Three-dimensional modeling method and equipment for interventional medical needles based on medical perspective drawings

Abstract

The present invention provides a method and device for three-dimensional modeling of an interventional medical needle based on a medical perspective image. The method is applicable to the field of medical imaging. The method comprises: obtaining a two-dimensional medical perspective image of a target interventional medical needle; obtaining the two-dimensional pixel coordinates of the needle tip and needle tail on the two-dimensional medical perspective image; performing coordinate conversion based on the two-dimensional pixel coordinates of the needle tip and needle tail to obtain the three-dimensional world coordinates of the needle tip and needle tail; generating a three-dimensional centerline of the needle tract of the target interventional medical needle based on the three-dimensional world coordinates of the needle tip and needle tail; obtaining radius information of the target interventional medical needle; determining a direction vector based on the coordinates of two adjacent points on the three-dimensional centerline of the needle tract; generating a spatial circular surface based on the coordinate points and radius information on the three-dimensional centerline of the needle tract; and constructing a three-dimensional volume model of the target interventional medical needle based on the spatial circular surface and the direction vector. The present invention improves the accuracy and efficiency of three-dimensional modeling of the target interventional medical needle.

Description

Technical Field

[0001] The present invention relates to the field of medical imaging, and in particular to a method and device for three-dimensional modeling of an interventional medical needle based on medical perspective drawings. Background Art

[0002] The rapid development of computer technology and medical image processing technology currently provides more reliable support for precision medicine. Among them, medical three-dimensional reconstruction technology can restore the surface information of organs or lesions, and the use of three-dimensional rendering technology makes the model more realistic. Compared with two-dimensional images, it can fully display the spatial position and posture of interventional medical devices (such as interventional needles / puncture needles). Three-dimensional modeling can accurately display the three-dimensional model of interventional medical devices in the body, and can display the position, direction and depth of the needle in real time, helping doctors or surgical robots to more accurately locate the target area (such as tumors or diseased tissues) and improve surgical accuracy.

[0003] Current technologies typically utilize CT and MRI for medical 3D reconstruction and surgical planning, but these technologies still have limitations. CT and MRI scans take relatively long, and during these scans, artifacts can easily be generated by patient movement, leading to artifacts and blurring in the images. Furthermore, accurate 3D modeling using CT and MRI images requires segmentation of the tissues corresponding to the images. Due to differences in individual patient and lesion characteristics, the segmentation process requires extensive parameter adjustments and optimization, resulting in a lengthy and inefficient transition from image acquisition to modeling. Summary of the Invention

[0004] In view of this, on the one hand, the present invention provides a three-dimensional modeling method of an interventional medical needle based on a medical perspective image, including: obtaining a two-dimensional medical perspective image of the target interventional medical needle; respectively obtaining the two-dimensional pixel coordinates of the needle tip and the needle tail on the two-dimensional medical perspective image; performing coordinate conversion according to the two-dimensional pixel coordinates of the needle tip and the needle tail to obtain the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail; generating a three-dimensional center line of the needle track of the target interventional medical needle according to the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail; obtaining the radius information of the target interventional medical needle; determining a direction vector according to the coordinates of two adjacent points on the three-dimensional center line of the needle track; generating a spatial circular surface according to the coordinate points and radius information on the three-dimensional center line of the needle track; and constructing a three-dimensional body model of the target interventional medical needle according to the spatial circular surface and the direction vector.

[0005] Optionally, the three-dimensional centerline of the needle path of the target interventional medical needle is generated based on the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail, including: calculating the slope of the line connecting the needle tip and the needle tail based on the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail; taking the needle tip coordinate point as the starting point, calculating the coordinate point between the needle tip and the needle tail based on the three-dimensional world coordinates of the needle tip, the slope and the preset step size, to obtain several coordinate points and three-dimensional world coordinates; connecting all the coordinate points to obtain the three-dimensional centerline of the needle path of the target interventional medical needle.

[0006] Optionally, a three-dimensional model of the target interventional medical needle is constructed based on the spatial circular surface and the direction vector, including: drawing two spatial circular surfaces with the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail as the center of the circle, and using the radius information as the radius of the circle; using the direction vector as the normal vector of the two spatial circular surfaces to obtain a cylinder; and generating a three-dimensional model of the target interventional medical needle based on the preset voxel value of the cylinder.

