A method and system for determining intracranial hemodynamic parameters

Abstract

An embodiment of the present specification provides a method for determining intracranial hemodynamic parameters, including: determining a three-dimensional vascular model based on CT angiography data; and determining boundary conditions of each inlet and / or each outlet of the three-dimensional vascular model based on CT perfusion imaging data and CT angiography data.

Description

Technical Field

[0001] This specification relates to the field of diagnostic scanning, and in particular to a method and system for determining intracranial hemodynamic parameters. Background Art

[0002] Numerous basic and clinical studies have shown that abnormal hemodynamic environment is an important cause of vascular endothelial cell damage and is closely related to the occurrence of various cardiovascular and cerebrovascular diseases. Therefore, conducting research on the occurrence, development, and treatment of cerebrovascular diseases from a hemodynamic perspective has important scientific value and clinical significance. Through numerical calculations of computational fluid dynamics, hemodynamic parameters such as blood pressure, blood flow velocity, wall shear stress, and oscillation shear index in the region of interest in the blood vessel can be determined. However, how to quickly and accurately simulate the inlet and outlet boundary conditions of the blood vessel has become a constraint that affects the efficiency and effectiveness of computational fluid dynamics calculations.

[0003] Therefore, it is desired to provide a method and system for determining intracranial hemodynamic parameters, so as to quickly and accurately determine the boundary conditions of intracranial blood vessels, thereby determining the intracranial hemodynamic parameters. Summary of the Invention

[0004] One of the embodiments of the present specification provides a method for determining intracranial hemodynamic parameters, the method comprising: determining a three-dimensional model of a blood vessel based on CT angiography data; and determining boundary conditions of each inlet and / or each outlet of the three-dimensional model of the blood vessel based on CT perfusion imaging data and the CT angiography data.

[0005] One of the embodiments of the present specification also provides a system for determining intracranial hemodynamic parameters, the system comprising: a first determination module for determining a three-dimensional model of a blood vessel based on CT angiography data; a second determination module for determining the boundary conditions of each inlet and / or each outlet of the three-dimensional model of the blood vessel based on CT perfusion imaging data and the CT angiography data.

[0006] One of the embodiments of this specification further provides an apparatus for determining intracranial hemodynamic parameters, comprising a processor, wherein the processor is configured to execute the method for determining intracranial hemodynamic parameters as described in any one of the above embodiments.

[0007] One of the embodiments of this specification also provides a computer-readable storage medium, which stores computer instructions. When a computer reads the computer instructions in the storage medium, the computer executes the method for determining intracranial hemodynamic parameters as described in any one of the above embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] This specification will be further described in the form of exemplary embodiments, which will be further described by the accompanying drawings. These embodiments are not limiting, and in these embodiments, the same numbers represent the same structure, wherein:

[0009] Figure 1 is a schematic diagram of an application scenario of a system for determining intracranial hemodynamic parameters according to some embodiments of this specification;

[0010] Figure 2 is an exemplary module diagram of a processing device according to some embodiments of this specification;

[0011] Figure 3 is a schematic diagram of a method for determining intracranial hemodynamic parameters according to some embodiments of the specification;

[0012] Figure 4 is a schematic diagram of determining boundary conditions of each inlet of a three-dimensional blood vessel model according to some embodiments of the specification;

[0013] Figure 5 is an exemplary flow chart for determining boundary conditions of each outlet of a three-dimensional blood vessel model according to some embodiments of the specification;

[0014] Figure 6 It is a schematic diagram of determining the hemodynamic parameters of a specified area in an adjusted three-dimensional blood vessel model according to some embodiments of the specification. DETAILED DESCRIPTION

[0015] To more clearly illustrate the technical solutions of the embodiments of this specification, the following briefly describes the drawings required for describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this specification. Those skilled in the art can apply this specification to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or otherwise noted, the same reference numerals in the figures represent the same structure or operation.

[0016] It should be understood that the terms "system," "device," "unit," and / or "module" used herein are a method for distinguishing different components, elements, parts, portions, or assemblies at different levels. However, if other terms can achieve the same purpose, the terms may be replaced by other expressions.

[0017] The words "first", "second" and similar words used in the specification and claims of this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "a" or "an" do not indicate a quantitative limitation, but rather indicate the presence of at least one. Unless otherwise indicated, words such as "front", "back", "lower" and / or "upper" are only for ease of description and are not limited to one position or one spatial orientation. Generally speaking, the terms "include" and "comprising" only indicate the inclusion of clearly identified steps and elements, and these steps and elements do not constitute an exclusive list, and the method or device may also include other steps or elements.

[0018] Flowcharts are used throughout this specification to illustrate the operations performed by systems according to embodiments of this specification. It should be understood that preceding or following operations do not necessarily need to be performed in exact order. Instead, the steps may be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0019] Figure 1 It is a schematic diagram of an application scenario of a system for determining intracranial hemodynamic parameters according to some embodiments of this specification.

[0020] The intracranial hemodynamic parameter determination system 100 can be used to calculate the hemodynamic parameters of intracranial blood vessels, wherein the hemodynamic parameters include but are not limited to blood pressure, blood velocity, blood flow, wall shear stress (WSS), oscillatory shear index (OSI), etc. Figure 1 As shown, in some embodiments, the application scenario of the intracranial hemodynamic parameter determination system 100 may include CT angiography data 110 , CT perfusion imaging data 120 , a terminal device 130 , a processing device 140 , a storage device 150 and a network 160 .

[0021] The CT angiography data 110 may refer to data information of a patient's blood vessels obtained through CT angiography technology. In some embodiments, based on the CT angiography data 110 , three-dimensional structural information of the patient's tissues and organs may be reflected.

[0022] The CT perfusion imaging data 120 may refer to data information of a patient's blood vessels obtained through CT perfusion imaging technology. In some embodiments, the blood supply status of the patient's tissues and organs may be reflected based on the CT perfusion imaging data 120 .

