Method, device and equipment for calculating blood flow reserve fraction and storage medium

Abstract

The application belongs to the technical field of data processing, and discloses a blood flow reserve fraction calculation method, device, equipment and storage medium. The method comprises the following steps: obtaining the blood vessel diameter of multiple nodes on the center line of a blood vessel and the blood vessel volume of the blood vessel according to a three-dimensional blood vessel model of the blood vessel; calculating the reference diameter of each node on the center line to determine the reference diameter of each node; determining a target narrow section in the blood vessel and a target narrow rate corresponding to the target narrow section according to the blood vessel diameter of each node and the reference diameter of each node; determining the volume flow of the blood vessel according to the target narrow rate corresponding to the target narrow section and the blood vessel volume, and determining the blood flow reserve fraction of the blood vessel based on the volume flow. In the foregoing manner, the volume flow is corrected, the accuracy of the determination of the volume flow is improved, and the accuracy of the calculation of the blood flow reserve fraction is effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of data processing, and in particular to a blood flow reserve fraction calculation method, device, equipment and storage medium. BACKGROUND

[0002] Fractional Flow Reserve (FFR): refers to the ratio of the maximum blood flow that the myocardial region supplied by the coronary artery with stenosis can obtain to the maximum blood flow that the same region can obtain under normal conditions. The current methods for obtaining FFR parameters include invasive and non-invasive methods; among them, the invasive measurement method mainly measures the average pressure of the stenosis distal end and the aortic entrance of the coronary artery under the condition of hyperemia through the pressure guide wire, and the ratio of the two average pressures is the value of FFR. This method is the current gold standard for obtaining FFR; and the non-invasive measurement techniques mainly include ct-FFR based on CT data and QFR (Quantitative Flow Ratio) based on coronary angiography data. The current FFR calculation based on angiography data mainly includes pressure drop calculation based on empirical formula or 0D / 3D simulation calculation. Both methods often determine the blood flow first, so the accuracy of the blood flow directly determines the accuracy of the final calculation result. In the current conventional method, the volume flow is often directly calculated by the volume of the blood vessel and the time, but the above method ignores the nonlinear relationship between the flow and the volume of the blood vessel, resulting in low accuracy of the blood flow calculation, and thus the calculation result of the blood flow reserve fraction is not accurate. SUMMARY

[0003] The main purpose of the present application is to provide a blood flow reserve fraction calculation method, device, equipment and storage medium, which aims to solve the technical problem of how to improve the accuracy of blood flow reserve fraction calculation in the prior art.

[0004] To achieve the above-mentioned purpose, the present application provides a blood flow reserve fraction calculation method, which comprises:

[0005] obtaining the vessel diameter of a plurality of nodes on the centerline of the blood vessel and the vessel volume of the blood vessel according to the three-dimensional blood vessel model of the blood vessel;

[0006] calculating the reference diameter of each node on the centerline to determine the reference diameter of each node;

[0007] determining the target stenosis segment in the blood vessel and the target stenosis rate corresponding to the target stenosis segment according to the vessel diameter of each node and the reference diameter of each node;

[0008] Determine a volume flow of the blood vessel according to the target stenosis rate corresponding to the target stenosis segment and the volume of the blood vessel, and determine a flow reserve of the blood vessel based on the volume flow.

[0009] Optionally, the calculating the reference pipe diameter of each node on the centerline comprises:

[0010] Calculating the reference pipe diameter of each node on the centerline to determine the initial pipe diameter of each node;

[0011] Verifying the initial pipe diameter of each node according to the node position of each node on the centerline to obtain a verification result;

[0012] When the verification result is a qualified result, performing difference calculation according to the blood vessel pipe diameter of each node and the initial pipe diameter of each node;

[0013] When the difference result meets a preset condition, taking the initial pipe diameter of each node as the reference pipe diameter of each node.