[0007] Optionally, the preset voxel value includes a voxel value inside the needle tract and a voxel value outside the needle tract, and the voxel value inside the needle tract is not equal to the voxel value outside the needle tract.

[0008] Optionally, the present invention provides a three-dimensional modeling method for an interventional medical needle based on a medical perspective view, further comprising: smoothing the three-dimensional body model according to preset smoothing parameters, wherein the preset smoothing parameters include isosurface values ​​and the number of isosurfaces.

[0009] Optionally, the needle tail is any point on the target interventional medical needle in the two-dimensional medical fluoroscopic image except the needle tip.

[0010] Optionally, coordinate transformation is performed based on the two-dimensional pixel coordinates of the needle tip and the needle tail to obtain the three-dimensional world coordinates of the needle tip and the needle tail, including: respectively obtaining image parameters of the two-dimensional medical fluoroscopic image, the image parameters being the basic properties of the medical fluoroscopic image and the geometric parameters of the imaging system; calculating the target coordinate transformation matrix based on the image parameters, the target coordinate transformation matrix being used to transform the two-dimensional pixel coordinates of the target point into three-dimensional world coordinates, wherein the target coordinate transformation matrix is ​​composed of transformation parameters of the two-dimensional pixel coordinate system, the two-dimensional image coordinate system, the three-dimensional camera coordinate system and the three-dimensional world coordinate system; taking the needle tip and the needle tail as the target points, the two-dimensional pixel coordinates of the needle tip and the needle tail of the dual perspectives are respectively substituted into the target coordinate transformation matrix to calculate the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail.

[0011] Optionally, the image parameters include image resolution of the medical fluoroscopic image, pixel pitch, distance from the light source point to the patient in the imaging system, distance from the light source point to the detection plate in the imaging system, first angle, second angle, first angle increment, and second angle increment.

[0012] Optionally, the two-dimensional pixel coordinates of the needle tip and the needle tail of the dual perspectives are respectively substituted into the target coordinate conversion matrix to calculate the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail, including: substituting the two-dimensional pixel coordinates of the needle tip and the needle tail into the target coordinate conversion matrix to calculate the three-dimensional world coordinates of the initial needle tip and the three-dimensional world coordinates of the initial needle tail of the dual perspectives; processing and calculating according to the initial needle tip and the initial needle tail of the dual perspectives and the three-dimensional world coordinates to obtain the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail.

[0013] A second aspect of the present invention provides a three-dimensional modeling device for interventional medical needles based on medical perspective views, the device comprising: a processor and a memory connected to the processor; wherein the memory stores instructions that can be executed by the processor, and the instructions are executed by the processor to enable the processor to execute the above-mentioned three-dimensional modeling method for interventional medical needles based on medical perspective views.

[0014] The present invention first obtains a two-dimensional medical perspective image of the target interventional medical needle. The two-dimensional medical perspective image has a fast acquisition speed and can avoid movement artifacts caused by the patient maintaining a posture for a long time, thereby ensuring the basic quality of the image. Then, the two-dimensional pixel coordinates of the needle tip and needle tail on the image are respectively obtained, and then converted into three-dimensional world coordinates, and then the three-dimensional center line of the needle track is generated. The coordinates of the needle tip and needle tail can be directly obtained from the perspective image, saving processing time. Then the radius information of the needle is obtained, and the direction vector is determined based on the coordinates of the adjacent points on the center line. The coordinate points on the center line and the radius information are used to generate a spatial circular surface. Finally, a three-dimensional body model of the target interventional medical needle is constructed based on the spatial circular surface and the direction vector. Due to the accurately acquired three-dimensional world coordinates of the needle tip and needle tail, a three-dimensional body model can be accurately constructed. The present invention does not require the segmentation of the corresponding tissue of the image and the adjustment and optimization of a large number of parameters, greatly shortening the time from image acquisition to modeling completion, thereby improving modeling efficiency. Moreover, the accurate three-dimensional model can intuitively and accurately display the position, direction and depth of the needle track and needle tip. Through three-dimensional modeling, doctors can simulate different puncture paths, avoid obstacles such as blood vessels and select the optimal path, ensure that the puncture probe can safely reach the center of the lesion, reduce surgical risks and improve the success rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 This is a flow chart of a method for three-dimensional modeling of an interventional medical needle based on a medical perspective view in an embodiment of the present invention;

[0017] Figure 2 This is a flowchart of another method for three-dimensional modeling of an interventional medical needle based on medical perspective drawings in an embodiment of the present invention. DETAILED DESCRIPTION

[0018] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0019] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present 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.

