Vessel centerline data application method, electronic device, and storage medium

Abstract

The application provides a blood vessel center line data application method, an electronic device and a storage medium, and the application method comprises the following steps: adopting a preset algorithm to explore center points on a blood vessel center line of a blood vessel region in a medical image, so as to extract the corresponding blood vessel center line; setting an index serial number for each center point on the blood vessel center line according to a first preset rule; determining two target center points on the blood vessel center line according to position information of two rough selection points on the medical image; determining all center points on a center line segment of interest on the blood vessel center line according to the index serial numbers corresponding to the two target center points; and acquiring a blood vessel parameter and / or simulating stent unfolding information of a blood vessel stent according to related data of the center points on the center line segment of interest. The application can help doctors to quantitatively analyze the health status of patients, reduce the risk in operation, shorten the operation time and reduce the physical burden of patients.

Description

Technical Field

[0001] This invention relates to the field of image processing technology, and in particular to a method for applying vascular centerline data, an electronic device, and a storage medium. Background Technology

[0002] The aorta is the largest and thickest artery in the human systemic circulation. Its function is to help the heart pump blood to all organs of the body. It is characterized by its elasticity and is structurally composed of three layers: the media (inner lining), the intima (inner lining), and the adventitia (outer lining). The heart ejects blood at high speed and pressure. When blood ruptures the intima of the aorta, it causes separation between the intima and media, resulting in aortic dissection. Local dilation can lead to aortic aneurysm. For example, the most common pathological dilation is atherosclerosis.

[0003] The advent of minimally invasive aortic interventional surgery has significantly increased the success rate of aortic procedures, reduced postoperative risks, and increased the production of aortic stents. However, differences in patients' height, weight, and age lead to variations in the stent type and parameters prepared by surgeons before surgery. For example, the same type of aortic dissection stent may have different lengths for people of different heights. Stent suppliers cannot provide an unlimited number of stents for a single surgery, and surgeons cannot fully guarantee that the stent type and parameters prepared before surgery will be able to accommodate unforeseen circumstances encountered by the patient during the procedure. For example, the aortic stent prepared for iliac artery intervention may fail to pass through the iliac artery normally, or the stent bifurcation may be found to be misaligned with the patient before stent placement and deployment—these are all unpredictable situations.

[0004] Preoperative measurement of key parameters of aortic deployment and simulation of aortic stent deployment in CT and MR images can help doctors conduct preoperative rehearsals for patients, find the best stent type and stent parameters, further reduce intraoperative risks, shorten operation time, and reduce the physical burden on patients.

[0005] It should be noted that the information disclosed in the background section of this invention is intended only to enhance the understanding of the general background of this invention, and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide a method, electronic device, and storage medium for applying vascular centerline data, which can help doctors quantitatively analyze patients' health status, further reduce intraoperative risks, shorten operation time, and reduce the physical burden on patients.

[0007] To achieve the above objectives, the present invention provides a method for applying vascular centerline data, comprising:

[0008] A preset algorithm is used to explore the center point of the vascular centerline in the acquired medical image to extract the corresponding vascular centerline.

[0009] An index number is assigned to each of the center points on the central line of the blood vessel according to the first preset rule;

[0010] Based on the obtained position information of two coarsely selected points on the medical image, two target center points are determined on the blood vessel centerline;

[0011] Based on the index numbers corresponding to the two target center points, all center points on the line segment of interest with the two target center points as the two endpoints are determined on the blood vessel center line.

[0012] Based on the relevant data of each center point on the line segment of interest, obtain the vascular parameters of the corresponding vascular segment of interest and / or simulate the stent deployment information of the vascular stent entering the vascular segment of interest.

[0013] Optionally, determining two target center points on the blood vessel centerline based on the acquired position information of two coarsely selected points on the medical image includes:

[0014] For each coarse selection point, the distance between each center point on the blood vessel centerline and the coarse selection point is calculated, and the center point with the smallest distance from the coarse selection point is taken as the target center point corresponding to the coarse selection point.

[0015] Optionally, setting an index number for each center point on the blood vessel centerline according to a first preset rule includes:

[0016] An index number is assigned to each center point on the centerline of the blood vessel according to the rule that the index number of the center point of the lower-level blood vessel is greater than the index number of the center point of the upper-level blood vessel, and that the index number of each blood vessel gradually increases along its extension direction.

[0017] Optionally, if the two target center points are located within the same blood vessel, then determining all center points on the line segment of interest with the two target center points as its two endpoints on the blood vessel centerline, based on the index numbers corresponding to the two target center points respectively, includes:

[0018] Take the larger index number of the two target center points as the starting point;

[0019] Starting from the origin, traverse forward the center points of the blood vessel centerline until another target center point is reached;

[0020] All the center points traversed are taken as the center points on the line segment of interest.

[0021] Optionally, if the two target center points are located in different blood vessels, then determining all center points on the line segment of interest with the two target center points as two endpoints on the blood vessel centerline according to the index numbers corresponding to the two target center points includes:

[0022] Step a1: Take the one with the larger index number of the two target center points as the starting point, and start from the starting point to traverse the center points of the blood vessel center line forward until the intersection center point of the blood vessel where the starting point is located and its superior blood vessel is reached.

[0023] Step b1: Determine whether the index number of the intersection center point is the same as the index number of the other target center point. If the determination result is yes, then execute step c1; if the determination result is no, then execute step d1.

[0024] Step c1: End the traversal and take all the traversed center points as the center points on the line segment of interest.

[0025] Step d1: Take the one with the larger index number between the intersection center point and the other target center point as the new starting point and the other as the ending point. Determine whether the new starting point and the ending point are located in the same blood vessel. If yes, execute step e1; otherwise, execute step f1.

[0026] Step e1: Starting from the new starting point, traverse forward to the center point of the blood vessel centerline until the endpoint is reached, and then return to execute step c1;

[0027] Step f1: Starting from the new starting point, traverse forward to the center point of the blood vessel centerline until the intersection of the blood vessel where the new starting point is located and its superior blood vessel is reached, and then return to execute step d1.

[0028] Optionally, the relevant data of the center point includes the location information of the center point, and the step of obtaining the vascular parameters of the corresponding vascular segment of interest based on the relevant data of each center point on the line segment of interest includes:

[0029] Based on the position information of each center point on the center line segment of interest, the distances between all adjacent two center points on the center line segment of interest are calculated and summed to obtain the center line path length of the blood vessel segment of interest.

[0030] Optionally, obtaining the vascular parameters of the corresponding vessel segment of interest further includes:

[0031] The tortuosity value of the blood vessel segment of interest is obtained by the ratio of the centerline path length of the segment of interest to the distance between the two target center points.

[0032] Optionally, the relevant data for the center point may also include the maximum diameter of the cross-section of the blood vessel where the center point is located;

[0033] The step of obtaining the vascular parameters of the corresponding vascular segment of interest based on the relevant data of each of the center points on the line segment of interest further includes:

[0034] Based on the maximum diameter of the blood vessel cross-section where each center point on the line segment of interest is located, the maximum diameter with the longest length is taken as the maximum maximum diameter of the blood vessel segment of interest, and the maximum diameter with the shortest length is taken as the minimum maximum diameter of the blood vessel segment of interest.

[0035] Optionally, the maximum diameter of the blood vessel cross-section at the center point is calculated using the following steps:

[0036] The cross-section of the blood vessel where the center point is located is mapped onto a two-dimensional plane with Z=0 to obtain the corresponding blood vessel mapping cross-section. Based on the contour points of the blood vessel mapping cross-section and the mapped center point, the maximum diameter of the blood vessel cross-section where the center point is located is calculated.

[0037] Optionally, calculating the maximum diameter of the blood vessel cross-section where the center point is located, based on each contour point of the mapped blood vessel cross-section and the mapped center point, includes:

[0038] A rectangular coordinate system is established with the mapped center point as the origin, and each contour point of the blood vessel mapping section is connected to the center point to form a corresponding line.

[0039] For each contour point of the blood vessel mapping section, calculate the absolute value of the sine of the angle formed by the line connecting the contour point and the mapped center point and the X-axis of the rectangular coordinate system.

[0040] The quadrant with fewer contour points in the first and third quadrants of the rectangular coordinate system is designated as the first target quadrant, and the other is designated as the second target quadrant; the quadrant with fewer contour points in the second and fourth quadrants is designated as the third target quadrant, and the other is designated as the fourth target quadrant.

[0041] For each first contour point in the first target quadrant, the error between the absolute value of the sine corresponding to the first contour point and the absolute value of the sine corresponding to each second contour point in the second target quadrant is calculated, and the line segment formed by the second contour point with the smallest absolute value of the error and the first contour point is taken as one of the diameters of the blood vessel cross section where the center point is located.

[0042] For each third contour point in the third target quadrant, the error between the absolute value of the sine corresponding to the third contour point and the absolute value of the sine corresponding to each fourth contour point in the fourth target quadrant is calculated, and the line segment formed by the fourth contour point with the smallest absolute value of the error and the third contour point is taken as one of the diameters of the blood vessel cross section where the center point is located.

[0043] The diameter with the longest length among all diameters of the blood vessel cross-section where the center point is located is taken as the maximum diameter of the blood vessel cross-section.

[0044] Optionally, the relevant data of the center point includes the location information of the center point and the normal vector of the cross-section of the blood vessel where the center point is located;

[0045] The step of simulating stent deployment information for a vascular stent entering the segment of interest based on relevant data of each of the center points on the line segment of interest includes:

[0046] Based on the position information of each of the center points on the line segment of interest, the entry path of the vascular stent is simulated;

[0047] Based on the position information of each center point on the entry path of the vascular stent and the normal vector of the cross-section of the blood vessel, the stent deployment cross section corresponding to each center point on the entry path of the vascular stent is simulated.

[0048] Optionally, simulating the entry path of the vascular stent based on the position information of each of the center points on the line segment of interest includes:

[0049] Based on the position information of each center point on the line segment of interest, one of the target center points is taken as the starting point of the path, and the other target center point is taken as the ending point of the path. In accordance with the principle that center points that are adjacent on the blood vessel centerline are also adjacent on the entry path of the blood vessel stent, all the center points on the line segment of interest are rearranged to simulate the entry path of the blood vessel stent.

[0050] Optionally, the step of simulating the stent deployment cross-section corresponding to each center point on the stent's entry path based on the position information of each center point on the stent's entry path and the normal vector of the cross-section of the blood vessel where the stent is located includes:

[0051] Step a2: For each center point on the entry path of the vascular stent, calculate the stent cross-sectional radius corresponding to the center point according to the second preset rule;

[0052] Step b2: Using the radius of the stent cross-section corresponding to the starting point of the path as the radius, the normal vector of the blood vessel cross-section where the starting point of the path is located as the normal vector, and the location of the starting point of the path as the center, simulate the unfolded cross-section of the stent corresponding to the starting point of the path;

[0053] Step c2: Divide the support unfolded section corresponding to the path starting point into N equal parts according to a preset angle to obtain N support outline points, and take the path starting point as the current path point and the support unfolded section corresponding to the path starting point as the current support section.

[0054] Step c2: Based on the position information of the N stent contour points of the current stent cross section, the normal vector of the current stent cross section, the position information of the neighboring center points adjacent to the current path point, the normal vector of the blood vessel cross section where the neighboring center points are located, and the stent cross section radius corresponding to the neighboring center points, determine N new stent contour points that correspond one-to-one with the N stent contour points, thereby simulating the stent deployment cross section corresponding to the neighboring center points.

[0055] Step d2: Take the neighboring center point as the new current path point, take the support unfolded section corresponding to the neighboring center point as the new current support section, and return to execute step c2 until the support unfolded section corresponding to the path endpoint is simulated.

[0056] Optionally, obtaining the radius of the support cross-section corresponding to the center point according to the second preset rule includes:

[0057] Use half the maximum diameter of the cross-section of the blood vessel where the path originates as the radius of the stent cross-section corresponding to that center point; and / or

[0058] Calculate the radius of the support section corresponding to the center point using the following formula:

[0059]

[0060] In the formula, r j r is the radius of the support cross-section corresponding to the center point. a r is half the maximum diameter of the cross-section of the blood vessel where the path originates. bn is half the maximum diameter of the cross-section of the blood vessel where the path ends. j n is the sequence number of the center point along the entry path of the vascular stent. b The path endpoint is the sequence number of the entry path of the vascular stent, wherein the path start point is the sequence number of 0 in the entry path of the vascular stent.

[0061] Optionally, determining N new stent contour points corresponding one-to-one with the N stent contour points based on the position information of the N stent contour points of the current stent cross-section, the normal vector of the current stent cross-section, the position information of the neighboring center points adjacent to the current center point, the normal vector of the blood vessel cross-section where the neighboring center points are located, and the stent cross-section radius corresponding to the neighboring center points includes:

[0062] Using the location of the neighboring center point as the center of the two-dimensional cross section and the normal vector of the blood vessel cross section where the neighboring center point is located as the normal vector of the two-dimensional cross section, the two-dimensional cross section corresponding to the neighboring center point is simulated.

[0063] For each support profile point of the current support cross section, based on the position information of the support profile point, a point is determined on the two-dimensional cross section that is parallel to the normal vector of the two-dimensional cross section by the straight line formed by the support profile point. The position of the target point is then corrected based on the support cross section radius corresponding to the adjacent center point, and the corrected target point is taken as the corresponding new support profile point.

[0064] Optionally, the stent deployment information simulating the vascular stent entering the segment of interest further includes:

[0065] Based on the stent deployment cross-section corresponding to each center point on the stent's entry path, the stent's inner and outer bending paths during deployment are simulated.

[0066] Optionally, simulating the inner and outer bending paths of the vascular stent during deployment based on the stent deployment cross-sections corresponding to each center point on the path includes:

[0067] The corresponding stent outline points on the stent unfolding cross section corresponding to each center point on the entry path of the vascular stent are sequentially connected to obtain N stent outline paths.

[0068] The longest support contour path among the N support contour paths is taken as the outer bending side path of the support, and the shortest support contour path is taken as the inner bending side path of the support.

[0069] Optionally, the relevant data for the center point includes the location information of the center point, and the method for applying the vascular centerline data further includes:

[0070] Based on the movement vector of one of the moved center points on the blood vessel centerline, the unmoved center points on the blood vessel centerline located within a first circular domain centered on the moved center point and with a first preset radius are moved synchronously in the same direction as the movement direction of the center point, according to the corresponding offset.

[0071] Optionally, the offset of the unmoved center point can be calculated using the following formula:

[0072]

[0073] In the formula, D is the offset of the unmoved center point, D0 is the moving distance of the moved center point; r is the first preset radius; and d is the distance between the unmoved center point and the moved center point.