[0023] The terminal device 130 may be any terminal for sending or receiving instructions. The terminal device 130 may communicate and / or connect with other components of the system 100 (e.g., the processing device 140). In some embodiments, the terminal device 130 may include one or any combination of a mobile device 131, a tablet computer 132, a laptop computer 133, a desktop computer 134, or other devices with input and / or output functions. In some embodiments, a user (e.g., a doctor, an operator) may operate the terminal device 130 and issue instructions to other components of the system 100.

[0024] The processing device 140 can process data and / or information obtained from other devices or various components of the system 100. For example, the processing device 140 can obtain CT angiography data 110 and CT perfusion imaging data 120 and analyze and process them. In some embodiments, the processing device 140 can be a single server or a server group. The server group can be centralized or distributed. In some embodiments, the processing device 140 can be local or remote. In some embodiments, the processing device 140 can be implemented on a cloud platform. For example, the cloud platform can include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an inter-cloud cloud, a multi-cloud, etc., or any combination thereof. In some embodiments, the processing device 140 can include one or more processors (e.g., a single-chip processor or a multi-chip processor). In some embodiments, the processing device 140 can be a standalone device. In some embodiments, the processing device 140 can be part of the terminal device 130. For example, the processing device 140 can be integrated into the terminal device 130.

[0025] The storage device 150 can store data, instructions, and / or any other information. For example, the storage device 150 can store CT angiography data 110 and CT perfusion imaging data 120. For another example, the storage device 150 can store data obtained from various components of the system 100, such as the processing device 140. In some embodiments, the storage device 150 can store data and / or instructions used by the processing device 140 to execute or use to complete the exemplary methods described in this specification. In some embodiments, the storage device 150 can include a mass storage device, a removable memory, a volatile read-write memory, a read-only memory (ROM), etc., or any combination thereof. In some embodiments, the storage device 150 can be implemented on a cloud platform.

[0026] Network 160 can connect the various components of system 100 and / or connect the system with external resources. In some embodiments, the various components of system 100 can exchange information and / or data via network 160. For example, processing device 140 and terminal device 130 can connect or communicate via network 160. In some embodiments, network 160 can include at least one network access point. For example, network 160 can include wired and / or wireless network access points, such as base stations and / or Internet exchange points. At least one component of system 100 can connect to network 160 via the access point to exchange data and / or information.

[0027] It should be noted that the application scenarios of the system 100 for determining intracranial hemodynamic parameters are provided for illustrative purposes only and are not intended to limit the scope of this application. For those skilled in the art, various modifications or variations can be made based on the description of this specification. For example, the system 100 for determining intracranial hemodynamic parameters can also include an information source (e.g., a scanning device) of CT angiography data 110 and CT perfusion imaging data 120. For another example, the system 100 for determining intracranial hemodynamic parameters can implement similar or different functions on other devices. However, these changes and modifications will not deviate from the scope of this application.

[0028] Figure 2 is an exemplary module diagram of a processing device according to some embodiments of the present specification.

[0029] like Figure 2 As shown, in some embodiments, the processing device 140 may include a first determination module 210 and a second determination module 220 .

[0030] The first determination module 210 can be used to determine a 3D blood vessel model based on CT angiography data. For more information about CT angiography data and 3D blood vessel models, see Figure 3 The related descriptions will not be repeated here.

[0031] The second determination module 220 can be used to determine the boundary conditions of each inlet and / or each outlet of the three-dimensional blood vessel model based on the CT perfusion imaging data and the CT angiography data. For more information about the boundary conditions of each inlet and / or each outlet of the CT perfusion imaging data and the three-dimensional blood vessel model, see Figure 3 The related descriptions will not be repeated here.

[0032] In some embodiments, the processing device 140 may further include an adjustment module 230 and a third determination module 240 .

[0033] The adjustment module 230 can be used to adjust the vascular three-dimensional model based on the adjustment parameters to obtain an adjusted vascular three-dimensional model. For more information about the adjustment parameters and the adjusted vascular three-dimensional model, please refer to Figure 6 The related descriptions will not be repeated here.

[0034] The third determination module 240 can be used to determine the hemodynamic parameters of the specified area in the adjusted 3D vascular model based on the adjusted 3D vascular model and its corresponding boundary conditions. For more information about the boundary conditions corresponding to the adjusted 3D vascular model and the hemodynamic parameters of the specified area in the adjusted 3D vascular model, please refer to Figure 6 The related descriptions will not be repeated here.

[0035] It should be understood that Figure 2 The various modules of the processing device 140 shown can be implemented in various ways. For example, in some embodiments, they can be implemented through hardware, software, or a combination of software and hardware. The above description of the various modules of the processing device 140 is for convenience only and does not limit this specification to the scope of the embodiments illustrated. It is understood that those skilled in the art, after understanding the principles thereof, may arbitrarily combine the various modules without departing from such principles, or form a subsystem connected to other modules. For example, the various functions of the first determination module 210, the second determination module 220, the adjustment module 230, and the third determination module 240 may be implemented on the same module, or the functions of the above modules may be implemented by multiple modules together.

[0036] Figure 3 FIG3 is a schematic diagram of a method for determining intracranial hemodynamic parameters according to some embodiments of the specification. In some embodiments, process 300 may be executed by processing device 140. Figure 3 As shown, process 300 includes the following steps:

[0037] Step 310 : Determine a three-dimensional blood vessel model based on the CT angiography data. In some embodiments, step 310 may be implemented by the first determination module 210 .

[0038] In some embodiments, the corresponding blood vessels of the patient can be modeled based on CT angiography data to obtain a three-dimensional vascular model of the patient's blood vessels. The three-dimensional vascular model can include at least one inlet and at least one outlet, wherein the inlet can refer to the inlet of blood flow in the three-dimensional vascular model, and the outlet can refer to the outlet of blood flow in the three-dimensional vascular model. The three-dimensional vascular model can be a complete cerebral arterial circle model including the lesion in the patient's skull, or a complete anterior cerebral circulation or posterior cerebral circulation model including the lesion, or a model of the affected side vascular segment including the lesion. The formats of the three-dimensional vascular model can include but are not limited to stl, stp, igs, etc.

