Method and Equipment for Determining Orientation Electrode Rotation Based on CT Images

Abstract

This invention relates to the field of image processing technology, specifically to a method and device for determining the rotation direction of directional electrodes based on CT images. The method includes: acquiring a CT image; removing metal artifacts from the CT image; obtaining cross-sectional images of the directional electrode contact points and the imaging marks based on artifact feature images, wherein the cross-sectional images are perpendicular to the electrode axis; determining the angles of each directional electrode segment in the same group based on artifact features in the cross-sectional images of the directional electrode contact points, and determining the angle of the imaging marks based on artifact features in the cross-sectional images of the imaging marks; and determining the electrode rotation angle based on the angles of each directional electrode segment and the angle of the imaging marks.

Description

Technical Field

[0001] This invention relates to the field of image processing technology, and specifically to a method and device for determining the rotation direction of directional electrodes based on CT images. Background Technology

[0002] A deep brain stimulation (DBS) device is a therapeutic device that uses electrodes to deliver electrical pulses to regulate and intervene in the activity of specific brain regions. DBS is an effective treatment for neurophysiological diseases such as Parkinson's disease. To ensure optimal postoperative efficacy, the DBS device needs to be programmed after implantation. This programming includes the selection of electrode contacts, pulse amplitude, pulse width, and frequency.

[0003] In deep brain stimulation therapy, compared with traditional ring electrodes, the use of directional electrodes as described in patent documents CN112316306A, CN111729193B, and CN112604155A can achieve precise stimulation, increase the range of the treatment window, reduce side effects, and reduce the power consumption of the pulse generator.

[0004] After electrodes are implanted in the human body, to ensure that the electrode contacts, especially the directional electrode contacts, are placed in the expected position and orientation, medical imaging equipment such as CT, MRI, and X-rays are needed to verify the electrode position. Current postoperative position identification of directional electrodes has several problems: In the typical electrode position identification process, doctors need to compare CT images with X-ray images, and this double scanning may increase the risk of ionizing radiation; doctors' subjective experience in judging the orientation of the directional electrode contacts has low accuracy, with an error of up to 45°, making it difficult to meet the needs of programmed control. Summary of the Invention

[0005] In view of this, the present invention provides a method for determining the rotation direction of directional electrodes based on CT images, comprising:

[0006] Acquire CT images, including images of nerve stimulation electrodes implanted in the human body, the nerve stimulation electrodes including directional electrode contacts and contrast markers;

[0007] Metal artifact removal is performed on the CT images to obtain artifact feature images;

[0008] Based on the artifact feature image, cross-sectional images of the directional electrode contact point and cross-sectional images of the development mark are obtained;

[0009] The angle of each directional electrode segment in the same group is determined based on the artifact features in the cross-sectional image at the directional electrode contact point, and the angle of the development mark is determined based on the artifact features in the cross-sectional image at the development mark.

[0010] The electrode rotation angle is determined based on the angle of the electrode segments in each direction and the angle of the development mark.

[0011] Optionally, the CT image is subjected to metal artifact removal to obtain an artifact feature image, including:

[0012] The Radon algorithm was used to remove metal artifacts from the CT image, resulting in an artifact feature image.

[0013] Optionally, the Radon algorithm is used to remove metal artifacts from the CT image to obtain an artifact feature image, including:

[0014] The CT image is subjected to Radon transform layer by layer to obtain the first image;

[0015] The metal portion of the CT image is extracted layer by layer according to the threshold, and Radon transform is performed to obtain the second image;

[0016] The first image and the second image are subtracted, and the result of the subtraction is subjected to an inverse Radon transform to obtain the artifact feature image.

[0017] Optionally, obtaining cross-sectional images of the directional electrode contact and the developing marks based on the artifact feature image includes:

[0018] A segmented image containing electrode artifact regions is extracted from the artifact feature image;

[0019] The sliced ​​image is rotated;

[0020] The cross-sectional image perpendicular to the electrode axis is obtained based on the rotated slice image.

