Vessel centerline extraction method, electronic device, and storage medium

Abstract

The application provides a blood vessel center line extraction method, an electronic device and a storage medium. The method comprises the following steps: acquiring a medical image to be extracted, which comprises a main branch blood vessel and a first branch blood vessel; exploring center points on center lines of the two first branch blood vessels according to two first end points synchronously until the distance between the latest explored center points of the two first branch blood vessels is less than a first threshold value; determining a first intersection point according to the latest explored center points of the two first branch blood vessels; exploring a center point on the center line of the main branch blood vessel according to a second end point until the distance between the latest explored center point of the main branch blood vessel and the first intersection point is less than a second threshold value; and extracting a blood vessel center line according to all the center points of the first branch blood vessels and all the center points of the main branch blood vessel. The application effectively avoids the problems of slow speed and high memory occupation caused by the prior art of first segmenting a large range of three-dimensional blood vessels and then extracting a blood vessel center line.

Description

Technical Field

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

[0002] The aorta is the largest and thickest artery in the human systemic circulation. It originates from the left ventricle of the heart, passing through the ascending aorta, aortic arch, and descending aorta in the chest, forming the thoracic aorta. The thoracic aorta descends to the abdominal aorta, where it branches into the celiac trunk, superior mesenteric artery, and left and right renal arteries. The abdominal aorta then descends to the left and right common iliac arteries, branching into the internal and external iliac arteries. The external iliac artery descends in sequence to the femoral artery, popliteal artery, anterior tibial artery, and posterior tibial artery. The aortic arch ascends to the left subclavian artery, left common carotid artery, and brachiocephalic trunk. Finally, the larger arteries of the aorta deliver blood to the smaller arteries throughout the body.

[0003] Common aortic diseases include aortic dissection and aortic aneurysm. The causes and structural characteristics of the aorta differ between the two. Aortic dissection occurs when blood flows from the tear in the aortic intima into the aortic media, causing blood to accumulate in the aortic media. Due to blood flow direction and gravity, this blood extends towards the descending aorta, creating a separation between the true and false lumens of the aorta. An aortic aneurysm is defined as a pathological dilation of the aorta exceeding 50% of its normal diameter; the most common pathological dilation is atherosclerosis. Surgeons aim to simulate aortic diseases to identify the optimal surgical approach, reduce surgical risks, and increase the success rate. To achieve this, computers need to provide surgeons with quantitative aortic bioparameters, including but not limited to the aortic cross-sectional area, perimeter, and maximum and minimum diameters. Quantitative bioparameter information for the aortic cross-section relies on the extracted aortic centerline.

[0004] Traditional methods for extracting vascular centerlines involve manually segmenting the blood vessels, using computer-aided algorithms for automatic segmentation, or a combination of manual and computer-aided segmentation. Based on the segmentation model, centerline extraction is performed. Traditional machine learning algorithms for centerline extraction include object thinning / skeletonization algorithms, shortest path algorithms, and rolling ball algorithms. In recent years, with the rapid development of deep learning, a class of deep learning algorithms based on vascular topology has emerged to calculate centerlines. These machine learning and deep learning-based centerline extraction methods show good performance in terms of accuracy, algorithm performance (computation speed, memory usage), and data generalization ability within localized vascular regions such as intracranial arteries, carotid arteries, and coronary arteries. However, the extraction results are less satisfactory in large-scale vascular regions.

[0005] In particular, existing vascular centerline extraction algorithms are unsatisfactory when extracting the aortic centerline. The main reasons include: the user's selection of the start and end points of the segment of interest deviates from the vessel center, causing the calculated centerline to deviate from the vessel center at the beginning and end. Furthermore, aortic dissection often occurs at single or multiple intimal tears, and intimal tears at the same location can present as double, triple, or even multiple lobes. The false lumen of the aorta can severely compress the true lumen, resulting in extreme narrowing of the true lumen in 3D imaging space. Single / multiple tears, double / multiple lobed tears, and extreme narrowing of the true lumen all contribute to the instability of the extracted aortic centerline in dissection algorithms, including large changes in the centerline across segments, the centerline entering the false lumen and then jumping back to the true lumen, and the centerline failing to jump back to the true lumen after entering the false lumen, leading to calculation failures.

[0006] Furthermore, existing vascular centerline extraction algorithms lack generalization ability for aortic disease data. The morphologies of aortic dissection and aortic aneurysm differ; dissection is characterized by a false lumen compressing the true lumen, while aneurysm is characterized by its excessive size in a localized area of ​​the aorta. Centerline algorithms suitable for aortic dissection data often suffer from poor speed and accuracy in calculating centerlines for aortic aneurysms. Moreover, even for the same disease, such as aortic aneurysm, the speed and accuracy of centerline calculation are unstable due to significant variations in aneurysm volume. While deep learning-based centerline calculation algorithms improve the success rate of vascular centerline calculation, they cannot directly guarantee the accuracy of the results. Currently, centerlines calculated directly through deep learning still require a series of post-processing steps to reduce redundant and erroneous centerline segments, achieving a fine-tuning effect. This fine-tuning operation not only tests the data generalization ability of the post-processing algorithm used but also exhibits unstable results as the data changes.

[0007] 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

[0008] The purpose of this invention is to provide a method, electronic device, and storage medium for extracting the centerline of blood vessels, which can achieve rapid and convenient extraction of the centerline of blood vessels over a large area without prior segmentation of the blood vessel region, while significantly improving the success rate of the extraction and the generalizability of the data processing.

[0009] To achieve the above objectives, the present invention provides a method for extracting the centerline of a blood vessel, comprising:

[0010] Acquire a medical image to be extracted, the medical image to be extracted includes a vascular region and a non-vascular region, the vascular region includes a main branch vessel and two first branch vessels, the two first branch vessels converge at the end of the main branch vessel;

[0011] A second endpoint is selected within the main branch vessel, and a first endpoint is selected within each of the first branch vessels.

[0012] Based on the two first endpoints obtained, the center point on the center line of the two first branch vessels is explored synchronously until the distance between the center points of the two newly explored first branch vessels is less than a first threshold, wherein the two first endpoints are located in the two first branch vessels respectively.

[0013] The first intersection point is determined based on the center points of the two newly discovered first branch vessels;

[0014] The center point on the center line of the main branch vessel is explored based on the obtained second endpoint until the distance between the newly explored center point of the main branch vessel and the first intersection point is less than a second threshold, wherein the second endpoint is located within the main branch vessel;

[0015] Based on all the center points of the first branch vessel and all the center points of the main branch vessel, the vessel centerline is extracted.