[0039] It should be understood that different patients have different physical conditions and health conditions. Therefore, there are differences in the three-dimensional blood vessel models determined based on the CT angiography data of each patient.

[0040] Step 320 : Based on the CT perfusion imaging data and the CT angiography data, determine the boundary conditions of each inlet and / or each outlet of the 3D blood vessel model. In some embodiments, step 320 may be implemented by the second determination module 220 .

[0041] In some embodiments, the boundary conditions of each inlet of the three-dimensional blood vessel model may include a corrected flow rate of each inlet of the three-dimensional blood vessel model. For more information on the corrected flow rate of each inlet, see Figure 4 In some embodiments, the boundary conditions of each outlet of the three-dimensional blood vessel model may include the arterial viscosity resistance, peripheral resistance and compliance of each outlet of the three-dimensional blood vessel model. For more information on the arterial viscosity resistance, peripheral resistance and compliance of each outlet, see Figure 5 In some embodiments, the boundary conditions of each inlet and each outlet of the three-dimensional blood vessel model may also include other parameters, such as the blood pressure at each inlet and each outlet.

[0042] In some embodiments, various data analysis algorithms, such as regression analysis and discriminant analysis, can be used to analyze and process CT perfusion imaging data and CT angiography data to determine the boundary conditions of each inlet and / or each outlet of the three-dimensional vascular model.

[0043] In some embodiments, the angiographic information of each inlet of the three-dimensional vascular model can be determined based on CT angiography data, the angiographic information of each inlet including the first intraluminal density attenuation gradient and / or the first CT value of each inlet of the three-dimensional vascular model; the first total cerebral blood flow of all inlets of the three-dimensional vascular model can be determined based on CT perfusion imaging data; and the boundary conditions of each inlet of the three-dimensional vascular model can be determined based on the angiographic information of each inlet in the three-dimensional vascular model and the first total cerebral blood flow. For more information on the above-mentioned embodiment of determining the boundary conditions of each inlet of the three-dimensional vascular model, see Figure 4 The relevant instructions will not be repeated here.

[0044] In some embodiments, the cerebral blood flow of each outlet of the three-dimensional vascular model and the second total cerebral blood flow of all outlets can be determined based on CT perfusion imaging data; the outlet area, the second intraluminal density attenuation gradient, and the second CT value of each outlet of the three-dimensional vascular model can be determined based on CT angiography data; the boundary conditions of each outlet of the three-dimensional vascular model can be determined based on one or more of the cerebral blood flow of each outlet, the second total cerebral blood flow of all outlets, the outlet area, the second intraluminal density attenuation gradient, and the second CT value. For more information on the boundary conditions of each outlet of the above-mentioned three-dimensional vascular model, please refer to Figure 5 And its related content will not be repeated here.

[0045] In some embodiments, hemodynamic parameters corresponding to the three-dimensional vascular model can be determined based on the three-dimensional vascular model and the boundary conditions of each inlet and outlet of the three-dimensional vascular model. For example, when the three-dimensional vascular model is a three-dimensional model of an intracranial vascular vessel, the intracranial hemodynamic parameters can be determined based on the three-dimensional vascular model and the boundary conditions of each inlet and outlet of the three-dimensional vascular model.

[0046] In some embodiments, the three-dimensional model of the blood vessel can be meshed based on a computational fluid dynamics solver to obtain a three-dimensional model of the blood vessel divided into different grids. The computational fluid dynamics solver can determine the hemodynamic parameters corresponding to the three-dimensional model of the blood vessel based on the boundary conditions of each inlet and each outlet of each three-dimensional model of the blood vessel. Among them, the computational fluid dynamics solver can be obtained in a variety of ways, for example, it can be obtained through the network. In some embodiments, the grid can be a structured grid or an unstructured grid. In some embodiments, it can also be selected whether to divide the boundary layer grid. In some embodiments, the grid of some positions in the three-dimensional model of the blood vessel can be encrypted. For example, the grid of the lesion area in the three-dimensional model of the blood vessel can be encrypted to obtain more and more detailed hemodynamic parameter information in the area.

[0047] Figure 4FIG4 is a schematic diagram of determining the boundary conditions of each inlet of the three-dimensional blood vessel model according to some embodiments of the present invention. In some embodiments, the process 400 can be executed by the second determination module 220. Figure 4 As shown, process 400 includes the following steps:

[0048] Step 410 : Determine angiography information of each inlet of the three-dimensional blood vessel model based on the CT angiography data. The angiography information of each inlet includes a first intraluminal density attenuation gradient and / or a first CT value of each inlet of the three-dimensional blood vessel model.

[0049] The angiographic information of each inlet may refer to information related to each inlet in a three-dimensional blood vessel model obtained based on CT angiography data. In some embodiments, the angiographic information of each inlet may include a first intraluminal density attenuation gradient and / or a first CT value of each inlet in the three-dimensional blood vessel model.

[0050] The first intraluminal density attenuation gradient may refer to the intraluminal density attenuation gradient at each inlet in the three-dimensional vascular model. The transluminal density attenuation gradient (TAG) is the linear regression coefficient between the intraluminal density attenuation and the length from the arterial opening to the end of the vessel. The intraluminal density attenuation gradient may be different at different locations in the vessel. In some embodiments, the first intraluminal density attenuation gradient may be obtained from CT angiography data.

[0051] The first CT value may refer to the CT value of each inlet in the three-dimensional vascular model. The CT value can measure the density of a local tissue or organ in the human body. In some embodiments, the first CT value may be obtained from CT angiography data. For example, the CT value of a certain inlet in the three-dimensional vascular model obtained from the CT angiography data is 32 HU.

[0052] Step 420 : Determine a first total cerebral blood flow of all inlets of the three-dimensional vascular model based on the CT perfusion imaging data.