[0021] Optionally, rotating the sliced ​​image includes:

[0022] Calculate the angle between the electrode and the axial plane in the sliced ​​image;

[0023] The electrodes are rotated around the SI axis into the coronal plane according to the included angle, and the electrodes are rotated around the AP axis to be parallel to the SI axis, so that the plane containing the artifact features of all electrodes is perpendicular to the coronal plane.

[0024] An affine transformation is performed on the image in which the plane containing the artifact features is perpendicular to the coronal plane, so that the plane containing all artifact features is perpendicular to the electrode axis.

[0025] Optionally, the angle of each directional electrode segment in the same group is determined based on the artifact features in the cross-sectional image at the directional electrode contact, including:

[0026] The cross-sectional image at the directional electrode contact is matched with a pre-stored electrode contact artifact template to obtain the angle of the cross-sectional image at the directional electrode segment, and the angle of other directional electrode segments in the same group is determined according to the angle period of the electrode segments.

[0027] Determining the angle of the development mark based on artifact features in the cross-sectional image at the development mark includes:

[0028] The cross-sectional image at the development mark is matched with a pre-stored development mark artifact template to obtain the angle of the cross-sectional image at the development mark.

[0029] Optionally, the angle of each directional electrode segment in the same group is determined based on the artifact features in the cross-sectional image at the directional electrode contact, including:

[0030] Extract the ray features of the directional electrode contacts in the cross-sectional image, then calculate the angle of the cross-sectional image at the directional electrode segment based on the ray features, and determine the angle of other directional electrode segments in the same group based on the angle period of the electrode segments.

[0031] Determining the angle of the development mark based on artifact features in the cross-sectional image at the development mark includes:

[0032] Extract the ray features of the developing marks in the cross-sectional image, and then calculate the angle of the cross-sectional image at the developing marks based on the ray features.

[0033] Optionally, the angle of each directional electrode segment in the same group is determined based on the artifact features in the cross-sectional image at the directional electrode contact, including:

[0034] Obtain a cylindrical slice image of the artifact feature image within the range of the electrode contact points with the electrode axis as the axis;

[0035] The cylindrical slice image is unfolded into an angle-grayscale image;

[0036] Calculate the angle of the electrode slices in each direction based on the information in the angle-grayscale image;

[0037] Determining the angle of the development mark based on artifact features in the cross-sectional image at the development mark includes:

[0038] Obtain a cylindrical slice image of the artifact feature image within the development mark range with the electrode axis as the axis;

[0039] The cylindrical slice image is unfolded into an angle-grayscale image;

[0040] The angle of the developing mark is calculated based on the information in the angle-grayscale image.

[0041] Optionally, the electrode rotation angle is determined based on the angle of the electrode slicing in each direction and the angle of the developing mark, including:

[0042] The angles of the electrode slices in each direction and the angles of the development marks are combined;

[0043] Calculate the difference between the angle of the directional electrode segment and the angle of the development mark in each combination;

[0044] A set of angles that satisfy the preset difference relationship is determined as the electrode rotation angle.

[0045] Accordingly, the present invention also provides a device for determining the orientation of CT-based electrodes, comprising: a processor and a memory connected to the processor; wherein the memory stores instructions executable by the processor, the instructions being executed by the processor to cause the processor to perform the aforementioned method for determining the orientation of CT-based electrodes.

[0046] The method and apparatus for determining the rotation direction of directional electrodes based on CT images provided by this invention removes metal artifacts from CT images, retaining sufficient image features for rotation localization. Then, rotation matching is performed on the data blocks after removing metal artifacts to find the rotation angles with the highest correlation between the electrode slice positions and the imaging marker positions and the template. Finally, the most likely rotation angle of the electrode is calculated based on the rotation periodic angles of the respective electrode slice positions and imaging marker positions. This solution does not require localization using X-ray images, nor does it require postoperative judgment by doctors. Instead, it obtains images that highlight the characteristics of directional electrode artifacts through image processing and improves the accuracy of electrode localization through rotation registration and other methods. Attached Figure Description

[0047] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0048] Figure 1 This is a flowchart illustrating the method for determining the rotation direction of the directional electrode provided in an embodiment of the present invention.