[0074] Optionally, the vascular region includes the main branch vessels and multiple branch vessels intersecting with the main branch vessels, and the relevant data of the center point includes the location information of the center point and the normal vector of the cross-section of the vessel where the center point is located.

[0075] The method for applying the vascular centerline data also includes:

[0076] For each branch vessel that intersects with the main branch vessel, the projection angle of the branch vessel is calculated based on the normal vector of the cross-section of the vessel at the starting center point of the branch vessel and the normal vector of the cross-section of the vessel at the intersection center point of the branch vessel and the main branch vessel.

[0077] To achieve the above objectives, the present invention also provides an electronic device, including a processor and a memory, wherein the memory stores a computer program, and when the computer program is executed by the processor, it implements the vascular centerline data application method described above.

[0078] To achieve the above objectives, the present invention also provides a readable storage medium storing a computer program, which, when executed by a processor, implements the vascular centerline data application method described above.

[0079] Compared with existing technologies, the vascular centerline data application method, electronic device, and storage medium provided by this invention have the following advantages: The vascular centerline data application method provided by this invention first explores the center points of the vascular centerlines in the acquired medical image using a preset algorithm to extract the corresponding vascular centerlines; then, according to a first preset rule, an index number is set for each center point on the vascular centerline; then, based on the position information of two coarsely selected points on the acquired medical image, two target center points are determined on the vascular centerline; then, based on the index numbers corresponding to the two target center points, all center points on the centerline segment of interest with the two target center points as the two endpoints are determined on the vascular centerline; finally, based on the relevant data of each center point on the centerline segment of interest, the vascular parameters of the corresponding vascular segment of interest and / or the stent deployment information of the vascular stent entering the vascular segment of interest are obtained. Therefore, this invention, by acquiring vascular parameters of the vessel segment of interest and / or simulating stent deployment information for the stent entering the vessel segment of interest based on vascular centerline data, can help doctors quantitatively analyze the patient's health status, further reducing intraoperative risks, shortening operation time, and alleviating the patient's physical burden. Simultaneously, based on the acquired vascular parameters and / or stent deployment information, more detailed and accurate quantitative vascular stent parameters can be provided to stent suppliers, helping them to provide more suitable stent preparations for patients before surgery and effectively reducing redundant stent preparations. Furthermore, by determining two target center points on the vessel centerline based on the location information of two coarse selection points, this invention makes it easier for users to pick the centerline segment of the vessel segment of interest (i.e., the centerline segment of interest).

[0080] Since the electronic device and storage medium provided by this invention belong to the same inventive concept as the vascular centerline data application method provided by this invention, the electronic device and storage medium provided by this invention have all the advantages of the vascular centerline data application method provided by this invention. Therefore, the beneficial effects of the electronic device and storage medium provided by this invention will not be described in detail here. Attached Figure Description

[0081] Figure 1 A flowchart illustrating a method for applying vascular centerline data according to an embodiment of the present invention;

[0082] Figure 2 A schematic diagram illustrating the principle of determining the target center point based on coarsely selected points according to an embodiment of the present invention;

[0083] Figure 3 A schematic diagram of a bidirectional circular queue linked storage structure provided in one embodiment of the present invention;

[0084] Figure 4 A flowchart illustrating the process of determining the center point on the line segment of interest, provided for a first embodiment of the present invention;

[0085] Figure 5 A schematic diagram of centerline traversal when two target center points are located within the same blood vessel, as provided in one embodiment of the present invention;

[0086] Figure 6 A flowchart illustrating the process of determining the center point on the line segment of interest, provided for a second embodiment of the present invention;

[0087] Figure 7 A schematic diagram of centerline traversal when one target center point is located inside the main branch vessel and the other target center point is located inside the branch vessel, according to an embodiment of the present invention.

[0088] Figure 8 A schematic diagram of centerline traversal when two target center points are located within two branch vessels of the same level, as provided in one embodiment of the present invention;

[0089] Figure 9 A schematic diagram of centerline traversal when two target center points are located within two branch vessels of different levels, as provided in one embodiment of the present invention;

[0090] Figure 10 A schematic diagram illustrating the calculation of tortuosity values ​​according to an embodiment of the present invention;

[0091] Figure 11 A schematic diagram of a blood vessel cross-section provided as a specific example of the present invention;

[0092] Figure 12 A schematic diagram illustrating the calculation of the diameter of the blood vessel cross-section in the first and third quadrants, provided as an embodiment of the present invention;

[0093] Figure 13 A schematic diagram illustrating the calculation of the diameter of the blood vessel cross-section in the second and fourth quadrants, provided as an embodiment of the present invention;

[0094] Figure 14 A schematic diagram showing all diameters of the calculated blood vessel cross-section;

[0095] Figure 15 A diagram illustrating the movement effect of the center line segment of interest on the blood vessel centerline according to an embodiment of the present invention;

[0096] Figure 16 This is a diagram illustrating the effect of blood vessel centerline movement according to an embodiment of the present invention.

[0097] Figure 17This is a diagram illustrating the movement effect when two first circular domains intersect, according to one embodiment of the present invention.

[0098] Figure 18 This is a schematic diagram of dividing the outline points of the support frame according to an embodiment of the present invention;

[0099] Figure 19 This is a schematic diagram of the simulated unfolded cross section of a vascular stent provided as a specific example of the present invention when the radius of the unfolded cross section of the vascular stent corresponding to each center point on the entry path is the same.

[0100] Figure 20 This is a schematic diagram of the stent deployment cross section simulated when the radius of the stent deployment cross section corresponding to each center point on the entry path changes linearly, as a specific example of the present invention.

[0101] Figure 21 A schematic diagram illustrating the simulation of the next support unfolding cross section based on the current support cross section, according to one embodiment of the present invention;

[0102] Figure 22 A schematic diagram of the maximum expanded shape of a branch vessel inlet under a vascular imaging angle provided in one embodiment of the present invention;

[0103] Figure 23 This is a block diagram of an electronic device according to one embodiment of the present invention. Detailed Implementation

[0104] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, further illustrates the vascular centerline data application method, electronic device, and storage medium proposed in this invention. The advantages and features of this invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, used only to facilitate and clearly illustrate the embodiments of this invention. Please refer to the drawings to make the objectives, features, and advantages of this invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes and to enable those skilled in the art to understand and read them, and are not intended to limit the implementation conditions of this invention. Any modifications to the structure, changes in proportions, or adjustments to the size, provided that the effects and objectives achieved by this invention are the same or similar, should still fall within the scope of the technical content disclosed in this invention.

[0105] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0106] Furthermore, in the description of this specification, the reference to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., means that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0107] The core idea of ​​this invention is to provide a method, electronic device, and storage medium for applying vascular centerline data, which can help doctors quantitatively analyze patients' health status, further reduce intraoperative risks, shorten operation time, and reduce the physical burden on patients.

[0108] It should be noted that the vascular centerline data application method provided by this invention can be applied to the electronic device provided by this invention. The electronic device can be a personal computer, a mobile terminal, etc., and the mobile terminal can be a mobile phone, tablet computer, or other hardware device with various operating systems. Furthermore, it should be noted that the medical images in this invention can be acquired through scanning and acquisition using various modal imaging systems, or transmitted through internal or external storage systems such as Picture Archiving and Communication Systems (PACS). These modalities include, but are not limited to, one or more combinations of magnetic resonance imaging (MRI), magnetic resonance angiography (MRA), computed tomography (CT), and positron emission tomography (PET).

[0109] To achieve the above-mentioned goals, this invention provides a method for applying vascular centerline data. Please refer to [the relevant documentation]. Figure 1 The diagram illustrates a flowchart of a method for applying vascular centerline data according to an embodiment of the present invention. Figure 1 As shown, the method for applying vascular centerline data provided by the present invention includes the following steps:

[0110] Step S100: Use a preset algorithm to explore the center point of the blood vessel center line in the acquired medical image to extract the corresponding blood vessel center line.

[0111] Step S200: Set an index number for each of the center points on the central line of the blood vessel according to the first preset rule.

[0112] Step S300: Based on the position information of the two coarsely selected points on the medical image, determine two target center points on the blood vessel centerline.

[0113] Step S400: Based on the index numbers corresponding to the two target center points, determine all center points on the line segment of interest with the two target center points as the two endpoints on the blood vessel center line.

[0114] Step S500: Based on the relevant data of each center point on the line segment of interest, obtain the vascular parameters of the corresponding vascular segment of interest and / or simulate the stent deployment information of the vascular stent entering the vascular segment of interest.

[0115] Therefore, this invention, by acquiring vascular parameters of the vessel segment of interest and / or simulating stent deployment information for the stent entering the vessel segment of interest based on vascular centerline data, can help doctors quantitatively analyze the patient's health status, further reducing intraoperative risks, shortening operation time, and alleviating the patient's physical burden. Simultaneously, based on the acquired vascular parameters and / or stent deployment information, more detailed and accurate quantitative vascular stent parameters can be provided to stent suppliers, helping them to provide more suitable stent preparations for patients before surgery and effectively reducing redundant stent preparations. Furthermore, by determining two target center points on the vessel centerline based on the location information of two coarse selection points, this invention makes it easier for users to pick the centerline segment of the vessel segment of interest (i.e., the centerline segment of interest).

[0116] In one exemplary embodiment, determining two target center points on the blood vessel centerline based on the acquired position information of two coarsely selected points located on the medical image includes:

[0117] For each coarse selection point, the distance between each center point on the blood vessel centerline and the coarse selection point is calculated, and the center point with the smallest distance from the coarse selection point is taken as the target center point corresponding to the coarse selection point.

[0118] For details, please refer to Figure 2 The diagram illustrates the principle of determining the target center point based on a coarsely selected point according to an embodiment of the present invention. Figure 2 As shown, the two coarse selection points selected by the user are A and B, and the extracted vessel centerline is the center point sequence {c}. j}(j=1,2,3,...,n), let the coordinates of the coarsely selected point A be (x A ,y A ,z A ), any center point c on the central line of the blood vessel j The coordinates are (x j ,y j ,z j Then, according to the distance formula between two points, the distances between the coarsely selected point A and each center point on the central line of the blood vessel can be calculated respectively. The calculation results are represented by the distance set {l j |j∈(1,n)} represents the distance between two points. The formula for the distance between two points is as follows:

[0119] Let C(x1,y1,z1) and D(x2,y2,z2) be any two points in three-dimensional space. The formulas and methods for calculating the distance between points C and D include, but are not limited to, the following:

[0120] 1) European distance:

[0121] 2) Manhattan distance: l = |x1-x2| + |y1-y2| + |z1-z2|;

[0122] 3) Chebyshev distance: l = max(|x1-x2|,|y1-y2|,|z1-z2|);

[0123] 4) Standardized European distance: (in (These represent the variances of the coordinates of two points along the x, y, and z axes, respectively).

[0124] If l i If the distance set is the minimum value, then the center point c i This is the target center point corresponding to the coarsely selected point A. Similarly, by calculating and comparing the distances between the coarsely selected point B and each center point on the blood vessel centerline, it is found that due to center point c... k The distance to the initially selected point B is the smallest, therefore the center point c is the smallest. kThis is the target center point corresponding to the coarsely selected point B.

[0125] In one exemplary embodiment, setting an index number for each of the center points on the blood vessel centerline according to a first preset rule includes:

[0126] An index number is assigned to each center point on the centerline of the blood vessel according to the rule that the index number of the center point of the lower-level blood vessel is greater than the index number of the center point of the upper-level blood vessel, and that the index number of each blood vessel gradually increases along its extension direction.

[0127] For details, please refer to Figure 2 ,like Figure 2 As shown, segment P1N1 is the main branch vessel 110, and segments P2N1, P3N1, P4N2, P5N3, P6N4, P7N5, P8N6, P9N7, and P... 10 Segment N8 consists of first-order branch vessels (i.e., branch vessels intersecting with the main branch vessel 110). These vessels branch off from segment P1N1 and are subordinate vessels of segment P1N1. It should be noted that, as those skilled in the art will understand, in some other embodiments, the first-order branch vessels may further branch into other, even lower-order branch vessels. Assuming any center point c... j The index number is j, and the point set {P} j}(j=1,2,...,n) represents the endpoints of the main branch vessel 110 and its various branch vessels, and the point set {N} j}(j=1,2,...,n) represents the confluence center point of each branch vessel and its superior vessel. In the main branch vessel 110, from the endpoint to the confluence center point (i.e., from P1→N1), the index number is from smallest to largest. In each branch vessel, from the endpoint to the confluence center point (e.g., from P2→N1), the index number is from largest to smallest. It can be seen that the index number of the center point on the lower-level vessel is larger than the index number of the center point on its superior vessel, and the index number of the center point on the branch vessel is larger than the index number of the center point on the main branch vessel 110. The direction indicated by the arrow in the figure is from largest to smallest index number. For ease of distinction, the two symmetrical first-level branch vessels P2N1 and P3N1 are both referred to as the first branch vessel 120. The segments P4N2, P5N3, P6N4, P7N5, P8N6, P9N7, and P... 10 These first-order branch vessels in segment N8 are all referred to as second-order branch vessels 130.

[0128] In one exemplary implementation, the step of exploring the center point of the vascular centerline in the acquired medical image using a preset algorithm includes:

[0129] The first preset algorithm is used to explore the center point on the center line of the two first branch vessels 120 simultaneously until the first termination condition is met. Then, the one of the termination center points of the two first branch vessels 120 that is located at the higher position is taken as the first intersection center point of the center line of the two first branch vessels 120 and replaces the termination center point of the other first branch vessel 120.

[0130] The second preset algorithm is used to explore the center point on the center line of the main branch vessel 110 until the second termination condition is met, then the first intersection center point is taken as the termination center point of the main branch vessel 110.

[0131] The third preset algorithm is used to explore the center point on the center line of the second branch vessel 130 until the third termination condition is met. Then, the center point where the distance between the main vessel and the termination center point of the second branch vessel 130 is less than the third threshold is determined as the second intersection center point corresponding to the second branch vessel 130 and replaces the termination center point of the second branch vessel 130.

[0132] Therefore, the preset algorithm provided by the present invention does not require segmenting the entire vascular region from the medical image first, thus avoiding the use of a heavy deep learning algorithm. This effectively avoids the problems of slow speed and high memory consumption caused by the prior art of segmenting a large area of ​​three-dimensional blood vessels and then extracting the vascular centerline. At the same time, it can also avoid the problem of insufficient accuracy of the calculated vascular centerline due to the low quality of the three-dimensional blood vessel segmentation results.

[0133] In one exemplary embodiment, the step of using a first preset algorithm to explore the center point on the centerline of the first branch vessel 120 until a first termination condition is met includes:

[0134] Step A1: Determine the initial center point on the center line of the first branch vessel 120 based on the first endpoint within the first branch vessel 120, and use the initial center point as the current forward point, and use the unit vector parallel to the Z-axis as the current forward direction vector.

