  • electric carrier signals telecommunication signals
  • software distribution media e.g., any entity or device capable of carrying computer program code, a recording medium, a USB flash drive, a mobile hard disk, a magnetic disk, an optical disc, a computer memory, a read-only memory (ROM, Read-Only Memory), random access Memory (RAM, Random Access Memory), electric carrier signals, telecommunication signals, and software distribution media.
  • the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of the legislation and patent practice in the jurisdiction.
  • the computer-readable medium does not include Electric carrier signals and telecommunication signals

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Abstract

The present invention pertains to the field of image processing, and provides a method, an apparatus, and a computing device for segmenting veins in a magnetic susceptibility weighted image, so as to accurately segment veins in a magnetic susceptibility weighted image. The method comprises: extracting and normalizing a brain region in an original brain SWI to obtain a normalized brain SWI; extracting a set of first image blocks and second image blocks having coincidental centers by using any one of sampling points defined in the normalized brain SWI at an interval of m voxels; inputting n sets of first image blocks and second image blocks into a trained convolutional neural network, such that the trained convolutional neural network marks veins in the n sets of first image blocks and second image blocks to obtain n sets of third image block pairs having marked veins; and mapping the veins in the n sets of third image block pairs back to the original brain SWI to obtain a vein segmentation result. The present invention enables accurate identification of veins in a brain SWI and an improvement in the precision of vein segmentation in the brain SWI.

Description

分割磁敏感加权图像中静脉血管的方法、装置和计算设备Method, device and computing device for segmenting venous blood vessels in magnetically sensitive weighted image 技术领域Technical field
本发明属于图像处理领域,尤其涉及一种分割磁敏感加权图像中静脉血管的方法、装置和计算设备。The invention belongs to the field of image processing, and particularly relates to a method, a device, and a computing device for segmenting a venous blood vessel in a magnetically sensitive weighted image.
背景技术Background technique
急性缺血性脑卒中具有高发病率、高死亡率和高复发率。近年来,研究表明,磁敏感加权图像(Susceptibility Weighted Image,SWI)比磁共振弥散加权图像(Diffusion Weighted Image,DWI)对于急性脑缺血更加敏感,能够在脑缺血脑部患侧呈现静脉低信号,从而得到越来越多的重视。利用脑缺血患者脑部患侧与正常侧的静脉非对称性特征,可以用来进行急性脑缺血诊断、治疗规划和预后预测。Acute ischemic stroke has high morbidity, high mortality, and high recurrence rate. In recent years, studies have shown that magnetically sensitive weighted images (SWI) are more sensitive to acute cerebral ischemia than magnetic resonance diffusion weighted images (DWI), and they can show lower veins on the affected side of cerebral ischemia Signals are getting more and more attention. The asymmetric features of the venous and normal sides of the brain in patients with cerebral ischemia can be used for diagnosis, treatment planning and prognosis prediction of acute cerebral ischemia.
目前多数工作是基于定性分析,而缺少定量分析手段。SWI定量分析的关键是静脉低信号的精确分割。由有经验的专家十分专注仔细地对SWI进行逐层手工标记静脉低信号可得到较好的分割结果。然而手工标记依赖于专家经验和投入的精力,是一项非常耗时耗力的工作,且可重复性差。因此,SWI静脉低信号的自动分割方法成为一个迫切需求。这也是本发明所要解决的技术问题。Most of the current work is based on qualitative analysis, but lack of quantitative analysis methods. The key to quantitative SWI analysis is accurate segmentation of low-vein signals. Experienced experts are very focused and carefully carry out layer-by-layer manual labeling of venous low signals on SWI to obtain better segmentation results. However, manual labeling depends on expert experience and effort, which is a very time-consuming and labor-intensive task and is not repeatable. Therefore, the automatic segmentation of SWI veins with low signal becomes an urgent need. This is also a technical problem to be solved by the present invention.
SWI静脉低信号分割具有如下挑战:1)相对于脑部动脉,SWI静脉更加细小。在狭窄区域半径只有1到2个体素;2)SWI静脉信号表观存在非常大的差异性,使得专家标注非常困难;3)受到脑缺血发生区域和严重程度影响,SWI静脉低信号的位置和灰度高低变化多样。The low signal segmentation of SWI veins has the following challenges: 1) Compared with cerebral arteries, SWI veins are smaller. There is only 1 to 2 voxels in the radius of the narrow area; 2) there is a very large difference in the apparent appearance of the SWI vein signal, which makes it difficult for experts to mark; And gray level changes are various.
针对这些挑战,现有技术通常使用浅层特征来对脑部计算机断层造影图像(CTA)或者磁共振造影图像(MRA)中的体素进行分类,实现脑动脉血管分割。例如,基于区域的主动轮廓方法能够同时利用灰度和形状信息,并通过水平集迭代方式进行优化,实现血管分割。然而,这种方法由于使用的是灰度、 形状等浅层特征,因而识别能力有限,分割精度较低。In response to these challenges, the prior art generally uses shallow features to classify voxels in a brain computed tomography image (CTA) or magnetic resonance imaging (MRA) image to achieve cerebral arterial segmentation. For example, the region-based active contour method can utilize both grayscale and shape information, and iteratively optimizes through level set to achieve blood vessel segmentation. However, because this method uses shallow features such as grayscale and shape, it has limited recognition ability and low segmentation accuracy.
发明内容Summary of the Invention
本发明的目的在于提供一种分割磁敏感加权图像中静脉血管的方法、装置和计算设备,以精确分割出磁敏感加权图像中的静脉血管。An object of the present invention is to provide a method, a device, and a computing device for segmenting a venous blood vessel in a magnetically sensitive weighted image to accurately segment a venous blood vessel in a magnetically sensitive weighted image.
本发明第一方面提供一种分割磁敏感加权图像中静脉血管的方法,所述方法包括:A first aspect of the present invention provides a method for segmenting a venous blood vessel in a magnetically sensitive weighted image. The method includes:
对原始脑磁敏感加权图像SWI中的脑部区域进行提取并标准化,得到标准化脑SWI;Extract and normalize the brain regions in the original brain magnetically sensitive weighted image SWI to obtain a standardized brain SWI;
以所述标准化脑SWI中每间隔m个体素定义的任意一个采样点为中心,提取一组中心重合的第一图像块和第二图像块,所述第一图像块的区域包含以M 1*M 1阶矩阵排布的体素,所述第二图像块的区域包含以M 2*M 2阶矩阵排布的体素,所述n、m、M 1和M 2为自然数,且M 2>M 1>m; A set of first image blocks and second image blocks with coincident centers are extracted centering on any one sampling point defined by m voxels per interval m in the standardized brain SWI. The area of the first image block includes M 1 * A voxel arranged in a M 1 order matrix, the region of the second image block includes a voxel arranged in a M 2 * M 2 order matrix, the n, m, M 1 and M 2 are natural numbers, and M 2 > M 1 >m;
输入所述n组第一图像块和第二图像块至已训练卷积神经网络,由所述已训练卷积神经网络对所述n组第一图像块和第二图像块中的静脉血管进行标记后得到标记了静脉血管的n组两个第三图像块,所述已训练卷积神经网络通过监督学习方式对卷积神经网络训练而成,所述第三图像块的区域包含以m*m阶矩阵排布的体素;Input the n groups of first image blocks and second image blocks to a trained convolutional neural network, and the trained convolutional neural network performs venous blood vessels in the n groups of first image blocks and second image blocks After labeling, two sets of three third image blocks labeled with venous blood vessels are obtained. The trained convolutional neural network is trained on the convolutional neural network through a supervised learning method, and the area of the third image block includes m * m-order matrix arranged voxels;
将所述n组两个第三图像块的静脉血管标记映射回所述原始脑磁敏感加权图像SWI以得到静脉血管的分割结果。Map the venous blood vessel labels of the two third image blocks of the n groups to the original brain magnetically sensitive weighted image SWI to obtain the venous blood vessel segmentation result.
本发明第二方面提供一种分割磁敏感加权图像中静脉血管的装置,所述装置包括:According to a second aspect of the present invention, a device for segmenting a venous blood vessel in a magnetically sensitive weighted image is provided. The device includes:
标准化模块,用于对原始脑磁敏感加权图像SWI中的脑部区域进行提取并标准化,得到标准化脑SWI;A normalization module for extracting and normalizing brain regions in the original brain magnetically sensitive weighted image SWI to obtain a standardized brain SWI;
图像块提取模块,用于以所述标准化脑SWI中每间隔m个体素定义的任意一个采样点为中心,提取一组中心重合的第一图像块和第二图像块,所述第一图像块的区域包含以M 1*M 1阶矩阵排布的体素,所述第二图像块的区域包含以M 2*M 2阶矩阵排布的体素,所述m、M 1和M 2为自然数,且M 2>M 1>m; An image block extraction module, for extracting a set of first image blocks and second image blocks with coincident centers centered on any one sampling point defined by every voxel in the standardized brain SWI The region of contains the voxels arranged in a M 1 * M 1 order matrix, and the region of the second image block contains the voxels arranged in a M 2 * M 2 order matrix, where m, M 1 and M 2 are Natural number, and M 2 > M 1 >m;
标记模块,用于输入n组第一图像块和第二图像块至已训练卷积神经网络, 由所述已训练卷积神经网络对所述n组第一图像块和第二图像块中的静脉血管进行标记后得到标记了静脉血管的n组两个第三图像块,所述已训练卷积神经网络通过监督学习方式对卷积神经网络训练而成,所述第三图像块的区域包含以m*m阶矩阵排布的体素,所述n为所述采样点的个数;A labeling module, configured to input n groups of first image blocks and second image blocks to a trained convolutional neural network, and the trained convolutional neural network The venous vessels are labeled to obtain two sets of n third image blocks labeled with venous vessels. The trained convolutional neural network is trained by a convolutional neural network in a supervised learning manner, and the area of the third image block includes Voxels arranged in an m * m order matrix, where n is the number of the sampling points;
映射模块,用于将所述n组两个第三图像块的静脉血管标记映射回所述原始脑磁敏感加权图像SWI以得到静脉血管的分割结果。A mapping module, configured to map the venous blood vessel marks of the n sets of two third image blocks back to the original brain magnetically sensitive weighted image SWI to obtain a venous blood vessel segmentation result.
本发明第三方面提供一种计算设备,包括存储器、处理器以及存储在所述存储器中并可在所述处理器上运行的计算机程序,所述处理器执行所述计算机程序时实现如下方法的步骤:A third aspect of the present invention provides a computing device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the following method is implemented: step:
对原始脑磁敏感加权图像SWI中的脑部区域进行提取并标准化,得到标准化脑SWI;Extract and normalize the brain regions in the original brain magnetically sensitive weighted image SWI to obtain a standardized brain SWI;
以所述标准化脑SWI中每间隔m个体素定义的任意一个采样点为中心,提取一组中心重合的第一图像块和第二图像块,所述第一图像块的区域包含以M 1*M 1阶矩阵排布的体素,所述第二图像块的区域包含以M 2*M 2阶矩阵排布的体素,所述m、M 1和M 2为自然数,且M 2>M 1>m; A set of first image blocks and second image blocks with coincident centers are extracted centering on any one sampling point defined by m voxels per interval m in the standardized brain SWI. The area of the first image block includes M 1 * A voxel arranged in a matrix of order M 1 , the region of the second image block includes a voxel arranged in a matrix of order M 2 * M 2 , the m, M 1 and M 2 are natural numbers, and M 2 > M 1 >m;
输入n组第一图像块和第二图像块至已训练卷积神经网络,由所述已训练卷积神经网络对所述n组第一图像块和第二图像块中的静脉血管进行标记后得到标记了静脉血管的n组两个第三图像块,所述已训练卷积神经网络通过监督学习方式对卷积神经网络训练而成,所述第三图像块的区域包含以m*m阶矩阵排布的体素,所述n为所述采样点的个数;Input n sets of first image blocks and second image blocks to a trained convolutional neural network, and the trained convolutional neural network marks the venous blood vessels in the n sets of first image blocks and second image blocks The n groups of two third image blocks labeled with venous blood vessels are obtained, and the trained convolutional neural network is trained on the convolutional neural network through a supervised learning method. The region of the third image block includes m * m orders. Voxels arranged in a matrix, where n is the number of sampling points;
将所述n组两个第三图像块的静脉血管标记映射回所述原始脑磁敏感加权图像SWI以得到静脉血管的分割结果。Map the venous blood vessel labels of the two third image blocks of the n groups to the original brain magnetically sensitive weighted image SWI to obtain the venous blood vessel segmentation result.