[0049] Figure 2 This is a schematic diagram of metal artifact removal processing of CT images in an embodiment of the present invention;

[0050] Figure 3 This is a schematic diagram illustrating the rotation processing of electrodes in a sliced ​​image according to an embodiment of the present invention.

[0051] Figure 4 This is a schematic diagram of extracting six-ray structural features from a cross-sectional image at the directional electrode contact point;

[0052] Figure 5 This is a schematic diagram of extracting two-ray structural features from a cross-sectional image of the directional electrode development mark;

[0053] Figure 6 This is a schematic diagram illustrating the relationship between ray characteristics and directional electrode contacts in an embodiment of the present invention.

[0054] Figure 7 This is a schematic diagram illustrating the relationship between ray characteristics and development marks in an embodiment of the present invention;

[0055] Figure 8 This is an angle-grayscale image of a cylindrical slice unfolded with the electrode axis as the axis in an embodiment of the present invention.

[0056] Figure 9 This is a schematic diagram showing the rotational position of the six high grayscale value regions calculated from the grayscale image in an embodiment of the present invention;

[0057] Figure 10 This is a schematic diagram of the directional electrode structure in an embodiment of the present invention;

[0058] Figure 11 This is a schematic diagram of the electrode rotation angle in an embodiment of the present invention. Detailed Implementation

[0059] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0060] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0061] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can also refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0062] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0063] like Figure 1 As shown, one embodiment of the present invention provides a method for determining the orientation of directional electrodes based on CT images. This method can be executed by electronic devices such as computers or servers, and includes the following operations:

[0064] S101, acquire CT images, including images of a nerve stimulation electrode implanted in the human body. The nerve stimulation electrode includes directional electrode contacts and contrast markers. In this embodiment, the directional electrode contacts located at at least one axial position of the electrode stimulation end are composed of a set of electrode segments in three different directions; the main body of the contrast marker extends circumferentially along the electrode stimulation end, with an extension length less than or equal to half the circumference of the electrode stimulation end. In optional embodiments, such as... Figure 10 As shown ( Figure 10 a is Figure 10 (b) The width of the extended end of the developing marker body is different from the width of the extended starting point, such as the extended end forming a convex tip.

[0065] S102, perform metal artifact removal on the CT image to obtain an artifact feature image. The original CT image may contain many metal artifacts. Subsequent steps require determining the electrode contact direction based on some of these artifact features. This step necessitates removing irrelevant artifact content. For example, if subsequent steps require the use of radial artifacts radiating outwards from the electrodes but not striped artifacts, a specific algorithm is used in this step to remove striped artifacts.

[0066] S103, obtain cross-sectional images of the directional electrode contact and the imaging marker based on the artifact feature image. The cross-sectional image of the electrode contact contains all electrode segments in the same group and their artifact features; the cross-sectional image of the imaging marker contains the main body extending circumferentially along the electrode stimulation end and its artifact features.

[0067] S104, determine the angle of each directional electrode segment in the same group based on the artifact characteristics in the cross-sectional image at the directional electrode contact point, and determine the angle of the developing mark based on the artifact characteristics in the cross-sectional image at the developing mark.

[0068] S105, determine the electrode rotation angle based on the angle of the electrode slicing in each direction and the angle of the development mark. The electrode rotation angle refers to the angle by which the current electrode rotates relative to the given / initial electrode along the electrode axis. Figure 11 For example, 2A, 2B, and 2C represent three directional electrode slices, respectively. Assume that the image on the left is a cross-sectional image of the given / initial electrode, and the image on the right is a cross-sectional image of the current electrode, with a rotation angle of 45° relative to the image on the left.

[0069] By determining the electrode rotation angle with the greatest correlation between the angle of electrode slicing in each direction and the angle of the imaging mark, the electrode positioning becomes more precise, reducing errors in doctor's operation and lowering the safety risks to patients.

[0070] In a preferred embodiment, S102, metal artifact removal is performed on the CT image to obtain an artifact feature image, including:

[0071] The Radon algorithm was used to remove metal artifacts from CT images, resulting in artifact feature images.