[0135] Step A2: Based on the current forward point and the current forward direction vector, explore the next new center point on the center line of the first branch blood vessel 120, and take the explored new center point as the current center point of the first branch blood vessel 120;

[0136] Step A3: Determine whether the distance between the current center point of the first branch vessel 120 and the current center point of another first branch vessel 120 is less than a first threshold.

[0137] If yes, proceed to step A4; otherwise, proceed to step A5.

[0138] Step A4: Take the current center point of the first branch vessel 120 as the termination center point of the first branch vessel 120 and end the exploration of the center point on the center line of the first branch vessel 120.

[0139] Step A5: Take the current center point of the first branch blood vessel 120 as the current forward point, take the unit vector pointing from the previous center point to the current center point as the current forward direction vector, and return to execute step A2.

[0140] It should be noted that, as those skilled in the art will understand, the purpose of selecting the first endpoint is to initialize the exploration path of the centerline of the first branch vessel 120 and to constrain the exploration path. The first endpoint within each of the first branch vessels 120 can be selected manually or by a computer according to a pre-set algorithm; this invention does not impose any limitations on this. Please continue to refer to [the relevant documentation / reference]. Figure 2 ,like Figure 2 As shown, the first endpoints P2 and P3 are preferably located close to the end of the first branch vessel 120. The first endpoints P2 and P3 do not need to be close to the center of the first branch vessel 120, as long as the first endpoints P2 and P3 are located within the first branch vessel 120.

[0141] In one exemplary embodiment, a low-position priority principle is adopted to synchronously and alternately explore the center points on the center lines of the two first branch vessels 120 using a first preset algorithm. Thus, by adopting the low-position priority principle to alternately explore the center lines of the left and right first branch vessels 120, it can be ensured that the exploration of the center lines of the left and right first branch vessels 120 is carried out synchronously. Specifically, the low-position priority principle means that the exploration of the center point on the center line of the first branch vessel 120 (represented as first branch vessel 120A for ease of distinction), where the first endpoint is farther from the main vessel, is prioritized. Once a center point on the center line of first branch vessel 120A is found to be above the first endpoint of another first branch vessel 120 (represented as first branch vessel 120B), the exploration of the center point on the center line of first branch vessel 120B begins. After a center point on the center line of first branch vessel 120B is found, the distance between the two most recently explored center points of the two first branch vessels 120 is determined. If the distance between the two newly discovered center points of the two first branch vessels 120A is not less than the first threshold, then the exploration of the center point on the center line of the first branch vessel 120A is performed. After a center point on the center line of the first branch vessel 120A is discovered, the exploration of the center point on the center line of the first branch vessel 120B is performed. After a center point on the center line of the first branch vessel 120B is discovered, it is then determined whether the distance between the two newly discovered center points of the two first branch vessels 120 is less than the first threshold. This process is repeated, and by alternately exploring the center points on the center lines of the two first branch vessels 120, the synchronous exploration of the center lines of the two first branch vessels 120 can be achieved. It should be noted that, as those skilled in the art can understand, when the coordinates of each pixel point on the medical image are represented by the position information in the LPS anatomical coordinate system (X-axis direction from right to left, Y-axis direction from front to back, Z-axis direction from bottom to top), the first endpoint with the smaller Z-coordinate is the first endpoint farther from the main vessel. Furthermore, it should be noted that, as those skilled in the art can understand, the one with the larger Z-coordinate among the termination center points of the two first branch vessels 120 is the one located at the higher position, that is, the one with the larger Z-coordinate among the termination center points of the two first branch vessels 120 is the first intersection center point N1.

[0142] Specifically, assume the coordinates of the previous center point are c. j-1 The current center point coordinates are c j Then the current forward direction vector The calculation formula is as follows:

[0143]

[0144] In one exemplary implementation, the step of exploring the next new center point on the centerline of the first branch vessel 120 based on the current advance point and the current advance direction vector includes:

[0145] Based on the current forward point and the current forward direction vector, extract the current two-dimensional cross-section of interest image from the medical image to be segmented;

[0146] The current two-dimensional cross-sectional image of interest is segmented to obtain the current two-dimensional blood vessel region;

[0147] The current two-dimensional blood vessel region is segmented into true and false lumens to segment out the current two-dimensional blood vessel true lumen region;

[0148] The new center point of the first branch vessel 120 is obtained based on the center point of the current two-dimensional vascular lumen region.

[0149] Therefore, by reducing the dimensionality of three-dimensional medical images to multiple consecutive two-dimensional cross-sectional images of interest, and exploring the center point on the vascular centerline based on the extracted two-dimensional cross-sectional images of interest, the extraction speed of three-dimensional vascular centerlines can be effectively improved, memory usage reduced, and a high-precision three-dimensional vascular centerline extraction function with strong data generalization can be achieved. Furthermore, since the center point on the vascular centerline in this invention is the center point of the corresponding two-dimensional vascular lumen region, it can be ensured that the finally extracted vascular centerline is located within the vascular lumen, thus meeting the extraction needs of aortic vascular centerlines for patients with diseases such as aortic dissection and aortic aneurysm. It should be noted that, as those skilled in the art will understand, after segmenting the current two-dimensional true lumen region of the blood vessel, the maximum radius of the current two-dimensional true lumen region of the blood vessel is taken as the maximum radius of the blood vessel cross section where its center point is located. The upper limit pixel value and lower limit pixel value corresponding to the blood vessel cross section where its center point is located are determined based on the gray average value of the pixels in the current two-dimensional true lumen region of the blood vessel. Specifically, assuming that the gray average value of the pixels in the current two-dimensional true lumen region of the blood vessel is h, the upper limit pixel value corresponding to the blood vessel cross section where its center point is located is h / λ1, and the lower limit pixel value is λ1h, where λ1 is a constant greater than 0 and less than 1.

[0150] Specifically, after segmenting the current two-dimensional vascular lumen region, the center point of this region can be calculated using the extreme erosion method. Therefore, by employing the extreme erosion method, the center point of the current two-dimensional vascular lumen region can be accurately calculated, ensuring that the calculated center point is located within the vascular lumen region. It should be noted that, as those skilled in the art will understand, further details regarding the calculation of the center point using the extreme erosion method can be found in existing technologies and will not be elaborated upon here.

[0151] In one exemplary implementation, the step of extracting the current two-dimensional section of interest image from the medical image to be segmented based on the current forward point and the current forward direction vector includes:

[0152] Based on the current forward point and the current forward direction vector, determine the center point of the current two-dimensional section of interest and the normal vector of the current two-dimensional section of interest, wherein the normal vector of the current two-dimensional section of interest is the current forward direction vector;

[0153] Based on the preset size, the center point of the current two-dimensional section of interest, and the normal vector of the current two-dimensional section of interest, the current two-dimensional section of interest image is extracted from the medical image to be segmented.

[0154] Therefore, by using the calculated center point of the current two-dimensional section of interest, the normal vector of the current two-dimensional section of interest, and the preset size, the current two-dimensional section of interest image can be accurately extracted from the medical image. It should be noted that, as those skilled in the art will understand, the preset size includes a width dimension and a height dimension; for ease of calculation, the width dimension is equal to the height dimension.

[0155] In one exemplary implementation, determining the center point of the current two-dimensional section of interest based on the current forward point and the current forward direction vector includes:

[0156] The current forward speed is determined based on the angle between the current forward direction vector (i.e., the current two-dimensional cross-section of interest normal vector) and the previous forward direction vector (i.e., the previous two-dimensional cross-section of interest normal vector).

[0157] The center point of the current two-dimensional cross-section of interest is determined based on the current forward point, the current forward direction vector, and the current forward velocity.

[0158] Specifically, assume the current forward direction vector is The previous forward direction vector is Then the current forward direction vector and the previous forward direction vector The formula for calculating the included angle θ between them is as follows:

[0159]

[0160] After calculating the current forward direction vector and the previous forward direction vector After determining the included angle θ, the current forward velocity v can be calculated using any one of the following formulas (3) to (6):

[0161] v=k*α*θ+b,θ∈[0,π] (3)

[0162] v=k*α*(cosθ+1)+b,θ∈[0,π] (4)

[0163]

[0164]

[0165] Where k, b, and β are constants, and α is the ratio of the area of ​​the previous two-dimensional true lumen region to the area of ​​the two-dimensional true lumen region where the starting center point is located.

[0166] It should be noted that, as those skilled in the art can understand, k and b in formulas (3) to (6) are pre-set, specifically calculated based on a large number of vascular centerlines (e.g., aortic centerlines), and β is an amplification factor used to control the maximum and minimum values ​​of the curve.

[0167] Therefore, by calculating the forward direction vector of the current forward point (i.e., the current forward direction vector) according to formula (2) and in combination with any one of formulas (3) to (6), the present invention can achieve adaptive adjustment of the forward speed of the exploration of the blood vessel centerline. That is, when the deflection angle is small or the blood vessel is thick, a larger forward speed is used to improve the exploration efficiency, and when the deflection angle is large or the blood vessel is thin, a smaller speed is used to improve the accuracy of the exploration of the blood vessel centerline.

[0168] After calculating the current forward velocity, the center point sc of the current two-dimensional section of interest can be calculated using the following formula. j :

[0169]

[0170] Among them, c j-1 As the current starting point, This is the current forward direction vector.

[0171] In one exemplary embodiment, the method further includes:

[0172] The maximum radius of the current two-dimensional vascular lumen region is determined based on the center point of the current two-dimensional vascular lumen region.

[0173] Based on the maximum radius of the current two-dimensional vascular lumen region, determine the locking radius corresponding to the current two-dimensional vascular lumen region;

[0174] The step of segmenting the blood vessel region in the current two-dimensional cross-sectional image of interest to segment the current two-dimensional blood vessel region includes:

[0175] Based on the average gray value of the pixels in the two-dimensional blood vessel lumen region, determine the second upper limit threshold and the second lower limit threshold for region growth.

[0176] Based on the locking radius corresponding to the previous two-dimensional true lumen region of the blood vessel and the center point of the current two-dimensional section of interest, the current circular region is determined in the current two-dimensional section of interest image;

[0177] In the current circular domain, a pixel with a value greater than the lower threshold and less than the upper threshold is selected as the second initial seed point for region growth;

[0178] Based on the second initial seed point, the second upper threshold, and the second lower threshold, the region growing method is used to segment the blood vessel region of the current two-dimensional cross-sectional image of interest, so as to segment the current two-dimensional blood vessel region.

[0179] In one exemplary embodiment, the method further includes:

[0180] The maximum radius of the current two-dimensional vascular lumen region is determined based on the center point of the current two-dimensional vascular lumen region.

[0181] The locking radius corresponding to the current two-dimensional blood vessel lumen region is determined based on the maximum radius of the current two-dimensional blood vessel lumen region.

[0182] Since the maximum radius of the explored artery suddenly decreases, such as when a dissection occurs or a sharp turn is encountered, continuing to explore the center point is prone to errors. Therefore, by setting a lock radius, the range of the second initial seed point used for region growth can be limited, thereby ensuring that the results obtained from region growth accurately include blood vessels.

[0183] Specifically, assuming the average grayscale value of the pixels in the two-dimensional true lumen region of the blood vessel is h j-1 Then the upper limit threshold is h j-1 / λ2, the lower threshold is λ2h j-1 Where λ2 is a constant greater than 0 and less than 1. Since there is a certain continuity between blood vessels in adjacent sections, this invention adds a circular domain and a dual threshold constraint including an upper threshold and a lower threshold to the basic region growing method. Using the position and pixel values ​​of the blood vessels in the previous section as prior information, interference from irrelevant tissues can be reduced, improving the accuracy of blood vessel region growing. It should be noted that, as those skilled in the art will understand, the relevant techniques for segmenting blood vessel regions in the current two-dimensional cross-section image of interest using the region growing method based on the second initial seed point, the second upper threshold, and the second lower threshold can be found in existing region growing methods, and therefore will not be elaborated upon here.

[0184] In one exemplary embodiment, determining the locking radius corresponding to the current two-dimensional vascular lumen region based on the maximum radius of the current two-dimensional vascular lumen region includes:

[0185] Determine whether the ratio of the square of the maximum radius of the previous two-dimensional vascular lumen region to the square of the maximum radius of the current two-dimensional vascular lumen region is greater than a preset ratio.

[0186] If so, the maximum radius of the previous two-dimensional true lumen region is used as the locking radius corresponding to the current two-dimensional true lumen region, so as to lock the locking radius of the current two-dimensional true lumen region.

[0187] If not, then the maximum radius of the current two-dimensional vascular lumen region is taken as the locking radius corresponding to the previous two-dimensional vascular lumen region.

[0188] Specifically, assuming the maximum radius of the true lumen region of the two-dimensional blood vessel is mr j-1 The maximum radius of the current two-dimensional vascular lumen region is mr. j The preset ratio is γ, γ≥1, if (mr j-1 ) 2 / (mr j If )2>γ, then the locking radius Ir of the current two-dimensional vascular true lumen region is... j For mr j-1 ;(mr j-1 ) 2 / (mr j If 2 ≤ γ, then the locking radius Ir of the current two-dimensional vascular true lumen region is... j For mr j It should be noted that, as those skilled in the art will understand, the specific value of the preset ratio γ can be set according to the actual situation, and the present invention does not limit it in this regard.

[0189] In one exemplary embodiment, if the locking radius of the previous two-dimensional vascular lumen region is locked, the method further includes, before segmenting the current two-dimensional vascular region into true and false lumens:

[0190] The current two-dimensional blood vessel region is eroded to remove interfering areas within it.

[0191] Specifically, if the locking radius Ir of the upper two-dimensional vascular true lumen region j-1 The maximum radius mr of the two-dimensional true lumen region of the blood vessel is above. j-2If the vascular centerline deviates significantly, it indicates that the exploration has entered the interlayer or has deviated significantly. Therefore, by performing minor erosion on the current two-dimensional vascular region, the adhesion between the blood vessel and other tissues can be removed, thereby effectively removing the interference area in the current two-dimensional vascular region and laying a good foundation for obtaining a high-precision vascular centerline.

[0192] In one exemplary embodiment, the segmentation of the current two-dimensional vascular region into true and false lumens to segment out the current two-dimensional vascular true lumen region includes:

[0193] Perform connected component analysis on the current two-dimensional blood vessel region, and extract the connected component closest to the center point of the current two-dimensional cross-section of interest as the current two-dimensional blood vessel true lumen region.

[0194] Since the current two-dimensional true lumen vessel region and the previous two-dimensional true lumen vessel region are continuous under the premise that the cross-sectional direction of the previous two-dimensional true lumen vessel region is correct, the current two-dimensional true lumen vessel region should be close to the center point of the current two-dimensional cross-section of interest. Therefore, the connected region closest to the center point of the current two-dimensional cross-section of interest should be the current two-dimensional true lumen vessel region.

