Aneurysm analysis method and device based on hemodynamics

Abstract

The present invention provides an aneurysm analysis method and device based on hemodynamics, including: receiving 3D-DSA image data of a patient, reconstructing a cerebral aneurysm model based on the 3D-DSA image data; obtaining a hemodynamic index A and blood flow velocity, the hemodynamic index A being the fluid impact energy on the blood vessel wall; calculating the wall shear stress contour of the deformation model at the intersection of the aneurysm-bearing vessels in the 3D-DSA image data, and obtaining the wall shear stress in the blood flow; calculating the biological indicators of the blood vessels and / or blood flow based on hemodynamics; and outputting the results after summarizing the hemodynamic index A, blood flow velocity, wall shear stress, and biological indicators of the blood vessels and / or blood flow. The geometric shapes of the patient's cerebral arteries and aneurysms are reconstructed based on medical data, and the blood flow is simulated by computational fluid dynamics to obtain the total wall pressure, non-sphericity index, average wall shear stress, and oscillatory shear index, and the obtained indicators are more accurate.

Description

Technical Field

[0001] The invention relates to an aneurysm and data processing technology, and in particular to an aneurysm analysis method and device based on hemodynamics. Background Art

[0002] Intracranial aneurysms are pathological dilatation diseases of the cerebrovascular system. The incidence of intracranial aneurysms is high, and rupture of aneurysms can lead to the death of patients. The pathogenesis of intracranial aneurysms includes three stages: initiation, growth, and rupture. The occurrence of aneurysms is considered to be the result of a complex interaction between local hemodynamic forces and the subsequent cellular-level biological processes in the vascular wall. Currently, little is known about the natural course of intracranial aneurysm-affected vessels, and the mechanisms of the occurrence, growth, and rupture of intracranial aneurysms are not fully understood. The interaction of hemodynamic forces on the vascular wall is generally considered a risk factor, so the process of intracranial aneurysm formation, development, and rupture is considered to be related to hemodynamics.

[0003] Endothelial cells have the ability to detect fluid wall shear stress (WSS) and thus adapt their spatial organization in the hemodynamic environment. Low oscillatory shear stress fields can lead to irregular shapes and loss of cell orientation. Low wall shear stress and oscillatory patterns promote intimal wall thickening and atherosclerosis. The cerebrovascular system, with its outer vascular elasticity, inner elastin, and supporting adventitia and perivascular tissues, is intrinsically susceptible to these mechanical forces, and fluid dynamics play an important role in the initiation, growth, clinical diagnosis, and prediction of rupture of intracranial aneurysms.

[0004] At the same time, in addition to the important wall shear stress indicators mentioned above, hemodynamics (CFD) also includes time-averaged wall shear stress (AWSS), oscillatory shear index (OSI), nonsphericity index (NSI), etc.

[0005] Increasing computational resources have enabled the widespread application of numerical methods in the study of neurovascular diseases. In particular, image-based hemodynamic simulations in intracranial aneurysms can estimate the probability of rupture in individuals or aid during treatment planning. However, most existing techniques require patient-specific boundary conditions to perform realistic hemodynamic simulations and only have access to the geometry of the brain vasculature without information on flow waveforms, such as those measured in intracranial arteries.

[0006] The fundamental quantity for calculating the hemodynamics of intracranial aneurysms is the wall shear stress, which is the hemodynamic force exerted on the vessel wall by the local tangentially aligned fluid flow. Since the hemodynamic forces act on the aneurysm, hemodynamic factors such as wall shear stress, pressure on the aneurysm, and secondary blood flow patterns are important parameters for aneurysm rupture. These factors depend not only on the geometry of the artery, but also on the shape of the aneurysm. Summary of the invention

[0007] The embodiment of the present invention provides an aneurysm analysis method and device based on hemodynamics, which reconstructs the geometric shapes of the patient's cerebral arteries and aneurysms according to medical data, and simulates the blood flow by computational fluid dynamics to obtain the total wall pressure, non-spherical index, average wall shear stress and oscillatory shear index, and the obtained indicators are more accurate.