[0053] The first total cerebral blood flow may refer to the sum of the cerebral blood flow of all inlets of the vascular three-dimensional model. In some embodiments, the first total cerebral blood flow may be obtained from CT perfusion imaging data. The perfusion parameters of the vascular three-dimensional model may be determined based on the CT perfusion imaging data. The perfusion parameters may include, but are not limited to, cerebral blood flow (CBF), local cerebral blood volume (CBV), etc., wherein cerebral blood flow may be a set of values ​​reflecting the cerebral blood flow at different time points in a cardiac cycle of a blood vessel, and local cerebral blood volume may reflect the values ​​of cerebral blood volume at different time points in a cardiac cycle of a region of interest (ROI) in a blood vessel. When there are multiple ROIs, the local cerebral blood volume may have multiple sets of values. The ROI of the vascular three-dimensional model may be the inlet or outlet of the vascular three-dimensional model. The ROI may be pre-selected by the user. When the vascular three-dimensional model is a complete cerebral artery circle model, the corresponding ROI can be selected on the bilateral internal carotid arteries and vertebral basilar arteries; when the vascular three-dimensional model is a complete anterior or posterior cerebral circulation, the corresponding ROI can be selected on the bilateral internal carotid arteries or vertebral basilar arteries respectively; when the vascular three-dimensional model is an affected-side vascular segment, the corresponding ROI can be selected at the beginning of the vascular segment. When the selected ROI is each inlet of the vascular three-dimensional model, the cerebral blood flow of each inlet can be obtained to obtain the first total cerebral blood flow. Correspondingly, when the selected ROI is each outlet of the vascular three-dimensional model, the cerebral blood flow of each outlet can be obtained to obtain the second total cerebral blood flow. For more information about the second total cerebral blood flow, see Figure 5 The related descriptions will not be repeated here.

[0054] When there is only one inlet in the three-dimensional vascular model, the cerebral blood flow curve of the inlet within one cardiac cycle can be directly calculated based on the time-density curve. When there are two or more inlets in the three-dimensional vascular model, the cerebral blood flow curve of each inlet calculated based on the time-density curve needs to be corrected to obtain a corrected flow curve for each inlet. The cerebral blood flow curve or the corrected flow curve can both reflect the cerebral blood flow corresponding to the ROI at different time points in one cardiac cycle. The corrected flow can refer to the cerebral blood flow obtained after correcting the ROI in the three-dimensional vascular model. For example, the corrected flow of each inlet can refer to the cerebral blood flow obtained after correcting the cerebral blood flow of each inlet in the three-dimensional vascular model.

[0055] Step 430 : Determine boundary conditions of each inlet of the three-dimensional blood vessel model based on the angiography information of each inlet of the three-dimensional blood vessel model and the first total cerebral blood flow.

[0056] In some embodiments, various data analysis algorithms may be used to process the angiographic information of each inlet in the three-dimensional vascular model and the first total cerebral blood flow to determine the boundary conditions of each inlet in the three-dimensional vascular model.

[0057] In some embodiments, for each inlet in the three-dimensional vascular model, a corrected flow rate at that inlet can be determined based on the ratio of the first intraluminal density attenuation gradient corresponding to that inlet to the total intraluminal density attenuation gradients of the inlets and the first total cerebral blood flow. The total intraluminal density attenuation gradient of the inlet can refer to the sum of the first intraluminal density attenuation gradients of all inlets in the three-dimensional vascular model.

[0058] In some embodiments, the corrected flow rate of each inlet of the three-dimensional blood vessel model can be determined based on formula (1):

[0059]

[0060] Where ΔQ i is the corrected flow rate of the i-th inlet in the 3D vascular model at a certain time point in a cardiac cycle; is the first total cerebral blood flow of the vascular three-dimensional model at that time point; Tag i is the density attenuation gradient within the first lumen of the i-th inlet in the blood vessel; is the density attenuation gradient of the total inlet lumen of the vascular three-dimensional model at that time point; n is the total number of inlets of the vascular three-dimensional model. In some embodiments, the corrected flow rate of each inlet of the vascular three-dimensional model can also be determined based on formula (2):

[0061]

[0062] Where ΔQ i 、 Tags i 、 The content represented by n has been explained in detail in formula (1) and will not be repeated here; α and β are correction coefficients for correcting the cerebral blood flow at each inlet based on the density attenuation gradient in the lumen, which can be preset.

[0063] In some embodiments, for each inlet in the three-dimensional vascular model, a corrected flow rate at the inlet may be determined based on the ratio of the first CT value corresponding to the inlet to the total CT value and the first total cerebral blood flow. The total CT value may refer to the sum of the first CT values ​​of all inlets in the three-dimensional vascular model. In some embodiments, the corrected flow rate for each inlet in the three-dimensional vascular model may be determined based on formula (3):

[0064]

[0065] Where ΔQ i 、 The content represented by n has been explained in detail in formula (1) and will not be repeated here; CT i is the first CT value of the i-th inlet in the blood vessel; is the total CT value of all inlets of the 3D vascular model at that time point; n is the total number of inlets of the 3D vascular model. In some embodiments, the corrected flow rate of each inlet of the 3D vascular model can also be determined based on formula (4):

[0066]

[0067] Where ΔQ i 、 CT i , CT i The contents represented by ω1 and n have been explained in detail in formula (3) and will not be repeated here. ω1 and β2 are correction coefficients for correcting the cerebral blood flow of each inlet based on the CT value and can be set in advance.

[0068] In some embodiments, for each inlet in the three-dimensional vascular model, a corrected flow rate is determined for the inlet based on the ratio of the first intraluminal density attenuation gradient corresponding to the inlet to the total intraluminal density attenuation gradient of the inlet, the ratio of the first CT value corresponding to the inlet to the total CT value, and the first total cerebral blood flow. In some embodiments, the corrected flow rate for each inlet in the three-dimensional vascular model can also be determined based on formula (5):

[0069]

[0070] Where ΔQ i 、 Tags i 、 CT i , CT i The contents represented by α2, ω2, and β3 have been explained in detail in formulas (1) and (3) and will not be repeated here. α2, ω2, and β3 are correction coefficients for correcting the cerebral blood flow at each inlet based on the intraluminal density attenuation gradient and CT value, and can be set in advance.