[0016] Optionally, the center point on the centerline of the first branch vessel can be explored using the following steps:

[0017] Step A1: Determine the initial center point on the centerline of the first branch vessel based on the first endpoint of the first branch vessel, 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.

[0018] Step A2: Based on the current forward point and the current forward direction vector, explore the next new center point on the centerline of the first branch blood vessel, and take the explored new center point as the current center point of the first branch blood vessel;

[0019] Step A3: Determine whether the distance between the current center point of the first branch vessel and the current center point of another first branch vessel is less than the first threshold.

[0020] If yes, proceed to step A4; otherwise, proceed to step A5.

[0021] Step A4: End the exploration of the center point on the center line of the first branch vessel;

[0022] Step A5: Take the current center point of the first branch blood vessel 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.

[0023] Optionally, if the determination result of step A3 is negative, then before executing step A5, the following steps are also included:

[0024] Determine whether the exploration direction of the current center point of the first branch vessel has backtracked;

[0025] If so, then stop exploring the center point on the center line of the first branch vessel.

[0026] Optionally, if the exploration direction of the current center point of the first branch vessel has not been backtracked, then before executing step A5, the following steps are also included:

[0027] Determine whether the selected position of the first endpoint of the first branch blood vessel meets the preset conditions;

[0028] If not, stop exploring the center point on the centerline of the first branch vessel and send a prompt message to reselect the first endpoint of the first branch vessel.

[0029] Optionally, the step of exploring the next new center point on the centerline of the first branch vessel based on the current forward point and the current forward direction vector includes:

[0030] 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;

[0031] The current two-dimensional cross-sectional image of interest is segmented to obtain the current two-dimensional blood vessel region;

[0032] 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;

[0033] The new center point of the first branch vessel is obtained based on the center point of the current two-dimensional vascular lumen region.

[0034] Optionally, extracting the current two-dimensional cross-sectional image of interest from the medical image to be extracted based on the current forward point and the current forward direction vector includes:

[0035] 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;

[0036] 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 extracted.

[0037] Optionally, determining the center point of the current two-dimensional cross-section of interest based on the current forward point and the current forward direction vector includes:

[0038] The current forward speed is determined based on the angle between the current forward direction vector and the previous forward direction vector;

[0039] 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.

[0040] Optionally, the method further includes:

[0041] 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.

[0042] 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;

[0043] 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:

[0044] Based on the average gray value of the pixels in the two-dimensional blood vessel lumen region, determine the upper and lower thresholds for region growth.

[0045] 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;

[0046] 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 initial seed point for region generation;

[0047] Based on the initial seed point, the upper threshold, and the 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.

[0048] Optionally, 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:

[0049] Determine whether the ratio of the maximum radius of the previous two-dimensional vascular lumen region to the maximum radius of the current two-dimensional vascular lumen region is greater than a preset ratio;

[0050] 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.

[0051] 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.

[0052] Optionally, if the locking radius of the previous two-dimensional vascular true lumen region is locked, then before segmenting the current two-dimensional vascular region into true and false lumens, the method further includes:

[0053] The current two-dimensional blood vessel region is eroded to remove interfering areas within it.

[0054] Optionally, the step of segmenting the current two-dimensional blood vessel region into true and false lumens to segment out the current two-dimensional blood vessel true lumen region includes:

[0055] 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.

[0056] Optionally, determining the initial center point on the centerline of the first branch vessel based on the first endpoint of the first branch vessel includes:

[0057] 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 extracted.

[0058] The initial two-dimensional cross-sectional image of interest is segmented into a vascular region to extract the initial two-dimensional vascular region;

[0059] The initial two-dimensional vascular region is segmented into true and false lumens to separate the initial two-dimensional vascular true lumen region;

[0060] Find the center point of the initial two-dimensional true lumen region of the blood vessel, and obtain the initial center point of the first branch blood vessel based on the center point of the initial two-dimensional true lumen region of the blood vessel.

[0061] Optionally, if the distance between the current center point of the first branch vessel and the current center point of another first branch vessel is less than the first threshold, then before performing step A4, the method further includes:

[0062] Determine if the number of explored center points is greater than a preset value;

[0063] If yes, proceed to step A4; otherwise, send a message indicating that the centerline exploration failed.

[0064] Optionally, the center point on the centerline of the main branch vessel can be explored using the following steps:

[0065] Step B1: Determine the initial center point on the center line of the main branch vessel based on the second endpoint of the main branch vessel, 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.

[0066] 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, and take the explored new center point as the current center point of the main branch vessel;

[0067] Step B3: Determine whether the distance between the current center point of the main branch vessel and the first intersection point is less than the second threshold.

[0068] If yes, proceed to step B4; otherwise, proceed to step B5.

[0069] Step B4: End the exploration of the center point on the centerline of the main branch vessel;

[0070] Step B5: Take the current center point of the main branch blood vessel 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.

[0071] Optionally, the vascular region further includes at least one second branch vessel intersecting with the main branch vessel, and the method further includes:

[0072] Select a third endpoint within each of the second branch vessels;

[0073] For each of the second branch vessels, the center point closest to the third endpoint of the second branch vessel is determined on the center line of the main branch vessel as the fourth endpoint of the second branch vessel, and the center line of the second branch vessel is extracted based on the third endpoint and the fourth endpoint.

[0074] Optionally, extracting the centerline of the second branch vessel based on the third and fourth endpoints of the second branch vessel includes:

[0075] The center point on the center line of the second branch vessel is explored based on the third and fourth endpoints of the second branch vessel until the minimum distance between the newly explored center point of the second branch vessel and each center point of the main branch vessel is less than the third threshold.

[0076] Based on all the center points of the second branch vessel, extract the center line of the second branch vessel.

[0077] Optionally, the center point on the centerline of the second branch vessel can be explored using the following steps:

[0078] Step C1: Determine the initial center point on the center line of the second branch vessel based on the third endpoint of the second branch vessel, 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 as the current forward direction vector.

[0079] Step C2: Based on the current forward point and the current forward direction vector, explore the next new center point on the centerline of the second branch vessel, and take the explored new center point as the current center point of the second branch vessel;

[0080] Step C3: Determine whether the minimum distance between the current center point of the second branch vessel and each center point of the main branch vessel is less than the third threshold.

[0081] If yes, proceed to step C4; otherwise, proceed to step C5.

[0082] Step C4: End the exploration of the center point on the central line of the second branch vessel;

[0083] Step C5: Take the current center point of the second branch blood vessel 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.

[0084] 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 extraction method described above.