[0008] A first aspect of an embodiment of the present invention provides an aneurysm analysis method based on hemodynamics, comprising:

[0009] receiving 3D-DSA image data of a patient, and reconstructing a cerebral aneurysm model based on the 3D-DSA image data;

[0010] Acquiring a hemodynamic index A and a blood flow velocity, wherein the hemodynamic index A is the fluid impact energy on the blood vessel wall;

[0011] Calculating the intersection of the aneurysm-bearing vessels in the 3D-DSA image data to obtain a wall shear stress contour of the deformation model, and obtaining the wall shear stress in the blood flow;

[0012] Calculate blood vessel and / or blood flow biomarkers based on hemodynamics;

[0013] The hemodynamic index A, blood flow velocity, wall shear stress and biological indexes of blood vessels and / or blood flow are summarized and the results are output.

[0014] Optionally, in a possible implementation of the first aspect, it is characterized in that:

[0015] The receiving 3D-DSA image data of the patient and reconstructing the cerebral aneurysm model based on the 3D-DSA image data comprises:

[0016] Convert 3D-DSA image data into preset DICOM files;

[0017] creating a 3D model based on grayscale values ​​in the DICOM file using a threshold;

[0018] Remove floating pixels in the 3D model using a preset tool to separate bones and blood vessels in the 3D model;

[0019] The mesh is extracted from the blood vessel through its luminal surface in a format suitable for introduction into the mesh generator.

[0020] Optionally, in a possible implementation of the first aspect, the hemodynamics is calculated based on the following formula:

[0021]

[0022]

[0023]

[0024] where ρ f is the density of the fluid, u is the blood velocity vector, the fluid velocity vector and the moving coordinate velocity are respectively, and μ is the blood dynamic viscosity (0.0035 Pa-s). In the arbitrary Lagrangian Euler (ALE) formula, uu g is the relative velocity of the fluid with respect to the moving coordinate velocity, and t is the deviatoric stress tensor.

[0025] Optionally, in a possible implementation of the first aspect, the method further includes:

[0026] The morphological parameters and cycle-averaged hemodynamic parameters were quantified;

[0027] The output results include total wall pressure, non-sphericity index, mean wall shear stress, and oscillatory shear index.

[0028] Optionally, in a possible implementation of the first aspect, different blood flow characteristics are obtained based on the following formula:

[0029]

[0030]

[0031]

[0032] Wherein, the NSI is the non-spherical index, the AWSS is the average wall shear stress, and the OSI is the oscillatory shear index.

[0033] A second aspect of an embodiment of the present invention provides an aneurysm analysis device based on hemodynamics, comprising:

[0034] A receiving-converting module, configured to receive 3D-DSA image data of a patient and reconstruct a cerebral aneurysm model based on the 3D-DSA image data;

[0035] An acquisition module, used to acquire a hemodynamic index A and a blood flow velocity, wherein the hemodynamic index A is the fluid impact energy on the blood vessel wall;

[0036] A first calculation module is used to calculate the intersection of the aneurysm-bearing vessels in the 3D-DSA image data to obtain the wall shear stress contour of the deformation model and obtain the wall shear stress in the blood flow;

[0037] A second calculation module is used to calculate the biological indexes of blood vessels and / or blood flow based on hemodynamics;

[0038] The result output module is used to summarize the hemodynamic index A, blood flow velocity, wall shear stress and biological indexes of blood vessels and / or blood flow and then output the result.

[0039] Optionally, in a possible implementation manner of the second aspect, it is characterized in that:

[0040] The receiving 3D-DSA image data of the patient and reconstructing the cerebral aneurysm model based on the 3D-DSA image data comprises:

[0041] Convert 3D-DSA image data into preset DICOM files;

[0042] creating a 3D model based on grayscale values ​​in the DICOM file using a threshold;

[0043] Remove floating pixels in the 3D model using a preset tool to separate bones and blood vessels in the 3D model;

[0044] The mesh is extracted from the blood vessel through its luminal surface in a format suitable for introduction into the mesh generator.

[0045] Optionally, in a possible implementation of the second aspect, the hemodynamics is calculated based on the following formula:

[0046]

[0047]

[0048]

[0049] where ρ f is the density of the fluid, u is the blood velocity vector, the fluid velocity vector and the moving coordinate velocity are respectively, and μ is the blood dynamic viscosity (0.0035 Pa-s). In the arbitrary Lagrangian Euler (ALE) formula, uu g is the relative velocity of the fluid with respect to the moving coordinate velocity, and t is the deviatoric stress tensor.

[0050] Optionally, in a possible implementation manner of the second aspect, the method further includes:

[0051] The morphological parameters and cycle-averaged hemodynamic parameters were quantified;

[0052] The output results include total wall pressure, non-sphericity index, mean wall shear stress, and oscillatory shear index.