[0020] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components; wireless connections or wired connections. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0021] In addition, 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.

[0022] like Figure 1 As shown, an embodiment of the present invention provides a method for three-dimensional modeling of an interventional medical needle based on a medical perspective view. The method is executed by an electronic device such as a computer or a server, and specifically includes:

[0023] S1, obtaining a two-dimensional medical perspective image of a target interventional medical needle.

[0024] The imaging system captures fluoroscopic images of interventional medical needles (e.g., interventional / puncture needles) in the human body. The imaging system is a C-arm X-ray machine, comprising a light source system. This light source system includes a transmitter and a receiver, located on either side of the medical bed. The transmitter emits X-rays, which attenuate after penetrating the body. The receiver then receives the attenuated signal, thereby capturing the fluoroscopic image. X-rays are not "light" in the traditional sense; in this context, they can be broadly understood as the radiation required for imaging. Therefore, the transmitter (i.e., X-ray source) can be considered part of the light source system, and the light source point mentioned below refers to the transmitter. The C-arm can also rotate around the patient to obtain more comprehensive fluoroscopic images from different angles.

[0025] Fluoroscopic images are two-dimensional pixel images, black and white images obtained through X-ray fluoroscopy technology. They use the different degrees of X-ray absorption by different tissues in the human body to form data of different brightness. Common ones include CBCT (Cone Beam CT) images and Digital Subtraction Angiography (DSA) images.

[0026] S2, respectively obtain the two-dimensional pixel coordinates of the needle tip and the needle tail on the two-dimensional medical fluoroscopic image.

[0027] The needle tip and needle tail can be automatically identified with the help of image segmentation technology, and then their two-dimensional pixel coordinates can be calculated; or the positions of the needle tip and needle tail in the image can be manually selected to determine their two-dimensional pixel coordinates.

[0028] S3, performing coordinate conversion based on the two-dimensional pixel coordinates of the needle tip and the needle tail to obtain the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail.

[0029] S4, generating a three-dimensional centerline of the needle track of the target interventional medical needle according to the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail.

[0030] The three-dimensional world coordinates of the needle tip and the needle tail can be used to calculate the parameters of the spatial straight line between the two points, and the three-dimensional center line of the needle track of the target interventional medical needle can be generated based on these parameters.

[0031] S5, obtaining radius information of the target interventional medical needle.

[0032] Because the target interventional needle's tip is conical, its radius is inconsistent with the radius of the needle tract. Therefore, the target interventional needle's radius is preferably the radius of the needle tract excluding the tip. Obtain the model and parameters of the target interventional needle. For example, if the needle is a microwave ablation needle with a diameter excluding the tip of 2 mm, then the radius of the target interventional needle is 1 mm.

[0033] S6, determining a direction vector according to the coordinates of two adjacent points on the three-dimensional center line of the needle track.

[0034] By using the three-dimensional world coordinates of two adjacent points and calculating the difference between the coordinate values ​​of the two adjacent points, a vector representing the direction of the line connecting the two points is obtained to reflect the direction of the needle track between the two points.

[0035] S7, generating a spatial circular surface according to the coordinate points and radius information on the three-dimensional center line of the needle track.

[0036] With the coordinate point of the three-dimensional center line of the needle track as the center of the circle, according to the radius, a complete circle is drawn on the plane perpendicular to the tangent direction of the needle track center line at that point. This circular plane formed in three-dimensional space is the spatial circular surface.

[0037] S8, constructing a three-dimensional model of the target interventional medical needle according to the spatial circular surface and the direction vector.