[0085] 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 extraction method described above.

[0086] Compared with existing technologies, the vascular centerline extraction method, electronic device, and storage medium provided by this invention have the following advantages:

[0087] The method for extracting the vascular centerline provided by this invention first selects a first endpoint within each first branch vessel in the acquired medical image to be extracted, and a second endpoint within the main branch vessel; then, based on the two first endpoints, the center points on the centerlines of the two first branch vessels are explored simultaneously until the distance between the newly explored center points of the two first branch vessels is less than a first threshold; then, the higher of the two newly explored center points of the first branch vessels is taken as the first intersection point; then, based on the second endpoint, the center points on the centerline of the main branch vessel are explored until the distance between the newly explored center point of the main branch vessel and the first intersection point is less than a second threshold; finally, the vascular centerline is extracted based on all the center points of the first branch vessels and all the center points of the main branch vessels. Therefore, the vascular centerline extraction method provided by this invention eliminates the need to segment the entire vascular region from the medical image to be extracted. This avoids the use of complex deep learning algorithms, effectively preventing the slow speed and high memory consumption problems caused by prioritizing large-scale 3D vascular segmentation before extracting the vascular centerline. It also avoids the problem of insufficient accuracy in the calculated vascular centerline due to low-quality 3D vascular segmentation results. This invention enables rapid and convenient vascular centerline extraction over large vascular regions, significantly improving the success rate of vascular centerline extraction and enhancing the generalization ability of data processing.

[0088] Since the electronic device and storage medium provided by this invention belong to the same inventive concept as the vascular centerline extraction method provided by this invention, the electronic device and storage medium provided by this invention have all the advantages of the vascular centerline extraction 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

[0089] Figure 1 A schematic flowchart of a method for extracting the centerline of blood vessels according to an embodiment of the present invention;

[0090] Figure 2 A schematic diagram illustrating the centerline exploration principle of the main branch vessel and the first branch vessel provided for a first specific example of the present invention;

[0091] Figure 3 A flowchart illustrating the exploration of the center point on the centerline of the first branch vessel, provided as an embodiment of the present invention;

[0092] Figure 4a This is a schematic diagram of a one- or two-dimensional cross-sectional image of interest.

[0093] Figure 4b A schematic diagram illustrating the determination of the circular region based on the lock radius;

[0094] Figure 4c This is a schematic diagram of a two-dimensional vascular region segmented using the region growing method;

[0095] Figure 4d A schematic diagram of the segmented two-dimensional true lumen region of a blood vessel;

[0096] Figure 5 A flowchart illustrating the process of exploring the center point on the centerline of the main branch blood vessel according to an embodiment of the present invention;

[0097] Figure 6 A schematic diagram illustrating the centerline exploration principle of the main branch vessel and the first branch vessel, provided for a second specific example of the present invention;

[0098] Figure 7 A schematic diagram illustrating the exploration of the next new center point of the main branch vessel according to one embodiment of the present invention;

[0099] Figure 8 A schematic diagram illustrating the centerline exploration principle of a second branch vessel according to an embodiment of the present invention;

[0100] Figure 9 A schematic diagram illustrating the initial direction for determining the centerline of a second branch vessel according to an embodiment of the present invention;

[0101] Figure 10 A schematic diagram of the centerline exploration process for a second branch vessel provided in one embodiment of the present invention;

[0102] Figure 11 This is a block diagram of an electronic device provided according to an embodiment of the present invention. Detailed Implementation

[0103] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, further illustrates the vascular centerline extraction 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 accompanying drawings are in a very simplified form and use non-precise proportions, intended only to facilitate and clearly illustrate the embodiments of this invention. Please refer to the accompanying 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.

[0104] 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.

[0105] The core idea of ​​this invention is to provide a method, electronic device and storage medium for extracting the centerline of blood vessels, which can realize fast and convenient extraction of the centerline of blood vessels, and at the same time, can significantly improve the success rate of the extraction of the centerline of blood vessels and improve the generalization of data processing.

[0106] It should be noted that the vascular centerline extraction method provided by this invention can be applied to the electronic device provided by this invention. This 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, as those skilled in the art will understand, although this invention uses the extraction of the aorta's centerline as an example for explanation, this does not constitute a limitation of the invention. This invention can also be applied to the extraction of the centerlines of other blood vessels such as the carotid artery, intracranial artery, and coronary artery.

[0107] It should also be noted that the medical images to be extracted in this invention can be acquired by scanning with 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).

[0108] To achieve the above-mentioned goal, this invention provides a method for extracting the centerline of blood vessels. Please refer to [the relevant documentation]. Figure 1 The diagram illustrates a flowchart of a method for extracting the vascular centerline according to an embodiment of the present invention. Figure 1 As shown, the method for extracting the vascular centerline provided by the present invention includes the following steps:

[0109] Step S100: Obtain the medical image to be extracted. The medical image to be extracted includes a vascular region and a non-vascular region. The vascular region includes a main branch vessel and two first branch vessels, and the two first branch vessels converge at the end of the main branch vessel.

[0110] Step S200: Based on the two first endpoints obtained, the center point on the center line of the two first branch vessels is explored synchronously until the distance between the center points of the two newly explored first branch vessels is less than a first threshold, wherein the two first endpoints are located in the two first branch vessels respectively.

[0111] Step S300: Take the higher of the two newly discovered center points of the first branch vessels as the first intersection point.

[0112] Step S400: Explore the center point on the center line of the main branch vessel based on the obtained second endpoint until the distance between the newly explored center point of the main branch vessel and the first intersection point is less than a second threshold, wherein the second endpoint is located within the main branch vessel.

[0113] Step S500: Extract the vessel centerline based on all the center points of the first branch vessel and all the center points of the main branch vessel.

[0114] Therefore, the vascular centerline extraction method provided by this invention does not require segmenting the entire vascular region from the medical image to be extracted. This eliminates the need for complex deep learning algorithms, effectively avoiding the slow speed and high memory consumption problems caused by segmenting a large area of ​​three-dimensional blood vessels before extracting the vascular centerline in existing technologies. It also avoids the problem of insufficient accuracy of the calculated vascular centerline due to low quality of the three-dimensional blood vessel segmentation results. It should be noted that, as those skilled in the art will understand, the purpose of selecting the first and second endpoints is to initialize and constrain the exploration path of the vascular centerline. The second endpoint P1 is preferably selected 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; the first endpoints P2 and P3 are preferably located close to the end of the first branch vessel 120, but the first endpoints P2 and P3 do not need to be close to the first branch vessel 120 (see...). Figure 2 The center of the vessel is such that the first endpoints P2 and P3 are located within the first branch vessel 120.