[0053] According to a third aspect of an embodiment of the present invention, a readable storage medium is provided, in which a computer program is stored. When the computer program is executed by a processor, it is used to implement the method of the first aspect of the present invention and various possible designs of the first aspect.

[0054] Such indicators calculated by the technical solution of the present invention can be used to observe various flows and shear structures and be used clinically. Currently, due to the lack of unified standards and imperfect technology, most patients with intracranial aneurysms do not receive a diagnosis related to hemodynamics in the aneurysm. At the same time, current technology cannot provide similar information in vivo through invasive or non-invasive measurements. The technology provided by the present invention reconstructs the vascular system through an algorithm and uses computational fluid dynamics formulas to simulate blood flow. By analyzing the blood vessel surface and calculating the impact component of the fluid dynamic pressure, an indicator of isolated fluid impact energy can be developed, so that the key parameters of hemodynamics in intracranial aneurysms can be obtained by non-invasive measurement.

[0055] The present invention provides a complete process including vascular model and hemodynamic numerical calculation. 1) Preprocessing, including image acquisition and reconstruction. 2) Blood flow simulation based on appropriate discretization, definition of boundary conditions, realistic approximation of blood and selection of adequate solver. 3) Analysis of the obtained values ​​by extracting parameters and flow characteristics or by visual exploration.

[0056] The purpose of the present invention is to compare the hemodynamic phenomena of cerebral arteries under realistic conditions. In order to study the hemodynamic characteristics of cerebral aneurysms, the geometric shape of the patient's cerebral arteries was reconstructed based on medical data, and the blood flow was simulated using computational fluid dynamics. After deriving the wall shear stress, the present invention uses formulas to calculate and derive other hemodynamic factors, such as wall shear stress gradient, non-sphericity index, oscillatory shear index and aneurysm formation index, by guiding endothelial damage, aneurysm histological remodeling, upper pro-vessel and correlation with the location of the aneurysm. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 A flowchart of a first embodiment of a method for analyzing an aneurysm based on hemodynamics;

[0058] Figure 2 A flowchart of a second embodiment of the aneurysm analysis method based on hemodynamics;

[0059] Figure 3 Schematic diagram of blood flow simulation;

[0060] Figure 4Schematic diagram of wall shear stress simulation;

[0061] Figure 5 It is a structural diagram of the first embodiment of the aneurysm analysis device based on hemodynamics. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0063] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present invention and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in sequences other than those illustrated or described herein.

[0064] It should be understood that in various embodiments of the present invention, the size of the sequence number of each process does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0065] It should be understood that in the present invention, "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0066] It should be understood that in the present invention, "plurality" refers to two or more than two. "And / or" is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects associated before and after are in an "or" relationship. "Contains A, B and C", "Contains A, B, C" means that A, B, and C are all included, "Contains A, B or C" means that one of A, B, and C is included, and "Contains A, B and / or C" means that any one, any two, or any three of A, B, and C are included.

[0067] It should be understood that in the present invention, "B corresponding to A", "B corresponding to A", "A corresponds to B" or "B corresponds to A" means that B is associated with A and B can be determined based on A. Determining B based on A does not mean determining B based only on A, but B can also be determined based on A and / or other information. A and B match when the similarity between A and B is greater than or equal to a preset threshold.

[0068] Depending on the context, "if" as used herein may be interpreted as "when" or "when" or "in response to determining" or "in response to detecting."

[0069] The technical solution of the present invention is described in detail with specific embodiments below. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described in detail in some embodiments.

[0070] The present invention provides an aneurysm analysis method based on hemodynamics, such as Figure 1 and Figure 2 As shown, including:

[0071] Step S10: receiving 3D-DSA image data of the patient, and reconstructing a cerebral aneurysm model based on the 3D-DSA image data.

[0072] In step S10, it also includes:

[0073] Convert 3D-DSA image data into preset DICOM files;

[0074] creating a 3D model based on grayscale values ​​in the DICOM file using a threshold;

[0075] Remove floating pixels in the 3D model using a preset tool to separate bones and blood vessels in the 3D model;

[0076] The mesh is extracted from the blood vessel through its luminal surface in a format suitable for introduction into the mesh generator.