[0038] This embodiment first obtains a two-dimensional medical perspective image of the target interventional medical needle. The two-dimensional medical perspective image has a fast acquisition speed and can avoid movement artifacts caused by the patient maintaining a posture for a long time, thereby ensuring the basic quality of the image. Then, the two-dimensional pixel coordinates of the needle tip and needle tail on the image are obtained respectively, and then converted into three-dimensional world coordinates, and then the three-dimensional center line of the needle track is generated. The coordinates of the needle tip and needle tail can be obtained directly from the perspective image, saving processing time. Then the radius information of the needle is obtained, and the direction vector is determined based on the coordinates of the adjacent points on the center line. The coordinate points on the center line and the radius information are used to generate a spatial circular surface. Finally, a three-dimensional body model of the target interventional medical needle is constructed based on the spatial circular surface and the direction vector. Due to the accurate acquisition of the three-dimensional world coordinates of the needle tip and needle tail, a three-dimensional body model can be accurately constructed. The present invention does not require the segmentation of the corresponding tissue of the image and the adjustment and optimization of a large number of parameters, which greatly shortens the time from image acquisition to modeling completion and improves modeling efficiency. Moreover, the accurate three-dimensional model can intuitively and accurately display the position, direction and depth of the needle track and needle tip. Through three-dimensional modeling, doctors can simulate different puncture paths, avoid obstacles such as blood vessels and select the optimal path, ensure that the puncture probe can safely reach the center of the lesion, reduce surgical risks and improve the success rate.

[0039] In some optional implementations of this embodiment, the needle tail may be any point on the target interventional needle in the 2D medical fluoroscopic image, excluding the needle tip. Because the target interventional needle may not fully enter the human body, the needle tail in the 2D fluoroscopic image is not strictly the needle tail; any point on the target interventional needle, excluding the needle tip, will suffice.

[0040] In one embodiment, step S4 generates a three-dimensional centerline of the needle tract of the target interventional medical needle based on the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail, including:

[0041] S41, calculating the slope of the line connecting the needle tip and the needle tail according to the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail.

[0042] S42, taking the needle tip coordinate point as the starting point, calculating the coordinate point between the needle tip and the needle tail according to the three-dimensional world coordinates of the needle tip, the slope and the preset step length, and obtaining a plurality of coordinate points and three-dimensional world coordinates.

[0043] The preset step size is the distance between two adjacent points. The preset step size can be flexibly set according to the accuracy or speed requirements. When higher accuracy is required, the preset step size can be set smaller, so that the calculated coordinate points will be denser and can more accurately describe the position of the needle in space. If more attention is paid to calculation speed, the preset step size can be appropriately increased to reduce the amount of calculation. This step uses the linear interpolation method to obtain several coordinate points, but is not limited to this method. The linear interpolation method has simple code and is easy to implement. In addition, the target interventional medical needle is generally a rigid needle, which is not prone to deformation.

[0044] S43, connecting all coordinate points to obtain the three-dimensional center line of the needle track of the target interventional medical needle.

[0045] This embodiment determines the three-dimensional centerline of the needle tract of a target interventional medical needle by acquiring multiple coordinate points between the needle tip and the needle tail. These coordinate points accurately reflect the actual trajectory of the needle within the body, significantly improving the accuracy and precision of the centerline. Furthermore, multi-point determination effectively reduces the influence of errors associated with single-point or small-point measurements, ensuring that the centerline more accurately reflects the actual situation. This provides a solid foundation for the subsequent construction of a precise three-dimensional model of the medical needle.

[0046] In one embodiment, step S8 constructs a three-dimensional model of the target interventional medical needle based on the spatial circular surface and the direction vector, including:

[0047] S81, using the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail as the center of the circle and the radius information as the radius of the circle, to draw two spatial circular surfaces.

[0048] With the three-dimensional world coordinates of the needle tip and the needle tail as the center of the circle and the radius information as the radius of the circle, two circular surfaces are drawn in the three-dimensional space. These two circular surfaces are like the "cross-sections" of the two ends of the needle.

[0049] S82, make the direction vector the normal vector of the two spatial circular surfaces to obtain a cylinder.

[0050] The direction vector represents the direction from the tip of the interventional needle. This direction vector is used as the normal vector for the two circular surfaces drawn earlier, making them perpendicular to it. Since the two circular surfaces have a fixed position (determined by the needle tip and tail coordinates) and the same radius, and their normal vectors are the same (i.e., pointing in the same direction), connecting the edges of the two surfaces forms a cylinder. This cylinder simulates the general shape of the interventional needle in three-dimensional space.

[0051] S83: Generate a three-dimensional model of the target interventional medical needle based on the preset voxel values ​​of the cylinder.

[0052] The preset voxel value refers to the value of each small cube (voxel) when discretizing an object in three-dimensional space. Based on the cylinder obtained in step S82, it is filled and assigned values ​​according to the preset voxel values. For example, a voxel value can represent the material properties (such as density) at that location. By assigning appropriate values ​​to the voxels within the cylinder, a complete three-dimensional model of the target interventional medical needle can be generated. This model is stored in the computer as three-dimensional data, providing a more intuitive display of the spatial form of the target interventional medical needle.