本发明第四方面提供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程序,所述计算机程序被处理器执行时实现如下方法的步骤:A fourth aspect of the present invention provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the following method are implemented:
对原始脑磁敏感加权图像SWI中的脑部区域进行提取并标准化,得到标准化脑SWI;Extract and normalize the brain regions in the original brain magnetically sensitive weighted image SWI to obtain a standardized brain SWI;
以所述标准化脑SWI中每间隔m个体素定义的任意一个采样点为中心,提取一组中心重合的第一图像块和第二图像块,所述第一图像块的区域包含以M 1*M 1阶矩阵排布的体素,所述第二图像块的区域包含以M 2*M 2阶矩阵排布 的体素,所述m、M 1和M 2为自然数,且M 2>M 1>m; A set of first image blocks and second image blocks with coincident centers are extracted centering on any one sampling point defined by m voxels per interval m in the standardized brain SWI. The area of the first image block includes M 1 * A voxel arranged in a matrix of order M 1 , the region of the second image block includes a voxel arranged in a matrix of order M 2 * M 2 , the m, M 1 and M 2 are natural numbers, and M 2 > M 1 >m;
输入n组第一图像块和第二图像块至已训练卷积神经网络,由所述已训练卷积神经网络对所述n组第一图像块和第二图像块中的静脉血管进行标记后得到标记了静脉血管的n组两个第三图像块,所述已训练卷积神经网络通过监督学习方式对卷积神经网络训练而成,所述第三图像块的区域包含以m*m阶矩阵排布的体素,所述n为所述采样点的个数;Input n sets of first image blocks and second image blocks to a trained convolutional neural network, and the trained convolutional neural network marks the venous blood vessels in the n sets of first image blocks and second image blocks The n groups of two third image blocks labeled with venous blood vessels are obtained, and the trained convolutional neural network is trained on the convolutional neural network through a supervised learning method. The region of the third image block includes m * m orders. Voxels arranged in a matrix, where n is the number of sampling points;
将所述n组两个第三图像块的静脉血管标记映射回所述原始脑磁敏感加权图像SWI以得到静脉血管的分割结果。Map the venous blood vessel labels of the two third image blocks of the n groups to the original brain magnetically sensitive weighted image SWI to obtain the venous blood vessel segmentation result.
从上述本发明技术方案可知,由于已训练卷积神经网络通过监督学习方式对卷积神经网络训练而成,因此,通过监督学习从已有数据中自动学习先验知识并提取深度特征,从而能够精确识别出脑SWI中的静脉血管,相比于现有技术,提高了脑SWI中静脉血管分割的精度。It can be known from the technical solution of the present invention that, since the trained convolutional neural network is trained on the convolutional neural network through a supervised learning method, the supervised learning automatically learns prior knowledge from existing data and extracts deep features, thereby being able to Accurately identifying the venous blood vessels in the brain SWI, compared with the prior art, the accuracy of venous blood vessel segmentation in the brain SWI is improved.
附图说明BRIEF DESCRIPTION OF THE DRAWINGS
图1是本发明实施例提供的分割磁敏感加权图像中静脉血管的方法的实现流程示意图;1 is a schematic flowchart of an implementation method of a method for segmenting a venous blood vessel in a magnetically sensitive weighted image according to an embodiment of the present invention;
图2本发明实施例提供的标准化脑SWI中体素及其采样点示意图;2 is a schematic diagram of a voxel and its sampling points in a standardized brain SWI according to an embodiment of the present invention;
图3是本发明实施例提供的卷积神经网络的结构示意图;3 is a schematic structural diagram of a convolutional neural network according to an embodiment of the present invention;
图4是本发明实施例提供的分割磁敏感加权图像中静脉血管的装置的结构示意图;FIG. 4 is a schematic structural diagram of a device for segmenting a venous blood vessel in a magnetically sensitive weighted image according to an embodiment of the present invention; FIG.
图5是本发明另一实施例提供的分割磁敏感加权图像中静脉血管的装置的结构示意图;5 is a schematic structural diagram of a device for segmenting a vein and a blood vessel in a magnetically sensitive weighted image according to another embodiment of the present invention;
图6是本发明实施例提供的计算设备的结构示意图。FIG. 6 is a schematic structural diagram of a computing device according to an embodiment of the present invention.
具体实施方式Detailed ways
为了使本发明的目的、技术方案及有益效果更加清楚明白,以下结合附图及实施例,对本发明进行进一步详细说明。应当理解,此处所描述的具体实施例仅仅用以解释本发明,并不用于限定本发明。In order to make the objectives, technical solutions, and beneficial effects of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.
以下描述中,为了说明而不是为了限定,提出了诸如特定系统结构、技术 之类的具体细节,以便透彻理解本发明实施例。然而,本领域的技术人员应当清楚,在没有这些具体细节的其它实施例中也可以实现本发明。在其它情况中,省略对众所周知的系统、装置、电路以及方法的详细说明,以免不必要的细节妨碍本发明的描述。In the following description, for the purpose of explanation rather than limitation, specific details such as a specific system structure and technology are provided in order to thoroughly understand the embodiments of the present invention. However, it should be clear to a person skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary details.
附图1是本发明实施例提供的分割磁敏感加权图像中静脉血管的方法的实现流程示意图,主要包括以下步骤S101至S104,以下详细说明:FIG. 1 is a schematic flowchart of an implementation method of a method for segmenting a venous blood vessel in a magnetically sensitive weighted image according to an embodiment of the present invention, which mainly includes the following steps S101 to S104, which are described in detail below:
S101,对原始脑磁敏感加权图像SWI中的脑部区域进行提取并标准化,得到标准化脑SWI。S101: Extract and normalize a brain region in the original brain magnetically sensitive weighted image SWI to obtain a standardized brain SWI.
在本发明实施例中,对原始脑磁敏感加权图像SWI中的脑部区域进行提取,目的是排除颅骨和其他非脑组织的干扰;提取SWI中的脑部区域即脑部掩膜图像属于预处理过程。具体地,对原始脑磁敏感加权图像SWI中的脑部区域进行提取并标准化,得到标准化脑SWI包括如下是实施过程:采用阈值方法提取原始脑SWI中灰度值小于50的所有背景体素,并提取最大连通区域;将最大连通区域取反后,利用一个3*3*3大小的结构元素进行形态学闭操作,以恢复阈值分割丢失的静脉体素;计算原始脑SWI中的脑部区域体素均值和标准差,将原始脑SWI中的脑部区域的每个体素减去均值并除以标准差以得到标准化脑SWI。In the embodiment of the present invention, the brain region in the original brain magnetically sensitive weighted image SWI is extracted in order to exclude the interference of the skull and other non-brain tissues; the extracted brain region in the SWI, that is, the brain mask image belongs to the pre- Process. Specifically, extracting and normalizing the brain region in the original brain magnetically sensitive weighted image SWI, and obtaining a standardized brain SWI includes the following implementation process: using a threshold method to extract all background voxels whose gray value in the original brain SWI is less than 50, And extract the largest connected region; after inverting the largest connected region, use a 3 * 3 * 3 size structural element to perform morphological closing operation to restore the threshold segmentation of the lost vein voxels; calculate the brain region in the original brain SWI Voxel mean and standard deviation, the mean value of each voxel of the brain region in the original brain SWI is subtracted from the mean and divided by the standard deviation to obtain a standardized brain SWI.
S102,以标准化脑SWI中每间隔m个体素定义的任意一个采样点为中心,提取一组中心重合的第一图像块和第二图像块,其中,第一图像块的区域包含以M 1*M 1阶矩阵排布的体素,第二图像块的区域包含以M 2*M 2阶矩阵排布的体素,m、M 1和M 2为自然数,且M 2>M 1>m。 S102. A set of first and second image blocks with coincident centers is extracted centered on any one sampling point defined by every voxel in the normalized brain SWI. The area of the first image block includes M 1 * The voxels are arranged in M 1 order matrix. The area of the second image block includes voxels arranged in M 2 * M 2 order matrix, m, M 1 and M 2 are natural numbers, and M 2 > M 1 > m.
经实验验证,m=9、M 1=25和M 2=57这样取值,对本发明而言,效果是最优的,因此,以下以m=9、M 1=25和M 2=57为例来说明本发明的技术方案。如附图2所示是一幅经步骤S101得到的标准化脑SWI的示例,小白圈和小黑圈表示标准化脑SWI的体素,其中,标号为1、2、3和4的小白圈表示采样点。显然,这些采样点本身也是体素,且间隔9个体素。本发明的技术方案就是以这些采样点为中心,提取一组中心重合的第一图像块和第二图像块。以M 1=25、M 2=57以及标号为1的采样点为例,提取一组中心重合的第一图像块和第二图像块就是提取区域包含以25*25阶矩阵排布的体素的图像块以及区域包含以 57*57阶矩阵排布的体素的图像块,这两个图像块为一组,且图像块的中心重合即都是以标号为1的采样点为中心;类似地,以M 1=25、M 2=57以及标号为2的采样点为例,提取一组中心重合的第一图像块和第二图像块就是提取区域包含以25*25阶矩阵排布的体素的图像块以及区域包含以57*57阶矩阵排布的体素的图像块,这两个图像块为一组,且图像块的中心重合即都是以标号为2的采样点为中心。 The experiments prove, m = 9, M 1 = 25 and M 2 = 57 and the phase value, for purposes of the present invention, the effect is optimal, following, therefore, m = 9, M 1 = 25 and M 2 = 57 to An example is used to explain the technical solution of the present invention. An example of the standardized brain SWI obtained in step S101 is shown in FIG. 2. The small white circles and small black circles represent the voxels of the standardized brain SWI. Among them, the small white circles labeled 1, 2, 3, and 4 Represents a sampling point. Obviously, these sampling points are also voxels, and are spaced apart by 9 voxels. The technical solution of the present invention is to use these sampling points as the center to extract a set of first image blocks and second image blocks with coincident centers. Taking M 1 = 25, M 2 = 57, and the sampling point labeled 1 as an example, extracting a set of first and second image blocks with coincident centers is an extraction region containing voxels arranged in a 25 * 25 order matrix. The image blocks and regions contain image blocks of voxels arranged in a 57 * 57 order matrix. These two image blocks are a group, and the centers of the image blocks are centered on the sampling point labeled 1. Groundly, taking M 1 = 25, M 2 = 57, and the sampling point labeled 2 as an example, extracting a set of first and second image blocks with coincident centers is an extraction region containing a 25 * 25 order matrix. The image block and region of the voxel contain image blocks of voxels arranged in a 57 * 57 order matrix. These two image blocks are a group, and the centers of the image blocks are centered on the sampling point labeled 2. .
S103,输入n组第一图像块和第二图像块至已训练卷积神经网络,由已训练卷积神经网络对所述n组第一图像块和第二图像块中的静脉血管进行标记后得到标记了静脉血管的n组两个第三图像块,其中,已训练卷积神经网络通过监督学习方式对卷积神经网络训练而成,第三图像块的区域包含以m*m阶矩阵排布的体素,n为采样点的个数。S103. Input n sets of first image blocks and second image blocks to the trained convolutional neural network, and after training the convolutional neural network to mark the venous blood vessels in the n sets of first image blocks and second image blocks The n groups of two third image blocks labeled with venous blood vessels are obtained. Among them, the trained convolutional neural network is trained on the convolutional neural network through supervised learning. The region of the third image block includes a matrix arranged in order of m * m order. The voxel of the cloth, n is the number of sampling points.