[0195] In one exemplary embodiment, after extracting the current two-dimensional section of interest image from the medical image and before segmenting the vascular region in the current two-dimensional section of interest image, the method further includes:

[0196] Map the current two-dimensional cross-sectional image of interest onto the two-dimensional plane with Z=0.

[0197] Correspondingly, the segmentation of the blood vessel region in the current two-dimensional cross-sectional image of interest to segment the current two-dimensional blood vessel region includes:

[0198] The current two-dimensional cross-sectional image of interest, mapped to a two-dimensional plane of Z=0, is segmented to extract the current two-dimensional blood vessel region.

[0199] Therefore, by mapping the current two-dimensional cross-sectional image of interest to the plane with Z=0, it can be ensured that the Z coordinate of each pixel in the mapped current two-dimensional cross-sectional image of interest is 0, which can effectively simplify the subsequent segmentation steps.

[0200] Specifically, suppose the coordinate matrix formed by the homogeneous coordinates of a pixel in the current two-dimensional cross-sectional image of interest in the three-dimensional coordinate system corresponding to the medical image is an m×4 matrix X. 3d , where X 3dEach row in the matrix corresponds to the homogeneous coordinates of a pixel in the current two-dimensional cross-section image of interest in the three-dimensional coordinate system corresponding to the medical image; the coordinate matrix formed by the homogeneous coordinates (where the Z coordinate is 0) of all pixels in the current two-dimensional cross-section image of interest mapped to the Z=0 two-dimensional plane in the two-dimensional cross-section coordinate system (the two-dimensional coordinate system with the center of the current two-dimensional cross-section image of interest mapped to the Z=0 two-dimensional plane as the origin) of the two-dimensional cross-section image of interest is an m×4 matrix X. 2d , where X 2d Each row in the table corresponds to the homogeneous coordinates of a pixel in the current two-dimensional cross-sectional image of interest in the two-dimensional cross-sectional coordinate system. Then X... 3d and X 2d The following relationship exists between them:

[0201] X 3d =X 2d R y R x R T (8)

[0202] Among them, R x Let R be the rotation matrix along the X-axis. y Let R be the rotation matrix along the Y-axis. T Translation matrix.

[0203] Furthermore, assume that the center point sc of the two-dimensional section of interest corresponding to the current two-dimensional section of interest image j The homogeneous coordinates in the three-dimensional coordinate system are: The normal vector of the current two-dimensional section of interest image. (i.e., the current forward direction vector) The homogeneous coordinates in a three-dimensional coordinate system are represented as follows: Then R x R y and R T The calculation formula is as follows:

[0204]

[0205]

[0206]

[0207]

[0208]

[0209]

[0210] sinβ=-x nj (15)

[0211] It should be noted that, as those skilled in the art will understand, offset is a pre-set parameter, and the specific value of offset can be 1e-6. Therefore, by setting the offset, it is possible to prevent [the problem caused by] y nj and z nj When the value is zero, it causes the problem that cosα and sinα cannot be calculated.

[0212] Therefore, after calculating the rotation matrix R x R y and the translation matrix R T Then, according to the above formula (8), the current two-dimensional cross-sectional image of interest extracted from the medical image can be transformed from the three-dimensional coordinate system to the two-dimensional cross-sectional coordinate system. After calculating the coordinates of the center point in the two-dimensional cross-sectional coordinate system, the coordinates of the center point in the three-dimensional coordinate system can be obtained by formula (8).

[0213] In one exemplary embodiment, if the determination result of step A3 is negative, then before executing step A5, the method further includes:

[0214] Determine whether the exploration direction of the current center point of the first branch vessel 120 has backtracked;

[0215] If so, stop exploring the center point on the center line of the first branch vessel 120 and send a message indicating that the center line exploration has failed.

[0216] Specifically, when the exploration direction of the blood vessel centerline reverses, it indicates that the exploration direction has deviated backward, meaning an error has occurred. Therefore, by determining whether the exploration direction of the current center point has reversed, we can promptly avoid continuing in the wrong direction.

[0217] Furthermore, the following steps can be used to determine whether the exploration direction of the current center point of the first branch vessel 120 has backtracked:

[0218] Determine whether the distance between the current center point and any of the most recently explored center points (of the first preset number) is less than a first preset distance threshold. If yes, backtracking has occurred; otherwise, no backtracking has occurred.

[0219] Since the exploration direction of the vessel centerline has deviated backward when the distance between the current center point and any of the most recently explored center points is less than the first preset distance threshold, it can be accurately determined whether the exploration direction of the current center point of the first branch vessel 120 has deviated backward by judging whether the distance between the current center point and any of the most recently explored center points is less than the first preset distance threshold.

[0220] In one exemplary embodiment, if the exploration direction of the current center point of the first branch vessel 120 has not been backtracked, then before executing step A5, the method further includes:

[0221] Determine whether the selected position of the first endpoint of the first branch vessel 120 meets the first preset condition;

[0222] If not, the search for the center point on the center line of the first branch vessel 120 is stopped, and a prompt message is sent to reselect the first endpoint of the first branch vessel 120.

[0223] Specifically, when the first endpoint selected by the user is not within the first branch vessel 120, or when the vessel at the location of the first endpoint selected by the user is relatively thin, that is, when the position of the selected first endpoint does not meet the first preset condition, the centerline exploration will be incorrect. Therefore, by judging whether the position of the selected first endpoint meets the first preset condition, the continued incorrect exploration can be avoided in time.

[0224] Furthermore, the following steps can be used to determine whether the selected position of the first endpoint of the first branch vessel 120 meets the first preset condition:

[0225] Determine whether the average maximum radius of the second preset number of recently extracted two-dimensional vascular lumen regions (including the current two-dimensional vascular lumen region) is less than a first preset radius threshold. If yes, determine that the selection position of the first endpoint does not meet the first preset condition; otherwise, determine that the selection position of the first endpoint meets the first preset condition.

[0226] Since the average maximum radius of the second preset number of two-dimensional vascular lumen regions (including the current two-dimensional vascular lumen region) is less than the first preset radius threshold, it indicates that the first endpoint is not located within the first branch vessel 120. Therefore, by determining whether the average maximum radius of the second preset number of two-dimensional vascular lumen regions (including the current two-dimensional vascular lumen region) is less than the first preset radius threshold, it is possible to accurately determine whether the selection position of the first endpoint of the first branch vessel 120 meets the first preset condition.

[0227] In one exemplary embodiment, if the distance between the current center point of the first branch vessel 120 and the current center point of another first branch vessel 120 is less than the first threshold, then before performing step A4, the method further includes:

[0228] If the number of explored center points is greater than a first preset value, the exploration of center points on the center line of the first branch vessel 120 is terminated; otherwise, a prompt message indicating that the center line exploration has failed is sent.

[0229] Specifically, when the selected position of the first endpoint does not meet the preset conditions, the exploration of the centerline of the first branch vessel 120 may stop too early. Therefore, by further determining whether the number of explored center points is greater than the first preset value when the distance between the current center point of the first branch vessel 120 and the current center point of another first branch vessel 120 is less than the first threshold, the problem of the exploration of the centerline of the first branch vessel 120 stopping too early due to the selected position of the first endpoint not meeting the preset conditions can be effectively avoided.

[0230] In one exemplary embodiment, determining the initial center point on the centerline of the first branch vessel 120 based on the acquired first endpoint within the first branch vessel 120 includes:

[0231] Using the first endpoint as the center point of the initial two-dimensional section of interest, and the unit vector parallel to the Z-axis as the normal vector of the initial two-dimensional section of interest, the initial two-dimensional section of interest image is extracted from the medical image to be segmented.

[0232] The initial two-dimensional cross-sectional image of interest is segmented into a vascular region to extract the initial two-dimensional vascular region;

[0233] The initial two-dimensional vascular region is segmented into true and false lumens to separate the initial two-dimensional vascular true lumen region;

[0234] The initial center point of the first branch vessel 120 is obtained based on the center point of the initial two-dimensional vascular lumen region.

[0235] The initial two-dimensional cross-section normal vector of the first branch vessel 120 The coordinates are represented as (0,0,1). For details on how to segment the vascular region in the initial two-dimensional cross-sectional image of interest and how to segment the true and false lumens of the initial two-dimensional vascular region, please refer to the relevant descriptions above. It should be noted that, as those skilled in the art will understand, the upper limit threshold for region growing the initial two-dimensional vascular true lumen region is h0 / λ, and the lower limit threshold is λh0, where h0 is the pixel value of the first endpoint. Further, when the side length of the initial two-dimensional cross-sectional image of interest is r, the radius of the initial circular domain of the second initial seed point used to define the region growing of the initial two-dimensional vascular true lumen region is r / 2.

[0236] In one exemplary embodiment, the step of using a second preset algorithm to explore the center point on the centerline of the main branch vessel 110 until a second termination condition is met includes:

[0237] Step B1: Determine the initial center point on the center line of the main branch vessel 110 based on the second endpoint obtained within the main branch vessel 110, and use the initial center point as the current forward point, and use the unit vector parallel to the Z-axis as the current forward direction vector.

[0238] Step B2: Based on the current forward point and the current forward direction vector, explore the next new center point on the centerline of the main branch vessel 110, and take the explored new center point as the current center point of the main branch vessel 110.

[0239] Step B3: Determine whether the distance between the current center point of the main branch vessel 110 and the first intersection center point is less than the second threshold.

[0240] If yes, proceed to step B4; otherwise, proceed to step B5.

[0241] Step B4: Replace the current center point with the first intersection center point as the termination center point of the main branch vessel 110 and end the exploration of the center point on the center line of the main branch vessel 110.

[0242] Step B5: Take the current center point of the main branch vessel 110 as the current forward point, take the unit vector pointing from the previous center point to the current center point as the current forward direction vector, and return to execute step B2.

[0243] It should be noted that, as those skilled in the art will understand, the purpose of selecting the second endpoint is to initialize and constrain the exploration path of the centerline of the main branch vessel 110. The second endpoint can be selected manually or by a computer according to a pre-set algorithm; this invention does not impose any limitations on this. Furthermore, the location of the second endpoint P1 is preferably close to the main branch vessel 110 (see...). Figure 2 The second endpoint P1 does not need to be close to the center of the main branch vessel 110, as long as it is located within the main branch vessel 110. It should be noted that, as those skilled in the art will understand, the second endpoint P1 can be selected manually or by a computer according to a pre-set algorithm, and the present invention does not impose any limitations on this. Furthermore, when the medical image includes the aorta, the selectable region of the second endpoint P1 includes the ascending aorta, aortic arch, descending aorta, and abdominal aorta of the thoracic aorta segment.

[0244] Furthermore, when the second endpoint P1 is located within a blood vessel extending towards the head (e.g., within the ascending aorta), the unit vector parallel to the Z-axis in step B1 should be a positive unit vector parallel to the Z-axis, meaning the coordinates of the unit vector parallel to the Z-axis in A1 are (0,0,1). When the second endpoint P1 is located within a blood vessel extending towards the foot (e.g., within the descending aorta), the unit vector parallel to the Z-axis in step B1 should be a negative unit vector parallel to the Z-axis, meaning the coordinates of the unit vector parallel to the Z-axis in A1 are (0,0,-1).

[0245] In one exemplary embodiment, the step of exploring the next new center point on the centerline of the main branch vessel 110 based on the current forward point and the current forward direction vector, and using the explored new center point as the current center point of the main branch vessel 110, includes:

[0246] Based on the current forward point and the current forward direction vector, extract the current two-dimensional cross-section image of interest from the medical image;

[0247] The current two-dimensional cross-sectional image of interest is segmented to obtain the current two-dimensional blood vessel region;

[0248] The current two-dimensional blood vessel region is segmented into true and false lumens to segment out the current two-dimensional blood vessel true lumen region;

[0249] The new center point of the main branch vessel 110 is obtained based on the center point of the current two-dimensional vascular lumen region.

[0250] Specifically, after exploring the center point c j-1Then, center point c j-1 As the current point of progress, it will be from the center point c. j-2 Pointing to the center point c j-1 The unit vector is used as the current forward vector. Then, the center point sc of the current two-dimensional cross-section of interest is determined according to formula (7) above. j Then, based on the preset size, the current two-dimensional section of interest image can be extracted from the medical image. It should be noted that, as those skilled in the art will understand, further details regarding how to extract the current two-dimensional section of interest image from the medical image based on the current forward point and the current forward direction vector, how to segment the vascular region of the current two-dimensional section of interest image to segment the current two-dimensional vascular region, and how to segment the true and false lumens of the current two-dimensional vascular region to segment the true lumen region of the current two-dimensional vascular region can be found in the specific content regarding the exploration of the center point of the first branch vessel 120 mentioned above, and will not be repeated here.

[0251] In one exemplary embodiment, if the determination result of step B3 is negative, then before executing step B5, the method further includes:

[0252] Determine whether the exploration direction of the current center point of the main branch vessel 110 has backtracked;

[0253] If so, the search for the center point on the center line of the main branch vessel 110 will be stopped, and a message indicating that the center line search has failed will be sent.

[0254] Furthermore, the following steps can be used to determine whether the exploration direction of the current center point of the main branch vessel 110 has backtracked:

[0255] Determine whether the distance between the current center point and any of the most recently explored center points (of the first preset number) is less than a second preset distance threshold. If yes, backtracking has occurred; otherwise, no backtracking has occurred.

[0256] In one exemplary embodiment, if the exploration direction of the current center point of the main branch vessel 110 has not been backtracked, then before executing step B5, the method further includes:

[0257] Determine whether the selected position of the second endpoint of the main branch vessel 110 meets the second preset condition;

[0258] If not, the search for the center point on the center line of the main branch vessel 110 is stopped, and a prompt message is sent to reselect the second endpoint of the main branch vessel 110.

[0259] Furthermore, the selection position of the second endpoint of the main branch vessel 110 can be determined through the following steps to see if it meets the second preset condition:

[0260] Determine whether the average maximum radius of the second preset number of recently extracted two-dimensional vascular lumen regions (including the current two-dimensional vascular lumen region) is less than the second preset radius threshold. If yes, determine that the selection position of the second endpoint does not meet the second preset condition; otherwise, determine that the selection position of the second endpoint meets the second preset condition.

[0261] In one exemplary embodiment, if the distance between the current center point of the main branch vessel 110 and the first confluence center point is less than the second threshold, then before performing step B4, the method further includes:

[0262] If the number of explored center points is greater than a second preset value, the exploration of center points on the center line of the main branch vessel 110 is terminated; otherwise, a prompt message indicating failure of center line exploration is sent.