[0053] This embodiment draws a spatial circular surface with the three-dimensional world coordinates of the needle tip and needle tail as the center of the circle, then uses the direction vector to construct a cylinder, and finally generates a three-dimensional model of the target interventional medical needle based on the preset voxel values. This can accurately simulate the actual shape of the interventional medical needle in three-dimensional space. This precise modeling helps doctors more intuitively understand the position and direction of the needle in the body during the surgical planning stage, thereby more accurately formulating the puncture path, avoiding important tissues and organs, and improving the safety and success rate of the operation. At the same time, the three-dimensional model provides basic data for subsequent surgical simulation, navigation and other operations, which is conducive to improving the accuracy and effectiveness of the entire interventional medical process.

[0054] The spatial circular surface drawn in step S81 may also be drawn by taking two adjacent coordinate points as the center of the circle and the radius information as the radius of the circle to obtain several groups of two spatial circular surfaces.

[0055] From a set of coordinate points on the 3D centerline, select two adjacent coordinate points in sequence. Each set of adjacent coordinate points is like the two endpoints of a small segment on the needle. Using the radius information as the radius of a circle, and the two adjacent coordinate points as the center of each circle, draw two spatial circular surfaces in 3D space. Repeating this operation will result in a set of multiple sets of two spatial circular surfaces.

[0056] The direction vector is used as the normal vector of the two spatial circular surfaces in each group to obtain several cylinders.

[0057] The direction vector here represents the orientation of the needle along the line segment formed by each adjacent coordinate point. For each set of two drawn spatial circular surfaces, the corresponding direction vector is used as their normal vector, that is, the two circular surfaces are perpendicular to the direction vector. Since the two circular surfaces have a fixed position (determined by the adjacent coordinate points) and the same radius, and their normal vectors are the same (i.e., they are in the same direction), then connecting the edges of the two circular surfaces forms a cylinder. Performing this operation on all groups of spatial circular surfaces will eventually result in several cylinders, which can be regarded as approximate models of each of the multiple segments of the needle.

[0058] Preset voxel values ​​are set for several cylinders to obtain a three-dimensional model of the interventional medical needle.

[0059] By assigning appropriate values ​​to the voxels of each cylinder and combining these cylinders with preset voxel values, a complete 3D model of the interventional needle can be obtained. This model exists in the form of 3D data in the computer and can fully and meticulously display the spatial form of the interventional needle.

[0060] This embodiment draws several groups of spatial circular surfaces with adjacent coordinate points as the center of the circle, uses direction vectors to construct several cylinders, and then sets preset voxel values ​​for the cylinders to generate a three-dimensional model of the interventional medical needle. It can simulate the actual shape of the interventional medical needle in three-dimensional space in a fine and accurate manner, providing doctors with a more intuitive and accurate basis for surgical planning, helping to accurately formulate puncture paths and reduce surgical risks. At the same time, it provides reliable basic data for operations such as surgical simulation and navigation, thereby improving the accuracy and effectiveness of interventional medicine.

[0061] The preset voxel value includes a voxel value inside the needle tract and a voxel value outside the needle tract, and the voxel value inside the needle tract is not equal to the voxel value outside the needle tract.

[0062] The in-vitro voxel value for the needle tract refers to the value of the corresponding voxel within the internal channel of an interventional medical needle, reflecting the internal conditions of the needle tract. The out-vitro voxel value for the needle tract refers to the value of the corresponding voxel outside the needle tract, representing the characteristics of the surrounding environment (e.g., human tissue). Due to the different physical properties inside and outside the needle tract, these values ​​are set to unequal to distinguish them in the 3D model. The specific voxel values ​​can be arbitrary, as long as they are different to distinguish between inside and outside the needle tract. For example, a voxel value of 1 for the in-vitro voxel and 0 for the out-vitro voxel can be used.

[0063] like Figure 2 As shown, after the three-dimensional model of the target interventional medical needle is constructed in step S8, the three-dimensional modeling method of the interventional medical needle based on the medical perspective view further includes:

[0064] S9, smoothing the three-dimensional model according to preset smoothing parameters, where the preset smoothing parameters include isosurface values ​​and the number of isosurfaces.