[0077] After the present invention obtains the data set in the spin sequence and acquires the patient's vascular images with a 512×512 pixel matrix size, all images are transferred to the workstation for volume rendering. A 3D digital subtraction angiography (DSA) image is digitally generated using a 3D reconstruction algorithm based on algebraic reconstruction technology, and then the 3D project is converted into a Digital Imaging and Communications in Medicine (DICOM) file with a cross-sectional thickness of 0.2 mm. The images produced by DSA are volume data containing 101 image slices of 2172×1,860 pixels. These DICOM image files are imported to reconstruct the cerebral aneurysm model. The slice thickness of the scan is 9.11 microns. After the image file is loaded, the user can see the axial, coronal and sagittal image routes. The most important first step in converting the image file into a 3D model is the segmentation process. During segmentation, the user uses a threshold to create a 3D model based on the grayscale values ​​in these DICOM files. The user can apply the "region growing" tool to remove any floating pixels in the image and separate the bones from the blood vessels. The acquired digital images and corresponding files can be directly imported to reconstruct the 3D project, from which the luminal surface of the blood vessel is extracted in a format suitable for import by the mesh generator. 3D image data in DICOM format can be directly imported by the software. The present invention can directly manipulate the original source output of the angiography machine without any modification and use it to extract the luminal surface. This method greatly contributes to the simplicity and stability of the operation and minimizes possible errors of image interpolation.

[0078] Step S20, obtaining a hemodynamic index A and a blood flow velocity, wherein the hemodynamic index A is the fluid impact energy on the blood vessel wall.

[0079] The present invention can measure a hemodynamic index A of the impact energy of a fluid isolated on the blood vessel wall. The A index is caused by the impact of a high-speed fluid column on the blood vessel wall at the starting point of the aneurysm. The derivation of this index can give a hemodynamic simulation with a "no slip" boundary condition, and by definition, the fluid velocity of all surface nodes is 0. In this way, the surface nodes are offset a small distance internally along the vector perpendicular to the blood vessel surface so as to sample the hemodynamic environment at a small distance from the wall. Then, by obtaining the projection of the velocity vector along the surface normal vector, the surface normal component of the fluid velocity can be obtained at these sampling points. The energy of the fluid is then obtained by calculating the dynamic pressure of the normal component of the fluid velocity. Therefore, this represents the energy of the fluid, which is pushed outward from the wall a small distance from the wall internally. Mesh independence is performed to determine the optimal number of elements.

[0080] To gain information on the mesh size for the flow model, the number of elements was gradually increased and the peak wall stress was calculated. Once the increase in peak stress did not exceed 5%, the optimal mesh size was determined. This metric exploits the commonality of flow deflection, subsequent impingement of a high-speed fluid column, and the formation of Dean vortices at all initiation locations. Another use of this metric is to provide a metric to informatively locate areas of the vasculature to focus on when studying aneurysm initiation. Hemodynamic impingement is an essential factor in the initiation of sidewall aneurysms because it forms the foundation or basis for the inflow jet to enter the future aneurysm. The intra-aneurysmal flow generated by the inflow jet is a major factor in aneurysm growth and rupture.

[0081] The present invention can derive a complete algorithmic vascular system and use computational fluid dynamics formulas to simulate blood flow, such as Figure 3 As shown. Red (light) areas indicate high blood flow velocity, and blue (dark) areas indicate low blood flow velocity. This model can not only accurately measure the vascular lumen, but also assess local wall thickness and heterogeneity.

[0082] Step S30, calculating the intersection of the aneurysm-bearing vessels in the 3D-DSA image data to obtain a wall shear stress contour of the deformation model, and obtaining the wall shear stress in the blood flow.

[0083] Hemodynamics were calculated based on the following formula,

[0084]

[0085]

[0086]

[0087] where ρ f is the density of the fluid, u is the blood velocity vector, the fluid velocity vector and the moving coordinate velocity are respectively, and μ is the blood dynamic viscosity (0.0035 Pa-s). In the arbitrary Lagrangian Euler (ALE) formula, uu g is the relative velocity of the fluid with respect to the moving coordinate velocity, and t is the deviatoric stress tensor.

[0088] The wall shear stress contour of the deformation model can be obtained by calculating the intersection of the aneurysm-bearing vessels in the 3D-DSA image. After obtaining the value of the wall shear stress in the specific blood flow simulated, such as Figure 4 As shown, the present invention can use a formula for numerical import and hemodynamic calculation. The formula assumes that the blood flow is laminar and Newtonian. The incompressible Navier-Stokes equation is used as a control equation applicable to the free swelling index (FSI) problem.