[0263] In one exemplary embodiment, determining the initial center point on the centerline of the main branch vessel 110 based on the second endpoint of the main branch vessel 110 includes:

[0264] Using the second endpoint as the center point of the initial two-dimensional section of interest, and the unit vector parallel to the Z-axis as the normal vector of the initial two-dimensional section of interest, the initial two-dimensional section of interest image is extracted from the medical image.

[0265] The initial two-dimensional cross-sectional image of interest is segmented into a vascular region to extract the initial two-dimensional vascular region;

[0266] The initial two-dimensional vascular region is segmented into true and false lumens to separate the initial two-dimensional vascular true lumen region;

[0267] The initial center point of the main branch vessel 110 is obtained based on the center point of the initial two-dimensional true lumen region of the vessel.

[0268] Specifically, when the second endpoint P1 is located within a blood vessel extending towards the head (e.g., within the ascending aorta), the initial two-dimensional cross-sectional normal vector of the main branch vessel 110 is... The coordinates are represented as (0,0,1); when the second endpoint P1 is located in a blood vessel extending towards the foot (e.g., in the descending aorta), the initial two-dimensional cross-section normal vector of the main branch vessel 110 is... The coordinates are represented as (0,0,-1).

[0269] In one exemplary embodiment, the step of using a third preset algorithm to explore the center point on the centerline of the second branch vessel 130 until a third termination condition is met includes:

[0270] Step C1: Determine the initial center point on the center line of the second branch vessel 130 based on the obtained third endpoint within the second branch vessel 130, and use the initial center point as the current forward point, and use the unit vector pointing from the third endpoint to the fourth endpoint corresponding to the second branch vessel 130 as the current forward direction vector, wherein the fourth endpoint is the center point on the center line of the main branch vessel 110 that is closest to the third endpoint of the second branch vessel 130.

[0271] Step C2: Based on the current forward point and the current forward direction vector, explore the next new center point on the center line of the second branch blood vessel 130, and take the explored new center point as the current center point of the second branch blood vessel 130;

[0272] Step C3: Determine whether the minimum distance between the current center point of the second branch vessel 130 and each center point of the main branch vessel 110 is less than a third threshold.

[0273] If yes, proceed to step C4; otherwise, proceed to step C5.

[0274] Step C4: Take the current center point as the termination center point of the second branch vessel 130 and end the exploration of the center point on the center line of the second branch vessel 130;

[0275] Step C5: Take the current center point of the second branch blood vessel 130 as the current forward point, take the unit vector pointing from the previous center point to the current center point as the current forward direction vector, and return to execute step C2.

[0276] For details, please refer to Figure 2 ,like Figure 2 As shown in the figure, points P4, P5, P6, P7, P8, P9, and P... 10This refers to the third endpoint corresponding to each of the second branch vessels 130. It should be noted that, as those skilled in the art will understand, the third endpoint of each second branch vessel 130 can be selected manually or by a computer according to a pre-set algorithm; this invention does not impose any limitations on this. Furthermore, it should be noted that, as those skilled in the art will understand, the purpose of selecting the third endpoint for each second branch vessel 130 is to initialize and constrain the exploration path of the centerline of that second branch vessel 130. The selected position of the third endpoint is preferably close to the end of the second branch vessel 130; the third endpoint does not need to be close to the center of the second branch vessel 130, as long as it is located within the second branch vessel 130.

[0277] It should be noted that, as those skilled in the art will understand, for each second branch vessel 130, by determining the second confluence center point corresponding to that second branch vessel 130, the center point of that second branch vessel 130 can be connected to the center line of the main branch vessel 110 at the second confluence center point corresponding to that second branch vessel 130, thereby allowing for rapid and accurate acquisition of the center line of the entire vascular region. Please continue to refer to... Figure 2 ,like Figure 2 As shown, the second confluence center point corresponding to the second branch vessel 130 where point P4 is located is N2; the second confluence center point corresponding to the second branch vessel 130 where point P5 is located is N3; the second confluence center point corresponding to the second branch vessel 130 where point P6 is located is N4; the second confluence center point corresponding to the second branch vessel 130 where point P7 is located is N5; the second confluence center point corresponding to the second branch vessel 130 where point P8 is located is N6; the second confluence center point corresponding to the second branch vessel 130 where point P9 is located is N7; and point P... 10 The second confluence center point corresponding to the second branch vessel 130 is N8.

[0278] In one exemplary embodiment, the step of exploring the next new center point on the centerline of the second branch vessel 130 based on the current forward point and the current forward direction vector, and using the explored new center point as the current center point of the second branch vessel 130, includes:

[0279] Based on the current forward point and the current forward direction vector, extract the current two-dimensional cross-section image of interest from the medical image to be extracted;

[0280] The current two-dimensional cross-sectional image of interest is segmented to obtain the current two-dimensional blood vessel region;

[0281] The current two-dimensional blood vessel region is segmented into true and false lumens to segment out the current two-dimensional blood vessel true lumen region;

[0282] The new center point of the second branch vessel 130 is obtained based on the center point of the current two-dimensional vascular lumen region.

[0283] Specifically, for more details on how to extract the current two-dimensional cross-section image of interest from the medical image to be extracted based on the current forward point and the current forward direction vector, how to segment the vascular region of the current two-dimensional cross-section image of interest to segment the current two-dimensional vascular region, and how to segment the true and false lumens of the current two-dimensional vascular region to segment the true lumen region of the current two-dimensional vascular region, please refer to the specific content on the exploration of the center point of the first branch vessel 120 above, which will not be repeated here.

[0284] In one exemplary embodiment, if the determination result of step C3 is negative, then before executing step C5, the method further includes:

[0285] Determine whether the exploration direction of the current center point of the second branch vessel 130 has backtracked;

[0286] If so, then stop exploring the center point on the center line of the second branch vessel 130.

[0287] Furthermore, the following steps can be used to determine whether the exploration direction of the current center point of the second branch vessel 130 has backtracked:

[0288] Determine whether the distance between the current center point and any of the most recently explored center points (of the first preset number) is less than a preset distance threshold. If yes, backtracking has occurred; otherwise, no backtracking has occurred.

[0289] In one exemplary embodiment, if the exploration direction of the current center point of the second branch vessel 130 has not been traced back, then before performing step C5, the method further includes:

[0290] Determine whether the selected position of the third endpoint of the second branch vessel 130 meets the third preset condition;

[0291] If not, the search for the center point on the center line of the second branch vessel 130 is stopped, and a prompt message is sent to reselect the third endpoint of the second branch vessel 130.

[0292] Furthermore, the selection position of the third endpoint of the second branch vessel 130 can be determined through the following steps to see if it meets the third preset condition:

[0293] Determine whether the average maximum radius of the second preset number of recently extracted two-dimensional vascular lumen regions (including the current two-dimensional vascular lumen region) is less than a third preset radius threshold. If yes, determine that the selection position of the third endpoint does not meet the third preset condition; otherwise, determine that the selection position of the third endpoint meets the third preset condition.

[0294] In one exemplary embodiment, if the distance between the current center point of the second branch vessel 130 and the first confluence center point is less than the third threshold, then before performing step C4, the method further includes:

[0295] If the number of explored center points is greater than a third preset value, the exploration of center points on the center line of the second branch vessel 130 is terminated; otherwise, a prompt message indicating that the center line exploration has failed is sent.

[0296] In one exemplary embodiment, determining the initial center point on the centerline of the second branch vessel 130 based on the third endpoint of the second branch vessel 130 includes:

[0297] Using the third endpoint as the center point of the initial two-dimensional section of interest, and the unit vector pointing from the third endpoint to the fourth endpoint corresponding to the second branch blood vessel 130 as the normal vector of the initial two-dimensional section of interest, the initial two-dimensional section of interest image is extracted from the medical image to be extracted.

[0298] The initial two-dimensional cross-sectional image of interest is segmented into a vascular region to extract the initial two-dimensional vascular region;

[0299] The initial two-dimensional vascular region is segmented into true and false lumens to separate the initial two-dimensional vascular true lumen region;

[0300] The initial center point of the second branch vessel 130 is obtained based on the center point of the initial two-dimensional vascular lumen region.

[0301] In one exemplary embodiment, the method for applying vascular centerline data further includes:

[0302] The relevant data and index number of each of the central points are stored in the same doubly linked circular queue storage structure.

[0303] Therefore, by using a bidirectional circular queue linked storage structure to store the relevant data of each center point on the blood vessel centerline, not only can the index numbers of the adjacent center points before and after the center point be stored in the node data packet corresponding to each center point, and the nodes are connected end to end for easy index addressing, but also the memory usage can be reduced and the parameter calculation speed can be accelerated.

[0304] Please continue to refer to this. Figure 3 This is a schematic diagram of a bidirectional circular queue linked storage structure provided in one embodiment of the present invention. Figure 3 As shown, the basic information of each segment in the doubly linked circular queue storage structure is as follows, P i The segment represents the central line of the blood vessel, marked by P. i For a main branch vessel 110 or a branch vessel at an endpoint, the nodes on each line segment are {s}. i}(i=1,2,...,n), each node s i The data packet stores relevant data for the corresponding center point and the index numbers of the preceding and following centers. The index numbers of the center points stored within the nodes of each line segment are ordered from smallest to largest. Based on the center point index numbers, all segments are arranged into a queue from smallest to largest. Segment P1 represents the main branch vessel 110, segments P2 and P3 represent branch vessels, and P... x The segment represents the last branch of the blood vessel. The nodes can be traversed based on the front and back index numbers of the corresponding center point stored in the data packet of each node.

[0305] It is particularly important to note that, except for the first and last nodes of the linked list (i.e., the doubly linked circular queue storage structure), the index number of the next center point stored in the last node of each line segment is the index number of the center point corresponding to the first node of the adjacent next line segment, such as... Figure 3 The arrow at the tail node an of segment P1 points to the first node b0 of segment P2; the index of the previous center point stored in the first node of each line segment is the index of its intersection center point with the previous blood vessel, such as... Figure 3 In the P2 and P3 segments, the arrows at the first nodes b0 and c0 both point to the last node an of the P1 segment. x The arrow at the first node z0 of segment P1 points to a node ai in segment P1. If the superior vessel of segment Px is not the main branch vessel 110 but another branch vessel, then it should point to the corresponding position of that other branch vessel. The index of the previous center point stored in the first node of the linked list is the index of the center point corresponding to the tail node of the linked list, and the index of the next center point stored in the tail node of the linked list is the index of the center point corresponding to the first node of the linked list. Figure 3 The double arrow connecting a0 and zn in the diagram.

[0306] Please continue to refer to this. Figure 4 The diagram illustrates the process of determining the center point on the center line segment of interest according to the first embodiment of the present invention. Figure 4 As shown, if the two target center points are located within the same blood vessel, then determining all center points on the line segment of interest with the two target center points as its two endpoints on the blood vessel centerline, based on the index numbers corresponding to the two target center points respectively, includes:

[0307] Take the larger index number of the two target center points as the starting point;

[0308] Starting from the origin, traverse forward the center points of the blood vessel centerline until another target center point is reached;

[0309] All the center points traversed are taken as the center points on the line segment of interest.

[0310] For details, please refer to Figure 5 This diagram schematically illustrates the centerline traversal when two target center points are located within the same blood vessel, according to an embodiment of the present invention. Figure 5 As shown, when the two target center points c i c k When both are on the center line of the main branch vessel 110, due to the target center point c i The index number is greater than the target center point c k The index number is then used to determine the target center point c. i Traverse forward to the target center point c k The end, i.e., the traversal path of the center line is {c i →c k}

[0311] Please continue to refer to this. Figure 6 The diagram illustrates the process of determining the center point on the center line segment of interest according to the second embodiment of the present invention. Figure 6 As shown, if the two target center points are located in different blood vessels, then determining all center points on the line segment of interest with the two target center points as the two endpoints on the blood vessel centerline according to the index numbers corresponding to the two target center points includes:

[0312] Step a1: Take the one with the larger index number of the two target center points as the starting point, and start from the starting point to traverse the center points of the blood vessel center line forward until the intersection center point of the blood vessel where the starting point is located and its superior blood vessel is reached.

[0313] Step b1: Determine whether the index number of the intersection center point is the same as the index number of the other target center point. If the determination result is yes, then execute step c1; if the determination result is no, then execute step d1.

[0314] Step c1: End the traversal and take all the traversed center points as the center points on the line segment of interest.

[0315] Step d1: Take the one with the larger index number between the intersection center point and the other target center point as the new starting point and the other as the ending point. Determine whether the new starting point and the ending point are located in the same blood vessel. If yes, execute step e1; otherwise, execute step f1.

[0316] Step e1: Starting from the new starting point, traverse forward to the center point of the blood vessel centerline until the endpoint is reached, and then return to execute step c1;

[0317] Step f1: Starting from the new starting point, traverse forward to the center point of the blood vessel centerline until the intersection of the blood vessel where the new starting point is located and its superior blood vessel is reached, and then return to execute step d1.

[0318] For details, please refer to Figure 7 This diagram schematically illustrates a centerline traversal diagram when one target center point is located within the main branch vessel 110 and the other target center point is located within a branch vessel, according to an embodiment of the present invention. Figure 7 As shown, the target center point c i Located on the center line of the branch vessel (specifically the first branch vessel 120), at the target center point c k Located on the central line of the main branch vessel 110, due to the target center point c i The index number is greater than the target center point c k The index number, thus from the target center point c i Traverse forward to the junction center point N1 with its superior vessel (i.e., main branch vessel 110); since the junction center point N1 and the target center point c k Located in the same blood vessel, and the index number of the intersection center point N1 is greater than that of the target center point c. k Given the index number, we then traverse forward from the intersection center point N1 to the target center point c. k The end, i.e., the traversal path of the center line is {c i →N1;N1→c k}

[0319] Please continue to refer to this. Figure 8 This schematically illustrates a centerline traversal diagram when two target center points are located within two branch vessels of the same level, according to an embodiment of the present invention. Figure 8 As shown, the target center point c i c k On the center line of the same level branch vessels, but not in the same branch vessel (where the center point is c) i Located on the first branch vessel 120, target center point c k Located on the second branch vessel 130), if the target center point c kThe index number is greater than the target center point c i The index number is then used to determine the target center point c. k Traverse forward to the center point N3 where it intersects with the superior vessel (i.e., the main branch vessel 110); since the target center point c i It is not on the same blood vessel as the intersection center point N3, and the target center point c i The index number is greater than the intersection center point N3, so it starts from the target center point c. i Traverse forward to the confluence center point N1 with the superior vessel (i.e., main branch vessel 110); since confluence center point N1 and confluence center point N3 are located in the same vessel, and the index number of confluence center point N1 is greater than the index number of confluence center point N3, continue traversing forward from confluence center point N1 to confluence center point N3 to end. Therefore, the traversal path of the centerline is {c k →N3;c i →N1;N1→N3}.

