Rapid planning method for cranial access path of neurosurgery operation
By using a spherical spiral scanning method to plan the intracranial access path, the problem of avoiding key brain tissues in neurosurgery has been solved, improving the safety and efficiency of the operation.
Patent Information
- Application Number
- CN202511034257.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-25
- Publication Date
- 2025-11-18
AI Technical Summary
In neurosurgery, it is difficult for surgeons to quickly plan a safe entry route into the skull by observing images to avoid critical brain tissue, resulting in high surgical risks.
Using the spherical spiral scanning method, an entry path that maintains a safe distance from critical tissues is calculated and planned based on the initial entry point and the target lesion. The path planning is achieved using the parametric equation of the spherical spiral and the safe distance judgment function.
It enables rapid and accurate planning of the intracranial access route, improving the safety of neurosurgical procedures and ensuring that critical tissues are not damaged.
Smart Images
Figure CN120959883A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of medical image processing, and relates to a fast planning method for a craniotomy path in neurosurgery. BACKGROUND
[0002] In neurosurgery, a doctor needs to plan a craniotomy path in a patient's brain to reach a lesion, which requires avoiding some key tissues in the brain, such as blood vessels, brain regions, and nerve fibers, and requires maintaining a certain safety distance from the craniotomy path to avoid causing fatal harm to the patient. In today's surgery, doctors can use digital devices to segment the key tissues in the brain and display all the tissues visually. However, it is still difficult for doctors to ensure that the planned craniotomy path avoids all-around tissue damage by observing the images alone. In the face of this surgical risk, being able to quickly plan a safe craniotomy path based on the lesion point will bring great convenience to doctors. SUMMARY
[0003] To solve the above problems, the application provides a fast planning method for a craniotomy path in neurosurgery, which aims to include key tissue images in the avoidance calculation according to a user-specified lesion target point and an initial craniotomy point, and quickly calculate and locate a new craniotomy point to ensure that the craniotomy path formed by the target point and the new craniotomy point maintains a preset safety distance from the surrounding key tissues.
[0004] The application mainly takes the initial craniotomy point as the starting point, scans the craniotomy point around the target point in the form of a spherical spiral, and calculates the perpendicular plane safety distance of each path in pixel units until a craniotomy point that meets the safety distance is scanned. The spherical spiral scanning is a high-efficiency method for traversing the three-dimensional space of the initial point field with the target point as the spherical center.
[0005] The specific scheme is as follows:
[0006] A fast planning method for a craniotomy path in neurosurgery, comprising the following steps:
[0007] S1, inputting a target point, an initial craniotomy point, and a key tissue image;
[0008] S2, establishing a scanning model and initializing scanning parameters;
[0009] S3, scanning a craniotomy point and judging the safety distance of the path.
[0010] Further, in step S1, the segmented blood vessels, brain regions, or nerve fibers are used independently or in combination as input images; a target point T is determined inside the image tissue, and an initial craniotomy point E0 is determined outside the tissue.
[0011] Further, in step S2, the intracranial point scanning model is a spherical spiral line, the scanning point E descends along the spherical axis zo while rotating around the axis zo, so as to establish a coordinate system x'o'y' through a horizontal tangent plane of a point in the trajectory projection of the scanning point E in the xoz coordinate system;
[0012] Supposing that the spherical radius is R, the elevation angle is θ, and the azimuth angle is φ, the parametric equation of the spherical spiral line is:
[0013]
[0014] wherein r=R*cosθ is the horizontal circle radius through the point, and the following is derived:
[0015] θ=asin(z / R)
[0016] According to the Pythagorean theorem, the following is obtained:
[0017]
[0018] In order to realize the uniform scanning of the intracranial point, the point E is required to rotate uniformly around the axis zo; supposing that the rotation arc length step is Δc, the rotation arc step is:
[0019]
[0020] The point E is required to descend uniformly along the axis zo, and supposing that the descending height step is Δh; since the clinical application only scans a half spherical surface, i.e. the point E starts from the vertex of the spherical surface along the zo and reaches the xoy plane, i.e. z∈[0, R], the traversal number of the scanning point is:
[0021] N=R / Δh
[0022] In addition, the initial value of the azimuth angle φ is 0, and the initial value of the horizontal circle radius is r0.
[0023] Further, in step S3, the scanning point E starts from the initial intracranial point E0 and establishes a path ET in real time, and the points P on the path ET are traversed in sequence; supposing that the safety distance of the path is d, the image space with the center of the point P and the radius of d is traversed on the perpendicular plane of the ET; if all the pixels are not key tissue pixels, the path is safe, i.e. the scanning is exited.
[0024] The present application has the beneficial effect that it can assist the doctors to quickly and accurately establish the craniopuncture path of the neurosurgery operation, and especially help to improve the safety of the craniopuncture operation. BRIEF DESCRIPTION OF DRAWINGS
[0025] Figure 1 is the flow chart of the method of the present application.
[0026] Figure 2The mathematical model of the spherical spiral scanning used in the application; wherein T is a set target point, E0 is an initial intracranial point, E is a scanned intracranial point, and the normal plane sequence on the path ET is a traversal diagram of a safety distance. According to the clinical application requirements, the maximum range of the spherical spiral scanning is limited to a hemispherical surface.
[0027] Figure 3 The application of the method based on a cerebral vascular image; wherein the red dots inside the cerebral vessels are target points, the green dots on the surface are initial intracranial points, and the blue dots are final scanned intracranial points.
[0028] Figure 4 The local enlarged view of different perspectives around the path; wherein 4.1 is a local enlarged view around the path Figure 1 , 4.2 is a local enlarged view around the path Figure 2 , and it can be seen that the final intracranial path completely avoids the surrounding blood vessels.