[0071] In some embodiments, the corrected flow rate for each inlet can also be determined by other means. For example, based on the density attenuation gradient within the first lumen, a corresponding correction coefficient is determined, and the cerebral blood flow at each inlet is corrected based on the correction coefficient to determine the corrected flow rate for each inlet. The correction coefficient corresponding to the density attenuation gradient within the first lumen can be determined based on a preset correspondence. For example, if the density attenuation gradient within the first lumen of a certain inlet of a blood vessel is -7.6HU / 10mm, the correction coefficient corresponding to the density attenuation gradient within the first lumen is 1.1, and the cerebral blood flow at the inlet is 20ml / 100g, the corrected flow rate for the inlet is determined to be 22ml / 100g.

[0072] Figure 5 This is an exemplary flow chart for determining the boundary conditions of each outlet of the three-dimensional blood vessel model according to some embodiments of the specification. In some embodiments, process 500 can be executed by the second determination module 220. Figure 5 As shown, process 500 includes the following steps:

[0073] Step 510: Determine the cerebral blood flow of each outlet of the three-dimensional vascular model and the second total cerebral blood flow of all outlets based on the CT perfusion imaging data.

[0074] The second total cerebral blood flow can refer to the sum of the cerebral blood flow of all outlets in the 3D vascular model. For more information on obtaining the cerebral blood flow of each outlet and the second total cerebral blood flow of all outlets based on CT perfusion imaging data, see Figure 4 The related descriptions will not be repeated here.

[0075] Step 520 : Determine the outlet area of ​​each outlet of the three-dimensional blood vessel model, the second intraluminal density attenuation gradient, and the second CT value based on the CT angiography data.

[0076] The second intraluminal density attenuation gradient may refer to the intraluminal density attenuation gradient of each outlet in the three-dimensional vascular model. The second CT value may refer to the CT value of each outlet in the three-dimensional vascular model. The second intraluminal density attenuation gradient and the second CT value may be directly obtained from CT angiography data. The outlet area of ​​each outlet may be determined based on the three-dimensional vascular model.

[0077] Step 530: Determine boundary conditions for each outlet of the three-dimensional vascular model based on one or more of the cerebral blood flow at each outlet, the second total cerebral blood flow, the outlet area, the second intraluminal density attenuation gradient, and the second CT value. In some embodiments, the boundary conditions for each outlet of the three-dimensional vascular model can be determined by analyzing and calculating based on one or more of the cerebral blood flow at each outlet, the second total cerebral blood flow, the outlet area, the second intraluminal density attenuation gradient, and the second CT value.

[0078] In some embodiments, for each outlet in the three-dimensional vascular model, the compliance of the outlet can be determined based on the proportion of the cerebral blood flow corresponding to the outlet to the second total cerebral blood flow and the total outlet compliance. The total outlet compliance is the sum of the compliances of all outlets in the three-dimensional vascular model. In some embodiments, the total outlet compliance can be calculated using formula (6):

[0079]

[0080] Among them, Q max , Q min are the sum of the peak value and the sum of the trough value of the corrected flow curves of all inlets of the 3D vascular model within one cardiac cycle; P max 、P min are the systolic pressure and diastolic pressure respectively obtained by measuring the patient's blood pressure; γ is the first adjustment coefficient, which can be preset; C total In some embodiments, the total outlet compliance can also be determined by other methods.

[0081] In some embodiments, the compliance of each outlet of the three-dimensional blood vessel model can be determined based on formula (7):

[0082]

[0083] Among them, C k is the compliance of the kth outlet of the 3D vascular model, Q k is the cerebral blood flow at the kth outlet of the 3D vascular model; is the second total cerebral blood flow; C total is the total outlet compliance; m is the total number of outlets in the three-dimensional vascular model; δ is the second adjustment coefficient, which can be preset.

[0084] In some embodiments, for each outlet in the three-dimensional vascular model, the compliance of each outlet can also be determined based on the ratio of the outlet area of ​​each outlet to the total outlet area, the ratio of the cerebral blood flow of each outlet to the second total cerebral blood flow, the ratio of the second CT value of each outlet to the sum of the second CT values ​​of all outlets, and the ratio of the second intraluminal density attenuation gradient of each outlet to the total intraluminal density attenuation gradient of the outlet, where the total intraluminal density attenuation gradient of the outlet can be the sum of the second intraluminal density attenuation gradients of all outlets, and the total outlet area can be the sum of the outlet areas of all outlets. In some embodiments, the compliance of each outlet can also be determined based on formula (8):

[0085]

[0086] Among them, C k , Q k 、 C total The meanings of A and m have been explained in formula (7) and will not be repeated here. k is the outlet area of ​​the kth outlet of the 3D blood vessel model; is the total outlet area; Tag k is the density attenuation gradient in the second lumen of the k-th outlet of the blood vessel; is the total outlet intraluminal density attenuation gradient; CT k is the second CT value of the kth outlet of the 3D vascular model; is the sum of the second CT values ​​of all exports; ∈, θ, a are the third, fourth, fifth and sixth adjustment coefficients respectively, which can be preset.

[0087] In some embodiments, for each outlet in the three-dimensional vascular model, the compliance of each outlet can be determined based on any one or more of the following: the ratio of the outlet area of ​​each outlet to the total outlet area, the ratio of the cerebral blood flow of each outlet to the second total cerebral blood flow, the ratio of the second CT value of each outlet to the sum of the second CT values ​​of all outlets, and the ratio of the second intraluminal density attenuation gradient of each outlet to the total intraluminal density attenuation gradient of the outlets. When determining the compliance of each outlet in the three-dimensional vascular model based on any one or more of the following: the ratio of the outlet area of ​​each outlet to the total outlet area, the ratio of the cerebral blood flow of each outlet to the second total cerebral blood flow, the ratio of the second CT value of each outlet to the sum of the second CT values ​​of all outlets, and the ratio of the second intraluminal density attenuation gradient of each outlet to the total intraluminal density attenuation gradient of the outlets, the various items included in Formula (8) can be deleted and their corresponding adjustment coefficients adjusted. For example, when the compliance of each outlet is determined based on the proportion of the outlet area of ​​each outlet to the total outlet area and the proportion of the cerebral blood flow of each outlet to the second total cerebral blood flow in the three-dimensional vascular model, formula (8) can be adjusted to obtain formula (9):

[0088]

[0089] Among them, C k , Q k 、 C total 、A k 、 The meaning of m has been explained in formula (8) and will not be repeated here; ∈1 and θ1 are the third and fourth adjustment coefficients after adjustment, respectively, and both can be preset.