[0320] Please continue to refer to this. Figure 9 This illustration shows a schematic diagram of the centerline traversal when two target center points are located within two branch vessels of different orders, according to an embodiment of the present invention. Figure 9 As shown, the target center point c i c k All are on the center line of the branch vessels, and the target center point c k Located on the lower branch vessel (specifically the second branch vessel 130) of the main branch vessel 110, the target center point c i Located on a subordinate branch vessel (specifically, the third branch vessel 140) of a branch vessel (specifically, the first branch vessel 120), due to the target center point c i The index number is greater than the target center point c k The index number, therefore, from the target center point c i Traverse forward to its intersection center point N9 with the superior vessel (i.e., branch vessel P3N1); since the target center point c k The intersection center point N9 is not on the same blood vessel, and the target center point c k The index number of the intersection center point N9 is greater than the index number of the intersection center point N9, so it starts from the target center point c. kTraverse forward to its confluence center point N3 with the superior vessel (i.e., main branch vessel 110); since confluence center point N3 and confluence center point N9 are not on the same vessel, and the index number of confluence center point N9 is greater than the index number of confluence center point N3, traverse forward from confluence center point N9 to its confluence center point N1 with the superior vessel (i.e., main branch vessel 110); since confluence center point N1 and confluence center point N3 are on the same vessel, and the index number of confluence center point N1 is greater than the index number of confluence center point N3, traverse forward from confluence center point N1 to confluence center point N3 to end. Therefore, the traversal path of the centerline is {c i →N9;c k →N3;N9→N1;N1→N3}. It should be noted that, as those skilled in the art will understand, the method for extracting the centerline of the third branch vessel 140 that intersects with the first branch vessel 120 or the second branch vessel 130 can refer to the method for extracting the centerline of the second branch vessel 130 described above. The difference is that, when extracting the centerline of the third branch vessel 140, the unit vector pointing from the fifth endpoint located within the third branch vessel 140 to the sixth endpoint corresponding to the third branch vessel 140 needs to be used as the initial forward direction vector, wherein the sixth endpoint is the center point on the centerline of the first branch vessel 120 or the second branch vessel 130 that intersects with the third branch vessel 140 that is closest to the fifth endpoint within the third branch vessel 140.

[0321] In one exemplary embodiment, the relevant data for the center point includes at least one of the following: the location information of the center point, the maximum diameter and minimum diameter of the cross-section of the blood vessel where the center point is located, the normal vector of the cross-section of the blood vessel where the center point is located, and the set of contour points of the cross-section of the blood vessel where the center point is located. Specifically, for each center point other than the initial center point on the main branch 110, the vector pointing from the previous adjacent center point to that center point can be used as the normal vector of the cross-section of the blood vessel where that center point is located. For the initial center point on the main branch 110, the normal vector of the two-dimensional section of interest corresponding to the initial center point can be used as the normal vector of the cross-section of the blood vessel where that center point is located, and the set of contour points of the two-dimensional true lumen region of the blood vessel where the center point is located can be used as the set of contour points of the cross-section of the blood vessel where the center point is located.

[0322] In one exemplary embodiment, obtaining the vascular parameters of the corresponding vascular segment of interest based on the relevant data of each of the center points on the line segment of interest includes:

[0323] Based on the position information of each center point on the center line segment of interest, the distances between all adjacent two center points on the center line segment of interest are calculated and summed to obtain the center line path length of the blood vessel segment of interest.

[0324] Specifically, the distance ΔL between two adjacent center points in each group can be calculated using the two-point distance formula described above. Finally, the distances between any two adjacent center points in all groups are summed to obtain the distance between any two center points c on the blood vessel centerline. i c k Centerline path length between:

[0325]

[0326] Where {i→k} represents the center point c on the vascular midline. i To the center point c k The traversal path is a set of centerline points arranged in traversal index order, where the index of each centerline point represents the index number of that centerline point on the blood vessel centerline.

[0327] In one exemplary embodiment, obtaining the vascular parameters of the corresponding vascular segment of interest further includes:

[0328] The tortuosity value of the blood vessel segment of interest is obtained by the ratio of the centerline path length of the segment of interest to the distance between the two target center points.

[0329] Specifically, the degree of tortuosity reflects the extent of meandering flow within a fluid conduit; in the human body, the degree of tortuosity in blood vessels represents the extent of meandering blood flow within them. Please refer to [reference needed]. Figure 10 The diagram illustrates, in a schematic representation, the calculation of the tortuosity value provided by one embodiment of the present invention. Figure 10 As shown, two target center points c are known on the central line of the blood vessel. i c k The dashed line represents the traversal path between two points on the centerline of the blood vessel, and the solid double-arrowed line represents the straight line segment path between the two points. The length of the centerline path between the two points (i.e., the length of the centerline path of the blood vessel segment of interest) L, as described above... {i→k} and the straight-line distance between two points l i→k The calculation method is as follows, and the tortuosity value of the vessel segment of interest is calculated according to the following method for calculating the tortuosity τ:

[0330]

[0331] In one exemplary embodiment, obtaining the vascular parameters of the corresponding vascular segment of interest based on the relevant data of each of the center points on the line segment of interest further includes:

[0332] Based on the maximum diameter of the blood vessel cross-section where each center point on the line segment of interest is located, the maximum diameter with the longest length is taken as the maximum maximum diameter of the blood vessel segment of interest, and the maximum diameter with the shortest length is taken as the minimum maximum diameter of the blood vessel segment of interest.

[0333] Specifically, assuming the two selected target center points c i c k The maximum diameter of the vessel cross-section corresponding to all center points on the centerline path (i.e., the centerline segment of the vessel segment of interest, or the centerline segment of interest) is the set {dmax}. j The maximum value of the set |j∈{i→k}} is the target center point c. i To the target center point c k The maximum diameter Dmax of the vessel segment of interest between the two vessels. {i→k} Similarly, the minimum value of the set is the target center point c. i To the target center point c k Minimum and maximum diameter Dmin of the vessel segment of interest {i→k} The specific calculation formula for D is as follows: {i→k} =max{dmax j j∈{i→k}}(18)

[0334] Dmin {i→k} =min{dmax j j∈{i→k}}(19)

[0335] In one exemplary embodiment, the maximum and minimum diameters of the blood vessel cross-section at the center point are calculated using the following steps:

[0336] The cross-section of the blood vessel where the center point is located is mapped onto a two-dimensional plane with Z=0 to obtain the corresponding blood vessel mapping cross-section. Based on the contour points of the blood vessel mapping cross-section and the mapped center point, the maximum and minimum diameters of the blood vessel cross-section where the center point is located are calculated.

[0337] Therefore, this invention effectively reduces the computational load by first mapping the cross-section of the blood vessel where the center point is located onto a two-dimensional plane with Z=0, and then calculating the maximum and minimum diameters of the blood vessel cross-section. Specifically, for each center point, the rotation matrix R corresponding to that center point can be used... x R y and the translation matrix R T Map the cross-section of the blood vessel containing the center point onto a two-dimensional plane with Z=0. How to obtain the rotation matrix R corresponding to this center point is a key question. x Ry and the translation matrix R T Please refer to the relevant descriptions above; they will not be repeated here. Please continue to refer to [the relevant resources / references]. Figure 11 The diagram illustrates a cross-section of a blood vessel provided in a specific example of the present invention. Figure 11 As shown, in this specific example, the center point c j The cross-section of the blood vessel S j The contour points are p1 to p9, where p2 and p6 represent the minimum diameter dmin of the vessel cross-section. j p3p7 is the maximum diameter dmax of the cross-section of the blood vessel. j .

[0338] In one exemplary embodiment, calculating the maximum diameter of the blood vessel cross-section at the center point, based on each contour point of the mapped blood vessel cross-section and the mapped center point, includes:

[0339] A rectangular coordinate system is established with the mapped center point as the origin, and each contour point of the blood vessel mapping section is connected to the center point to form a corresponding line.

[0340] For each contour point of the blood vessel mapping section, calculate the absolute value of the sine of the angle formed by the line connecting the contour point and the mapped center point and the X-axis of the rectangular coordinate system.

[0341] The quadrant with fewer contour points in the first and third quadrants of the rectangular coordinate system is designated as the first target quadrant, and the other is designated as the second target quadrant; the quadrant with fewer contour points in the second and fourth quadrants is designated as the third target quadrant, and the other is designated as the fourth target quadrant.

[0342] For each first contour point in the first target quadrant, the error between the absolute value of the sine corresponding to the first contour point and the absolute value of the sine corresponding to each second contour point in the second target quadrant is calculated, and the line segment formed by the second contour point with the smallest absolute value of the error and the first contour point is taken as one of the diameters of the blood vessel cross section where the center point is located.

[0343] For each third contour point in the third target quadrant, the error between the absolute value of the sine corresponding to the third contour point and the absolute value of the sine corresponding to each fourth contour point in the fourth target quadrant is calculated, and the line segment formed by the fourth contour point with the smallest absolute value of the error and the third contour point is taken as one of the diameters of the blood vessel cross section where the center point is located.

[0344] The diameter with the longest length among all diameters of the blood vessel cross-section where the center point is located is taken as the maximum diameter of the blood vessel cross-section, and the diameter with the shortest length among all diameters of the blood vessel cross-section where the center point is located is taken as the minimum diameter of the blood vessel cross-section.

[0345] For details, please refer to Figures 12 to 14 ,in Figure 12 A schematic diagram illustrating the calculation of the diameter of the blood vessel cross-section in the first and third quadrants according to an embodiment of the present invention is provided. Figure 13 A schematic diagram illustrating the calculation of the diameter of the blood vessel cross-section in the second and fourth quadrants according to an embodiment of the present invention is provided. Figure 14 A schematic diagram illustrating all the diameters of the calculated blood vessel cross-section is provided. For example... Figure 12 As shown, with center point c j Establish a rectangular coordinate system with the origin. Connect each contour point on the blood vessel's cross-section to the origin, and denote the angle formed by the line and the x-axis as θ. Calculate the value of each |sinθ| (the absolute value of the sine). In the first and third quadrants, calculate the error value (difference) of |sinθ| between each contour point in the quadrant with fewer contour points (the first target quadrant) and all contour points in the other quadrant (the second target quadrant). Then, each contour point (the first contour point) in the quadrant with fewer contour points (the first target quadrant) will find the contour point with the smallest absolute value of its |sinθ| error value in the other quadrant (the second target quadrant). Connect this contour point to the first contour point to obtain the diameter of the blood vessel's cross-section. It can be seen that the number of diameters found in the first and third quadrants is the number of contour points (the first contour points) in the quadrant with fewer contour points (the first target quadrant). Figure 13 As shown, since the number of contour points in the fourth quadrant is less than that in the second quadrant, the contour points p5 and p6 in the fourth quadrant (i.e., the third target quadrant) are compared with the contour points p1, p2, and p9 in the second quadrant (i.e., the fourth target quadrant) to calculate the error value of |sinθ|. The point p1 corresponding to p5 and p2 corresponding to p6 when the error is minimized (i.e., the absolute value of the error is minimized) are found. Therefore, p5p1 and p6p2 are the diameters of the blood vessel cross-section. The cross-sectional area S of the blood vessel is then calculated using the above method. j After considering all diameters, the diameter with the longest length is denoted as the maximum diameter dmax of the cross-section. j The smallest diameter among them is denoted as the minimum diameter dmin of the cross section. j .like Figure 14As shown, the diameters of the blood vessel cross-section are p3p7, p4p8, p5p1, and p6p2, respectively. It can be seen that the number of diameters of the blood vessel cross-section is equal to the sum of the number of contour points in the first and third quadrants, and in the second and fourth quadrants (i.e., the sum of the number of contour points in the first and third target quadrants). Furthermore, the maximum diameter dmax of the blood vessel cross-section can be determined. j Equal to p3p7, minimum diameter dmin j It equals p2p6.

[0346] In one exemplary embodiment, the method for applying vascular centerline data further includes:

[0347] Based on the movement vector of one of the moved center points on the blood vessel centerline, the unmoved center points on the blood vessel centerline located within a first circular domain centered on the moved center point and with a first preset radius are moved synchronously in the same direction as the movement direction of the center point, according to the corresponding offset.

[0348] Therefore, by adjusting the position of a center point on the centerline and linking it with the set of center points on the centerlines of blood vessels within a certain range, users can easily and quickly adjust the centerline of the region of interest (i.e., the first circular domain). Please refer to [reference needed]. Figure 15 The diagram schematically illustrates the movement effect of the center line segment of interest on the blood vessel centerline according to an embodiment of the present invention. The upper region of interest includes only the main branch vessels 110, while the lower region of interest includes both a portion of the main branch vessels 110 and a portion of the branch vessels. The dashed line represents the shape before the center line movement, and the solid line represents the shape after the center line movement. This indicates that the center point c has been moved. j The movement vector, Indicates that the center point c has not been moved. t The movement vector, where direction and The directions are the same, and The size is equal to the unmoved center point c t The offset, without moving the center point c t Able to press Move the size and direction to point c t '.

[0349] In one exemplary implementation, the offset of the unmoved center point is calculated according to the following formula:

[0350]

[0351] In the formula, D is the offset of the unmoved center point, D0 is the moving distance of the moved center point; r is the first preset radius; and d is the distance between the unmoved center point and the moved center point.

[0352] As can be seen from the above offset calculation formula, the farther the unmoved center point is from the moved center point, that is, the larger d is, the smaller the offset will be, and the offset of the center point located on the first circular domain contour is 0.

[0353] Specifically, this invention supports both lateral and medial movement of the vascular centerline. Please refer to [reference needed]. Figure 16 The diagram illustrates the effect of blood vessel centerline movement according to an embodiment of the present invention. Figure 16 As shown, since the centerline of a blood vessel usually has a certain curvature tendency, the moved centerline of the blood vessel is generally also a smooth line with a curvature tendency, as shown in figure l. b l c l d In extreme cases, moving the object inward a certain distance or outward an infinite distance can create a straight line segment or a straight line segment with an inflection point, as shown in the figure (l). a l e .

[0354] Because doctors often need to make multiple, segment-by-segment adjustments to the shape of a blood vessel's centerline, and want to ensure that the already adjusted portion of the centerline remains unchanged regardless of subsequent adjustments, this requires ensuring that the shape of the blood vessel's centerline within one of the two or more first circular regions is not affected by movement operations within other first circular regions. Taking two first circular regions as an example, there are three possible scenarios:

[0355] (1) As Figure 15 As shown, when two first circular domains do not intersect, they will not affect each other.

[0356] (2) Please refer to Figure 17 The diagram illustrates the movement effect when two first circular domains intersect, according to an embodiment of the present invention. Figure 17 As shown, when the two first circular domains intersect, it can be seen that the center line within the first circular domain R1 is not affected by the second circular domain R2.