[0089] The present invention can quantitatively analyze the segmentation and hemodynamic variability relative to the vascular domain. Although the vascular radius shows inconsistent relative standard deviations throughout the centerline of all three data sets, the change in velocity magnitude through the formula can increase with the increase in centerline length. Therefore, this formula assumes that zero pressure is used at the outlet boundary and anti-slip conditions are applied to the surface of the arterial wall. Five different times (t1, t2, t3, t4, t5) are selected in the calculation to analyze the hemodynamic behavior. The inflow at the entrance of the middle cerebral artery accelerates early in the inlet velocity time waveform t1=0.05s and reaches a maximum value of 0.61m / s at t2=0.08s. Thereafter, the velocity amplitude begins to decrease and drops to 0.42m / s at t3=0.18s. Then, the blood flow is at 0.385m / s (t4=0.52s) and 0.35m / s (t5=0.88s).

[0090] The present invention can calculate the mass flow rate at the outlet and the velocity of two points that deviate from the vessel wall near the aneurysm area. In one cardiac cycle, the average inlet velocity varies between 0.35m / s5 and 0.61m / s. The Reynolds numbers at the maximum, minimum and average blood flow rates are approximately 220, 124 and 154, respectively. In order to obtain a stable solution, the calculation will run four cardiac cycles in clinical measurement, and the results of the fourth cardiac cycle will be used to output the results so as to reduce the numerical error to less than 1% compared with the results of the third cardiac cycle, so as to minimize the misdiagnosis rate.

[0091] Step S40, calculating biological indicators of blood vessels and / or blood flow based on hemodynamics;

[0092] In the calculation, the present invention first uses the vessel centerline to quantify the overall intergroup variability. In this regard, the local maximum inscribed sphere radius (segmented) and local velocity amplitude (hemodynamics) are evaluated, and the standard deviation is calculated. Secondly, the present invention can quantify the morphological parameters (stomation area, parent vessel area adjacent to the stoma, aneurysm volume, non-sphericity index) and cycle-averaged hemodynamic (aneurysm neck inflow rate, parent vessel flow velocity, spatial average aneurysm velocity) parameters. Here, the mouth is defined as the minimum common plane between the aneurysm and the corresponding parent vessel to make the results comparable. Finally, the velocity surface, average wall shear stress (Average wall shear stress, AWSS), and oscillatory shear index (oscillatory shear index, OSI) are calculated to observe the various flow and shear structures. The final output parameters will show the total wall pressure, non-sphericity index (Nonsphericity index, NSI), average wall shear stress (Average wall shearstress, AWSS), and oscillatory shear index (OSI). Based on the local vessel radius and velocity magnitude along the centerline, segmentation and hemodynamic variability relative to the vascular domain can be quantitatively analyzed.

[0093] Different blood flow characteristics are obtained based on the following formulas,

[0094]

[0095]

[0096]

[0097] Wherein, the NSI is the non-spherical index, the AWSS is the average wall shear stress, and the OSI is the oscillatory shear index.

[0098] The parameters used are volume (V), surface area (S), cycle time (T) and wall shear stress of the corresponding aneurysm. All the parameters used are clinical results obtained by modeling.

[0099] Step S50: Summarize the hemodynamic index A, blood flow velocity, wall shear stress, and biological indexes of blood vessels and / or blood flow and output the result.

[0100] The present invention also has the following advantages, including:

[0101] 1. The application of hemodynamics as an auxiliary tool for studying patient-specific hemodynamics is becoming increasingly practical. Since hemodynamic impact plays an important role in the initiation of sidewall aneurysms, the detection of the rupture area of ​​intracranial aneurysms before surgery is crucial for every neurosurgeon. The computational blood flow modeling of intracranial aneurysms in the present invention has great potential in evaluating highly resolved hemodynamics and derived wall pressures, which can improve knowledge in important research areas, such as rupture risk assessment and treatment optimization. At the same time, when the present invention is used to analyze clinically relevant morphological and hemodynamic parameters, it is highly sensitive to the selection of aneurysm orifice and neck curves. It shows that the present invention can fully fill the gap in the existing clinical non-invasive measurement of key hemodynamic parameters in intracranial aneurysms. At the same time, it can also locate the vascular system area to be concerned when studying aneurysm attacks in an information-based manner. This practical method simplifies the geometry of patient-specific aneurysms in numerical simulation models to reduce calculation time. By considering the basic elastic characteristics of blood vessels and aneurysms, patient-specific computer modeling, combined with information from other imaging methods, can provide important insights into hemodynamics before and after surgical or endovascular treatment.