[0072] In this embodiment, metallic objects cause artifacts in CT images, which can interfere with our observation and analysis of other tissue structures and lesions. By applying the Radon algorithm, the impact of metal artifacts can be effectively reduced, improving image quality and accuracy.

[0073] Furthermore, the Radon algorithm is used to remove metal artifacts from CT images, resulting in artifact feature images, including:

[0074] The first image is obtained by performing Radon transform on each layer of the CT image;

[0075] The metal portion of the CT image is extracted layer by layer based on a threshold, and then Radon transform is performed to obtain a second image. Specifically, during the layer-by-layer extraction of the metal portion, pixels with values ​​above the threshold are retained, while those below the threshold are set to zero, thus obtaining the metal portion. The threshold can be set according to specific circumstances.

[0076] The artifact feature image is obtained by subtracting the first image and the second image, and then performing an inverse Radon transform on the difference result.

[0077] like Figure 2As shown, a Radon transform is first performed on the CT image to obtain the first image A. This allows for intensity correction, eliminating intensity deviations and ensuring more accurate and consistent intensity across different regions. It also reduces image noise, resulting in a clearer image. Next, the metal portion is extracted layer by layer from the CT image, and a Radon transform is performed on the metal image to obtain the second image B. This accurately locates the position of the metal object in the image and extracts its features. The Radon-transformed metal portion image provides feature information about the metal object, such as its shape, orientation, and intensity, which helps improve the quality and visualization of medical images. Finally, the difference between the first image A and the second image B is calculated, and an inverse Radon transform is performed on the difference result C to obtain the artifact feature image D. The difference operation between the first and second images extracts the difference information between them. The difference image shows the differences between the two images, which may include the motion of the target object, changes in shape, or differences in brightness. The role of the inverse Radon transform in the processing of difference images is to remove or reduce artifact features. Therefore, performing a difference operation on the first and second images and then performing an inverse Radon transform on the difference image can help eliminate some artifact features while retaining artifact features that can be used for rotation localization, thereby improving the results of image processing and analysis.

[0078] In a preferred embodiment, S103, obtaining cross-sectional images of the directional electrode contact and the developing mark based on the artifact feature image includes:

[0079] Based on the electrode contact coordinates calculated by the electrode tracking algorithm, a segmented image containing the electrode artifact region is divided in the artifact feature image.

[0080] Resample the segmented image to 0.5*0.5*0.5mm 3 Resolution;

[0081] The electrodes in the resampled block image are rotated.

[0082] The electrode contacts in the rotated slice image are cropped to obtain cross-sectional images of the directional electrode contacts and the development marks.

[0083] In this embodiment, the image region corresponding to the electrode contact coordinates is divided, isolating the electrode of interest from other parts. The divided image segments are then resampled, which helps to unify the image resolution and facilitates subsequent operations. The electrodes in the resampled image are then rotated to correct their orientation. Finally, a cross-sectional image of the electrode is captured, yielding cross-sectional images located at the directional electrode contact and the developing mark.

[0084] Furthermore, the electrodes in the resampled sliced ​​image are rotated, including:

[0085] Calculate the angle between the electrode and the axial plane in the resampled block image;

[0086] Based on the included angle, rotate the electrode around the SI axis into the coronal plane, and rotate the electrode around the AP axis to be parallel to the SI axis, so that the plane containing the artifact features of all electrodes is perpendicular to the coronal plane;

[0087] An affine transformation is performed on the image in which the plane containing the artifact features is perpendicular to the coronal plane, so that the plane containing all artifact features is perpendicular to the electrode axis.

[0088] like Figure 3 As shown, image a is obtained by resampling the segmented image. The angle between the electrode and the axial plane is calculated. This angle can be obtained by measuring the angle between the direction vector of the electrode and the normal vector of the axial plane. Then, based on the angle, the electrode is rotated around the SI axis to adjust it into the coronal plane, resulting in image b. Then, with the electrode rotated into the coronal plane, it is rotated around the AP axis to adjust it to be parallel to the SI axis, resulting in image c. Finally, an affine transformation is used to adjust the plane containing all artifact rays to be perpendicular to the motor axis, resulting in image d. The data processed in the above way will show a six-fold symmetrical ray pattern at the contact point, as shown in the image. Figure 4 As shown; the cross-section at the development mark will exhibit a double-symmetric ray pattern, such as... Figure 5 As shown.