[0090] In some embodiments, for each outlet in the three-dimensional vascular model, the outlet resistance of the outlet can be determined based on the proportion of the cerebral blood flow corresponding to the outlet to the second total cerebral blood flow and the total outlet resistance. The total outlet resistance can be the sum of the outlet resistances of all outlets in the three-dimensional vascular model. In some embodiments, the total outlet resistance can be determined based on formula (10):

[0091]

[0092] Among them, R total is the total outlet resistance; P mean is the average value of the patient's blood pressure, which can be obtained by averaging the blood pressure of the patient; Q mean The average cerebral blood flow of each inlet of the three-dimensional vascular model can be determined based on the first total cerebral blood flow and the number of inlets of the three-dimensional vascular model.

[0093] In some embodiments, the outlet resistance of each outlet can be determined according to formula (11):

[0094]

[0095] Among them, Q k 、 R total The meaning has been explained in formula (10) and will not be repeated here; R k is the outlet resistance value of the kth outlet of the three-dimensional blood vessel model; μ is the sixth adjustment coefficient, which can be preset.

[0096] In some embodiments, for each outlet in the three-dimensional vascular model, the outlet resistance of each outlet can be determined based on the ratio of the outlet area of ​​each outlet to the total outlet area, the ratio of the cerebral blood flow of each outlet to the second total cerebral blood flow, the ratio of the second CT value of each outlet to the sum of the second CT values ​​of all outlets, and the ratio of the second intraluminal density attenuation gradient of each outlet to the total intraluminal density attenuation gradient of the outlet. In some embodiments, the outlet resistance of each outlet can also be determined based on formula (12):

[0097]

[0098] Among them, R k 、C k , Q k 、 C total 、A k 、 Tags k 、 CT k 、 R totalThe meanings of ρ, σ, τ, and b are the seventh, eighth, ninth, and tenth adjustment coefficients, respectively, and can be preset.

[0099] In some embodiments, for each outlet in the three-dimensional vascular model, the outlet resistance of each outlet may be determined based on any one or more of the following: the ratio of the outlet area of ​​each outlet to the total outlet area, the ratio of the cerebral blood flow of each outlet to the second total cerebral blood flow, the ratio of the second CT value of each outlet to the sum of the second CT values ​​of all outlets, and the ratio of the second intraluminal density attenuation gradient of each outlet to the total intraluminal density attenuation gradient of the outlet. When determining the outlet resistance of each outlet based on any one or more of the ratio of the outlet area of ​​each outlet to the total outlet area, the ratio of the cerebral blood flow of each outlet to the second total cerebral blood flow, the ratio of the second CT value of each outlet to the sum of the second CT values ​​of all outlets, and the ratio of the second intraluminal density attenuation gradient of each outlet to the total intraluminal density attenuation gradient of the outlet, the various items included in formula (12) may be deleted and their corresponding adjustment coefficients adjusted to determine the value. For example, when the outlet resistance of each outlet is determined based on the proportion of the cerebral blood flow of each outlet to the second total cerebral blood flow and the proportion of the density attenuation gradient in the second lumen of each outlet to the density attenuation gradient in the total outlet lumen, formula (12) can be adjusted to obtain formula (13):

[0100]

[0101] Among them, σ1 and τ1 are the eighth and ninth adjustment coefficients after adjustment, respectively, and both can be preset. The meanings of other elements in formula (13) can be found in the above text of this specification and will not be repeated here.

[0102] In some embodiments, for each outlet in the three-dimensional blood vessel model, the arterial viscosity resistance and the peripheral resistance of the outlet are determined based on the outlet resistance value of the outlet in the three-dimensional blood vessel model.

[0103] The outlet resistance value of each outlet in the three-dimensional vascular model can be the sum of the arterial viscous resistance and peripheral resistance of the outlet. In some embodiments, the arterial viscous resistance and peripheral resistance are proportional. Therefore, the arterial viscous resistance and peripheral resistance of each outlet can be determined based on formula (14):

[0104]

[0105] Among them, R p is the arterial viscosity resistance at a certain outlet of the 3D vascular model; R d is the peripheral resistance of the outlet; It is a preset ratio and can be determined by presetting.

[0106] Figure 6 FIG6 is a schematic diagram of determining hemodynamic parameters of a specified region in an adjusted three-dimensional blood vessel model according to some embodiments of the present disclosure. In some embodiments, process 600 may be executed by the processing device 140 . Figure 6 As shown, process 600 includes the following steps:

[0107] Step 610 , adjusting the vascular three-dimensional model based on the adjustment parameters to obtain an adjusted vascular three-dimensional model. In some embodiments, step 610 may be performed by the adjustment module 230 .

[0108] In some embodiments, morphological parameters of a three-dimensional blood vessel model may be adjusted based on adjustment parameters to obtain an adjusted three-dimensional blood vessel model. Morphological parameters may refer to parameters that characterize the morphology of the three-dimensional blood vessel model. Adjustment parameters may refer to pre-set parameters for adjusting the three-dimensional blood vessel model, which may be pre-set by the user.

[0109] Step 620 : Based on the adjusted 3D blood vessel model and its corresponding boundary conditions, determine the hemodynamic parameters of the designated region in the adjusted 3D blood vessel model. In some embodiments, step 620 may be performed by the third determining module 240 .