[0065] After constructing the 3D model of the target interventional medical needle, the Marching Cubes algorithm in VTK is used to smooth the model to improve rendering quality. This algorithm determines whether the cube's eight vertices are within or outside an isosurface. The algorithm then inputs a centerline and radius, sets the isosurface value and the number of isosurfaces. The isosurface value helps define the threshold of the 3D model surface, while the number of isosurfaces adjusts the surface refinement. The algorithm then calculates the isosurface normal vectors and generates the needle's 3D volume data for rendering. This results in a smoother, more continuous surface, reducing jaggedness and irregularities, significantly improving rendering quality and providing a superior visual presentation.

[0066] In one embodiment, step S3 performs coordinate conversion based on the two-dimensional pixel coordinates of the needle tip and the needle tail to obtain the three-dimensional world coordinates of the needle tip and the needle tail, including:

[0067] S31 , respectively obtaining image parameters of the two-dimensional medical fluoroscopic image, where the image parameters are basic attributes of the medical fluoroscopic image and geometric parameters of the imaging system.

[0068] A C-arm X-ray machine is used to rotate at a predetermined angle to acquire a number of fluoroscopic images. From these, fluoroscopic images are selected from any number of perspectives (the number should be significantly less than the total number of fluoroscopic images). Preferably, dual-perspective fluoroscopic images are selected. For example, if the C-arm X-ray machine rotates 180° halfway, 180 frames of fluoroscopic images are acquired, and two frames of fluoroscopic images from two perspectives are selected. Selecting fluoroscopic images from multiple perspectives avoids information loss from a single perspective and reduces image acquisition and algorithm computation time. Excessive fluoroscopic images from too many perspectives increase computational costs. Therefore, two or more perspectives can provide complementary information, reduce processing overhead, and enable rapid acquisition of accurate information. Preferably, when selecting fluoroscopic images, the angle between the first and second perspectives should be controlled between 30° and 150°.

[0069] Image parameters are default values ​​that can be read from standard DICOM (Digital Imaging and Communications in Medicine) image formats, or can be obtained through self-testing by technicians or doctors based on actual conditions.

[0070] S32, calculating a target coordinate transformation matrix based on the image parameters, where the target coordinate transformation matrix is ​​used to transform the two-dimensional pixel coordinates of the target point into three-dimensional world coordinates, wherein the target coordinate transformation matrix is ​​composed of transformation parameters of a two-dimensional pixel coordinate system, a two-dimensional image coordinate system, a three-dimensional camera coordinate system, and a three-dimensional world coordinate system.

[0071] The transformation matrix between the 2D pixel coordinate system, 2D image coordinate system, 3D camera coordinate system and 3D world coordinate system is calculated according to the image parameters, which is used to convert the 2D pixel coordinates of the target point into 3D world coordinates. All coordinate systems satisfy the right-hand coordinate system.

[0072] S33, taking the needle tip and needle tail as target points, respectively substitute the two-dimensional pixel coordinates of the needle tip and needle tail from the dual perspectives into the target coordinate transformation matrix to calculate the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail.

[0073] This embodiment selects a two-dimensional medical fluoroscopic image under any two-dimensional perspectives, obtains the two-dimensional pixel coordinates of the needle tip and needle tail on the fluoroscopic image, establishes a target coordinate transformation matrix based on known perspective geometry parameters, and converts the two-dimensional pixel coordinates into three-dimensional world coordinates. Compared with traditional multi-perspective shooting and reconstruction algorithms, this method only needs to select fluoroscopic images under any two-dimensional perspectives, which greatly reduces the shooting time and the amount of computation required for the reconstruction algorithm. In addition, this method has low requirements for the acquisition of fluoroscopic data and is suitable for medical fluoroscopic image processing in various environments. It does not require additional in vitro markers or pre-calibration, reducing operational complexity and preparation work. Specifically, by selecting two perspectives to obtain fluoroscopic images, the loss of single-perspective information is avoided, while reducing processing volume and computational costs.

[0074] Specifically, the image parameters include the image resolution of the medical fluoroscopic image, the pixel pitch, the distance from the light source point to the patient in the imaging system, the distance from the light source point to the detection plate in the imaging system, the first angle, the second angle, the first angle increment, and the second angle increment.

[0075] The image parameters include the image resolution row, cols, pixel spacing of the medical fluoroscopic image, the distance SOD from the light source to the patient in the imaging system, the distance SID from the light source to the detector plate in the imaging system, the first angle , second angle , first angle increment , second angle increment .