显然,按照附图2的示例,有多少个采样点,就能得到多少组第一图像块和第二图像块,因此,当有n个采样点时,按照附图2示例的方法能够得到n组第一图像块和第二图像块。每次输入一组第一图像块和第二图像块至已训练卷积神经网络,由已训练卷积神经网络对所述一组第一图像块和第二图像块中的静脉血管进行标记后,每一个第一图像块能够得到标记了静脉血管的一个第三图像块,每一个第二图像块能够标记了静脉血管的第三图像块,得到标记了静脉血管的n组两个第三图像块。因此,当输入n组第一图像块和第二图像块至已训练卷积神经网络时,由已训练卷积神经网络对所述n组第一图像块和第二图像块中的静脉血管进行标记后,即可得到标记了静脉血管的n组两个第三图像块,其中,第三图像块的区域包含以m*m阶矩阵排布的体素,在m=9时,第三图像块的区域包含以9*9阶矩阵排布的体素。Obviously, according to the example of FIG. 2, how many sets of first image blocks and second image blocks can be obtained with how many sampling points, so when there are n sampling points, n can be obtained according to the method illustrated in FIG. 2. Group a first image block and a second image block. Each time a set of first image blocks and second image blocks are input to the trained convolutional neural network, and the trained convolutional neural network marks the venous blood vessels in the set of first image blocks and the second image blocks Each third image block can be labeled with a third image block of the venous blood vessel, each second image block can be labeled with a third image block of the venous blood vessel, and n sets of two third images are labeled with the venous blood vessel. Piece. Therefore, when n sets of first image blocks and second image blocks are input to the trained convolutional neural network, the trained convolutional neural network performs venous blood vessels in the n sets of first image blocks and second image blocks. After labeling, two sets of three third image blocks labeled with venous blood vessels can be obtained, where the region of the third image block contains voxels arranged in a matrix of order m * m. When m = 9, the third image The area of the block contains voxels arranged in a 9 * 9 order matrix.
在本发明实施例中,已训练卷积神经网络通过监督学习方式对卷积神经网络训练而成,其可以在对原始脑SWI中的脑部区域进行提取并标准化,得到标准化脑SWI之前完成,即,在对原始脑SWI中的脑部区域进行提取并标准化,得到标准化脑SWI之前,还包括以下方法的步骤S1031至S1033:In the embodiment of the present invention, the trained convolutional neural network is trained on the convolutional neural network through a supervised learning method, which can be extracted and standardized from the brain region in the original brain SWI to obtain a standardized brain SWI. That is, before the brain region in the original brain SWI is extracted and standardized to obtain a standardized brain SWI, steps S1031 to S1033 of the following method are further included:
S1031,从用于训练的脑SWI中提取训练图像块对以及与训练图像块对相应的静脉分割金标准图像块,其中,训练图像块对由第一训练图像块和第二训练图像块组成。S1031: Extract a training image block pair and a vein segmentation gold standard image block corresponding to the training image block pair from the brain SWI for training, where the training image block pair is composed of a first training image block and a second training image block.
在本发明实施例中,所提取的训练图像块对以及与训练图像块对相应的静脉分割金标准图像块用于训练卷积神经网络,其中,静脉分割金标准图像块是依靠人工(一般是专家)经验对训练图像中的静脉低信号进行标记得到的图像块,它们都是分别从用于训练的脑SWI中静脉区域和背景区域随机采集数目相同的样本体素,并以每个样本体素为中心提取得到。需要说明的是,第一训练图像块和第二训练图像块的大小分别与前述实施例中以标准化脑SWI中每间隔m个体素定义的任意一个采样点为中心提取的一组中心重合的第一图像块和第二图像块的大小相同,即,第一训练图像块的区域包含以M 1*M 1阶矩阵排布的体素,第二训练图像块的区域包含以M 2*M 2阶矩阵排布的体素,而静脉分割金标准图像块的大小与前述实施例中第三图像块的大小相同,即,静脉分割金标准图像块的区域包含以m*m阶矩阵排布的体素。当前述实施例中第一图像块的区域包含的是以25*25阶矩阵排布的体素,第二图像块的区域包含的是以57*57阶矩阵排布的体素时,相应地,第一训练图像块的区域包含以25*25阶矩阵排布的体素,第二训练图像块的区域包含以57*57阶矩阵排布的体素;当前述实施例中第三图像块的区域包含的是以9*9阶矩阵排布的体素,静脉分割金标准图像块的区域包含以9*9阶矩阵排布的体素。 In the embodiment of the present invention, the extracted training image block pair and the vein segmentation gold standard image block corresponding to the training image block pair are used to train a convolutional neural network, wherein the vein segmentation gold standard image block is based on artificial (generally (Experts) Experience The image blocks obtained by labeling the venous low signal in the training image are all randomly collected the same number of sample voxels from the venous region and the background region of the brain SWI used for training. Extracted as the center. It should be noted that the sizes of the first training image block and the second training image block are respectively a set of center coincident with a set of centers extracted from any one of the sampling points defined in the normalized brain SWI in each interval m voxels. One image block and the second image block are the same size, that is, the area of the first training image block contains voxels arranged in a M 1 * M 1 order matrix, and the area of the second training image block contains M 2 * M 2 Order voxels, and the size of the gold standard image block for vein segmentation is the same as the size of the third image block in the previous embodiment, that is, the area of the gold standard image block for vein segmentation includes the m * m order matrix. Voxels. When the area of the first image block in the foregoing embodiment contains voxels arranged in a 25 * 25 order matrix, and the area of the second image block contains voxels arranged in a 57 * 57 order matrix, accordingly The area of the first training image block contains voxels arranged in a 25 * 25 order matrix, and the area of the second training image block contains voxels arranged in a 57 * 57 order matrix; when the third image block in the foregoing embodiment The region of contains the voxels arranged in a 9 * 9 order matrix, and the area of the gold standard image block for vein segmentation contains the voxels arranged in a 9 * 9 order matrix.
考虑到数据增强有助于提高卷积神经网络的性能,因此,为了增加训练用图像数量,从用于训练的脑SWI中提取训练图像块对以及与所述训练图像块对相应的静脉分割金标准图像块之前,还包括对所述用于训练的脑SWI分别沿着二维坐标系的X轴和Y轴进行对称反转,而为了增强卷积神经网络对于灰度变化的鲁棒性,从用于训练的脑SWI中提取训练图像块对以及与所述训练图像块对相应的静脉分割金标准图像块之后,还包括对第一训练图像块和第二训练图像块的体素灰度按照公式I' S=I S+r*σ c进行变换,其中,r为从正态分布N(0,1)采样的随机数,σ c为第一训练图像块或第二训练图像块中灰度标准差,I' S为对第一训练图像块或第二训练图像块内灰度I S变换后的灰度值。 Considering that data augmentation helps to improve the performance of the convolutional neural network, in order to increase the number of training images, a training image block pair is extracted from the brain SWI used for training and the vein segmentation gold corresponding to the training image block pair Before the standard image block, the SWI of the brain used for training is also symmetrically reversed along the X-axis and Y-axis of the two-dimensional coordinate system, and in order to enhance the robustness of the convolutional neural network to grayscale changes, After extracting a training image block pair from a brain SWI used for training and dividing a vein standard gold standard image block corresponding to the training image block pair, the method further includes a voxel grayscale for the first training image block and the second training image block. Transform according to the formula I ' S = I S + r * σ c , where r is a random number sampled from a normal distribution N (0,1), and σ c is the first training image block or the second training image block The gray standard deviation, I ′ S is a gray value after transforming the gray I S in the first training image block or the second training image block.
S1032,构造卷积神经网络。S1032. Construct a convolutional neural network.
在本发明实施例中,构造卷积神经网络包括构造第一卷积路径、第二卷积路径、第三卷积路径和分类器并对所述第一卷积路径、第二卷积路径、第三卷积路径和分类器进行连接,其中,第一卷积路径用于对第一训练图像块进行处 理,第二卷积路径用于对第二训练图像块进行处理,第一卷积路径或第二卷积路径包含8个卷积模块和3个串联层,第二卷积路径还包含一个降采样单元和一个升采样单元,第三卷积路径包含3个卷积模块和2个串联层,8个卷积模块中卷积模块1至8依次串联后,卷积模块2和卷积模块4的输出端分别与第串联层1的输入端连接,串联层1的输出端和卷积模块6的输出端分别与串联层2的输入端连接,串联层2的输出端和卷积模块8的输出端分别与串联层3的输入端连接;第二卷积路径中卷积模块1的输入端与降采样单元的输出端连接,第二卷积路径中串联层3的输出端与升采样单元的输入端连接,升采样单元的输出端和第一卷积路径中串联层3的输出端分别与第三卷积路径中串联层1的输入端连接;第三卷积路径中卷积模块1与卷积模块2串联,第三卷积路径中卷积模块1的输入端与第三卷积路径中串联层1的输出端连接,第三卷积路径中卷积模块2的输出端和第三卷积路径中串联层1的输出端分别与第三卷积路径中串联层2的输入端连接,第三卷积路径中串联层2的输出端与第三卷积路径中卷积模块3的输入端,第三卷积路径中卷积模块3的输出端与分类器连接,整个卷积神经网络的结构如附图3所示。In the embodiment of the present invention, constructing a convolutional neural network includes constructing a first convolution path, a second convolution path, a third convolution path, and a classifier, and the first convolution path, the second convolution path, A third convolution path is connected to the classifier, where the first convolution path is used to process the first training image block, the second convolution path is used to process the second training image block, and the first convolution path Or the second convolution path includes 8 convolution modules and 3 series layers, the second convolution path also includes a downsampling unit and an upsampling unit, and the third convolution path includes 3 convolution modules and 2 series Layer, the convolution modules 1 to 8 of the eight convolution modules are connected in series, and the outputs of convolution module 2 and convolution module 4 are connected to the input of layer 1 in series, and the output of layer 1 and convolution are connected in series. The output of module 6 is connected to the input of serial layer 2 respectively, the output of serial layer 2 and the output of convolution module 8 are connected to the input of serial layer 3 respectively; The input is connected to the output of the downsampling unit, and the second convolution The output of serial layer 3 in the path is connected to the input of the upsampling unit. The output of the upsampling unit and the output of serial layer 3 in the first convolution path are connected to the input of serial layer 1 in the third convolution path. Connection; convolution module 1 in the third convolution path is connected in series with convolution module 2, the input end of convolution module 1 in the third convolution path is connected to the output end of series layer 1 in the third convolution path, and the third volume The output of convolution module 2 in the convolution path and the output of series layer 1 in the third convolution path are connected to the input of series layer 2 in the third convolution path, and the output of series layer 2 in the third convolution path. And the input of the convolution module 3 in the third convolution path, and the output of the convolution module 3 in the third convolution path is connected to the classifier. The structure of the entire convolutional neural network is shown in FIG. 3.
需要说明的是,从第一卷积路径用于对第一训练图像块进行处理,第二卷积路径用于对第二训练图像块进行处理可知,附图3示例的本发明的卷积神经网络是一个多尺度卷积神经网络,多尺度卷积神经网络经训练好之后得到多尺度的已训练卷积神经网络。It should be noted that the first convolution path is used to process the first training image block, and the second convolution path is used to process the second training image block. It can be seen that the convolution nerve of the present invention illustrated in FIG. 3 The network is a multi-scale convolutional neural network. After the multi-scale convolutional neural network is trained, a multi-scale trained convolutional neural network is obtained.