[0110] In some embodiments, boundary conditions corresponding to the adjusted three-dimensional model can be determined based on the adjustment parameters. The boundary conditions corresponding to the adjusted three-dimensional vascular model can include boundary conditions at the inlet and outlet of the adjusted three-dimensional vascular model. The boundary conditions corresponding to the adjusted three-dimensional vascular model can be determined based on the boundary conditions corresponding to the three-dimensional vascular model and the adjustment parameters, using a pre-set corresponding adjustment relationship between the adjustment parameters and the boundary conditions. The boundary conditions corresponding to the three-dimensional vascular model can include boundary conditions at the inlet and outlet of the three-dimensional vascular model.

[0111] In some embodiments, the adjusted three-dimensional vascular model can be gridded, and the gridded mesh and boundary conditions corresponding to the adjusted three-dimensional vascular model can be input into a computational fluid dynamics solver to determine the hemodynamic parameters corresponding to each grid point, thereby determining the hemodynamic parameters of a specified region within the vessel corresponding to the adjusted three-dimensional vascular model. For example, the hemodynamic parameters of a lesion within the vessel corresponding to the adjusted three-dimensional vascular model can be determined. For another example, the hemodynamic parameters of the entire vessel corresponding to the adjusted three-dimensional vascular model can be determined.

[0112] Some embodiments of this specification also disclose a device for determining intracranial hemodynamic parameters, including a processor, characterized in that the processor is used to execute the above-mentioned method for determining intracranial hemodynamic parameters.

[0113] Some embodiments of this specification further disclose a computer-readable storage medium, which stores computer instructions. When a computer reads the computer instructions in the storage medium, the computer executes the above-mentioned method for determining intracranial hemodynamic parameters.

[0114] The beneficial effects that may be brought about by the embodiments of this specification include but are not limited to: 1) the ability to calculate and process based on CT angiography data and CT perfusion imaging data without invasiveness, and accurately, quickly and efficiently determine the boundary conditions of each inlet and / or outlet of the three-dimensional vascular model, thereby determining the hemodynamic parameters of the blood vessel; 2) the flow curve calculated based on the CT perfusion imaging data is corrected using the first intraluminal density attenuation gradient obtained based on the CT angiography data to obtain a corrected flow curve, and computational fluid dynamics calculations can be performed more accurately based on the corrected flow curve without repeated iterations; 3) the three-dimensional vascular model can be adjusted to obtain the hemodynamic parameters of the patient's lesion area at different lesion stages (for example, lesion formation, lesion development and lesion relief periods) for analysis and processing.

[0115] It should be noted that the description of the above processes is only for illustration and explanation, and does not limit the scope of application of this specification. For those skilled in the art, various modifications and changes can be made to the processes under the guidance of this specification, and these modifications and changes are still within the scope of this specification.

[0116] While the basic concepts have been described above, it will be apparent to those skilled in the art that the detailed disclosure is merely illustrative and does not limit this specification. Although not explicitly stated herein, various modifications, improvements, and revisions to this specification may be made by those skilled in the art. Such modifications, improvements, and revisions are suggested in this specification and remain within the spirit and scope of the exemplary embodiments of this specification.

[0117] This specification also uses specific terms to describe the embodiments of this specification. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a feature, structure, or characteristic associated with at least one embodiment of this specification. Therefore, it should be emphasized and noted that references to "one embodiment," "an embodiment," or "an alternative embodiment" two or more times in different locations in this specification do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of this specification may be appropriately combined.

[0118] In addition, unless expressly stated in the claims, the order of the processing elements and sequences, the use of alphanumeric characters, or the use of other names described in this specification are not intended to limit the order of the processes and methods of this specification. Although the above disclosure discusses some of the invention embodiments currently considered useful through various examples, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the spirit and scope of the embodiments of this specification. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on an existing server or mobile device.

[0119] Similarly, it should be noted that, in order to simplify the presentation of this specification and thus facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this specification sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not imply that the subject matter of this specification requires more features than those recited in the claims. In fact, an embodiment may have fewer features than all of the features of a single disclosed embodiment.

[0120] Each patent, patent application, patent application publication, and other materials, such as articles, books, specifications, publications, and documents, cited in this specification is hereby incorporated by reference in its entirety. This includes application history documents that are inconsistent with or conflict with the content of this specification, as well as documents (currently or subsequently attached to this specification) that limit the broadest scope of the claims of this specification. It should be noted that if the descriptions, definitions, and / or terminology used in the accompanying materials are inconsistent or conflicting with the content of this specification, the descriptions, definitions, and / or terminology used in this specification will control.

[0121] Finally, it should be understood that the embodiments described in this specification are intended only to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly described and illustrated in this specification.

Claims

1. A method for determining intracranial hemodynamic parameters, characterized in that: include: Determine the three-dimensional model of blood vessels based on CT angiography data; Determining boundary conditions of each inlet of the three-dimensional blood vessel model or determining boundary conditions of each inlet and each outlet of the three-dimensional blood vessel model based on the CT perfusion imaging data and the CT angiography data; Wherein, determining the boundary conditions of each inlet of the three-dimensional blood vessel model based on the CT perfusion imaging data and the CT angiography data includes: determining angiography information of each inlet of the three-dimensional blood vessel model based on the CT angiography data, wherein the angiography information of each inlet includes a first intraluminal density attenuation gradient and / or a first CT value of each inlet of the three-dimensional blood vessel model; determining a first total cerebral blood flow of all inlets of the three-dimensional vascular model based on the CT perfusion imaging data; Based on the angiography information of each inlet in the three-dimensional blood vessel model and the first total cerebral blood flow, boundary conditions of each inlet in the three-dimensional blood vessel model are determined.