[0014] Optionally, the determining the target stenosis segment in the blood vessel and the target stenosis rate corresponding to the target stenosis segment according to the stenosis rate of each node in the suspected stenosis segment comprises:

[0015] Performing difference calculation according to the blood vessel pipe diameter of each node and the reference pipe diameter of each node to obtain a pipe diameter difference value of each node;

[0016] When there is a pipe diameter difference value that is not a preset value in the pipe diameter difference value of each node, determining a suspected stenosis segment in the blood vessel according to the node corresponding to the pipe diameter difference value that is not the preset value;

[0017] Calculating a stenosis rate of each node in the suspected stenosis segment according to the pipe diameter difference value of each node in the suspected stenosis segment and the reference pipe diameter of each node;

[0018] Determining the target stenosis segment in the blood vessel and the target stenosis rate corresponding to the target stenosis segment according to the stenosis rate of each node in the suspected stenosis segment.

[0019] Optionally, the determining the target stenosis segment in the blood vessel and the target stenosis rate corresponding to the target stenosis segment according to the stenosis rate of each node in the suspected stenosis segment comprises:

[0020] Sorting the stenosis rate of each node in the suspected stenosis segment, and determining the target stenosis rate corresponding to the suspected stenosis segment according to a sorting result;

[0021] Comparing the target stenosis rate corresponding to the suspected stenosis segment with a stenosis rate threshold;

[0022] when the target stenosis rate corresponding to the suspected stenosis segment is greater than the stenosis rate threshold, the suspected stenosis segment is regarded as a target stenosis segment.

[0023] Optionally, the volume flow rate of the blood vessel is determined according to the target stenosis rate corresponding to the target stenosis segment and the volume of the blood vessel, comprising:

[0024] When there are multiple target stenosis segments, the target stenosis rates corresponding to the multiple target stenosis segments are sorted to determine an extreme stenosis segment and a target stenosis rate corresponding to the extreme stenosis segment.

[0025] The reagent flow time is determined according to the angiography data of the blood vessel.

[0026] The volume flow rate of the blood vessel is determined by flow rate calculation according to the reagent flow time, the target stenosis rate corresponding to the extreme stenosis segment, the volume of the blood vessel, and a preset volume coefficient.

[0027] Optionally, the reagent flow time is determined according to the angiography data of the blood vessel, comprising:

[0028] The starting cross section of the blood vessel, the ending cross section of the blood vessel, and the filling state of the reagent in each angiography image are determined according to the angiography data of the blood vessel.

[0029] The reagent starting frame and the reagent ending frame are determined according to the starting cross section of the blood vessel, the ending cross section of the blood vessel, and the filling state of the reagent in each angiography image.

[0030] The actual flow time is obtained according to the reagent starting frame, the reagent ending frame, and a preset angiography frequency.

[0031] Optionally, the blood flow reserve fraction of the blood vessel is determined based on the volume flow rate, comprising:

[0032] The target pressure drop is obtained by pressure drop calculation according to the volume flow rate, a preset viscous resistance coefficient, and a preset inertial resistance coefficient.

[0033] The blood flow reserve fraction of the blood vessel is determined according to the target pressure drop and the root pressure of the target blood vessel.

[0034] In addition, to achieve the above-mentioned purpose, the application further provides a blood flow reserve fraction calculation device, which comprises:

[0035] The processing module is used for obtaining the vessel diameter of multiple nodes on the centerline of the blood vessel and the volume of the blood vessel according to the three-dimensional blood vessel model of the blood vessel.

[0036] The calculation module is used for calculating the reference vessel diameter of each node on the centerline to determine the reference vessel diameter of each node.

[0037] The processing module is further configured to determine a target stenosis segment in the blood vessel and a target stenosis rate corresponding to the target stenosis segment according to the vessel diameter of each node and the reference vessel diameter of each node.

[0038] The processing module is further configured to determine a volume flow of the blood vessel according to the target stenosis rate corresponding to the target stenosis segment and the volume of the blood vessel, and determine a flow reserve fraction of the blood vessel based on the volume flow.

[0039] In addition, to achieve the above object, the present application further provides a flow reserve fraction calculation device, which comprises a memory, a processor and a flow reserve fraction calculation program stored in the memory and executable on the processor, and the flow reserve fraction calculation program is configured to implement the flow reserve fraction calculation method as described above.

[0040] In addition, to achieve the above object, the present application further provides a storage medium, which stores a flow reserve fraction calculation program, and the flow reserve fraction calculation program is executed by a processor to implement the flow reserve fraction calculation method as described above.