附图3示例的卷积神经网络中,第一卷积路径、第二卷积路径和第三卷积路径的卷积模块都具有相同的结构,均包含批标准化BN层、非线性映射PReLU层和卷积层Conv,其中,标准化BN层通过对传入卷积层的特征图进行标准化以解决神经网络中协方差偏移问题,非线性映射PReLU层实现卷积特征的非线性映射,并避免传统激励函数,例如Sigmoid函数饱和导致的梯度消失问题并加快收敛,卷积层Conv定义了卷积核(第一卷积路径和第二卷积路径中卷积核大小是3x3,第三卷积路径中卷积核大小是1x1),实现卷积运算(卷积步长为1):In the convolutional neural network illustrated in FIG. 3, the convolution modules of the first convolution path, the second convolution path, and the third convolution path all have the same structure, and each includes a batch standardized BN layer and a non-linear mapping PReLU layer. And conv layer Conv, where the normalized BN layer solves the covariance shift problem in the neural network by normalizing the feature map of the incoming convolution layer, and the non-linear mapping PReLU layer implements the non-linear mapping of convolution features and avoids Conventional excitation functions, such as the disappearance of the gradient caused by saturation of the Sigmoid function, accelerate the convergence. The conv layer Conv defines the convolution kernel (the size of the convolution kernel in the first and second convolution paths is 3x3, and the third convolution The size of the convolution kernel in the path is 1x1), and the convolution operation is implemented (the convolution step is 1):
Figure PCTCN2018089899-appb-000001
Figure PCTCN2018089899-appb-000001
其中,
Figure PCTCN2018089899-appb-000002
表示第l卷积层第m个神经元的卷积核,第l卷积层接收前一卷积层输出的特征图作为输入,因此,
Figure PCTCN2018089899-appb-000003
表示第l-1卷积层输出的第n个特征图,n l-1表示第l-1卷积层输出的特征图的数目,
Figure PCTCN2018089899-appb-000004
表示第l卷积层第m个神经元的偏置,*为卷积操作,
Figure PCTCN2018089899-appb-000005
表示第l卷积层输出的第m个特征图。
among them,
Figure PCTCN2018089899-appb-000002
Represents the convolution kernel of the mth neuron of the l-th convolutional layer, and the l-th convolutional layer receives as input the feature map output by the previous convolutional layer.
Figure PCTCN2018089899-appb-000003
Represents the n-th feature map output by the l-1 convolution layer, n l-1 represents the number of feature maps output by the l-1 convolution layer,
Figure PCTCN2018089899-appb-000004
Represents the bias of the mth neuron of the l-th convolution layer, * is the convolution operation,
Figure PCTCN2018089899-appb-000005
Represents the m-th feature map output by the l-th convolution layer.
在附图3示例的卷积神经网络中,通过串联层实现密集连接,以保护神经网络信号,提高深度卷积网络可训练性。本发明中通过将两个卷积层的特征图进行串联实现:In the convolutional neural network exemplified in FIG. 3, dense connections are achieved through series layers to protect the neural network signals and improve the trainability of the deep convolutional network. In the present invention, the feature maps of the two convolutional layers are implemented in series:
Figure PCTCN2018089899-appb-000006
Figure PCTCN2018089899-appb-000006
其中,[·]表示示串联运算,x l表示第l卷积层输出的特征图,
Figure PCTCN2018089899-appb-000007
表示第l-2卷积层输出的特征图x l-2的中心部分,其大小与x l一致。
Among them, [·] represents a tandem operation, and x l represents a feature map of the output of the l-th convolution layer,
Figure PCTCN2018089899-appb-000007
The center part of the feature map x l-2 representing the output of the l-2 convolution layer is the same as x l .
在第二卷积路径的末尾添加了一个升采样单元,实现两个卷积路径的输出特征图大小匹配。将经升采样单元上采样后的特征图与第一卷积路径第3个串联层输出的特征图进行串联后由第三卷积路径进行处理。第三卷积路径同样由卷积模块和串联层组成,不同的是,第三卷积路径的卷积模块中卷积层的卷积核大小都为1x1,步长为1,因此第三卷积路径不会改变输出特征图的大小。最后,将第三卷积路径中第3个卷积模块输出端处理后的特征图由分类器,例如Softmax分类器进行处理即可得到输入图像块中心m*m个体素属于静脉血管或者背景的概率和标记。An upsampling unit is added at the end of the second convolution path to achieve the output feature map size matching of the two convolution paths. The feature maps sampled by the upsampling unit and the feature maps output from the third series layer of the first convolution path are connected in series and processed by the third convolution path. The third convolution path also consists of a convolution module and a series layer. The difference is that the convolution kernels of the convolution layer in the convolution module of the third convolution path have a size of 1x1 and a step size of 1, so the third volume The product path does not change the size of the output feature map. Finally, the feature map processed by the output of the third convolution module in the third convolution path is processed by a classifier, such as a Softmax classifier, to obtain the input image block center m * m. The individual voxels belong to the vein or background. Probability and labeling.
S1033,将第一训练图像块和第二训练图像块输入卷积神经网络,并根据静脉分割金标准图像块训练卷积神经网络,得到已训练卷积神经网络。S1033. The first training image block and the second training image block are input to a convolutional neural network, and the convolutional neural network is trained according to the vein segmentation gold standard image block to obtain a trained convolutional neural network.
具体地,将第一训练图像块和第二训练图像块输入卷积神经网络,并根据静脉分割金标准图像块训练卷积神经网络,得到已训练卷积神经网络可通过如下步骤S1和S2实现:Specifically, the first training image block and the second training image block are input to the convolutional neural network, and the convolutional neural network is trained according to the vein segmentation gold standard image block. The trained convolutional neural network can be achieved through the following steps S1 and S2 :
S1,利用预测图像块和所述静脉分割金标准图像块定义损失函数S1. Use a predicted image block and the vein segmentation gold standard image block to define a loss function
Figure PCTCN2018089899-appb-000008
Figure PCTCN2018089899-appb-000008
上述损失函数是采用Dice系数定义的损失函数,其中,预测图像块是第一训练图像块和第二训练图像块输入卷积神经网络后预测的输出结果,B为对卷积神经网络训练过程中一次处理的训练图像块对的数量,N为预测图像块中体 素的数量,p ij为第i个训练图像块对相应的预测图像块中第j个体素属于静脉血管的概率,y ij为第i个训练图像块对相应的静脉分割金标准图像块中第j个体素的真实标记,训练图像块对即前述实施例中提及的第一训练图像块和第二训练图像块组成的一对训练图像块。 The above loss function is a loss function defined by the Dice coefficient, where the predicted image block is the predicted output result after the first training image block and the second training image block are input to the convolutional neural network, and B is the process of training the convolutional neural network. The number of training image block pairs processed at a time, N is the number of voxels in the predicted image block, p ij is the probability that the jth voxel in the corresponding prediction image block of the i-th training image block belongs to the vein, and y ij The i-th training image block is the true label of the j-th voxel in the corresponding vein segmentation gold standard image block, and the training image block pair is a combination of the first training image block and the second training image block mentioned in the foregoing embodiment. Pair of training image blocks.
S2,以第一训练图像块和第二训练图像块作为输入特征,基于批量梯度下降算法训练卷积神经网络,在最小化损失函数时获得卷积神经网络的参数。S2. Using the first training image block and the second training image block as input features, train a convolutional neural network based on a batch gradient descent algorithm, and obtain parameters of the convolutional neural network while minimizing a loss function.
在最小化损失函数
Figure PCTCN2018089899-appb-000009
时获得的卷积神经网络的参数就是已训练卷积神经网络的参数,意味着卷积神经网络已经训练完成,可以用于数据的预测即分割磁敏感加权图像中静脉血管,具体就是将提取出来的n组第一图像块和第二图像块中每一组的第一图像块输入已训练神经网络的第一卷积路径,每一组的第二图像块输入已训练神经网络的第二卷积路径,经已训练神经网络的一系列处理,每一组第一图像块和第二图像块相应得到标记了静脉血管的一组两个第三图像块。
Minimizing the loss function
Figure PCTCN2018089899-appb-000009
The parameters of the convolutional neural network obtained at that time are the parameters of the trained convolutional neural network, which means that the convolutional neural network has been trained and can be used for data prediction, that is, to segment the vein blood vessels in the magnetically sensitive weighted image. Specifically, it will be extracted. The first image block of each of the n groups of the first image block and the second image block is input to the first convolution path of the trained neural network, and the second image block of each group is input to the second volume of the trained neural network. The product path, after a series of processing by the trained neural network, each group of the first image block and the second image block respectively obtains a group of two third image blocks labeled with a venous blood vessel.
如前所述,由于本发明的已训练卷积神经网络是一种多尺度已训练卷积神经网络,输入n组第一图像块和第二图像块至已训练卷积神经网络,由所述多尺度已训练卷积神经网络对所述n组第一图像块和第二图像块中的静脉血管进行标记时,通过大小不同的第一图像块和第二图像块以获取不同范围的上下文信息,其中,小图像块主要捕捉局部信息,而大图像块更关注于全局信息。两种信息相互补充,从而提高卷积神经网络性能和静脉分割的精度。As mentioned before, since the trained convolutional neural network of the present invention is a multi-scale trained convolutional neural network, n sets of first image blocks and second image blocks are input to the trained convolutional neural network. When multi-scale trained convolutional neural network marks the venous blood vessels in the n sets of first image blocks and second image blocks, different sizes of first image blocks and second image blocks are used to obtain different ranges of context information Among them, small image blocks mainly capture local information, while large image blocks focus more on global information. The two kinds of information complement each other, thereby improving the performance of the convolutional neural network and the accuracy of vein segmentation.
S104,将n组两个第三图像块的静脉血管标记映射回原始脑磁敏感加权图像SWI以得到静脉血管的分割结果。S104. Map the venous blood vessel labels of the two third image blocks in the n groups to the original brain magnetically sensitive weighted image SWI to obtain the venous blood vessel segmentation result.
以第三图像块包含以9*9阶矩阵排布的体素为例,当经过步骤S103时,就得到标记了静脉血管的n组两个第三图像块,将n组两个第三图像块的每一组第三图像块的静脉血管标记映射回原始脑磁敏感加权图像SWI就可以得到静脉血管的分割结果,具体映射方法是根据每个第三图像块的中心在原始图像中的空间位置,将该第三图像块中心周围的9x9大小的预测标记映射至原始图像中。例如,一个第三图像块的中心坐标为(100,100),经过已训练卷积神经网络进行静脉血管的分割后得到一个9x9的标记区域,则将该标记映射至[96:104,96:104]的区域即得到静脉血管的分割结果。Taking the third image block containing voxels arranged in a 9 * 9 order matrix as an example, after step S103, n groups of two third image blocks labeled with venous vessels are obtained, and n groups of two third images are obtained. The venous blood vessel label of each third image block of the block is mapped back to the original brain magnetically sensitive weighted image SWI to obtain the venous blood vessel segmentation result. The specific mapping method is based on the space of the center of each third image block in the original image. Position, map a 9x9 size prediction marker around the center of the third image block to the original image. For example, the center coordinate of a third image block is (100, 100). After segmentation of venous blood vessels by a trained convolutional neural network, a 9x9 labeled area is obtained, and the label is mapped to [96: 104, 96: 104] to obtain the segmentation results of venous blood vessels.
以下表1是本发明提供的方法与现有技术的几种方法的效果对比The following Table 1 compares the effects of the method provided by the present invention with several methods of the prior art.
表1Table 1
方法method Dice系数Dice coefficient 敏感性Sensitivity 特异性Specificity
本发明提供的方法Method provided by the present invention 0.736±0.0460.736 ± 0.046 0.821±0.0260.821 ± 0.026 0.223±0.0030.223 ± 0.003
单预测方式卷积神经网络Single prediction method convolutional neural network 0.705±0.0690.705 ± 0.069 0.875±0.0760.875 ± 0.076 0.990±0.0040.990 ± 0.004
多尺度血管增强Multi-scale vascular enhancement 0.615±0.060.615 ± 0.06 0.714±0.0450.714 ± 0.045 0.989±0.0060.989 ± 0.006
多方向直线灰度分布Multi-directional straight gray distribution 0.388±0.0370.388 ± 0.037 0.44±0.0960.44 ± 0.096 0.985±0.0030.985 ± 0.003
从上述表1可得出的结论是:本发明提供的卷积神经网络能够提取识别能力更强的深度特征。相对于灰度、形状等浅层特征,深度特征对于静脉血管的灰度不均匀、静脉与背景灰度重叠等问题都具有较好的识别能力。另外,本发明提供的卷积网络加入残差连接,并利用Dice系数定义的损失函数来指导卷积神经网络的训练,卷积神经网络的性能进一步得到提升。如表1中本发明提供的方法,其分割结果的Dice系数最高;单预测方式型卷积网络采用与本发明提供的卷积神经网络相同的结构,但是其输入图像块大小为17x17,此时仅能预测输入图像块中心体素的标记。由于数目相同的静脉血管样本和背景样本参加训练,不同于样本的实际分布(背景样本远大于静脉样本),使得分割结果出现过分割,更多的背景样本被分类为静脉血管。因此敏感性在提高的同时降低了特异性,Dice系数也相应的下降。另外两种方法,使用了灰度、形状等浅层特征,识别能力有限,因此其分割精度较低。It can be concluded from the above Table 1 that the convolutional neural network provided by the present invention can extract deep features with stronger recognition capabilities. Compared with shallow features such as grayscale and shape, depth features have a better ability to identify problems such as uneven grayscale of veins and veins and background grayscale overlap. In addition, the convolutional network provided by the present invention adds residual connections, and uses the loss function defined by the Dice coefficient to guide the training of the convolutional neural network, and the performance of the convolutional neural network is further improved. As shown in Table 1, the method provided by the present invention has the highest Dice coefficient in the segmentation result. The single prediction type convolutional network adopts the same structure as the convolutional neural network provided by the present invention, but its input image block size is 17x17. At this time, Only the label of the center voxel of the input image block can be predicted. Because the same number of venous blood samples and background samples participate in the training, the actual distribution of the samples is different (the background samples are much larger than the venous samples), so the segmentation results appear over segmentation, and more background samples are classified as venous blood vessels. Therefore, while the sensitivity is increased, the specificity is reduced, and the Dice coefficient is correspondingly decreased. The other two methods use shallow features such as grayscale and shape, and have limited recognition capabilities, so their segmentation accuracy is low.