[0102] 2. The algorithm-specific parameter A is used in the calculation. In clinical diagnosis and treatment, the local increase of A is closely related to the location of the aneurysm orifice, and the universality of the starting point promotes the practicality of the predictive ability of A. This information can greatly help doctors obtain more information on hemodynamics and intracranial aneurysms.

[0103] 3. The present invention can be used to measure the visibility of intracranial artery side branches (such as ophthalmic artery, anterior choroidal artery and posterior communicating artery). There is little information on intracranial artery side branches in the current medical clinical database, and the present invention can further improve it.

[0104] The embodiment of the present invention also provides an aneurysm analysis device based on hemodynamics, such as Figure 4 As shown, including:

[0105] A receiving-converting module, configured to receive 3D-DSA image data of a patient and reconstruct a cerebral aneurysm model based on the 3D-DSA image data;

[0106] An acquisition module, used to acquire a hemodynamic index A and a blood flow velocity, wherein the hemodynamic index A is the fluid impact energy on the blood vessel wall;

[0107] A first calculation module is used to calculate the intersection of the aneurysm-bearing vessels in the 3D-DSA image data to obtain the wall shear stress contour of the deformation model and obtain the wall shear stress in the blood flow;

[0108] A second calculation module is used to calculate the biological indexes of blood vessels and / or blood flow based on hemodynamics;

[0109] The result output module is used to summarize the hemodynamic index A, blood flow velocity, wall shear stress and biological indexes of blood vessels and / or blood flow and then output the result.

[0110] In one embodiment, receiving 3D-DSA image data of a patient and reconstructing a cerebral aneurysm model based on the 3D-DSA image data comprises:

[0111] Convert 3D-DSA image data into preset DICOM files;

[0112] creating a 3D model based on grayscale values ​​in the DICOM file using a threshold;

[0113] Remove floating pixels in the 3D model using a preset tool to separate bones and blood vessels in the 3D model;

[0114] The mesh is extracted from the blood vessel through its luminal surface in a format suitable for introduction into the mesh generator.

[0115] In one embodiment, hemodynamics is calculated based on the following formula,

[0116]

[0117]

[0118]

[0119] where ρ f is the density of the fluid, u is the blood velocity vector, the fluid velocity vector and the moving coordinate velocity are respectively, and μ is the blood dynamic viscosity (0.0035 Pa-s). In the arbitrary Lagrangian Euler (ALE) formula, uu g is the relative velocity of the fluid with respect to the moving coordinate velocity, and t is the deviatoric stress tensor.

[0120] In one embodiment, it further includes:

[0121] The morphological parameters and cycle-averaged hemodynamic parameters were quantified;

[0122] The output results include total wall pressure, non-sphericity index, mean wall shear stress, and oscillatory shear index.

[0123] Among them, the readable storage medium can be a computer storage medium or a communication medium. The communication medium includes any medium that facilitates the transmission of a computer program from one place to another. The computer storage medium can be any available medium that can be accessed by a general-purpose or special-purpose computer. For example, a readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can be located in an application-specific integrated circuit (Application Specific Integrated Circuits, abbreviated as: ASIC). In addition, the ASIC can be located in a user device. Of course, the processor and the readable storage medium can also exist in a communication device as discrete components. The readable storage medium can be a read-only memory (ROM), a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, and an optical data storage device, etc.

[0124] The present invention also provides a program product, which includes an execution instruction, which is stored in a readable storage medium. At least one processor of a device can read the execution instruction from the readable storage medium, and at least one processor executes the execution instruction so that the device implements the methods provided in the above various embodiments.