[0089] In this embodiment, the resampled sliced ​​image is rotated and affine transformed to adjust the direction of the plane where the artifact rays are located, which can reduce the superposition effect of artifacts and make the cross-sectional image more accurate. Moreover, the obtained data at the contact point or development mark is transformed into a ray pattern showing multiple symmetries, indicating that the electrode has obvious features at the contact point or development mark, and the shape, position and geometric features of the electrode can be accurately extracted.

[0090] In a preferred embodiment, S104, determining the angle of each directional electrode segment in the same group based on artifact features in the cross-sectional image at the directional electrode contact point includes:

[0091] The cross-sectional image at the directional electrode contact is matched with the pre-stored electrode contact artifact template to obtain the angle of the cross-sectional image at the directional electrode segment, and the angle of other directional electrode segments in the same group is determined according to the angle period of the electrode segments.

[0092] The angle of the development mark is determined based on the artifact features in the cross-sectional image at the development mark, including:

[0093] The cross-sectional image at the development mark is matched with the pre-stored development mark artifact template to obtain the angle of the cross-sectional image at the development mark.

[0094] This embodiment first introduces a method for determining the angles of electrode segments and development marks within the same group. Pre-stored electrode contact artifact templates include cross-sectional images of electrode contacts from 0 to 360°, and pre-stored development mark artifact templates include cross-sectional images of development marks from 0 to 360°. These templates are obtained experimentally. The cross-sectional image of the current electrode contact is matched with the pre-stored templates for each angle to obtain the angle of the current electrode contact. Since the angular period between electrode segments is known to be 120°, a set of angles for the directional electrode segments is (angle1, angle1+120°, angle1+240°). The cross-sectional image of the current development mark is matched with the pre-stored templates for each angle to obtain the angle of the current development mark. Since the angular period of the development mark is 180°, a set of angles for the development mark is recorded as (angle2, angle2+180°). The above process determines the possible angle combinations of the current directional electrode contact and development marks by accurately matching known images.

[0095] In another embodiment, S104, determining the angle of each directional electrode segment in the same group based on artifact features in the cross-sectional image at the directional electrode contact includes:

[0096] The six-ray feature of the directional electrode contact point in the cross-sectional image is extracted using the straight line extraction technique (there are six rays in the three directional electrode segments), and the angle of the cross-sectional image at the directional electrode contact point is calculated based on the six-ray feature.

[0097] The angle of the development mark is determined based on the artifact features in the cross-sectional image at the development mark, including:

[0098] The two-ray feature (one developing mark has two rays) of the developing mark in the cross-sectional image is extracted using the straight line extraction technique, and the angle of the cross-sectional image at the developing mark is calculated based on the two-ray feature.

[0099] This embodiment is a second method for determining the angles of electrode contacts and development marks in each direction within the same group. Figure 4-5 The image shows a six-ray feature image of the directional electrode contact and a two-ray feature image of the developing mark. Straight lines can be extracted using techniques such as Hough transform, and the angles of all directional electrode segments can be calculated based on the angles between the straight lines. Figure 6-7This diagram illustrates the exponential edge gradient effect (EEGE) of CT artifacts. When two metallic regions are adjacent to a CT ray and located on the same side, the ray produces dark fringes; conversely, if they are on opposite sides, they produce bright fringes. This phenomenon originates from the characteristics of the CT imaging inverse transform algorithm. This phenomenon manifests as a six-fold dark ray characteristic structure on a three-lobed directional electrode and a two-fold dark ray characteristic structure on a circumferentially extending imaging marker. For a three-lobed directional electrode with uniformly distributed rotation, the angle between adjacent rays is 60°, and there are three sets of bright rays between the dark rays. The orientation of the directional electrode contact can be determined based on the distribution of dark and bright fringes in the image. Based on the same principle, dark and bright fringes conforming to the above pattern also exist in the cross-sectional image at the imaging marker. The orientation of the imaging marker can be determined based on the distribution of dark and bright fringes in the image.