[0076] In the imaging system, the distance from the light source to the detector plate is the distance from the transmitting end to the receiving end of the C-arm X-ray machine; the first angle and the second angle are the initial angles of the two selected frames of fluoroscopic images, and the first angle increment and the second angle increment correspond to the angle of the image rotation of the frame. For example, the angle of the 90th frame is the initial angle plus the angle increment, which is the angle of the corresponding viewing angle. The following description uses the dual viewing angles of 0° and 90° as an example. In one embodiment, the target coordinate transformation matrix is ​​calculated based on the image parameters. The target coordinate transformation matrix is ​​obtained by the transformation matrix between the two-dimensional pixel coordinate system and the two-dimensional image coordinate system, the transformation matrix between the two-dimensional image coordinate system and the three-dimensional camera coordinate system, and the transformation matrix between the three-dimensional camera coordinate system and the three-dimensional world coordinate system. The transformation matrix between the two-dimensional pixel coordinate system and the two-dimensional image coordinate system is calculated based on the image resolution and pixel pitch, the transformation matrix between the two-dimensional image coordinate system and the three-dimensional camera coordinate system is obtained based on the distance from the light source to the patient, and the transformation matrix between the three-dimensional camera coordinate system and the three-dimensional world coordinate system is calculated based on the first angle, the second angle, the first angle increment, and the second angle increment.

[0077] For example, based on the two-dimensional pixel coordinates (u, v), the canvas center pixel coordinates (row / 2, col / 2), and the two-dimensional image coordinates (x, y), the transformation matrix between the two-dimensional pixel coordinate system and the two-dimensional image coordinate system is as follows:

[0078] ,

[0079] According to the coordinates (Xc, Yc, Zc) in the 3D camera coordinate system, the transformation matrix between the 2D image coordinate system and the 3D camera coordinate system is as follows:

[0080] ,

[0081] The current perspective image is rotated around the Z axis by an angle of , the rotation angle around the X axis is , the coordinates (Xw, Yw, Zw) in the three-dimensional world coordinate system, the transformation matrix between the three-dimensional camera coordinate system and the three-dimensional world coordinate system are as follows:

[0082] ,

[0083] ,

[0084] ,

[0085] Finally, the target coordinate transformation matrix is ​​calculated:

[0086] ，

[0087] in, represents the three-dimensional world coordinates, represents the two-dimensional pixel coordinates, Indicates the number of pixels of the perspective image in the vertical direction, Indicates the number of pixels of the perspective image in the horizontal direction, represents the pixel pitch, Indicates the distance from the light source to the patient, Indicates the distance from the light source to the detection board, is the rotation matrix, and T represents the offset vector.

[0088] Furthermore, in step S33, the two-dimensional pixel coordinates of the needle tip and the needle tail in the dual-view are respectively substituted into the target coordinate transformation matrix to calculate the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail, including:

[0089] S331, respectively substitute the two-dimensional pixel coordinates of the needle tip and the needle tail into the target coordinate transformation matrix to calculate the three-dimensional world coordinates of the initial needle tip and the initial three-dimensional world coordinates of the needle tail in dual perspectives.

[0090] S332 , processing and calculating the initial needle tip and the initial needle tail and the three-dimensional world coordinates of the dual perspectives to obtain the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail.

[0091] Since the image parameters may be inaccurate, the world coordinates obtained by the target coordinate conversion matrix may be inaccurate, so reprocessing is required to obtain the accurate three-dimensional world coordinates of the needle tip and the needle tail. Specifically, taking the needle tip as an example, the target coordinate conversion matrix is ​​used to calculate the three-dimensional world coordinates of the light source point in dual perspectives; the light source point of the first perspective is connected to the corresponding initial needle tip to obtain the first line, and the light source point of the second perspective is connected to the corresponding initial needle tip to obtain the second line; a point is selected on the first line and the second line respectively, so that the midpoint of the line connecting the two selected points is the closest to the first line and the second line; the midpoint is used as the needle tip, and the three-dimensional world coordinates of the needle tip are obtained to obtain the accurate three-dimensional world coordinates of the needle tip. Then, the three-dimensional world coordinates of the needle tail can be obtained by following the same steps.