[0125] In the above-mentioned terminal or server embodiments, it should be understood that the processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), etc. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the present invention may be directly implemented as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

[0126] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for analyzing aneurysms based on hemodynamics, characterized in that: include: receiving 3D-DSA image data of a patient, and reconstructing a cerebral aneurysm model based on the 3D-DSA image data; Acquiring a hemodynamic index A and a blood flow velocity, wherein the hemodynamic index A is the fluid impact energy on the blood vessel wall; The hemodynamic index A is caused by the high-speed fluid column hitting the blood vessel wall at the starting point of the aneurysm. The surface node will be offset a short distance inside along the vector perpendicular to the blood vessel surface so as to sample the hemodynamic environment at a short distance from the wall. Then, the surface normal component of the fluid velocity is obtained at the sampling point by obtaining the projection of the velocity vector along the surface normal vector. The energy of the fluid is obtained by calculating the dynamic pressure of the normal component of the fluid velocity. Calculating the intersection of the aneurysm-bearing vessels in the 3D-DSA image data to obtain a wall shear stress contour of the deformation model, and obtaining the wall shear stress in the blood flow; Calculate blood vessel and / or blood flow biomarkers based on hemodynamics; The hemodynamic index A, blood flow velocity, wall shear stress and biological indexes of blood vessels and / or blood flow are summarized and the results are output.

2. The aneurysm analysis method based on hemodynamics according to claim 1, characterized in that: The receiving 3D-DSA image data of the patient and reconstructing the cerebral aneurysm model based on the 3D-DSA image data comprises: Convert 3D-DSA image data into preset DICOM files; creating a 3D model based on grayscale values ​​in the DICOM file using a threshold; Remove floating pixels in the 3D model using a preset tool to separate bones and blood vessels in the 3D model; The mesh is extracted from the blood vessel through its luminal surface in a format suitable for introduction into the mesh generator.

3. The aneurysm analysis method based on hemodynamics according to claim 1, characterized in that: Also includes: The morphological parameters and cycle-averaged hemodynamic parameters were quantified; The output results include total wall pressure, non-sphericity index, mean wall shear stress, and oscillatory shear index.

4. The aneurysm analysis method based on hemodynamics according to claim 3, characterized in that: Different blood flow characteristics are obtained based on the following formulas, Wherein, the NSI is the non-sphericity index, the AWSS is the average wall shear stress, the OSI is the oscillatory shear index, V is the volume of the aneurysm, S is the surface area of ​​the aneurysm, T is the cardiac cycle, and WSS is is the fluid wall shear stress.

5. An aneurysm analysis device based on hemodynamics, characterized in that: include: A receiving-converting module, configured to receive 3D-DSA image data of a patient and reconstruct a cerebral aneurysm model based on the 3D-DSA image data; An acquisition module, used to acquire a hemodynamic index A and a blood flow velocity, wherein the hemodynamic index A is the fluid impact energy on the blood vessel wall; The hemodynamic index A is caused by the high-speed fluid column hitting the blood vessel wall at the starting point of the aneurysm. The surface node will be offset a short distance inside along the vector perpendicular to the blood vessel surface so as to sample the hemodynamic environment at a short distance from the wall. Then, the surface normal component of the fluid velocity is obtained at the sampling point by obtaining the projection of the velocity vector along the surface normal vector. The energy of the fluid is obtained by calculating the dynamic pressure of the normal component of the fluid velocity. A first calculation module is used to calculate the intersection of the aneurysm-bearing vessels in the 3D-DSA image data to obtain the wall shear stress contour of the deformation model and obtain the wall shear stress in the blood flow; A second calculation module is used to calculate the biological indexes of blood vessels and / or blood flow based on hemodynamics; The result output module is used to summarize the hemodynamic index A, blood flow velocity, wall shear stress and biological indexes of blood vessels and / or blood flow and then output the result.

6. The aneurysm analysis device based on hemodynamics according to claim 5, characterized in that: The receiving 3D-DSA image data of the patient and reconstructing the cerebral aneurysm model based on the 3D-DSA image data comprises: Convert 3D-DSA image data into preset DICOM files; creating a 3D model based on grayscale values ​​in the DICOM file using a threshold; Remove floating pixels in the 3D model using a preset tool to separate bones and blood vessels in the 3D model; The mesh is extracted from the blood vessel through its luminal surface in a format suitable for introduction into the mesh generator.

7. The aneurysm analysis device based on hemodynamics according to claim 5, characterized in that: Also includes: The morphological parameters and cycle-averaged hemodynamic parameters were quantified; The output results include total wall pressure, non-sphericity index, mean wall shear stress, and oscillatory shear index.

8. A readable storage medium, characterized in that: The readable storage medium stores a computer program, and the computer program is used to implement any one of the methods of claims 1 to 4 when executed by a processor.

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