需要说明的是,缺血性脑卒中是医疗界公认的世界难题,其诊断过程相当复杂,本发明的技术方案虽然结合卷积神经网络,通过图像处理的方式精确分割出磁敏感加权图像中的静脉血管,但这个处理过程只是作为获得一种中间结果的过程,其结果也只是作为一种中间结果,并不能直接作为缺血性脑卒中这一疾病的诊断结果,也不能据此就认为已经直接获得缺血性脑卒中患者的健康状况。It should be noted that ischemic stroke is a recognized worldwide problem in the medical community, and its diagnosis process is quite complicated. Although the technical solution of the present invention combines a convolutional neural network, it accurately segmentes the magnetically sensitive weighted images through image processing. Venous blood vessels, but this process is only used as a process to obtain an intermediate result, and the result is only used as an intermediate result. It cannot be directly used as a diagnosis of ischemic stroke. Obtain the health status of patients with ischemic stroke directly.
从上述附图1示例的分割磁敏感加权图像中静脉血管的方法可知,由于已训练卷积神经网络通过监督学习方式对卷积神经网络训练而成,因此,通过监督学习从已有数据中自动学习先验知识并提取深度特征,从而能够精确识别出脑SWI中的静脉血管,相比于现有技术,提高了脑SWI中静脉血管分割的精度。From the method for segmenting venous blood vessels in the magnetically sensitive weighted image shown in the example in FIG. 1 above, since the trained convolutional neural network is trained on the convolutional neural network through a supervised learning method, the supervised learning is automatically used from the existing data. Learning prior knowledge and extracting deep features can accurately identify venous blood vessels in the brain SWI. Compared with the prior art, the accuracy of venous blood vessel segmentation in the brain SWI is improved.
图4是本发明实施例提供的分割磁敏感加权图像中静脉血管的装置的示意图,主要包括标准化模块401、图像块提取模块402、标记模块403和映射模块404,详细说明如下:FIG. 4 is a schematic diagram of a device for segmenting a venous blood vessel in a magnetically sensitive weighted image according to an embodiment of the present invention, which mainly includes a normalization module 401, an image block extraction module 402, a labeling module 403, and a mapping module 404. The detailed description is as follows:
标准化模块401,用于对原始脑磁敏感加权图像SWI中的脑部区域进行提取并标准化,得到标准化脑SWI;A normalization module 401, configured to extract and normalize brain regions in the original brain magnetically sensitive weighted image SWI to obtain a standardized brain SWI;
图像块提取模块402,用于以标准化脑SWI中每间隔m个体素定义的任意一个采样点为中心,提取一组中心重合的第一图像块和第二图像块,其中,第一图像块的区域包含以M 1*M 1阶矩阵排布的体素,第二图像块的区域包含以M 2*M 2阶矩阵排布的体素,m、M 1和M 2为自然数,且M 2>M 1>m; An image block extraction module 402 is used to extract a set of first image blocks and second image blocks with coincident centers around any one sampling point defined by m voxels per interval m in standardized brain SWI. The region contains voxels arranged in a matrix of order M 1 * M 1 , the region of the second image block contains voxels arranged in matrix of order M 2 * M 2 , m, M 1 and M 2 are natural numbers, and M 2 > M 1 >m;
标记模块403,用于输入n组第一图像块和第二图像块至已训练卷积神经网络,由已训练卷积神经网络对n组第一图像块和第二图像块中的静脉血管进行标记后得到标记了静脉血管的n组两个第三图像块,其中,已训练卷积神经网络通过监督学习方式对卷积神经网络训练而成,第三图像块的区域包含以m*m阶矩阵排布的体素,n为采样点的个数;A labeling module 403, configured to input n sets of first image blocks and second image blocks to a trained convolutional neural network, and the trained convolutional neural network performs venous blood vessels in the n sets of first image blocks and second image blocks After labeling, two sets of third image blocks labeled with venous blood vessels are obtained. Among them, the trained convolutional neural network is trained on the convolutional neural network through a supervised learning method. The area of the third image block includes m * m orders. Voxels arranged in a matrix, n is the number of sampling points;
映射模块404,用于将n组两个第三图像块的静脉血管标记映射回原始脑磁敏感加权图像SWI以得到静脉血管的分割结果。The mapping module 404 is configured to map the venous blood vessel marks of the n sets of two third image blocks back to the original brain magnetically sensitive weighted image SWI to obtain the venous blood vessel segmentation result.
需要说明的是,本发明实施例提供的装置,由于与本发明方法实施例基于同一构思,其带来的技术效果与本发明方法实施例相同,具体内容可参见本发明方法实施例中的叙述,此处不再赘述。It should be noted that, because the device provided by the embodiment of the present invention is based on the same concept as the method embodiment of the present invention, the technical effects brought by it are the same as those of the method embodiment of the present invention. For specific content, refer to the description in the method embodiment of the present invention , Will not repeat them here.
附图4示例的标准化模块401可以包括提取单元501、取反单元502和计算单元503,如附图5示例的分割磁敏感加权图像中静脉血管的装置,其中:The normalization module 401 illustrated in FIG. 4 may include an extraction unit 501, a negation unit 502, and a calculation unit 503, such as the device for segmenting a vein and blood vessel in a magnetically sensitive weighted image illustrated in FIG. 5, where:
提取单元501,用于采用阈值方法提取所述原始脑SWI中灰度值小于50的所有背景体素,并提取最大连通区域;An extraction unit 501, configured to extract all background voxels with a gray value less than 50 in the original brain SWI by using a threshold method, and extract a maximum connected region;
取反单元502,用于将最大连通区域取反后,利用一个3*3*3大小的结构元素进行形态学闭操作,以恢复阈值分割丢失的静脉体素;The inversion unit 502 is configured to perform a morphological closing operation using a 3 * 3 * 3 size structural element after inverting the largest connected region to restore the threshold segmentation of the lost vein voxels;
计算单元503,用于计算原始脑SWI中的脑部区域体素均值和标准差,将原始脑SWI中的脑部区域的每个体素减去均值并除以标准差以得到标准化脑SWI。The calculation unit 503 is configured to calculate the mean and standard deviation of the voxels of the brain region in the original brain SWI, subtract the mean value of each voxel of the brain region in the original brain SWI, and divide by the standard deviation to obtain a standardized brain SWI.
附图4示例的装置还可以包括训练图像块提取模块、构造模块和训练模块, 其中:The apparatus illustrated in FIG. 4 may further include a training image block extraction module, a construction module, and a training module, where:
训练图像块提取模块,用于从用于训练的脑SWI中提取训练图像块对以及与所述训练图像块对相应的静脉分割金标准图像块,所述训练图像块对由第一训练图像块和第二训练图像块组成,所述第一训练图像块的区域包含以M 1*M 1阶矩阵排布的体素,所述第二训练图像块的区域包含以M 2*M 2阶矩阵排布的体素,所述静脉分割金标准图像块的区域包含以m*m阶矩阵排布的体素; A training image block extraction module is configured to extract a training image block pair from a brain SWI used for training and a vein standard gold standard image block corresponding to the training image block pair. The training image block pair is composed of a first training image block. And a second training image block, the region of the first training image block includes voxels arranged in a M 1 * M 1 order matrix, and the region of the second training image block includes a M 2 * M 2 order matrix Arranged voxels, the region of the vein-segmented gold standard image block including voxels arranged in an m * m order matrix;
构造模块,用于构造卷积神经网络;A construction module for constructing a convolutional neural network;
训练模块,用于将所述第一训练图像块和第二训练图像块输入所述卷积神经网络,并根据所述静脉分割金标准图像块训练所述卷积神经网络,得到所述已训练卷积神经网络。A training module, configured to input the first training image block and the second training image block into the convolutional neural network, and train the convolutional neural network according to the vein segmentation gold standard image block to obtain the trained Convolutional neural network.
上述实施例的装置还包括反转模块和变换模块,其中:The apparatus of the above embodiment further includes an inversion module and a transformation module, where:
反转模块,用于训练图像块提取模块从用于训练的脑SWI中提取训练图像块对以及与所述训练图像块对相应的静脉分割金标准图像块之前,对所述用于训练的脑SWI分别沿着二维坐标系的X轴和Y轴进行对称反转;Inversion module, used for training image block extraction module to extract the training image block pair from the brain SWI used for training and before dividing the vein standard gold standard image block corresponding to the training image block pair to the training brain block SWI performs symmetrical inversions along the X and Y axes of the two-dimensional coordinate system, respectively;
变换模块,用于训练图像块提取模块从用于训练的脑SWI中提取训练图像块对以及与所述训练图像块对相应的静脉分割金标准图像块之后,对所述第一训练图像块和第二训练图像块的体素灰度按照公式I' S=I S+r*σ c进行变换,其中,r为从正态分布N(0,1)采样的随机数,σ c为第一训练图像块或第二训练图像块中灰度标准差,I' S为对第一训练图像块或第二训练图像块内灰度I S变换后的灰度值。 A transformation module for training image block extraction module to extract a training image block pair from a brain SWI used for training and a vein segmentation gold standard image block corresponding to the training image block pair, and then to the first training image block and The voxel gray level of the second training image block is transformed according to the formula I ′ S = I S + r * σ c , where r is a random number sampled from a normal distribution N (0,1), and σ c is the first standard deviation of gray training image blocks or the second training image blocks, I 'S is the value of gradation after gradation conversion I S training image block within the first or the second training image blocks.