[0092] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0093] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts 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, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0094] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0095] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0096] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A three-dimensional modeling method for an interventional medical needle based on a medical perspective drawing, characterized in that: include: Acquire a two-dimensional medical perspective image of the target interventional medical needle under any two-viewing angles; Respectively obtaining the two-dimensional pixel coordinates of the needle tip and the needle tail on the two-dimensional medical fluoroscopic image of dual viewing angles; Performing coordinate conversion based on the two-dimensional pixel coordinates of the needle tip and the needle tail in dual perspectives to obtain the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail; generating a three-dimensional centerline of the needle tract of the target interventional medical needle according to the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail; Obtaining radius information of the target interventional medical needle; determining a direction vector according to the coordinates of two adjacent points on the three-dimensional center line of the needle track; Using two adjacent coordinate points as the center of the circle and the radius information as the radius of the circle, several groups of two spatial circular surfaces are drawn; A three-dimensional model of the target interventional medical needle is constructed based on the spatial circular surface and the direction vector, wherein the direction vector is used as the normal vector of the two spatial circular surfaces in each group to obtain a plurality of cylinders; preset voxel values ​​are set for the plurality of cylinders to obtain a three-dimensional model of the interventional medical needle, wherein the preset voxel values ​​include voxel values ​​inside the needle tract and voxel values ​​outside the needle tract, and the voxel values ​​inside the needle tract are not equal to the voxel values ​​outside the needle tract.

2. The method according to claim 1, characterized in that Generating the three-dimensional centerline of the needle track of the target interventional medical needle according to the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail includes: Calculating the slope of the line connecting the needle tip and the needle tail according to the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail; Taking the needle tip coordinate point as a starting point, calculating the coordinate point between the needle tip and the needle tail according to the three-dimensional world coordinate of the needle tip, the slope and a preset step length, to obtain a plurality of coordinate points and three-dimensional world coordinates; All coordinate points are connected to obtain the three-dimensional center line of the needle track of the target interventional medical needle.

3. The method according to claim 1, characterized in that Also includes: The three-dimensional model is smoothed according to preset smoothing parameters, wherein the preset smoothing parameters include isosurface values ​​and the number of isosurfaces.

4. The method according to claim 1, wherein The needle tail is any point on the target interventional medical needle in the two-dimensional medical perspective image except the needle tip.

5. The method according to claim 1, wherein The step of performing coordinate conversion based on the two-dimensional pixel coordinates of the needle tip and the needle tail to obtain the three-dimensional world coordinates of the needle tip and the needle tail includes: respectively acquiring image parameters of the two-dimensional medical fluoroscopic images, wherein the image parameters are basic attributes of the medical fluoroscopic images and geometric parameters of the imaging system; Calculating a target coordinate transformation matrix based on the image parameters, wherein the target coordinate transformation matrix is ​​used to transform the two-dimensional pixel coordinates of the target point into three-dimensional world coordinates, wherein the target coordinate transformation matrix is ​​composed of transformation parameters of a two-dimensional pixel coordinate system, a two-dimensional image coordinate system, a three-dimensional camera coordinate system, and a three-dimensional world coordinate system; Taking the needle tip and the needle tail as target points, the two-dimensional pixel coordinates of the needle tip and the needle tail in dual perspectives are respectively substituted into the target coordinate transformation matrix to calculate the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail.

6. The method according to claim 5, characterized in that The image parameters include image resolution of the medical fluoroscopic image, pixel pitch, distance from the light source point to the patient in the imaging system, distance from the light source point to the detection plate in the imaging system, first angle, second angle, first angle increment, and second angle increment.

7. The method according to claim 5, characterized in that Substituting the two-dimensional pixel coordinates of the needle tip and the needle tail from the dual perspectives into the target coordinate transformation matrix to calculate the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail includes: Substituting the two-dimensional pixel coordinates of the needle tip and the needle tail into the target coordinate transformation matrix respectively, and calculating the three-dimensional world coordinates of the initial needle tip and the initial three-dimensional world coordinates of the needle tail in dual perspectives; Processing and calculation are performed according to the initial needle tip and the initial needle tail of the dual perspectives and the three-dimensional world coordinates to obtain the three-dimensional world coordinates of the needle tip and the three-dimensional world coordinates of the needle tail.

8. A three-dimensional modeling device for interventional medical needles based on medical perspective drawings, characterized in that: include: A processor and a memory connected to the processor; wherein the memory stores instructions that can be executed by the processor, and the instructions are executed by the processor to enable the processor to execute the three-dimensional modeling method of interventional medical needles based on medical perspective views as described in any one of claims 1 to 7.

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