[0115] It should be noted that, as those skilled in the art will understand, the second endpoint P1 and the first endpoints P2 and P3 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 to be extracted is a medical image including the aorta, the user can manually select three endpoints that reflect the anatomical structure of the aorta (i.e., one second endpoint P1 and two first endpoints P2 and P3). The selectable region of the second endpoint P1 includes the ascending aorta, aortic arch, descending aorta, and abdominal aorta of the thoracic aorta segment. The first endpoints P2 and P3 exhibit left-right anatomical characteristics; that is, when one of the first endpoints P2 is located within the region of the left common iliac artery, left internal iliac artery, left external iliac artery, left femoral artery, left popliteal artery, left anterior tibial artery, or left posterior tibial artery segment, the other first endpoint P3 is located correspondingly within the region of the right common iliac artery, right internal iliac artery, right external iliac artery, right femoral artery, right popliteal artery, right anterior tibial artery, or right posterior tibial artery segment. Specifically, when the medical image to be extracted is an aortic medical image of a normal person or a patient suspected of having aortic dissection, the main branch vessels 110 of the center line to be extracted need to be composed of at least the thoracic aorta, the abdominal aorta, and the left and right iliac arteries; when the medical image to be extracted is an aortic medical image of a patient suspected of having an abdominal aortic aneurysm, the main branch vessels 110 of the center line to be extracted need to be composed of at least the abdominal aorta and the left and right iliac arteries.

[0116] Please continue to refer to this. Figure 2 The diagram schematically illustrates the centerline exploration principle of the main branch vessel 110 and the first branch vessel 120 provided in the first specific example of the present invention. Figure 2 As shown, in this specific example, the second endpoint P1 is located in the ascending aorta, the first endpoint P2 is located in the left common iliac artery, and the first endpoint P3 is located in the right common iliac artery.

[0117] In one exemplary embodiment, the center points on the center lines of the two first branch vessels 120 are explored alternately using a low-position priority principle. Thus, by alternately exploring the center lines of the left and right first branch vessels 120 using a low-position priority principle, 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-priority principle means that the exploration of the center point on the centerline of the first branch vessel 120 (represented as first branch vessel A for easy distinction), which is located at the first endpoint farther from the main branch vessel 110, is carried out first. After a center point on the centerline of the first branch vessel A is found to be above the first endpoint of another first branch vessel 120 (represented as first branch vessel B), the exploration of the center point on the centerline of the first branch vessel B begins. After a center point on the centerline of the first branch vessel B is found, it is determined whether the distance between the two most recently found center points of the two first branch vessels 120 is less than the first threshold. If not, the exploration of the center point on the centerline of the first branch vessel A is carried out again. After a center point on the centerline of the first branch vessel A is found, the exploration of the center point on the centerline of the first branch vessel B is carried out again. After a center point on the centerline of the first branch vessel B is found, it is determined whether the distance between the two most recently found center points of the two first branch vessels 120 is less than the first threshold, and so on. By alternately exploring the center points on the centerlines of the two first branch vessels 120, the synchronous exploration of the centerlines of the two first branch vessels 120 can be achieved. It should be noted that, as those skilled in the art will understand, when the coordinates of each pixel in the medical image to be extracted are represented by positional 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 branch vessel 110. Furthermore, it should be noted that, as those skilled in the art will understand, if the distance between the center points of the two newly discovered first branch vessels 120 is less than a first threshold, then the higher center point of the two newly discovered first branch vessels 120 can be taken as the first intersection point N0. The first intersection point N0 is the termination center point on the vessel centerline of the two first branch vessels 120, and the first intersection point N0 is also the termination center point on the vessel centerline of the main branch vessel 110.

[0118] Please continue to refer to this. Figure 3 The diagram illustrates a flowchart of an embodiment of the present invention for exploring the center point on the centerline of the first branch vessel 120. Figure 3As shown, in one exemplary embodiment, the center point on the centerline of the first branch vessel 120 is explored using the following steps:

[0119] Step A1: Determine the initial center point on the center line of the first branch vessel 120 based on the first endpoint of 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.

[0120] 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;

[0121] 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 the first threshold.

[0122] If yes, proceed to step A4; otherwise, proceed to step A5.

[0123] Step A4: End the exploration of the center point on the center line of the first branch vessel 120;

[0124] 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.

[0125] Therefore, by determining the initial center point on the centerline of the first branch vessel 120 based on its first endpoint, and then using this initial center point as the current starting point to explore the next center point (new center point), it can be ensured that the extracted vessel centerline will not deviate from the vessel center at either end, thereby further guaranteeing the accuracy of the extracted vessel centerline. It should be noted that, as those skilled in the art will understand, since the first branch vessel 120 is located below the main branch vessel 110, the unit vector parallel to the Z-axis in step A1 should be a positive unit vector parallel to the Z-axis, that is, the coordinates of the unit vector parallel to the Z-axis in A1 are represented as (0,0,1).

[0126] It should be noted that, as those skilled in the art will understand, the coordinates of the previous center point are assumed to be c. j-1 The current center point coordinates are c j Then the current forward direction vector The calculation formula is as follows:

[0127]

[0128] 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 forward point and the current forward direction vector includes:

[0129] 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;

[0130] The current two-dimensional cross-sectional image of interest is segmented to obtain the current two-dimensional blood vessel region;

[0131] 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;

[0132] 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.

[0133] Therefore, by reducing the dimensionality of the three-dimensional medical image to be extracted 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 the three-dimensional vascular centerline 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.

[0134] 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.

[0135] In one exemplary implementation, extracting the current two-dimensional section of interest image from the medical image to be extracted based on the current forward point and the current forward direction vector includes:

[0136] 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;

[0137] 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 extracted.

[0138] Therefore, by using the calculated center point of the current two-dimensional section of interest (ROI), the normal vector of the current two-dimensional ROI, and the preset dimensions, the current ROI image can be accurately extracted from the medical image to be extracted. It should be noted that, as those skilled in the art will understand, the preset dimensions include a width dimension and a height dimension; for ease of calculation, the width dimension is equal to the height dimension.

[0139] 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:

[0140] 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).

[0141] 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.

[0142] 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:

[0143]

[0144] 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):

[0145] v=k*α*θ+b,θ∈[0,π] (3)

[0146] v=k*α*(cosθ+1)+b,θ∈[0,π] (4)

[0147]

[0148]

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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 :

[0153]

[0154] Among them, c j-1 As the current starting point, This is the current forward direction vector.