2. The method according to claim 1, characterized in that Determining the boundary conditions of each inlet of the three-dimensional blood vessel model based on the angiographic information of each inlet of the three-dimensional blood vessel model and the first total cerebral blood flow includes: For each of the inlets in the three-dimensional vascular model, determining a corrected flow rate for the inlet based on a ratio of the first intraluminal density attenuation gradient corresponding to the inlet to the total intraluminal density attenuation gradient of the inlet and the first total cerebral blood flow; or For each of the inlets in the three-dimensional vascular model, determining a corrected flow rate of the inlet based on a ratio of the first CT value corresponding to the inlet to the total CT value and the first total cerebral blood flow; or For each of the inlets in the three-dimensional vascular model, the corrected flow rate of the inlet is determined based on the proportion of the first intraluminal density attenuation gradient corresponding to the inlet to the total intraluminal density attenuation gradient of the inlet, the proportion of the first CT value corresponding to the inlet to the total CT value, and the first total cerebral blood flow.

3. The method according to claim 1, characterized in that Also includes: Adjusting the three-dimensional blood vessel model based on the adjustment parameters to obtain an adjusted three-dimensional blood vessel model; Based on the adjusted three-dimensional blood vessel model and its corresponding boundary conditions, hemodynamic parameters of a designated area in the adjusted three-dimensional blood vessel model are determined.

4. The method according to claim 3, characterized in that Also includes: Based on the adjustment parameters, the boundary conditions corresponding to the adjusted three-dimensional blood vessel model are determined.

5. A method for determining intracranial hemodynamic parameters, characterized in that: include: Determine the three-dimensional model of blood vessels based on CT angiography data; Determining boundary conditions of each outlet of the three-dimensional blood vessel model or determining boundary conditions of each inlet and each outlet of the three-dimensional blood vessel model based on the CT perfusion imaging data and the CT angiography data; Wherein, determining the boundary conditions of each outlet of the three-dimensional blood vessel model based on the CT perfusion imaging data and the CT angiography data includes: determining the cerebral blood flow of each outlet of the three-dimensional vascular model and a second total cerebral blood flow of all outlets based on the CT perfusion imaging data; determining, based on the CT angiography data, an outlet area of ​​each outlet of the three-dimensional blood vessel model, a second intraluminal density attenuation gradient, and a second CT value; Boundary conditions of each outlet of the three-dimensional blood vessel model are determined based on one or more of the cerebral blood flow of each outlet, the second total cerebral blood flow, the outlet area, the second intraluminal density attenuation gradient, and the second CT value.

6. The method according to claim 5, characterized in that Determining the boundary conditions of each outlet of the three-dimensional blood vessel model based on one or more of the cerebral blood flow of each outlet, the second total cerebral blood flow, the outlet area, the second intraluminal density attenuation gradient, and the second CT value includes: For each of the outlets in the three-dimensional vascular model, determining an outlet resistance of the outlet based on a proportion of the cerebral blood flow corresponding to the outlet to the second total cerebral blood flow and a total outlet resistance; Based on the outlet resistance value of the outlet, the arterial viscosity resistance and the peripheral resistance of the outlet are determined.

7. The method according to claim 5, characterized in that Determining the boundary conditions of each outlet of the three-dimensional blood vessel model based on one or more of the cerebral blood flow of each outlet, the second total cerebral blood flow, the outlet area, the second intraluminal density attenuation gradient, and the second CT value includes: For each outlet in the three-dimensional blood vessel model, the compliance of the outlet is determined based on the proportion of the cerebral blood flow corresponding to the outlet to the second total cerebral blood flow and the total outlet compliance.

8. A system for determining intracranial hemodynamic parameters, characterized in that: The system comprises: A first determination module is used to determine a three-dimensional blood vessel model based on CT angiography data; a second determining module, configured to determine, based on the CT perfusion imaging data and the CT angiography data, boundary conditions of each inlet of the three-dimensional blood vessel model or boundary conditions of each inlet and each outlet of the three-dimensional blood vessel model, wherein the second determining module is further configured to: determining angiography information of each inlet of the three-dimensional blood vessel model based on the CT angiography data, wherein the angiography information of each inlet includes a first intraluminal density attenuation gradient and / or a first CT value of each inlet of the three-dimensional blood vessel model; determining a first total cerebral blood flow of all inlets of the three-dimensional vascular model based on the CT perfusion imaging data; Based on the angiography information of each inlet in the three-dimensional blood vessel model and the first total cerebral blood flow, boundary conditions of each inlet in the three-dimensional blood vessel model are determined.

9. The system according to claim 8, characterized in that Also includes: an adjustment module, configured to adjust the three-dimensional blood vessel model based on adjustment parameters to obtain an adjusted three-dimensional blood vessel model; The third determining module is configured to determine the hemodynamic parameters of a designated area in the adjusted three-dimensional blood vessel model based on the adjusted three-dimensional blood vessel model and its corresponding boundary conditions.

10. A system for determining intracranial hemodynamic parameters, characterized in that: The system comprises: A first determination module is used to determine a three-dimensional blood vessel model based on CT angiography data; a second determining module, configured to determine, based on the CT perfusion imaging data and the CT angiography data, boundary conditions of each outlet of the three-dimensional blood vessel model or boundary conditions of each inlet and each outlet of the three-dimensional blood vessel model, wherein the second determining module is further configured to: determining the cerebral blood flow of each outlet of the three-dimensional vascular model and a second total cerebral blood flow of all outlets based on the CT perfusion imaging data; determining, based on the CT angiography data, an outlet area of ​​each outlet of the three-dimensional blood vessel model, a second intraluminal density attenuation gradient, and a second CT value; Boundary conditions of each outlet of the three-dimensional blood vessel model are determined based on one or more of the cerebral blood flow of each outlet, the second total cerebral blood flow, the outlet area, the second intraluminal density attenuation gradient, and the second CT value.

11. A device for determining intracranial hemodynamic parameters, comprising a processor, wherein the processor is configured to execute the method for determining intracranial hemodynamic parameters according to any one of claims 1 to 7.

12. A computer-readable storage medium storing computer instructions, wherein when a computer reads the computer instructions in the storage medium, the computer executes the method for determining intracranial hemodynamic parameters according to any one of claims 1 to 7.

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