上述实施例的构造模块具体用于构造第一卷积路径、第二卷积路径、第三卷积路径和分类器并对所述第一卷积路径、第二卷积路径、第三卷积路径和分类器进行连接,所述第一卷积路径用于对所述第一训练图像块进行处理,所述第二卷积路径用于对所述第二训练图像块进行处理,所述第一卷积路径或第二卷积路径包含8个卷积模块和3个串联层,所述第二卷积路径还包含一个降采样单元和一个升采样单元,所述第三卷积路径包含3个卷积模块和2个串联层;所述8个卷积模块中第1至8个卷积模块依次串联后,第2个卷积模块和第4个卷积模块的输出端分别与第1个串联层的输入端连接,第1个串联层的输出端和第6个卷积模块的输出端分别与第2个串联层的输入端连接,第2个串联 层的输出端和第8个卷积模块的输出端分别与第3个串联层的输入端连接;所述第二卷积路径中第1个卷积模块的输入端与所述降采样单元的输出端连接,所述第二卷积路径中第3个串联层的输出端与所述升采样单元的输入端连接,所述升采样单元的输出端和所述第一卷积路径中第3个串联层的输出端分别与所述第三卷积路径中第1个串联层的输入端连接;所述第三卷积路径中第1个卷积模块与第2个卷积模块串联,所述第三卷积路径中第1个卷积模块的输入端与所述第三卷积路径中第1个串联层的输出端连接,所述第三卷积路径中第2个卷积模块的输出端和第三卷积路径中第1个串联层的输出端分别与所述第三卷积路径中第2个串联层的输入端连接,所述第三卷积路径中第2个串联层的输出端与所述第三卷积路径中第3个卷积模块的输入端,所述第三卷积路径中第3个卷积模块输出端与所述分类器连接。The construction module of the above embodiment is specifically configured to construct a first convolution path, a second convolution path, a third convolution path, and a classifier, and perform the first convolution path, the second convolution path, and the third convolution. The path and the classifier are connected, the first convolution path is used to process the first training image block, the second convolution path is used to process the second training image block, and the first A convolution path or a second convolution path includes 8 convolution modules and 3 series layers, the second convolution path further includes a downsampling unit and an upsampling unit, and the third convolution path includes 3 Convolution modules and two series layers; after the first to eighth convolution modules of the eight convolution modules are connected in series, the output ends of the second and fourth convolution modules are respectively connected to the first The inputs of the two series layers are connected, the output of the first series layer and the output of the sixth convolution module are connected to the inputs of the second series layer, the output of the second series layer and the eighth The output end of the convolution module is respectively connected to the input end of the third series layer; the second volume The input of the first convolution module in the path is connected to the output of the downsampling unit, and the output of the third series layer in the second convolution path is connected to the input of the upsampling unit. The output end of the upsampling unit and the output end of the third series layer in the first convolution path are respectively connected to the input end of the first series layer in the third convolution path; the third convolution The first convolution module in the path is connected in series with the second convolution module, and the input of the first convolution module in the third convolution path is connected to the output of the first series layer in the third convolution path. And the output end of the second convolution module in the third convolution path and the output end of the first series layer in the third convolution path are respectively connected to the second series layer in the third convolution path. The input end of the third convolution path is connected to the output end of the second series layer in the third convolution path and the input end of the third convolution module in the third convolution path. An output end of each convolution module is connected to the classifier.
上述实施例的训练模块还包括函数定义单元和网络训练单元,其中:The training module of the above embodiment further includes a function definition unit and a network training unit, where:
函数定义单元,用于利用预测图像块和所述静脉分割金标准图像块定义损失函数
Figure PCTCN2018089899-appb-000010
其中,预测图像块是所述第一训练图像块和第二训练图像块输入卷积神经网络后预测的输出结果,B为对卷积神经网络训练过程中一次处理的训练图像块对的数量,N为预测图像块中体素的数量,p ij为第i个训练图像块对相应的预测图像块中第j个体素属于静脉血管的概率,y ij为第i个训练图像块对相应的静脉分割金标准图像块中第j个体素的真实标记;
A function defining unit, configured to define a loss function using a predicted image block and the vein segmentation gold standard image block
Figure PCTCN2018089899-appb-000010
Wherein, the predicted image block is a predicted output result after the first training image block and the second training image block are input to a convolutional neural network, and B is the number of training image block pairs processed at one time during the training process of the convolutional neural network, N is the number of voxels in the predicted image block, p ij is the probability that the j-th voxel in the corresponding predicted image block belongs to the vein vein, and y ij is the i-th training image block paired with the corresponding vein Segment the true label of the jth voxel in the gold standard image block;
网络训练单元,用于以第一训练图像块和第二训练图像块作为输入特征,基于批量梯度下降算法训练卷积神经网络,在最小化损失函数时获得卷积神经网络的参数。A network training unit is configured to use a first training image block and a second training image block as input features to train a convolutional neural network based on a batch gradient descent algorithm, and obtain parameters of the convolutional neural network while minimizing a loss function.
图6是本发明一实施例提供的计算设备的结构示意图。如图6所示,该实施例的计算设备6包括:处理器60、存储器61以及存储在存储器61中并可在处理器60上运行的计算机程序62,例如分割磁敏感加权图像中静脉血管的方法的程序。处理器60执行计算机程序62时实现上述分割磁敏感加权图像中静脉血管的方法实施例中的步骤,例如图1所示的步骤S101至S104。或者,处理器60执行计算机程序62时实现上述各装置实施例中各模块/单元的功能,例如图4所示标准化模块401、图像块提取模块402、标记模块403和映射模块 404的功能。FIG. 6 is a schematic structural diagram of a computing device according to an embodiment of the present invention. As shown in FIG. 6, the computing device 6 of this embodiment includes a processor 60, a memory 61, and a computer program 62 stored in the memory 61 and executable on the processor 60, such as segmentation of a venous vessel in a magnetically sensitive weighted image Method of Procedure. When the processor 60 executes the computer program 62, the steps in the embodiment of the method for segmenting venous blood vessels in the magnetically sensitive weighted image described above are implemented, for example, steps S101 to S104 shown in FIG. Alternatively, when the processor 60 executes the computer program 62, the functions of the modules / units in the foregoing device embodiments are realized, such as the functions of the standardization module 401, image block extraction module 402, marking module 403, and mapping module 404 shown in FIG.
示例性的,分割磁敏感加权图像中静脉血管的方法的计算机程序62主要包括:对原始脑磁敏感加权图像SWI中的脑部区域进行提取并标准化,得到标准化脑SWI;以标准化脑SWI中每间隔m个体素定义的任意一个采样点为中心,提取一组中心重合的第一图像块和第二图像块,第一图像块的区域包含以M 1*M 1阶矩阵排布的体素,第二图像块的区域包含以M 2*M 2阶矩阵排布的体素,m、M 1和M 2为自然数,且M 2>M 1>m;输入n组第一图像块和第二图像块至已训练卷积神经网络,由已训练卷积神经网络对所述n组第一图像块和第二图像块中的静脉血管进行标记后得到标记了静脉血管的n组两个第三图像块,已训练卷积神经网络通过监督学习方式对卷积神经网络训练而成,第三图像块的区域包含以m*m阶矩阵排布的体素,n为采样点的个数;将n组两个第三图像块的静脉血管标记映射回原始脑磁敏感加权图像SWI以得到静脉血管的分割结果。计算机程序62可以被分割成一个或多个模块/单元,一个或者多个模块/单元被存储在存储器61中,并由处理器60执行,以完成本发明。一个或多个模块/单元可以是能够完成特定功能的一系列计算机程序指令段,该指令段用于描述计算机程序62在计算设备6中的执行过程。例如,计算机程序62可以被分割成标准化模块401、图像块提取模块402、标记模块403和映射模块404的功能(虚拟装置中的模块),各模块具体功能如下:标准化模块401,用于对原始脑磁敏感加权图像SWI中的脑部区域进行提取并标准化,得到标准化脑SWI;图像块提取模块402,用于以标准化脑SWI中每间隔m个体素定义的任意一个采样点为中心,提取一组中心重合的第一图像块和第二图像块,第一图像块的区域包含以M 1*M 1阶矩阵排布的体素,第二图像块的区域包含以M 2*M 2阶矩阵排布的体素,m、M 1和M 2为自然数,且M 2>M 1>m;标记模块403,用于输入n组第一图像块和第二图像块至已训练卷积神经网络,由已训练卷积神经网络对n组第一图像块和第二图像块中的静脉血管进行标记后得到标记了静脉血管的n组两个第三图像块,已训练卷积神经网络通过监督学习方式对卷积神经网络训练而成,第三图像块的区域包含以m*m阶矩阵排布的体素,n为采样点的个数;映射模块404,用于将n组两个第三图像块的静脉血管标记映射回原始脑磁敏感加权图像SWI以得到静脉血管的分割结果。 Exemplarily, the computer program 62 of the method for segmenting venous blood vessels in a magnetically sensitive weighted image mainly includes: extracting and normalizing a brain region in the original brain magnetically sensitive weighted image SWI to obtain a standardized brain SWI; An arbitrary sampling point defined by an interval m voxels is taken as the center, and a set of first and second image blocks with coincident centers is extracted. The area of the first image block includes voxels arranged in a M 1 * M 1 order matrix. The region of the second image block contains voxels arranged in a M 2 * M 2 order matrix, m, M 1 and M 2 are natural numbers, and M 2 > M 1 >m; input n groups of the first image block and the second The image block to the trained convolutional neural network, and the trained convolutional neural network marks the venous vessels in the n sets of first and second image blocks to obtain two sets of n labeled third venous vessels Image block, which has been trained by the trained convolutional neural network through supervised learning. The area of the third image block contains voxels arranged in a matrix of order m * m, and n is the number of sampling points. Venous vessel marking of two third image blocks in n groups Exit back to the original brain susceptibility-weighted images to obtain the segmentation result SWI's vein. The computer program 62 may be divided into one or more modules / units, and the one or more modules / units are stored in the memory 61 and executed by the processor 60 to complete the present invention. One or more modules / units may be a series of computer program instruction segments capable of performing a specific function, and the instruction segments are used to describe the execution process of the computer program 62 in the computing device 6. For example, the computer program 62 may be divided into functions (modules in a virtual device) of the normalization module 401, the image block extraction module 402, the marking module 403, and the mapping module 404. The specific functions of each module are as follows: The brain region in the brain magnetically sensitive weighted image SWI is extracted and standardized to obtain a standardized brain SWI. The image block extraction module 402 is used to center any one of the sampling points defined by m voxels in the standardized brain SWI as The first image block and the second image block coincide with the center of the group. The area of the first image block contains voxels arranged in a M 1 * M 1 order matrix, and the area of the second image block contains a M 2 * M 2 order matrix. The arranged voxels, m, M 1 and M 2 are natural numbers, and M 2 > M 1 >m; the labeling module 403 is used to input n sets of first image blocks and second image blocks to the trained convolutional neural network , After training the convolutional neural network to label the venous blood vessels in the n groups of the first image block and the second image block, two sets of n third image blocks labeled with the venous blood vessel are obtained. The trained convolutional neural network passes the supervision Learning style Product neural network training, the area of the third image block contains voxels arranged in a matrix of order m * m, n is the number of sampling points; the mapping module 404 is used to convert n groups of two third image blocks into Vein vein markers are mapped back to the original brain magnetically sensitive weighted image SWI to obtain the segmentation results of vein veins.
计算设备6可包括但不仅限于处理器60、存储器61。本领域技术人员可以理解,图6仅仅是计算设备6的示例,并不构成对计算设备6的限定,可以包括比图示更多或更少的部件,或者组合某些部件,或者不同的部件,例如计算设备还可以包括输入输出设备、网络接入设备、总线等。The computing device 6 may include, but is not limited to, a processor 60 and a memory 61. Those skilled in the art can understand that FIG. 6 is only an example of the computing device 6 and does not constitute a limitation on the computing device 6. It may include more or fewer components than shown in the figure, or combine some components or different components. For example, computing devices may also include input and output devices, network access devices, and buses.
所称处理器60可以是中央处理单元(Central Processing Unit,CPU),还可以是其他通用处理器、数字信号处理器(Digital Signal Processor,DSP)、专用集成电路(Application Specific Integrated Circuit,ASIC)、现成可编程门阵列(Field-Programmable Gate Array,FPGA)或者其他可编程逻辑器件、分立门或者晶体管逻辑器件、分立硬件组件等。通用处理器可以是微处理器或者该处理器也可以是任何常规的处理器等。The so-called processor 60 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), Ready-made programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
存储器61可以是计算设备6的内部存储单元,例如计算设备6的硬盘或内存。存储器61也可以是计算设备6的外部存储设备,例如计算设备6上配备的插接式硬盘,智能存储卡(Smart Media Card,SMC),安全数字(Secure Digital,SD)卡,闪存卡(Flash Card)等。进一步地,存储器61还可以既包括计算设备6的内部存储单元也包括外部存储设备。存储器61用于存储计算机程序以及计算设备所需的其他程序和数据。存储器61还可以用于暂时地存储已经输出或者将要输出的数据。The memory 61 may be an internal storage unit of the computing device 6, such as a hard disk or a memory of the computing device 6. The memory 61 may also be an external storage device of the computing device 6, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) card, and a flash memory card (Flash) provided on the computing device 6. Card) and so on. Further, the memory 61 may also include both an internal storage unit of the computing device 6 and an external storage device. The memory 61 is used to store computer programs and other programs and data required by the computing device. The memory 61 may also be used to temporarily store data that has been output or is to be output.