[0155] In one exemplary embodiment, the method further includes:

[0156] 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.

[0157] 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.

[0158] 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 initial seed point used for region growth can be limited, thereby ensuring that the results obtained from region growth accurately include blood vessels.

[0159] In one exemplary implementation, segmenting the blood vessel region of the current two-dimensional cross-sectional image of interest to segment the current two-dimensional blood vessel region includes:

[0160] Based on the average gray value of the pixels in the two-dimensional blood vessel lumen region, determine the upper and lower thresholds for region growth.

[0161] 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;

[0162] 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 initial seed point for region generation;

[0163] Based on the initial seed point, the upper threshold, and the 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.

[0164] 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 / λ, the lower threshold is λh j-1 , where λ is a constant greater than 0 and less than 1. Please refer to the following: Figures 4a to 4d ,in Figure 4a A schematic diagram of a two-dimensional cross-sectional image of interest is given; Figure 4b A schematic diagram illustrating the determination of the circular domain based on the lock radius (Ir in the diagram) is given. j-1 That is, the locking radius corresponding to the true lumen region of the previous two-dimensional blood vessel; Figure 4c A schematic diagram of a two-dimensional vascular region segmented using the region growing method is shown (the white elliptical area in the figure represents the two-dimensional vascular region). Figure 4d A schematic diagram of the segmented two-dimensional true lumen region of a blood vessel is shown (the white area in the diagram represents the two-dimensional true lumen region of the blood vessel). Figures 4a to 4d As shown, 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 initial seed point, the upper threshold, and the lower threshold can be found in existing region growing techniques, and therefore will not be elaborated upon here.

[0165] 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:

[0166] Determine whether the ratio of the maximum radius of the previous two-dimensional vascular lumen region to the maximum radius of the current two-dimensional vascular lumen region is greater than a preset ratio;

[0167] 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.

[0168] 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.

[0169] 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 / mr j If Ir > γ, then the locking radius Ir of the current two-dimensional vascular true lumen region j For mr j-1 ;mr j-1 / mr j If ≤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.

[0170] 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:

[0171] The current two-dimensional blood vessel region is eroded to remove interfering areas within it.

[0172] 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-2 If 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.

[0173] 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:

[0174] 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.

[0175] 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.

[0176] In one exemplary embodiment, after extracting the current two-dimensional section of interest image from the medical image to be extracted, and before segmenting the vascular region in the current two-dimensional section of interest image, the method further includes:

[0177] Map the current two-dimensional cross-sectional image of interest onto the two-dimensional plane with Z=0.

[0178] 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:

[0179] 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.

[0180] 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.

[0181] 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 to be extracted is an m×4 matrix X. 3d , where X 3d Each 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 to be extracted; 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 two-dimensional plane of Z=0 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 two-dimensional plane of Z=0 as the origin) 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 X2d The following relationship exists between them:

[0182] X 3d =X 2d R y R x R T (8)

[0183] 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 It is a translation matrix.

[0184] 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 (x scj ,y scj ,z scj ,1), the normal vector of the current two-dimensional section of interest corresponding to 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:

[0185]

[0186]

[0187]

[0188]

[0189]

[0190]

[0191] sinβ=-x nj (15)

[0192] 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.

[0193] Therefore, after calculating the rotation matrix R x Ry and the translation matrix R T Then, according to the above formula (8), the current two-dimensional cross-section image of interest can be extracted from the medical image to be extracted. The image is transformed from the three-dimensional coordinate system to the two-dimensional cross-section coordinate system. After calculating the coordinates of the center point in the two-dimensional cross-section coordinate system, the coordinates of the center point in the three-dimensional coordinate system can be obtained by formula (8).

[0194] In one exemplary embodiment, if the determination result of step A3 is negative, then before executing step A5, the method further includes:

[0195] Determine whether the exploration direction of the current center point of the first branch vessel 120 has backtracked;

[0196] If so, then stop exploring the center point on the center line of the first branch vessel 120.

[0197] 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.

[0198] 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:

[0199] 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.

[0200] 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:

[0201] Determine whether the selected position of the first endpoint of the first branch vessel 120 meets the preset conditions;

[0202] 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.

[0203] 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 preset conditions, the centerline exploration will be incorrect. Therefore, by judging whether the position of the selected first endpoint meets the preset conditions, the exploration can be avoided in time.

[0204] 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 preset conditions:

[0205] 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 preset radius threshold. If yes, determine that the selection position of the first endpoint does not meet the preset condition; otherwise, determine that the selection position of the first endpoint meets the preset condition.

[0206] 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:

[0207] Determine whether the number of explored center points is greater than a preset value.

[0208] If yes, proceed to step A4; otherwise, send a message indicating that the centerline exploration failed.

[0209] 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 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.

[0210] In one exemplary embodiment, determining the initial center point on the centerline of the first branch vessel 120 based on the first endpoint of the first branch vessel 120 includes:

[0211] 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 extracted.

[0212] The initial two-dimensional cross-sectional image of interest is segmented into a vascular region to extract the initial two-dimensional vascular region;

[0213] The initial two-dimensional vascular region is segmented into true and false lumens to separate the initial two-dimensional vascular true lumen region;

[0214] Find the center point of the initial two-dimensional true lumen region of the blood vessel, and obtain the initial center point of the first branch blood vessel 120 based on the center point of the initial two-dimensional true lumen region of the blood vessel.

[0215] Specifically, such as Figure 2 As shown, the coordinates of the initial two-dimensional cross-section normal vector d0 of the first branch vessel 120 are represented as (0,0,1). For details on how to segment the vessel region in the initial two-dimensional cross-section image and how to segment the true and false lumens of the initial two-dimensional vessel region, please refer to the relevant descriptions above. It should be noted that, as those skilled in the art will understand, the upper threshold for region growth of the initial two-dimensional vessel true lumen region is h0 / λ, and the lower threshold is λh0, where h0 is the pixel value of the first endpoint. Further, when the side length of the initial two-dimensional cross-section image is r, the radius of the initial circular domain used to define the initial seed point for region growth of the initial two-dimensional vessel true lumen region is r / 2.

[0216] Please continue to refer to this. Figure 5 The diagram illustrates a flowchart of an embodiment of the present invention for exploring the center point on the centerline of the main branch vessel 110. Figure 5 As shown, in one exemplary embodiment, the center point on the centerline of the main branch vessel 110 is explored using the following steps:

[0217] Step B1: Determine the initial center point on the center line of the main branch vessel 110 based on the second endpoint of 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.