[0357] (3) When one circular domain contains another circular domain, theoretically the center line of the contained circular domain is not affected by the outer circular domain, but this situation is not common in clinical practice.

[0358] In one exemplary embodiment, simulating stent deployment information for a vascular stent entering the segment of interest based on relevant data from each of the center points on the line segment of interest includes:

[0359] Based on the position information of each of the center points on the line segment of interest, the entry path of the vascular stent is simulated;

[0360] Based on the position information of each center point on the entry path of the vascular stent and the normal vector of the cross-section of the blood vessel, the stent deployment cross section corresponding to each center point on the entry path of the vascular stent is simulated.

[0361] Therefore, by simulating the entry path and deployment cross-section of the vascular stent, quantitative simulation values ​​of the vascular stent can be provided, laying a good foundation for doctors and stent suppliers to prepare appropriate stent models and stent parameters for patients in advance.

[0362] In one exemplary embodiment, simulating the entry path of the vascular stent based on the position information of each of the center points on the line segment of interest includes:

[0363] Based on the position information of each center point on the line segment of interest, one of the target center points is taken as the starting point of the path, and the other target center point is taken as the ending point of the path. In accordance with the principle that center points that are adjacent on the blood vessel centerline are also adjacent on the entry path of the blood vessel stent, all the center points on the line segment of interest are rearranged to simulate the entry path of the blood vessel stent.

[0364] Specifically, suppose we are interested in the center line segment c. a c b (where point c) a The target center point corresponding to the initial coarse selection point chosen by the user, point c b The centerline traversal path for the target center point (corresponding to the user-selected termination coarse selection point) is {a→b}. The center points within {a→b} are then traversed according to the target center point c. a Let c be the starting point of the path and the center point of the destination. b As the endpoint of the path, the center points adjacent to each other on the actual blood vessel centerline are rearranged according to a rule that also makes them adjacent on the stent entry path, thus obtaining the stent entry path {c}. a →c b}

[0365] In one exemplary embodiment, simulating the stent deployment cross-section corresponding to each center point on the stent's entry path based on the position information of each center point on the stent's entry path and the normal vector of the cross-section of the blood vessel where the stent is located includes:

[0366] Step a2: For each center point on the entry path of the vascular stent, calculate the stent cross-sectional radius corresponding to the center point according to the second preset rule;

[0367] Step b2: Using the radius of the stent cross-section corresponding to the starting point of the path as the radius, the normal vector of the blood vessel cross-section where the starting point of the path is located as the normal vector, and the location of the starting point of the path as the center, simulate the unfolded cross-section of the stent corresponding to the starting point of the path;

[0368] Step c2: Divide the support unfolded section corresponding to the path starting point into N equal parts according to a preset angle to obtain N support outline points, and take the path starting point as the current path point and the support unfolded section corresponding to the path starting point as the current support section.

[0369] Step c2: Based on the position information of the N stent contour points of the current stent cross section, the normal vector of the current stent cross section, the position information of the neighboring center points adjacent to the current path point, the normal vector of the blood vessel cross section where the neighboring center points are located, and the stent cross section radius corresponding to the neighboring center points, determine N new stent contour points that correspond one-to-one with the N stent contour points, thereby simulating the stent deployment cross section corresponding to the neighboring center points.

[0370] Step d2: Take the neighboring center point as the new current path point, take the support unfolded section corresponding to the neighboring center point as the new current support section, and return to execute step c2 until the support unfolded section corresponding to the path endpoint is simulated.

[0371] For details, please refer to Figure 18 The diagram illustrates a schematic representation of the bracket contour points provided by an embodiment of the present invention. Figure 18 As shown, each support's unfolded cross-section is divided into N parts at equal angles θ, resulting in N support contour points, where the center point c... j The corresponding support unfolded cross section (radius r) j The bracket profile point set is represented by {q}. j,i The number} (i = 1, 2, ..., N) represents the points along the support profile. If the 'i' in the names of the points are the same across different cross-sections of the support, it indicates that the angles are the same and that they are corresponding points.

[0372] In one exemplary embodiment, obtaining the radius of the support cross-section corresponding to the center point according to a second preset rule includes:

[0373] The radius of the stent cross-section corresponding to the center point is half the maximum diameter of the blood vessel cross-section where the path originates; and / or

[0374] Calculate the radius of the support section corresponding to the center point using the following formula:

[0375]

[0376] In the formula, r j r is the radius of the support cross-section corresponding to the center point. a The starting point c of the path a half the maximum diameter of the cross-section of the blood vessel, r b The endpoint c of the path b Half the maximum diameter of the cross-section of the blood vessel, n j n is the sequence number of the center point along the entry path of the vascular stent. b The endpoint c of the path b The sequence number along the entry path of the vascular stent, wherein the starting point c of the path a The sequence number on the entry path of the vascular stent is 0.

[0377] Therefore, when the radius of the stent deployment cross-section corresponding to each center point on the path for the stent to be inserted is the same, the starting point c of the path can be... a Half the maximum diameter of the blood vessel's cross-section is used as the radius of the stent's deployed cross-section (i.e., the stent cross-sectional radius) corresponding to each center point along the entry path. When it is necessary to set the stent cross-sectional radius to change linearly at each center point along the stent's entry path, the stent cross-sectional radius corresponding to each center point along the entry path can be calculated using the stent cross-sectional radius calculation formula mentioned above. Please refer to... Figure 19 and Figure 20 ,in Figure 19 The present invention schematically illustrates a simulated vascular stent deployment cross-section when the radius of the vascular stent deployment cross-section corresponding to each center point on the entry path is the same. Figure 20 The present invention schematically illustrates a specific example of the present invention, which shows the simulated stent deployment cross-section of a vascular stent when the radius of the stent deployment cross-section corresponding to each center point on the entry path changes linearly. The circles in the figure represent the simulated stent deployment cross-section of the vascular stent.

[0378] In one exemplary embodiment, determining N new stent contour points corresponding one-to-one with the N stent contour points based on the position information of the N stent contour points of the current stent cross-section, the normal vector of the current stent cross-section, the position information of the neighboring center points adjacent to the current center point, the normal vector of the blood vessel cross-section where the neighboring center points are located, and the stent cross-section radius corresponding to the neighboring center points includes:

[0379] Using the location of the neighboring center point as the center of the two-dimensional cross section and the normal vector of the blood vessel cross section where the neighboring center point is located as the normal vector of the two-dimensional cross section, the two-dimensional cross section corresponding to the neighboring center point is simulated.

[0380] For each support profile point of the current support cross section, based on the position information of the support profile point, a point is determined on the two-dimensional cross section that is parallel to the normal vector of the two-dimensional cross section by the straight line formed by the support profile point. The position of the target point is then corrected based on the support cross section radius corresponding to the adjacent center point, and the corrected target point is taken as the corresponding new support profile point.

[0381] For details, please refer to Figure 21 This illustration shows a schematic diagram of simulating the unfolded cross section of the next support based on the current support cross section, according to an embodiment of the present invention. Figure 21 As shown, for the center point c j any support profile point q corresponding to the current support cross section j,i Then at the center point c j+1 Find the corresponding target point O on the corresponding two-dimensional cross section. j+1,i The core idea of ​​the location is: to find the point that is both at point q and in the middle. j,i And with On a parallel straight line, and at point c j+1 The corresponding point on the two-dimensional cross-section is the support profile point q. j,i The corresponding target point O j+1,i Assumption: Support profile point q j,i The coordinates are (x0, y0, z0), and the center point is c. j+1 The coordinates are (X0, Y0, Z0). The coordinates are represented as (A, B, C).

[0382] Then passing through point q j,i Target point O j+1,i The point-normal form of the straight line is:

[0383]

[0384] center point c j+1 The corresponding point-normal equation for the two-dimensional section is:

[0385] A(x-x0)+B(y-y0)+C(z-z0)=0(23)

[0386] Suppose there exists a value t such that the solution (x, y, z) that holds true is the target point O we are looking for. j+1,i Coordinates:

[0387]

[0388] We can solve for:

[0389]

[0390] It is known that this solution also satisfies the condition of center point c. j+1 Substituting the corresponding point-normal equation of the two-dimensional section, we get:

[0391] A(x0+At-X0)+B(y0+Bt-Y0)+C(z0+Ct-Z0)=0(26)

[0392] Solving for:

[0393]

[0394] Substituting t back into the solution containing the variable t, we obtain the final solution (x, y, z), which is the support profile point q of the current support section. j,i The corresponding target point O j+1,i The location coordinates of the target point O. j+1,i After determining the position coordinates, based on the center point c j+1 The corresponding support cross-sectional radius r j+1 For the target point O j+1,i The position is corrected to obtain the corresponding correction point q. j+1,i Correction point q j+1,i That is, the support profile point q relative to the current support cross-section. j,i The corresponding support contour point on the next support unfolded cross section. Specifically, such as... Figure 21 As shown, the correction point q j+1,i The position coordinates must simultaneously satisfy the following conditions: and direction and They are in the same direction.

[0395] Using the same method, the support profile point q on the current support cross-section can be calculated. j,k The corresponding support profile point q on the next support unfolded section j+1,kAnd the support contour points on the next support unfolded cross section corresponding to other support contour points on the current support cross section. It should be noted that, as those skilled in the art will understand, by performing the above operation on each of the center points on the entry path, the support unfolded cross section corresponding to each of the center points on the entry path can be simulated.

[0396] In one exemplary embodiment, the stent deployment information simulating the vascular stent entering the segment of interest further includes:

[0397] Based on the stent deployment cross-section corresponding to each center point on the stent's entry path, the stent's inner and outer bending paths during deployment are simulated.

[0398] Therefore, by simulating the inward and outward bending paths of the stent during its deployment, doctors can be quantitatively informed of the approximate length of the stent, thus helping them prepare a stent of appropriate length before surgery.

[0399] In one exemplary embodiment, simulating the inner and outer curvature paths of the vascular stent during deployment, based on the stent deployment cross-sections corresponding to each of the center points along the path, includes:

[0400] The corresponding stent outline points on the stent unfolding cross section corresponding to each center point on the entry path of the vascular stent are sequentially connected to obtain N stent outline paths.

[0401] The longest support contour path among the N support contour paths is taken as the outer bending side path of the support, and the shortest support contour path is taken as the inner bending side path of the support.

[0402] Specifically, after finding the entry path {c a →c b The coordinates of N sets of corresponding stent contour points on the unfolded cross-sectional contour of all stents are obtained. By connecting the corresponding stent contour points of each set sequentially, all paths on the vascular stent contour can be obtained, numbering N. The stent contour path with the shortest length is determined as the inner curvature path of the stent, and the stent contour path with the longest length is determined as the outer curvature path of the stent. Figure 19 and Figure 20 As shown in the figure, curve R i For the inner curved side path of the support, R o This is the path on the outer curved side of the support.

[0403] In one exemplary embodiment, the method for applying vascular centerline data further includes:

[0404] For each branch vessel that intersects with the main branch vessel 110, the projection angle of the branch vessel is calculated based on the normal vector of the cross-section of the vessel at the starting center point of the branch vessel and the normal vector of the cross-section of the vessel at the intersection center point of the branch vessel and the main branch vessel 110.

[0405] Specifically, the vascular projection angle refers to the set of angles at which X-ray imaging equipment used for real-time observation of the human body during minimally invasive vascular stent surgery observes specific locations of blood vessels when the equipment is rotated to a specific anatomical angle of interest to the surgeon. X-ray imaging equipment includes, but is not limited to, C-arm X-ray machines. A specific location refers to any branch vessel connected to the main branch vessel 110. A specific angle refers to the maximum expanded shape of the branch vessel observed by the X-ray imaging equipment at that specific location. Please refer to [reference needed]. Figure 22 The diagram illustrates the maximum expansion morphology of a branch vessel inlet under a vascular imaging angle according to an embodiment of the present invention. Figure 22 As shown, when a branch vessel expands to its maximum extent, the opening area of ​​the branch vessel inlet section is at its largest on the X-ray imaging equipment. When the opening area of ​​the vessel inlet section reaches its maximum, this cross-section appears as a line segment on the image. The clinical significance of the vascular projection angle is to observe the morphology of the branch vessels when the lower-level branches of the main branch 110 are in their maximum opening state on X-ray images. This helps doctors determine whether the blood flow to the branch vessels is affected due to improper placement of the deployed vascular stent, thus avoiding serious consequences such as insufficient blood supply or even critical illness in the patient after surgery.

[0406] Because branch vessels exhibit their maximum expansion shape under the vascular projection angle, the cross-sectional image at this angle is geometrically perpendicular to both the cross-section of the vessel at the origin center point of the branch vessel and the cross-section at the intersection center point of the branch vessel and the main branch vessel 110. Therefore, the normal vector of the plane containing the vascular projection angle... Simultaneously, the normal vector perpendicular to the cross-section of the vessel at the origin center point of the branch vessel. And the normal vector of the cross-section of the vessel at the center point of the intersection of the branch vessel and the main branch vessel 110. Assumption Let (x1, y1, z1) be the integers. For (x) node ,y node ,z node Then we can obtain the following formula:

[0407]

[0408]

[0409] For ease of calculation, the input... The formula for normalization is as follows:

[0410]

[0411] It should be noted that if Parallel to Then determine whether the normal vector of the blood vessel cross-section located at the previous center point before the intersection center point is equal to the index number. If the lines are still parallel, continue iterating forward until a center point is found whose normal vector at the cross-section of the blood vessel is not parallel to the center point. Parallelism is not possible because the shape of blood vessels in human anatomy is curved, and it is impossible for the cross-section of all main branches to be parallel to the starting cross-section of the branch. Therefore, there is no dead loop.

[0412] Because there are two observation angles in opposite directions on the plane where the vascular projection angle is located, that is, normal vectors in opposite directions, there are two normal vector results. Considering the limitations of the equipment structure of some medical devices, after calculating the two sets of equipment rotation angles for vascular projection angles, the rotation direction with the smaller sum of rotation angles in the angle set will be selected first for rotation, or the equipment will be rotated according to the rotation angle set selected by the user.

[0413] Furthermore, the angle set for vascular projection includes: first rotating by an angle α around the X-axis, and then rotating by an angle β around the Y-axis. Specifically, the vascular projection angles α and β can be calculated using the following formulas:

[0414]

[0415]

[0416] Based on the same inventive concept, the present invention also provides an electronic device, please refer to... Figure 23 A block diagram illustrating an embodiment of the electronic device provided by the present invention is shown. Figure 23 As shown, the electronic device includes a processor 210 and a memory 230. The memory 230 stores a computer program. When the computer program is executed by the processor 210, it implements the vascular centerline data application method described above. Since the electronic device provided by this invention and the vascular centerline data application method provided by this invention belong to the same inventive concept, the electronic device provided by this invention has all the advantages of the vascular centerline data application method provided by this invention. Therefore, the beneficial effects of the electronic device provided by this invention will not be elaborated further here.