[0100] In another embodiment, S104, determining the angle of each directional electrode segment in the same group based on artifact features in the cross-sectional image at the directional electrode contact point includes:

[0101] Obtain a cylindrical slice image of the electrode contact point within the direction of the electrode axis as the axis of the artifact feature image;

[0102] Unfold the sliced ​​image of the cylinder into an angle-grayscale image;

[0103] The angles of the electrode segments in each direction are calculated based on the information in the angle-grayscale image.

[0104] The angle of the development mark is determined based on the artifact features in the cross-sectional image at the development mark, including:

[0105] Obtain a cylindrical slice image of the development mark area with the electrode axis as the axis for artifact feature image acquisition;

[0106] Unfold the sliced ​​image of the cylinder into an angle-grayscale image;

[0107] The angle of the developing mark is calculated based on the information in the angle-grayscale image.

[0108] This embodiment represents a third method for determining the angles of electrode sections and development marks within the same group. For example... Figure 8 As shown, a cylindrical slice within a certain range with the electrode axis as its axis is then unfolded into an angle-grayscale image. For example... Figure 9As shown in the image above, the horizontal axis represents the rotation angle (ranging from 0 to 360°), and the vertical axis represents the grayscale values ​​of the cylindrical slice from the inside to the outside along the ray direction at the corresponding angle. In the image below, the horizontal axis represents the rotation angle, and the vertical axis represents the sum of all grayscale values ​​corresponding to each angle. Six peak-valley cycles can be identified from this image. The rotation angle corresponding to the directional electrode contact can be obtained using the position of the highest peak. The angle calculation for the developing mark is the same as that for the directional electrode contact, the difference being the number and cycle of peaks and valleys, which will not be elaborated further here.

[0109] In a preferred embodiment, S105, determining the electrode rotation angle based on the angle of the electrode slices in each direction and the angle of the developing mark includes:

[0110] Combine the angles of the electrode slices in each direction with the angles of the development marks;

[0111] Calculate the difference between the angle of the directional electrode segment and the angle of the development mark in each combination;

[0112] The angle with the smallest difference is determined as the electrode rotation angle.

[0113] In this embodiment, two sets of angles have been obtained: the angle of the electrode slices in each direction and the angle of the development mark. Then, the two sets of angles are combined in pairs to obtain six pairs of angles. The difference between each pair of angles (modulo 360° congruent) is calculated, and the angle with the smallest difference is selected as the electrode rotation angle.

[0114] As an example, assuming the above steps yield three directional electrode contact rotation angles of 20°, 140°, and 260°, and two developing marks with rotation angles of 70° and 250°, six pairs of angles and their differences are obtained: (20°, 70°) difference is 50, (20°, 250°) difference is 230, (140°, 70°) difference is 70, (140°, 250°) difference is 110, (260°, 70°) difference is 190, and (260°, 250°) difference is 10. The sixth pair of angles has the smallest difference; therefore, the electrode rotation angle is determined to be 260 degrees, and the developing mark rotation angle is determined to be 250 degrees. The reason for selecting the angle with the smallest difference as the electrode rotation angle is that during electrode manufacturing, one segment of the directional electrode and one end of the developing mark are kept basically aligned. Of course, if there are other angular relationships (difference relationships) between the splitting and developing marks during manufacturing, other angular relationships (difference relationships) can be selected, and a set of angles that satisfy the preset difference relationship can be determined as the electrode rotation angle.

[0115] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0116] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0117] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0118] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0119] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for determining the rotation direction of directional electrodes based on CT images, characterized in that, include: Acquire CT images, including images of nerve stimulation electrodes implanted in the human body, the nerve stimulation electrodes including directional electrode contacts and contrast markers; Metal artifact removal is performed on the CT images to obtain artifact feature images; In the artifact feature image, a segmented image containing the electrode artifact region is divided, and the segmented image is rotated. Based on the rotated segmented image, an electrode contact cross-sectional image and a development mark cross-sectional image perpendicular to the electrode axis are obtained. The angles of the electrode segments in each direction within the same group are determined based on the artifact features in the cross-sectional image of the electrode contact, and the angles of the developing marks are determined based on the artifact features in the cross-sectional image of the developing marks. The electrode rotation angle is determined based on the angle of the electrode segments in each direction and the angle of the development mark.