[0218] Step B2: Based on the current forward point and the current forward direction vector, explore the next new center point on the center line of the main branch vessel 110, and take the explored new center point as the current center point of the main branch vessel 110.

[0219] Step B3: Determine whether the distance between the current center point of the main branch vessel 110 and the first intersection point is less than the second threshold.

[0220] If yes, proceed to step B4; otherwise, proceed to step B5.

[0221] Step B4: End the exploration of the center point on the center line of the main branch vessel 110;

[0222] 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.

[0223] Specifically, please refer to 2 and Figure 6 ,in Figure 6 A schematic diagram illustrating the centerline exploration principle of the main branch vessel 110 and the first branch vessel 120 provided in a second specific example of the present invention is given. Figure 2 and Figure 6 As shown, when the second endpoint P1 is located in a blood vessel segment 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, that is, the coordinates of the unit vector parallel to the Z-axis in A1 are represented as (0,0,1); when the second endpoint P1 is located in a blood vessel segment 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, that is, the coordinates of the unit vector parallel to the Z-axis in A1 are represented as (0,0,-1).

[0224] 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:

[0225] 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;

[0226] The current two-dimensional cross-sectional image of interest is segmented to obtain the current two-dimensional blood vessel region;

[0227] 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;

[0228] 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.

[0229] Please continue to refer to this. Figure 7 This schematically illustrates a diagram of exploring the next new center point of the main branch vessel 110 according to an embodiment of the present invention. Figure 7 As shown, after exploring the center point c j-1 Then, 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. jThen, based on the preset size, the current two-dimensional cross-sectional image of interest can be extracted from the medical image to be extracted. It should be noted that, as those skilled in the art will understand, more details regarding how to extract the current two-dimensional cross-sectional 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-sectional 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 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.

[0230] In one exemplary embodiment, if the determination result of step B3 is negative, then before executing step B5, the method further includes:

[0231] Determine whether the exploration direction of the current center point of the main branch vessel 110 has backtracked;

[0232] If so, then the exploration of the center point on the center line of the main branch vessel 110 shall be stopped.

[0233] 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:

[0234] 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.

[0235] 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:

[0236] Determine whether the selected position of the second endpoint of the main branch vessel 110 meets the preset conditions;

[0237] 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.

[0238] 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 preset conditions:

[0239] 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 preset radius threshold. If yes, determine that the selection position of the second endpoint does not meet the preset condition; otherwise, determine that the selection position of the second endpoint meets the preset condition.

[0240] In one exemplary embodiment, if the distance between the current center point of the main branch vessel 110 and the first junction point is less than the second threshold, then before performing step B4, the method further includes:

[0241] Determine whether the number of explored center points is greater than a preset value.

[0242] If yes, proceed to step B4; otherwise, send a message indicating that the centerline exploration failed.

[0243] 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:

[0244] 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 to be extracted;

[0245] The initial two-dimensional cross-sectional image of interest is segmented into a vascular region to extract the initial two-dimensional vascular region;

[0246] The initial two-dimensional vascular region is segmented into true and false lumens to separate the initial two-dimensional vascular true lumen region;

[0247] 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.

[0248] Specifically, such as Figure 2 and Figure 6 As shown, when the second endpoint P1 is located in a blood vessel segment extending towards the head (e.g., within the ascending aorta), the coordinates of the initial two-dimensional cross-sectional normal vector d0 of the main branch blood vessel 110 are represented as (0,0,1); when the second endpoint P1 is located in a blood vessel segment extending towards the foot (e.g., within the descending aorta), the coordinates of the initial two-dimensional cross-sectional normal vector d0 of the main branch blood vessel 110 are represented as (0,0,-1).

[0249] In one exemplary embodiment, the vascular region further includes at least one second branch vessel 130 intersecting with the main branch vessel 110, and the method further includes:

[0250] A third endpoint is selected within each of the second branch vessels 130;

[0251] For each of the second branch vessels 130, the center point closest to the third endpoint of the second branch vessel 130 is determined on the center line of the main branch vessel 110 as the fourth endpoint of the second branch vessel 130, and the center line of the second branch vessel 130 is extracted based on the third endpoint and the fourth endpoint of the second branch vessel 130.

[0252] Specifically, please refer to 8, which schematically illustrates the principle of centerline exploration of the second branch vessel 130 according to an embodiment of the present invention. Figure 8 As shown in the figure, points P4, P5, P6, P7, P8, P9, and P... 10 This 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, for each second branch vessel 130, the purpose of selecting the third endpoint is to initialize and constrain the exploration path of the centerline of that second branch vessel 130. The location of the third endpoint is preferably close to the end of the main branch vessel; 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. Further, please refer to... Figure 9 This schematically illustrates an embodiment of the present invention, showing the initial direction for determining the centerline of the second branch vessel 130. Figure 9 As shown in the figure, point P0 is the fourth endpoint corresponding to the second branch vessel 130 where point P6 is located.

[0253] In one exemplary embodiment, extracting the centerline of the second branch vessel 130 based on its third and fourth endpoints includes:

[0254] Based on the third and fourth endpoints of the second branch vessel 130, the center point on the center line of the second branch vessel 130 is explored until the minimum distance between the newly explored center point of the second branch vessel 130 and each center point of the main branch vessel 110 is less than the third threshold.

[0255] Based on all the center points of the second branch vessel 130, the center line of the second branch vessel 130 is extracted.

[0256] Furthermore, the method also includes:

[0257] The center point of the main branch vessel 110 whose distance from the center point of the newly discovered second branch vessel 130 is less than the third threshold is determined as the second intersection point corresponding to the second branch vessel 130.

[0258] The centerline of the vascular region is obtained based on the centerline of the main branch vessel 110, the centerline of the first branch vessel 120, the second intersection point corresponding to each of the second branch vessels 130, and the centerline of the second branch vessels 130.

[0259] Therefore, for each second branch vessel 130, by determining the second junction point corresponding to that second branch vessel 130, the center point of that second branch vessel 130 and the center line of the main branch vessel 110 can be connected at the second junction point corresponding to that second branch vessel 130, thereby quickly and accurately obtaining the center line of the entire vascular region. Please continue to refer to... Figure 8 ,like Figure 8 As shown, the second junction point corresponding to the second branch vessel 130 where point P4 is located is N1; the second junction point corresponding to the second branch vessel 130 where point P5 is located is N2; the second junction point corresponding to the second branch vessel 130 where point P6 is located is N3; the second junction point corresponding to the second branch vessel 130 where point P7 is located is N4; the second junction point corresponding to the second branch vessel 130 where point P8 is located is N5; the second junction point corresponding to the second branch vessel 130 where point P9 is located is N6; and point P... 10 The second junction point corresponding to the second branch vessel 130 is N7.