[0029] Figure 5 The spherical spiral model in the embodiment.
[0030] Figure 6 The safety distance detection of the path in the embodiment. DETAILED DESCRIPTION
[0031] The application will be further illustrated below in combination with the drawings and specific embodiments, and it should be understood that the following specific embodiments are only used to illustrate the application and not to limit the scope of the application.
[0032] As shown in Figure 1 , the application provides a fast planning method for an intracranial path in neurosurgery, which comprises the following steps:
[0033] S1, inputting a target point, an initial intracranial point and a key tissue image
[0034] The path planning mainly avoids some key brain tissues, and the blood vessels, brain regions or nerve fibers obtained by segmentation can be used as input images independently or in combination. A target point T is determined inside the tissue of the image, and an initial intracranial point E0 is determined outside the tissue. In order to fully verify that the path planned by the method can effectively "avoid obstacles", the point T and the point E0 can be intentionally set in a region with dense tissue structure.
[0035] S2, establishing a scanning model and initializing scanning parameters
[0036] As shown in Figure 2 , the intracranial point scanning model of the method is a spherical spiral. As shown in Figure 5As shown: the scanning point E descends along the spherical axis zo while simultaneously rotating around the axis zo. Points 8 to 0 in the figure represent the trajectory projection of point E in the xoz coordinate system. Taking point 4 as an example, a coordinate system x'o'y' is established using the horizontal tangent passing through point 4, and points 8' to 0' represent the trajectory projection of point E in the coordinate system x'o'y'.
[0037] Let the radius of the sphere be R, the elevation angle be θ, and the azimuth angle be φ. Then the parametric equation of the spherical helix is:
[0038]
[0039] Where r = R·cosθ, is the radius of the horizontal circle passing through point 4. It can also be derived that:
[0040] θ = asin(z / R)
[0041] According to the Pythagorean theorem:
[0042]
[0043] To achieve uniform scanning of the entry point, point E must rotate at a constant speed around axis zo. Let the rotation arc length step be Δc, then the rotation radian step is:
[0044]
[0045] Furthermore, point E is required to descend at a uniform speed along the axis z0, with a descent step of Δh. Since clinical applications only require scanning the hemisphere, i.e., starting from the vertex z0 of the sphere and scanning until reaching the xoy plane (i.e., z∈[0,R]), the number of points traversed is:
[0046] N = R / Δh
[0047] In addition, let's assume that the initial value of the azimuth angle φ is 0 and the initial value of the horizontal circle radius is r0.
[0048] 1. Scanning the cranial entry point and determining the safe distance for the path.
[0049] After establishing the scanning model, the scanning point E is started from the initial entry point E0, and the path ET is established in real time. Points P along the path ET are then traversed sequentially. For example... Figure 6 As shown, assuming the safe distance of the path is d, the image space centered at point P with radius d is traversed on the perpendicular plane of ET. If all pixels are non-critical organization pixels, the path is safe, and the scan can be exited.
[0050] Based on the above process, pseudocode for rapid craniotomy point planning is established:
[0051]
[0052]
[0053] Here, Safe(E[n]) is the path safety distance judgment function, which returns true if the path is safe, and false otherwise.
[0054] like Figure 3 and 4 As shown, the method of the present invention completely avoids the surrounding blood vessels in the final intracranial entry path.
[0055] The technical means disclosed in this invention are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention.
Claims
1. A rapid planning method for intracranial access pathways in neurosurgery, characterized in that, Includes the following steps: S1. Input target point, initial entry point, and key tissue images; S2. Establish the scanning model and initialize the scanning parameters; S3. Scan the cranial entry point and determine the safe distance for the path.
2. The rapid planning method for intracranial access pathway in neurosurgery according to claim 1, characterized in that, In step S1, the segmented blood vessels, brain regions, or nerve fibers are used independently or in combination as input images; a target point T is determined inside the tissue of the image, and an initial entry point E0 is determined outside the tissue.
3. The rapid planning method for neurosurgical intracranial access pathway according to claim 2, characterized in that, In step S2, the cranial entry point scanning model is a spherical spiral. The scanning point E descends along the spherical axis zo and rotates around the axis zo. The coordinate system x'o'y' is established by the horizontal tangent of a point in the trajectory projection of the scanning point E in the xoz coordinate system. Let the radius of the sphere be R, the elevation angle be θ, and the azimuth angle be φ. Then the parametric equation of the spherical helix is: Where r = R·cosθ is the radius of the horizontal circle passing through that point, from which we derive: θ = asin(z / R) According to the Pythagorean theorem: To achieve uniform scanning of the entry point, point E must rotate at a constant speed around axis zo; let the rotation arc length step be Δc, then the rotation radian step is: Furthermore, point E is required to descend uniformly along the axis z0, with a descent step of Δh. Since clinical applications only scan the hemisphere, i.e., starting from the vertex z0 of the sphere and scanning until reaching the xoy plane, i.e., z∈[0,R], the number of scan points is: N = R / Δh Additionally, let the initial value of the azimuth angle φ be 0, and the initial value of the horizontal circle radius be r0.
4. The rapid planning method for neurosurgical intracranial access pathway according to claim 3, characterized in that, In step S3, starting from the initial entry point E0, scan point E and establish path ET in real time, and traverse point P on path ET in turn; assuming the safe distance of the path is d, traverse the image space with point P as the center and radius d on the vertical plane of ET; if all pixels are not critical tissue pixels, then the path is safe, and the scan is exited.