所属领域的技术人员可以清楚地了解到,为了描述的方便和简洁,仅以上述各功能单元、模块的划分进行举例说明,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单元、模块完成,即将装置的内部结构划分成不同的功能单元或模块,以完成以上描述的全部或者部分功能。实施例中的各功能单元、模块可以集成在一个处理单元中,也可以是各个单元单独物理存在,也可以两个或两个以上单元集成在一个单元中,上述集成的单元既可以采用硬件的形式实现,也可以采用软件功能单元的形式实现。另外,各功能单元、模块的具体名称也只是为了便于相互区分,并不用于限制本申请的保护范围。上述系统中单元、模块的具体工作过程,可以参考前述方法实施例中的对应过程,在此不再赘述。Those skilled in the art can clearly understand that, for the convenience and brevity of the description, only the above-mentioned division of functional units and modules is used as an example. In practical applications, the above functions can be assigned by different functional units, Module completion, that is, the internal structure of the device is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment may be integrated into one processing unit, or each unit may exist separately physically, or two or more units may be integrated into one unit, and the integrated unit may use hardware. It can be implemented in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the protection scope of the present application. For specific working processes of the units and modules in the above system, reference may be made to corresponding processes in the foregoing method embodiments, and details are not described herein again.
在上述实施例中,对各个实施例的描述都各有侧重,某个实施例中没有详述或记载的部分,可以参见其它实施例的相关描述。In the foregoing embodiments, the description of each embodiment has its own emphasis. For a part that is not detailed or recorded in an embodiment, reference may be made to related descriptions of other embodiments.
本领域普通技术人员可以意识到,结合本文中所公开的实施例描述的各示例的单元及算法步骤,能够以电子硬件、或者计算机软件和电子硬件的结合来实现。这些功能究竟以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。专业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 of ordinary skill in the art may realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. A person skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.
在本发明所提供的实施例中,应该理解到,所揭露的装置/计算设备和方法,可以通过其它的方式实现。例如,以上所描述的装置/计算设备实施例仅仅是示意性的,例如,模块或单元的划分,仅仅为一种逻辑功能划分,实际实现时可以有另外的划分方式,例如多个单元或组件可以结合或者可以集成到另一个系统,或一些特征可以忽略,或不执行。另一点,所显示或讨论的相互之间的耦合或直接耦合或通讯连接可以是通过一些接口,装置或单元的间接耦合或通讯连接,可以是电性,机械或其它的形式。In the embodiments provided by the present invention, it should be understood that the disclosed apparatus / computing device and method may be implemented in other ways. For example, the device / computing device embodiments described above are only schematic. For example, the division of modules or units is only a logical function division. In actual implementation, there may be another division manner, such as multiple units or components. Can be combined or integrated into another system, or some features can be ignored or not implemented. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection through some interfaces, devices or units, which may be electrical, mechanical or other forms.
作为分离部件说明的单元可以是或者也可以不是物理上分开的,作为单元显示的部件可以是或者也可以不是物理单元,即可以位于一个地方,或者也可以分布到多个网络单元上。可以根据实际的需要选择其中的部分或者全部单元来实现本实施例方案的目的。The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, may be located in one place, or may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the objective of the solution of this embodiment.
另外,在本发明各个实施例中的各功能单元可以集成在一个处理单元中,也可以是各个单元单独物理存在,也可以两个或两个以上单元集成在一个单元中。上述集成的单元既可以采用硬件的形式实现,也可以采用软件功能单元的形式实现。In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist separately physically, or two or more units may be integrated into one unit. The above integrated unit may be implemented in the form of hardware or in the form of software functional unit.
集成的模块/单元如果以软件功能单元的形式实现并作为独立的产品销售或使用时,可以存储在一个计算机可读取存储介质中。基于这样的理解,本发明实现上述实施例方法中的全部或部分流程,也可以通过计算机程序来指令相关的硬件来完成,分割磁敏感加权图像中静脉血管的方法的计算机程序可存储于一计算机可读存储介质中,该计算机程序在被处理器执行时,可实现上述各个方法实施例的步骤,即,对原始脑磁敏感加权图像SWI中的脑部区域进行提取并标准化,得到标准化脑SWI;以标准化脑SWI中每间隔m个体素定义的任意一个采样点为中心,提取一组中心重合的第一图像块和第二图像块,第一图像块的区域包含以M 1*M 1阶矩阵排布的体素,第二图像块的区域包含以 M 2*M 2阶矩阵排布的体素,m、M 1和M 2为自然数,且M 2>M 1>m;输入n组第一图像块和第二图像块至已训练卷积神经网络,由已训练卷积神经网络对所述n组第一图像块和第二图像块中的静脉血管进行标记后得到标记了静脉血管的n组两个第三图像块,已训练卷积神经网络通过监督学习方式对卷积神经网络训练而成,第三图像块的区域包含以m*m阶矩阵排布的体素,n为采样点的个数;将n组两个第三图像块的静脉血管标记映射回原始脑磁敏感加权图像SWI以得到静脉血管的分割结果。其中,计算机程序包括计算机程序代码,计算机程序代码可以为源代码形式、对象代码形式、可执行文件或某些中间形式等。计算机可读介质可以包括:能够携带计算机程序代码的任何实体或装置、记录介质、U盘、移动硬盘、磁碟、光盘、计算机存储器、只读存储器(ROM,Read-Only Memory)、随机存取存储器(RAM,Random Access Memory)、电载波信号、电信信号以及软件分发介质等。需要说明的是,计算机可读介质包含的内容可以根据司法管辖区内立法和专利实践的要求进行适当的增减,例如在某些司法管辖区,根据立法和专利实践,计算机可读介质不包括电载波信号和电信信号。以上实施例仅用以说明本发明的技术方案,而非对其限制;尽管参照前述实施例对本发明进行了详细的说明,本领域的普通技术人员应当理解:其依然可以对前述各实施例所记载的技术方案进行修改,或者对其中部分技术特征进行等同替换;而这些修改或者替换,并不使相应技术方案的本质脱离本发明各实施例技术方案的精神和范围,均应包含在本发明的保护范围之内。 When integrated modules / units are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the method of the above embodiment, and can also be performed by a computer program instructing related hardware. The computer program of the method for segmenting a vein in a magnetically sensitive weighted image can be stored in a computer In a readable storage medium, when the computer program is executed by a processor, it can implement the steps of the above method embodiments, that is, extract and normalize the brain region in the original brain magnetically sensitive weighted image SWI to obtain a standardized brain SWI ; Extracting a set of first and second image blocks that coincide with each other at the center of any sampling point defined by every voxel in the normalized brain SWI. The area of the first image block includes M 1 * M 1 order Voxels arranged in a matrix, the region of the second image block includes voxels arranged in a matrix of order M 2 * M 2 , m, M 1 and M 2 are natural numbers, and M 2 > M 1 >m; input n groups The first image block and the second image block to the trained convolutional neural network, and the trained convolutional neural network marks the venous vessels in the n groups of the first image block and the second image block to obtain a label The n groups of two third image blocks of the venous blood vessels are trained by the trained convolutional neural network to train the convolutional neural network through a supervised learning method. The region of the third image block contains voxels arranged in a m * m order matrix. , N is the number of sampling points; map the venous blood vessel marks of the two third image blocks of the n groups back to the original brain magnetic sensitive weighted image SWI to obtain the venous blood vessel segmentation result. The computer program includes computer program code, and the computer program code may be in a source code form, an object code form, an executable file, or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying computer program code, a recording medium, a USB flash drive, a mobile hard disk, a magnetic disk, an optical disc, a computer memory, a read-only memory (ROM, Read-Only Memory), random access Memory (RAM, Random Access Memory), electric carrier signals, telecommunication signals, and software distribution media. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of the legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to the legislation and patent practice, the computer-readable medium does not include Electric carrier signals and telecommunication signals. The above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still apply the foregoing embodiments. The recorded technical solutions are modified, or some of the technical features are equivalently replaced; and these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the present invention Within the scope of protection.

Claims (10)

  1. 一种分割磁敏感加权图像中静脉血管的方法,其特征在于,所述方法包括:A method for segmenting venous blood vessels in a magnetically sensitive weighted image, wherein the method includes:
    对原始脑磁敏感加权图像SWI中的脑部区域进行提取并标准化,得到标准化脑SWI;Extract and normalize the brain regions in the original brain magnetically sensitive weighted image SWI to obtain a standardized brain SWI;
    以所述标准化脑SWI中每间隔m个体素定义的任意一个采样点为中心,提取一组中心重合的第一图像块和第二图像块,所述第一图像块的区域包含以M 1*M 1阶矩阵排布的体素,所述第二图像块的区域包含以M 2*M 2阶矩阵排布的体素,所述m、M 1和M 2为自然数,且M 2>M 1>m; A set of first image blocks and second image blocks with coincident centers are extracted centering on any one sampling point defined by m voxels per interval m in the standardized brain SWI. The area of the first image block includes M 1 * A voxel arranged in a matrix of order M 1 , the region of the second image block includes a voxel arranged in a matrix of order M 2 * M 2 , the m, M 1 and M 2 are natural numbers, and M 2 > M 1 >m;
    输入n组第一图像块和第二图像块至已训练卷积神经网络,由所述已训练卷积神经网络对所述n组第一图像块和第二图像块中的静脉血管进行标记后得到标记了静脉血管的n组两个第三图像块,所述已训练卷积神经网络通过监督学习方式对卷积神经网络训练而成,所述第三图像块的区域包含以m*m阶矩阵排布的体素,所述n为所述采样点的个数;Input n sets of first image blocks and second image blocks to a trained convolutional neural network, and the trained convolutional neural network marks the venous blood vessels in the n sets of first image blocks and second image blocks The n groups of two third image blocks labeled with venous blood vessels are obtained, and the trained convolutional neural network is trained on the convolutional neural network through a supervised learning method. The region of the third image block includes m * m orders. Voxels arranged in a matrix, where n is the number of sampling points;
    将所述n组两个第三图像块的静脉血管标记映射回所述原始脑磁敏感加权图像SWI以得到静脉血管的分割结果。Map the venous blood vessel labels of the two third image blocks of the n groups to the original brain magnetically sensitive weighted image SWI to obtain the venous blood vessel segmentation result.
  2. 如权利要求1所述的分割磁敏感加权图像中静脉血管的方法,其特征在于,所述对原始脑磁敏感加权图像SWI中的脑部区域进行提取并标准化,得到标准化脑SWI,包括:The method for segmenting venous vessels in a magnetically sensitive weighted image according to claim 1, wherein the extracting and normalizing the brain region in the original brain magnetically sensitive weighted image SWI to obtain a standardized brain SWI includes:
    采用阈值方法提取所述原始脑SWI中灰度值小于50的所有背景体素,并提取最大连通区域;Using a threshold method to extract all background voxels with a gray value less than 50 in the original brain SWI, and extract the largest connected region;
    将所述最大连通区域取反后,利用一个3x3x3大小的结构元素进行形态学闭操作,以恢复阈值分割丢失的静脉体素;After inverting the maximum connected region, using a 3x3x3 size structural element to perform a morphological closing operation to restore the threshold segmentation of the lost vein voxels;
    计算所述原始脑SWI中的脑部区域体素均值和标准差,将所述原始脑SWI中的脑部区域的每个体素减去均值并除以标准差以得到所述标准化脑SWI。Calculate the mean and standard deviation of the voxels of the brain region in the original brain SWI, subtract the mean of each voxel of the brain region in the original brain SWI, and divide by the standard deviation to obtain the standardized brain SWI.