[0260] Please continue to refer to this. Figure 10 The diagram illustrates the centerline exploration process of the second branch vessel 130 according to an embodiment of the present invention. Figure 10 As shown, in one exemplary embodiment, the center point on the centerline of the second branch vessel 130 is explored using the following steps:

[0261] Step C1: Determine the initial center point on the center line of the second branch vessel 130 based on the third endpoint of 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.

[0262] 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;

[0263] 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.

[0264] If yes, proceed to step C4; otherwise, proceed to step C5.

[0265] Step C4: End the exploration of the center point on the center line of the second branch vessel 130;

[0266] 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.

[0267] For details, please refer to Figure 9 ,like Figure 9 As shown, the initial forward direction vector for the second branch vessel 130 where point P6 is located is the unit vector d0 pointing from point P6 to point P0.

[0268] 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:

[0269] 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;

[0270] The current two-dimensional cross-sectional image of interest is segmented to obtain the current two-dimensional blood vessel region;

[0271] 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;

[0272] 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.

[0273] 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.

[0274] In one exemplary embodiment, if the determination result of step C3 is negative, then before executing step C5, the method further includes:

[0275] Determine whether the exploration direction of the current center point of the second branch vessel 130 has backtracked;

[0276] If so, then stop exploring the center point on the center line of the second branch vessel 130.

[0277] 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:

[0278] 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.

[0279] 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:

[0280] Determine whether the selected position of the third endpoint of the second branch vessel 130 meets the preset conditions;

[0281] 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.

[0282] 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 preset conditions:

[0283] 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 preset radius threshold. If yes, determine that the selection position of the third endpoint does not meet the preset conditions; otherwise, determine that the selection position of the third endpoint meets the preset conditions.

[0284] In one exemplary embodiment, if the distance between the current center point of the second branch vessel 130 and the first junction point is less than the second threshold, then before performing step C4, the method further includes:

[0285] Determine whether the number of explored center points is greater than a preset value.

[0286] If yes, proceed to step C4; otherwise, send a message indicating that the centerline exploration failed.

[0287] 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:

[0288] 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 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.

[0289] The initial two-dimensional cross-sectional image of interest is segmented into a vascular region to extract the initial two-dimensional vascular region;

[0290] The initial two-dimensional vascular region is segmented into true and false lumens to separate the initial two-dimensional vascular true lumen region;

[0291] 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.

[0292] In summary, the vascular centerline extraction method provided by this invention employs a self-designed method to explore the centerline path of a spatial tubular channel along the three-dimensional vascular direction. This solves the problem of traditional vascular centerline extraction algorithms requiring pre-segmentation of the entire vascular body, effectively avoiding the low accuracy, low success rate, and slow speed of extracted vascular centerlines due to poor segmentation quality. This invention reduces the dimensionality of the three-dimensional vascular (e.g., aorta) centerline extraction problem to the problem of exploring the center point of a continuous two-dimensional vascular (e.g., two-dimensional aorta) cross-section, enabling rapid and convenient extraction of vascular centerlines while significantly improving the success rate. Furthermore, by setting a forward vector and locking radius, this invention can directionally lock the exploration direction of the vascular centerline, effectively preventing the exploration direction from deviating from the vascular (e.g., aorta). While calculating the vascular centerline, it also meets the doctor's requirement that the centerline be within the true lumen of the vascular (e.g., aorta), making it suitable for extracting the vascular centerline of aortic vessels with diseases such as aortic dissection and aortic aneurysm.

[0293] Based on the same inventive concept, the present invention also provides an electronic device, please refer to... Figure 11 A block diagram illustrating an embodiment of the electronic device provided by the present invention is shown. Figure 11As shown, the electronic device includes a processor 310 and a memory 330. The memory 330 stores a computer program, which, when executed by the processor 310, implements the aforementioned method for extracting the vascular centerline. Since the electronic device provided by this invention and the vascular centerline extraction method provided by this invention belong to the same inventive concept, the electronic device provided by this invention possesses all the advantages of the vascular centerline extraction method provided by this invention. Therefore, the beneficial effects of the electronic device provided by this invention will not be elaborated upon here.

[0294] like Figure 11 As shown, the electronic device also includes a communication interface 320 and a communication bus 340, wherein the processor 310, the communication interface 320, and the memory 330 communicate with each other via the communication bus 340. The communication bus 340 can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus 340 can be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is used to represent it in the figure, but this does not indicate that there is only one bus or one type of bus. The communication interface 320 is used for communication between the aforementioned electronic device and other devices.

[0295] The processor 310 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 310 is the control center of the electronic device, connecting various parts of the entire electronic device through various interfaces and lines.

[0296] The memory 330 can be used to store the computer program. The processor 310 implements various functions of the electronic device by running or executing the computer program stored in the memory 330 and calling the data stored in the memory 330.

[0297] The memory 330 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.

[0298] This invention also provides a readable storage medium storing a computer program that, when executed by a processor, can implement the aforementioned method for extracting the vascular centerline. Since the readable storage medium and the vascular centerline extraction method provided by this invention belong to the same inventive concept, the readable storage medium possesses all the advantages of the vascular centerline extraction method provided by this invention. Therefore, the beneficial effects of the readable storage medium provided by this invention will not be elaborated upon here.

[0299] 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.

[0300] 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.

[0301] It should be noted that, as those skilled in the art will understand, computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof. These programming languages ​​include 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 can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0302] 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. 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.