2. The method according to claim 1, characterized in that, Metal artifact removal is performed on the CT image to obtain an artifact feature image, including: The Radon algorithm was used to remove metal artifacts from the CT image, resulting in an artifact feature image.

3. The method according to claim 2, characterized in that, The Radon algorithm is used to remove metal artifacts from the CT image, resulting in an artifact feature image, including: The CT image is subjected to Radon transform layer by layer to obtain the first image; The metal portion of the CT image is extracted layer by layer according to the threshold, and Radon transform is performed to obtain the second image; The first image and the second image are subtracted, and the result of the subtraction is subjected to an inverse Radon transform to obtain the artifact feature image.

4. The method according to claim 1, characterized in that, Rotating the sliced ​​image includes: Calculate the angle between the electrode and the axial plane in the sliced ​​image; The electrodes are rotated around the SI axis into the coronal plane according to the included angle, and the electrodes are rotated around the AP axis to be parallel to the SI axis, so that the plane containing the artifact features of all electrodes is perpendicular to the coronal plane. An affine transformation is performed on the image in which all the planes containing artifact features are perpendicular to the coronal plane, so that all the planes containing artifact features are perpendicular to the electrode axis.

5. The method according to claim 1, characterized in that, The angles of the electrode segments in each direction within the same group are determined based on the artifact features in the cross-sectional image of the electrode contact, including: The cross-sectional image of the electrode contact is matched with a pre-stored electrode contact artifact template to obtain the angle of the cross-sectional image at the directional electrode segment, and the angle of other directional electrode segments in the same group is determined according to the angle period of the electrode segments. Determining the angle of the development mark based on artifact features in the cross-sectional image of the development mark includes: The angle of the developing mark cross-section image is obtained by matching the developing mark cross-section image with a pre-stored developing mark artifact template.

6. The method according to claim 1, characterized in that, The angles of the electrode segments in each direction within the same group are determined based on the artifact features in the cross-sectional image of the electrode contact, including: Extract the ray features of the directional electrode contacts from the cross-sectional image of the electrode contacts, then calculate the angle of the cross-sectional image at the directional electrode segment based on the ray features, and determine the angle of other directional electrode segments in the same group based on the angle period of the electrode segments. Determining the angle of the development mark based on artifact features in the cross-sectional image of the development mark includes: Extract the ray features of the developing marks in the cross-sectional image of the developing marks, and then calculate the angle of the cross-sectional image at the developing marks based on the ray features.

7. The method according to claim 1, characterized in that, The angles of the electrode segments in each direction within the same group are determined based on the artifact features in the cross-sectional image of the electrode contact, including: Obtain a cylindrical slice image of the artifact feature image within the range of the electrode contact points with the electrode axis as the axis; The cylindrical slice image is unfolded into an angle-grayscale image; Calculate the angle of the electrode slices in each direction based on the information in the angle-grayscale image; Determining the angle of the development mark based on artifact features in the cross-sectional image of the development mark includes: Obtain a cylindrical slice image of the artifact feature image within the development mark range with the electrode axis as the axis; The cylindrical slice image is unfolded into an angle-grayscale image; The angle of the developing mark is calculated based on the information in the angle-grayscale image.

8. The method according to claim 1, characterized in that, The electrode rotation angle is determined based on the angle of the electrode slices in each direction and the angle of the development mark, including: The angles of the electrode slices in each direction and the angles of the development marks are combined; Calculate the difference between the angle of the directional electrode segment and the angle of the development mark in each combination; A set of angles that satisfy the preset difference relationship is determined as the electrode rotation angle.

9. A device for determining the orientation of a directional electrode based on CT images, characterized in that, include: A processor and a memory connected to the processor; wherein the memory stores instructions executable by the processor, the instructions being executed by the processor to cause the processor to perform the directional electrode rotation determination method based on CT images as described in any one of claims 1-8.

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