[0417] like Figure 23As shown, the electronic device also includes a communication interface 220 and a communication bus 240, wherein the processor 210, the communication interface 220, and the memory 230 communicate with each other via the communication bus 240. The communication bus 240 can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus 240 can be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is used in the figure, but this does not indicate that there is only one bus or one type of bus. The communication interface 220 is used for communication between the aforementioned electronic device and other devices.

[0418] The processor 210 referred to in this invention can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor. The processor 210 is the control center of the electronic device, connecting various parts of the entire electronic device through various interfaces and lines.

[0419] The memory 230 can be used to store the computer program. The processor 210 implements various functions of the electronic device by running or executing the computer program stored in the memory 230 and calling the data stored in the memory 230.

[0420] The memory 230 may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0421] This invention also provides a readable storage medium storing a computer program, which, when executed by a processor, can implement the aforementioned method for applying vascular centerline data. Since the readable storage medium provided by this invention and the method for applying vascular centerline data provided by this invention belong to the same inventive concept, the readable storage medium provided by this invention possesses all the advantages of the method for applying vascular centerline data provided by this invention. Therefore, the beneficial effects of the readable storage medium provided by this invention will not be elaborated upon here.

[0422] The readable storage medium of embodiments of the present invention can be any combination of one or more computer-readable media. The readable medium can be a computer-readable signal medium or a computer-readable storage medium. Computer-readable storage media can be, for example, but not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: electrical connections having one or more wires, portable computer hard disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, apparatus, or device.

[0423] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of transmitting, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wireline, optical fiber, RF, etc., or any suitable combination thereof.

[0424] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as "C" or similar languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0425] It should be noted that the apparatus and methods disclosed in the embodiments herein can also be implemented in other ways. The apparatus embodiments described above are merely illustrative; for example, the flowcharts and block diagrams in the accompanying drawings show the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments herein. In this regard, each block in a flowchart or block diagram may represent a module, program, or part of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system to perform the specified function or action, or can be implemented using a combination of dedicated hardware and computer instructions.

[0426] In addition, the functional modules in the various embodiments of this article can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0427] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure are within the protection scope of the present invention. Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the present invention and its equivalents, the present invention also intends to include these modifications and variations.

Claims

1. A method for applying vascular centerline data, characterized in that, include: A preset algorithm is used to explore the center point of the vascular centerline in the acquired medical image to extract the corresponding vascular centerline. An index number is assigned to each of the center points on the central line of the blood vessel according to the first preset rule; Based on the obtained position information of two coarsely selected points on the medical image, two target center points are determined on the blood vessel centerline; Based on the index numbers corresponding to the two target center points, all center points on the line segment of interest with the two target center points as the two endpoints are determined on the blood vessel center line. Based on the relevant data of each center point on the line segment of interest, the vascular parameters of the corresponding blood vessel segment of interest and the stent deployment information of the vascular stent entering the blood vessel segment of interest are obtained. The relevant data for the center point includes the location information of the center point and the normal vector of the cross-section of the blood vessel where the center point is located; The step of simulating stent deployment information for a vascular stent entering the segment of interest based on relevant data of each of the center points on the line segment of interest includes: Based on the position information of each center point on the line segment of interest, one of the target center points is taken as the starting point of the path, and the other target center point is taken as the ending point of the path. In accordance with the principle that center points that are adjacent on the blood vessel center line are also adjacent on the entry path of the blood vessel stent, all the center points on the line segment of interest are rearranged to simulate the entry path of the blood vessel stent. Based on the position information of each center point on the entry path of the vascular stent and the normal vector of the cross-section of the blood vessel, the unfolded cross section of the stent corresponding to each center point on the entry path of the vascular stent is simulated. The step of simulating the unfolded cross section of the stent corresponding to each center point on the stent's entry path, based on the position information of each center point on the stent's entry path and the normal vector of the corresponding cross section of the blood vessel, includes: Step a2: For each center point on the entry path of the vascular stent, calculate the stent cross-sectional radius corresponding to the center point according to the second preset rule; Step b2: Using the radius of the stent cross-section corresponding to the starting point of the path as the radius, the normal vector of the blood vessel cross-section where the starting point of the path is located as the normal vector, and the location of the starting point of the path as the center, simulate the unfolded cross-section of the stent corresponding to the starting point of the path; Step c2: Divide the support unfolded section corresponding to the path starting point into N equal parts according to a preset angle to obtain N support outline points, and take the path starting point as the current path point and the support unfolded section corresponding to the path starting point as the current support section. Step c2: Based on the position information of the N stent contour points of the current stent cross section, the normal vector of the current stent cross section, the position information of the neighboring center points adjacent to the current path point, the normal vector of the blood vessel cross section where the neighboring center points are located, and the stent cross section radius corresponding to the neighboring center points, determine N new stent contour points that correspond one-to-one with the N stent contour points, thereby simulating the stent deployment cross section corresponding to the neighboring center points. Step d2: Take the neighboring center point as the new current path point, take the support unfolded section corresponding to the neighboring center point as the new current support section, and return to execute step c2 until the support unfolded section corresponding to the path endpoint is simulated.

2. The method for applying vascular centerline data according to claim 1, characterized in that, The step of determining two target center points on the blood vessel centerline based on the acquired position information of two coarsely selected points on the medical image includes: For each coarse selection point, the distance between each center point on the blood vessel centerline and the coarse selection point is calculated, and the center point with the smallest distance from the coarse selection point is taken as the target center point corresponding to the coarse selection point.

3. The method for applying vascular centerline data according to claim 1, characterized in that, The step of setting an index number for each center point on the central line of the blood vessel according to a first preset rule includes: An index number is assigned to each center point on the center line of the blood vessel according to the rule that the index number of the center point of the lower-level blood vessel is greater than the index number of the center point of the upper-level blood vessel, and that the index number of each blood vessel gradually increases along its extension direction.

4. The method for applying vascular centerline data according to claim 3, characterized in that, If the two target center points are located within the same blood vessel, then, based on the index numbers corresponding to the two target center points, determining all center points on the line segment of interest with the two target center points as its two endpoints along the blood vessel centerline includes: Take the larger index number of the two target center points as the starting point; Starting from the origin, traverse forward the center points of the blood vessel centerline until another target center point is reached; All the center points traversed are taken as the center points on the line segment of interest.

5. The method for applying vascular centerline data according to claim 3, characterized in that, If the two target center points are located in different blood vessels, then, based on the index numbers corresponding to the two target center points, determining all center points on the line segment of interest with the two target center points as the two endpoints on the blood vessel centerline includes: Step a1: Take the one with the larger index number of the two target center points as the starting point, and start from the starting point to traverse the center points of the blood vessel center line forward until the intersection center point of the blood vessel where the starting point is located and its superior blood vessel is reached. Step b1: Determine whether the index number of the intersection center point is the same as the index number of the other target center point. If the determination result is yes, then execute step c1; if the determination result is no, then execute step d1. Step c1: End the traversal and take all the traversed center points as the center points on the line segment of interest. Step d1: Take the one with the larger index number between the intersection center point and the other target center point as the new starting point and the other as the ending point. Determine whether the new starting point and the ending point are located in the same blood vessel. If yes, execute step e1; otherwise, execute step f1. Step e1: Starting from the new starting point, traverse forward to the center point of the blood vessel centerline until the endpoint is reached, and then return to execute step c1; Step f1: Starting from the new starting point, traverse forward to the center point of the blood vessel centerline until the intersection of the blood vessel where the new starting point is located and its superior blood vessel is reached, and then return to execute step d1.

6. The method for applying vascular centerline data according to claim 1, characterized in that, The step of obtaining the vascular parameters of the corresponding vascular segment of interest based on the relevant data of each of the center points on the line segment of interest includes: Based on the position information of each center point on the center line segment of interest, the distances between all adjacent two center points on the center line segment of interest are calculated and summed to obtain the center line path length of the blood vessel segment of interest.

7. The method for applying vascular centerline data according to claim 6, characterized in that, The step of obtaining the vascular parameters of the corresponding vascular segment of interest also includes: The tortuosity value of the blood vessel segment of interest is obtained by the ratio of the centerline path length of the segment of interest to the distance between the two target center points.

8. The method for applying vascular centerline data according to claim 1, characterized in that, The relevant data for the center point also includes the maximum diameter of the cross-section of the blood vessel where the center point is located. The step of obtaining the vascular parameters of the corresponding vascular segment of interest based on the relevant data of each of the center points on the line segment of interest further includes: Based on the maximum diameter of the blood vessel cross-section where each center point on the line segment of interest is located, the maximum diameter with the longest length is taken as the maximum maximum diameter of the blood vessel segment of interest, and the maximum diameter with the shortest length is taken as the minimum maximum diameter of the blood vessel segment of interest.

9. The method for applying vascular centerline data according to claim 8, characterized in that, The maximum diameter of the blood vessel cross-section at the center point is calculated using the following steps: The cross-section of the blood vessel where the center point is located is mapped onto a two-dimensional plane with Z=0 to obtain the corresponding blood vessel mapping cross-section. Based on the contour points of the blood vessel mapping cross-section and the mapped center point, the maximum diameter of the blood vessel cross-section where the center point is located is calculated.

10. The method for applying vascular centerline data according to claim 9, characterized in that, The step of calculating the maximum diameter of the blood vessel cross-section at the center point, based on each contour point of the mapped blood vessel cross-section and the mapped center point, includes: A rectangular coordinate system is established with the mapped center point as the origin, and each contour point of the blood vessel mapping section is connected to the center point to form a corresponding line. For each contour point of the blood vessel mapping section, calculate the absolute value of the sine of the angle formed by the line connecting the contour point and the mapped center point and the X-axis of the rectangular coordinate system. The quadrant with fewer contour points in the first and third quadrants of the rectangular coordinate system is designated as the first target quadrant, and the other is designated as the second target quadrant; the quadrant with fewer contour points in the second and fourth quadrants is designated as the third target quadrant, and the other is designated as the fourth target quadrant. For each first contour point in the first target quadrant, the error between the absolute value of the sine corresponding to the first contour point and the absolute value of the sine corresponding to each second contour point in the second target quadrant is calculated, and the line segment formed by the second contour point with the smallest absolute value of the error and the first contour point is taken as one of the diameters of the blood vessel cross section where the center point is located. For each third contour point in the third target quadrant, the error between the absolute value of the sine corresponding to the third contour point and the absolute value of the sine corresponding to each fourth contour point in the fourth target quadrant is calculated, and the line segment formed by the fourth contour point with the smallest absolute value of the error and the third contour point is taken as one of the diameters of the blood vessel cross section where the center point is located. The diameter with the longest length among all diameters of the blood vessel cross-section where the center point is located is taken as the maximum diameter of the blood vessel cross-section.

11. The method for applying vascular centerline data according to claim 1, characterized in that, The step of calculating the radius of the support cross-section corresponding to the center point according to the second preset rule includes: Use half the maximum diameter of the cross-section of the blood vessel where the path originates as the radius of the stent cross-section corresponding to that center point; and / or Calculate the radius of the support section corresponding to the center point using the following formula: In the formula, r j r is the radius of the support cross-section corresponding to the center point. a r is half the maximum diameter of the cross-section of the blood vessel where the path originates. b n is half the maximum diameter of the cross-section of the blood vessel where the path ends. j n is the sequence number of the center point along the entry path of the vascular stent. b The path endpoint is the sequence number of the entry path of the vascular stent, wherein the path start point is the sequence number of 0 in the entry path of the vascular stent.

12. The method for applying vascular centerline data according to claim 1, characterized in that, The step of determining N new stent contour points corresponding one-to-one with the N stent contour points based on the position information of the N stent contour points of the current stent cross section, the normal vector of the current stent cross section, the position information of the neighboring center points adjacent to the current path point, the normal vector of the blood vessel cross section where the neighboring center points are located, and the stent cross section radius corresponding to the neighboring center points includes: Using the location of the neighboring center point as the center of the two-dimensional cross section and the normal vector of the blood vessel cross section where the neighboring center point is located as the normal vector of the two-dimensional cross section, the two-dimensional cross section corresponding to the neighboring center point is simulated. For each support profile point of the current support cross section, based on the position information of the support profile point, a point is determined on the two-dimensional cross section that is parallel to the normal vector of the two-dimensional cross section by the straight line formed by the support profile point. The position of the target point is then corrected based on the support cross section radius corresponding to the adjacent center point, and the corrected target point is taken as the corresponding new support profile point.

13. The method for applying vascular centerline data according to claim 1, characterized in that, The stent deployment information simulated for entering the segment of interest also includes: Based on the stent deployment cross-section corresponding to each center point on the stent's entry path, the stent's inner and outer bending paths during deployment are simulated.

14. The method for applying vascular centerline data according to claim 13, characterized in that, The step of simulating the inward and outward bending paths of the stent during deployment, based on the stent deployment cross-sections corresponding to each center point along the stent's entry path, includes: The corresponding stent outline points on the stent unfolding cross section corresponding to each center point on the entry path of the vascular stent are sequentially connected to obtain N stent outline paths. The longest support contour path among the N support contour paths is taken as the outer bending side path of the support, and the shortest support contour path is taken as the inner bending side path of the support.

15. The method for applying vascular centerline data according to claim 1, characterized in that, The method for applying the vascular centerline data also includes: Based on the movement vector of one of the moved center points on the blood vessel centerline, the unmoved center points on the blood vessel centerline located within a first circular domain centered on the moved center point and with a first preset radius are moved synchronously in the same direction as the movement direction of the center point, according to the corresponding offset.

16. The method for applying vascular centerline data according to claim 15, characterized in that, Calculate the offset of the unmoved center point using the following formula: In the formula, D is the offset of the unmoved center point, D0 is the moving distance of the moved center point; r is the first preset radius; and d is the distance between the unmoved center point and the moved center point.

17. The method for applying vascular centerline data according to claim 1, characterized in that, The vascular region includes the main branch vessels and multiple branch vessels that intersect with the main branch vessels; The method for applying the vascular centerline data also includes: For each branch vessel that intersects with the main branch vessel, the projection angle of the branch vessel is calculated based on the normal vector of the cross-section of the vessel at the starting center point of the branch vessel and the normal vector of the cross-section of the vessel at the intersection center point of the branch vessel and the main branch vessel.

18. An electronic device, characterized in that, It includes a processor and a memory, wherein the memory stores a computer program, which, when executed by the processor, implements the method for applying vascular centerline data as described in any one of claims 1 to 17.

19. A readable storage medium, characterized in that, The readable storage medium stores a computer program, which, when executed by a processor, implements the method for applying vascular centerline data as described in any one of claims 1 to 17.

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