[0303] 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 extracting the centerline of a blood vessel, characterized in that, include: Acquire a medical image to be extracted, the medical image to be extracted includes a vascular region and a non-vascular region, the vascular region includes a main branch vessel and two first branch vessels, the two first branch vessels converge at the end of the main branch vessel; Based on the two first endpoints obtained, the center point on the center line of the two first branch vessels is explored synchronously until the distance between the center points of the two newly explored first branch vessels is less than a first threshold, wherein the two first endpoints are located in the two first branch vessels respectively. The higher of the two newly discovered center points of the first branch vessels is taken as the first intersection point; The center point on the center line of the main branch vessel is explored based on the obtained second endpoint until the distance between the newly explored center point of the main branch vessel and the first intersection point is less than a second threshold, wherein the second endpoint is located within the main branch vessel; Based on all the center points of the first branch vessel and all the center points of the main branch vessel, the vessel centerline is extracted; The following steps were used to explore the center point on the centerline of the first branch vessel: Step A1: Determine the initial center point on the centerline of the first branch vessel based on the first endpoint of the first branch vessel, 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. Step A2: Based on the current forward point and the current forward direction vector, explore the next new center point on the centerline of the first branch blood vessel, and take the explored new center point as the current center point of the first branch blood vessel; Step A3: Determine whether the distance between the current center point of the first branch vessel and the current center point of another first branch vessel is less than the first threshold. If yes, proceed to step A4; otherwise, proceed to step A5. Step A4: End the exploration of the center point on the center line of the first branch vessel; Step A5: Take the current center point of the first branch blood vessel as the current forward point, take the unit vector from the previous center point to the current center point as the current forward direction vector, and return to execute step A2; The step of exploring the next new center point on the centerline of the first branch vessel based on the current forward point and the current forward direction vector includes: 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; The current two-dimensional cross-sectional image of interest is segmented to obtain the current two-dimensional blood vessel region; 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; The new center point of the first branch vessel is obtained based on the center point of the current two-dimensional vascular lumen region.

2. The method for extracting the vascular centerline according to claim 1, characterized in that, If the determination result of step A3 is negative, then before executing step A5, the following steps are also included: Determine whether the exploration direction of the current center point of the first branch vessel has backtracked; If so, then stop exploring the center point on the center line of the first branch vessel.

3. The method for extracting the vascular centerline according to claim 2, characterized in that, If the exploration direction of the current center point of the first branch vessel has not been backtracked, then before executing step A5, the process also includes: Determine whether the selected position of the first endpoint of the first branch blood vessel meets the preset conditions; If not, stop exploring the center point on the centerline of the first branch vessel and send a prompt message to reselect the first endpoint of the first branch vessel.

4. The method for extracting the vascular centerline according to claim 1, characterized in that, The step of extracting the current two-dimensional cross-sectional image of interest from the medical image to be extracted based on the current forward point and the current forward direction vector includes: 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; 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 extracted.

5. The method for extracting the vascular centerline according to claim 4, characterized in that, 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: The current forward speed is determined based on the angle between the current forward direction vector and the previous forward direction vector; 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.

6. The method for extracting the vascular centerline according to claim 1, characterized in that, The method further includes: 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. 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; 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: Based on the average gray value of the pixels in the two-dimensional blood vessel lumen region, determine the upper and lower thresholds for region growth. 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; 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 initial seed point for region generation; Based on the initial seed point, the upper threshold, and the 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.

7. The method for extracting the vascular centerline according to claim 6, characterized in that, The step of 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: Determine whether the ratio of the maximum radius of the previous two-dimensional vascular lumen region to the maximum radius of the current two-dimensional vascular lumen region is greater than a preset ratio; 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. If not, then the maximum radius of the current two-dimensional vascular lumen region is taken as the locking radius corresponding to the current two-dimensional vascular lumen region.

8. The method for extracting the vascular centerline according to claim 4, characterized in that, The step of segmenting the current two-dimensional blood vessel region into true and false lumens to segment out the current two-dimensional blood vessel true lumen region includes: 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.

9. The method for extracting the vascular centerline according to claim 1, characterized in that, Determining the initial center point on the centerline of the first branch vessel based on the first endpoint of the first branch vessel includes: 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 extracted. The initial two-dimensional cross-sectional image of interest is segmented into a vascular region to extract the initial two-dimensional vascular region; The initial two-dimensional vascular region is segmented into true and false lumens to separate the initial two-dimensional vascular true lumen region; Find the center point of the initial two-dimensional true lumen region of the blood vessel, and obtain the initial center point of the first branch blood vessel based on the center point of the initial two-dimensional true lumen region of the blood vessel.

10. The method for extracting the vascular centerline according to claim 1, characterized in that, If the distance between the current center point of the first branch vessel and the current center point of another first branch vessel is less than the first threshold, then before executing step A4, the method further includes: Determine if the number of explored center points is greater than a preset value; If yes, proceed to step A4; otherwise, send a message indicating that the centerline exploration failed.

11. The method for extracting the vascular centerline according to claim 1, characterized in that, The center point on the centerline of the main branch vessel was explored using the following steps: Step B1: Determine the initial center point on the center line of the main branch vessel based on the second endpoint of the main branch vessel, 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. 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, and take the explored new center point as the current center point of the main branch vessel; Step B3: Determine whether the distance between the current center point of the main branch vessel and the first intersection point is less than the second threshold. If yes, proceed to step B4; otherwise, proceed to step B5. Step B4: End the exploration of the center point on the centerline of the main branch vessel; Step B5: Take the current center point of the main branch blood vessel 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.

12. The method for extracting the vascular centerline according to claim 1, characterized in that, The vascular region further includes at least one second branch vessel intersecting with the main branch vessel, and the method further includes: Select a third endpoint within each of the second branch vessels; For each of the second branch vessels, the center point closest to the third endpoint of the second branch vessel is determined on the center line of the main branch vessel as the fourth endpoint of the second branch vessel, and the center line of the second branch vessel is extracted based on the third endpoint and the fourth endpoint.

13. The method for extracting the vascular centerline according to claim 12, characterized in that, The step of extracting the centerline of the second branch vessel based on the third and fourth endpoints of the second branch vessel includes: The center point on the center line of the second branch vessel is explored based on the third and fourth endpoints of the second branch vessel until the minimum distance between the newly explored center point of the second branch vessel and each center point of the main branch vessel is less than the third threshold. Based on all the center points of the second branch vessel, extract the center line of the second branch vessel.

14. The method for extracting the vascular centerline according to claim 13, characterized in that, The center point of the centerline of the second branch vessel was explored using the following steps: Step C1: Determine the initial center point on the center line of the second branch vessel based on the third endpoint of the second branch vessel, 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 as the current forward direction vector. Step C2: Based on the current forward point and the current forward direction vector, explore the next new center point on the centerline of the second branch blood vessel, and take the explored new center point as the current center point of the second branch blood vessel; Step C3: Determine whether the minimum distance between the current center point of the second branch vessel and each center point of the main branch vessel is less than the third threshold. If yes, proceed to step C4; otherwise, proceed to step C5. Step C4: End the exploration of the center point on the central line of the second branch vessel; Step C5: Take the current center point of the second branch blood vessel as the current forward point, take the unit vector from the previous center point to the current center point as the current forward direction vector, and return to execute step C2.

15. 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 extracting the vascular centerline as described in any one of claims 1 to 14.

16. 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 extracting the vascular centerline as described in any one of claims 1 to 14.

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