  3. 如权利要求1所述的分割磁敏感加权图像中静脉血管的方法,其特征在于,所述对原始脑磁敏感加权图像SWI中的脑部区域进行提取并标准化,得到标准化脑SWI之前,所述方法还包括:The method for segmenting venous blood vessels in a magnetically sensitive weighted image according to claim 1, wherein the brain region in the original brain magnetically sensitive weighted image SWI is extracted and standardized, and before the standardized brain SWI is obtained, the The method also includes:
    从用于训练的脑SWI中提取训练图像块对以及与所述训练图像块对相应的静脉分割金标准图像块,所述训练图像块对由第一训练图像块和第二训练图像块组成,所述第一训练图像块的区域包含以M 1*M 1阶矩阵排布的体素,所述第二训练图像块的区域包含以M 2*M 2阶矩阵排布的体素,所述静脉分割金标准图像块的区域包含以m*m阶矩阵排布的体素; Extracting a training image block pair from the brain SWI used for training and a vein standard gold standard image block corresponding to the training image block pair, the training image block pair consisting of a first training image block and a second training image block, A region of the first training image block includes voxels arranged in a M 1 * M 1 order matrix, and a region of the second training image block includes voxels arranged in a M 2 * M 2 order matrix, the The region of the gold standard image block for vein segmentation includes voxels arranged in a matrix of order m * m;
    构造卷积神经网络;Construct a convolutional neural network;
    将所述第一训练图像块和第二训练图像块输入所述卷积神经网络,并根据所述静脉分割金标准图像块训练所述卷积神经网络,得到所述已训练卷积神经网络。The first training image block and the second training image block are input to the convolutional neural network, and the convolutional neural network is trained according to the vein segmentation gold standard image block to obtain the trained convolutional neural network.
  4. 如权利要求3所述的分割磁敏感加权图像中静脉血管的方法,其特征在于,所述从用于训练的脑SWI中提取训练图像块对以及与所述训练图像块对相应的静脉分割金标准图像块之前,所述方法还包括:对所述用于训练的脑SWI分别沿着二维坐标系的X轴和Y轴进行对称反转;The method for segmenting venous blood vessels in a magnetically sensitive weighted image according to claim 3, wherein the training image block pair extracted from the brain SWI for training and the vein segmentation gold corresponding to the training image block pair Before the standard image block, the method further includes: performing symmetrical inversion of the brain SWI for training along the X-axis and Y-axis of the two-dimensional coordinate system, respectively;
    所述从用于训练的脑SWI中提取训练图像块对以及与所述训练图像块对相应的静脉分割金标准图像块之后,所述方法还包括:对所述第一训练图像块和第二训练图像块的体素灰度按照公式I' S=I S+r*σ c进行变换,所述r为从正态分布N(0,1)采样的随机数,所述σ c为所述第一训练图像块或第二训练图像块中灰度标准差,所述I' S为对所述第一训练图像块或第二训练图像块内灰度I S变换后的灰度值。 After the extracting a training image block pair from a brain SWI for training and a vein segmentation gold standard image block corresponding to the training image block pair, the method further includes: dividing the first training image block and the second training image block The voxel gray level of the training image block is transformed according to the formula I ′ S = I S + r * σ c , where r is a random number sampled from a normal distribution N (0,1), and σ c is the a first standard deviation of gray training image block or the second training image blocks, the I 'S is the value of gradation after gradation conversion I S training image block within the first or the second training image blocks.
  5. 如权利要求3所述的分割磁敏感加权图像中静脉血管的方法,其特征在于,所述构造卷积神经网络,包括:The method for segmenting venous blood vessels in a magnetically sensitive weighted image according to claim 3, wherein said constructing a convolutional neural network comprises:
    构造第一卷积路径、第二卷积路径、第三卷积路径和分类器并对所述第一卷积路径、第二卷积路径、第三卷积路径和分类器进行连接,所述第一卷积路径用于对所述第一训练图像块进行处理,所述第二卷积路径用于对所述第二训练图像块进行处理,所述第一卷积路径或第二卷积路径包含8个卷积模块和3个串联层,所述第二卷积路径还包含一个降采样单元和一个升采样单元,所述第三卷积路径包含3个卷积模块和2个串联层;Constructing a first convolution path, a second convolution path, a third convolution path, and a classifier, and connecting the first convolution path, the second convolution path, the third convolution path, and the classifier, where A first convolution path is used to process the first training image block, and a second convolution path is used to process the second training image block. The first convolution path or the second convolution path The path includes 8 convolution modules and 3 series layers. The second convolution path also includes a downsampling unit and an upsampling unit. The third convolution path includes 3 convolution modules and 2 series layers. ;
    所述8个卷积模块中卷积模块1至8依次串联后,卷积模块2和卷积模块4的输出端分别与串联层1的输入端连接,串联层1的输出端和卷积模块6的 输出端分别与串联层2的输入端连接,串联层2的输出端和卷积模块8的输出端分别与串联层3的输入端连接;After the convolution modules 1 to 8 of the eight convolution modules are connected in series, the outputs of the convolution module 2 and the convolution module 4 are connected to the input of the series layer 1, respectively, and the output of the series layer 1 and the convolution module are connected. The output of 6 is connected to the input of serial layer 2 respectively, and the output of serial layer 2 and the output of convolution module 8 are connected to the input of serial layer 3 respectively;
    所述第二卷积路径中卷积模块1的输入端与所述降采样单元的输出端连接,所述第二卷积路径中串联层3的输出端与所述升采样单元的输入端连接,所述升采样单元的输出端和所述第一卷积路径中串联层3的输出端分别与所述第三卷积路径中串联层1的输入端连接;The input end of the convolution module 1 in the second convolution path is connected to the output end of the downsampling unit, and the output end of the series layer 3 in the second convolution path is connected to the input end of the upsampling unit. An output end of the upsampling unit and an output end of series layer 3 in the first convolution path are respectively connected to an input end of series layer 1 in the third convolution path;
    所述第三卷积路径中卷积模块1与卷积模块2串联,所述第三卷积路径中卷积模块1的输入端与所述第三卷积路径中串联层1的输出端连接,所述第三卷积路径中卷积模块2的输出端和第三卷积路径中串联层1的输出端分别与所述第三卷积路径中串联层2的输入端连接,所述第三卷积路径中串联层2的输出端与所述第三卷积路径中卷积模块3的输入端,所述第三卷积路径中卷积模块3的输出端与所述分类器连接。The convolution module 1 in the third convolution path is connected in series with the convolution module 2. The input terminal of the convolution module 1 in the third convolution path is connected to the output terminal of the series layer 1 in the third convolution path. The output of the convolution module 2 in the third convolution path and the output of the series layer 1 in the third convolution path are connected to the input of the series layer 2 in the third convolution path, respectively. The output end of the serial layer 2 in the three convolution paths is connected to the input end of the convolution module 3 in the third convolution path, and the output end of the convolution module 3 in the third convolution path is connected to the classifier.
  6. 如权利要求3所述的分割磁敏感加权图像中静脉血管的方法,其特征在于,所述将所述第一训练图像块和第二训练图像块输入所述卷积神经网络,并根据所述静脉分割金标准图像块训练所述卷积神经网络,得到所述已训练卷积神经网络,包括:The method for segmenting venous blood vessels in a magnetically sensitive weighted image according to claim 3, wherein the first training image block and the second training image block are input to the convolutional neural network, and according to the convolutional neural network, Training the convolutional neural network with a gold standard image block for vein segmentation to obtain the trained convolutional neural network includes:
    利用预测图像块和所述静脉分割金标准图像块定义损失函数
    Figure PCTCN2018089899-appb-100001
    所述预测图像块是所述第一训练图像块和第二训练图像块输入所述卷积神经网络后预测的输出结果,所述B为对所述卷积神经网络训练过程中一次处理的训练图像块对的数量,所述N为所述预测图像块中体素的数量,所述p ij为第i个训练图像块对相应的预测图像块中第j个体素属于静脉血管的概率,所述y ij为第i个训练图像块对相应的静脉分割金标准图像块中第j个体素的真实标记;
    Defining a loss function using a predicted image block and the vein segmentation gold standard image block
    Figure PCTCN2018089899-appb-100001
    The predicted image block is a predicted output result after the first training image block and the second training image block are input to the convolutional neural network, and the B is a training for one processing in the convolutional neural network training process. The number of image block pairs, where N is the number of voxels in the predicted image block, and p ij is the probability that the j-th voxel in the corresponding predicted image block of the i-th training image block belongs to a vein. Let y ij be the true label of the jth voxel in the i-th training image block to the corresponding vein segmentation gold standard image block;
    以所述第一训练图像块和第二训练图像块作为输入特征,基于批量梯度下降算法训练所述卷积神经网络,在最小化所述损失函数时获得所述卷积神经网络的参数。With the first training image block and the second training image block as input features, the convolutional neural network is trained based on a batch gradient descent algorithm, and parameters of the convolutional neural network are obtained when the loss function is minimized.
  7. 一种分割磁敏感加权图像中静脉血管的装置,其特征在于,所述装置包括:A device for segmenting a venous blood vessel in a magnetically sensitive weighted image, wherein the device includes:
    标准化模块,用于对原始脑磁敏感加权图像SWI中的脑部区域进行提取并 标准化,得到标准化脑SWI;A normalization module for extracting and normalizing brain regions in the original brain magnetically sensitive weighted image SWI to obtain a standardized brain SWI;
    图像块提取模块,用于以所述标准化脑SWI中每间隔m个体素定义的任意一个采样点为中心,提取一组中心重合的第一图像块和第二图像块,所述第一图像块的区域包含以M 1*M 1阶矩阵排布的体素,所述第二图像块的区域包含以M 2*M 2阶矩阵排布的体素,所述m、M 1和M 2为自然数,且M 2>M 1>m; An image block extraction module, for extracting a set of first image blocks and second image blocks with coincident centers centered on any one sampling point defined by every voxel in the standardized brain SWI The region of contains the voxels arranged in a M 1 * M 1 order matrix, and the region of the second image block contains the voxels arranged in a M 2 * M 2 order matrix, where m, M 1 and M 2 are Natural number, and M 2 > M 1 >m;
    标记模块,用于输入n组第一图像块和第二图像块至已训练卷积神经网络,由所述已训练卷积神经网络对所述n组第一图像块和第二图像块中的静脉血管进行标记后得到标记了静脉血管的n组两个第三图像块,所述已训练卷积神经网络通过监督学习方式对卷积神经网络训练而成,所述第三图像块的区域包含以m*m阶矩阵排布的体素,所述n为所述采样点的个数;A labeling module, configured to input n groups of first image blocks and second image blocks to a trained convolutional neural network, and the trained convolutional neural network The venous vessels are labeled to obtain two sets of n third image blocks labeled with venous vessels. The trained convolutional neural network is trained by a convolutional neural network in a supervised learning manner, and the area of the third image block includes Voxels arranged in an m * m order matrix, where n is the number of the sampling points;
    映射模块,用于将所述n组两个第三图像块的静脉血管标记映射回所述原始脑磁敏感加权图像SWI以得到静脉血管的分割结果。A mapping module, configured to map the venous blood vessel marks of the n sets of two third image blocks back to the original brain magnetically sensitive weighted image SWI to obtain a venous blood vessel segmentation result.
  8. 如权利要求7所述的分割磁敏感加权图像中静脉血管的装置,其特征在于,所述标准化模块包括:The device for segmenting venous blood vessels in a magnetically sensitive weighted image according to claim 7, wherein the normalization module comprises:
    提取单元,用于采用阈值方法提取所述原始脑SWI中灰度值小于50的所有背景体素,并提取最大连通区域;An extraction unit, configured to use a threshold method to extract all background voxels with a gray value less than 50 in the original brain SWI, and extract a maximum connected region;
    取反单元,用于将所述最大连通区域取反后,利用一个3*3*3大小的结构元素进行形态学闭操作,以恢复阈值分割丢失的静脉体素;A negation unit, configured to perform a morphological closing operation using a 3 * 3 * 3 size structural element after inverting the maximum connected region to restore the threshold voxel segmentation;
    计算单元,用于计算所述原始脑SWI中的脑部区域体素均值和标准差,将所述原始脑SWI中的脑部区域的每个体素减去均值并除以标准差以得到所述标准化脑SWI。A calculation unit for calculating a mean value and a standard deviation of a voxel of a brain region in the original brain SWI, subtracting a mean value of each voxel of the brain region in the original brain SWI and dividing by a standard deviation to obtain the Standardized brain SWI.
  9. 一种计算设备,包括存储器、处理器以及存储在所述存储器中并可在所述处理器上运行的计算机程序,其特征在于,所述处理器执行所述计算机程序时实现如权利要求1至6任意一项所述方法的步骤。A computing device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the processor implements claims 1 to Steps of the method of any one of 6.
  10. 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程序,其特征在于,所述计算机程序被处理器执行时实现如权利要求1至6任意一项所述方法的步骤。A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.
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