[0041] The present application obtains the vessel diameter of a plurality of nodes on the centerline of the blood vessel and the volume of the blood vessel according to the three-dimensional blood vessel model of the blood vessel, calculates the reference vessel diameter of each node on the centerline to determine the reference vessel diameter of each node, determines a target stenosis segment in the blood vessel and a target stenosis rate corresponding to the target stenosis segment according to the vessel diameter of each node and the reference vessel diameter of each node, determines a volume flow of the blood vessel according to the target stenosis rate corresponding to the target stenosis segment and the volume of the blood vessel, and determines a flow reserve fraction of the blood vessel based on the volume flow. In this way, the target stenosis segment in the blood vessel and the target stenosis rate corresponding to the target stenosis segment are determined based on the vessel diameter of each node on the centerline of the blood vessel and the reference vessel diameter of each node, the volume flow of the blood vessel is determined based on the target stenosis rate corresponding to the target stenosis segment and the volume of the blood vessel, and the flow reserve fraction is determined based on the volume flow. The volume flow is corrected, the accuracy of determining the volume flow is improved, and the accuracy of calculating the flow reserve fraction is effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 FIG. 1 is a structural schematic diagram of a flow reserve fraction calculation device of a hardware running environment involved in an embodiment scheme of the present application;

[0043] Figure 2 FIG. 2 is a flowchart of a flow reserve fraction calculation method according to a first embodiment of the present application;

[0044] Figure 3Flowchart of a second embodiment of the blood flow reserve fraction calculation method of the present application.

[0045] Figure 4 Structure block diagram of a first embodiment of the blood flow reserve fraction calculation device of the present application.

[0046] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0047] It should be understood that the specific embodiments described herein are merely exemplary and do not limit the present application.

[0048] Reference Figure 1 , Figure 1 Structure diagram of the blood flow reserve fraction calculation device of the hardware running environment involved in the embodiment of the present application.

[0049] As Figure 1 shown, the blood flow reserve fraction calculation device can include a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. The communication bus 1002 is used to realize the connection and communication between the components. The user interface 1003 can include a display, an input unit such as a keyboard, and can also include a standard wired interface, a wireless interface. The network interface 1004 can optionally include a standard wired interface, a wireless interface (such as a wireless fidelity (Wi-Fi) interface). The memory 1005 can be a high-speed random access memory (RAM) memory, or a stable non-volatile memory (NVM), such as a disk memory. The memory 1005 can also be a storage device independent of the aforementioned processor 1001.

[0050] Those skilled in the art can understand Figure 1 that the structure shown in the figure does not constitute a limitation on the blood flow reserve fraction calculation device, and can include more or fewer components than the figure, or combine certain components, or different component arrangements.

[0051] As Figure 1 shown, the memory 1005 as a storage medium can include an operating system, a network communication module, a user interface module, and a blood flow reserve fraction calculation program.

[0052] In Figure 1The network interface 1004 is mainly used for data communication with a network server; the user interface 1003 is mainly used for data interaction with a user; the processor 1001 and the memory 1005 in the blood flow reserve fraction calculation device can be arranged in the blood flow reserve fraction calculation device, the blood flow reserve fraction calculation device calls the blood flow reserve fraction calculation program stored in the memory 1005 through the processor 1001, and executes the blood flow reserve fraction calculation method provided in the embodiment of the application.

[0053] The embodiment of the application provides a blood flow reserve fraction calculation method, which refers to Figure 2 , Figure 2 FIG. 1 is a flowchart of a blood flow reserve fraction calculation method according to a first embodiment of the application.

[0054] The blood flow reserve fraction calculation method comprises the following steps:

[0055] Step S10: obtaining a blood vessel diameter of a plurality of nodes on a center line of the blood vessel and a blood vessel volume of the blood vessel according to a three-dimensional blood vessel model of the blood vessel.

[0056] It should be noted that the execution subject of the embodiment is a blood flow reserve fraction calculation device, wherein the blood flow reserve fraction calculation device has functions of data processing, data communication and program running, and can be an integrated controller, a control computer or other devices with similar functions, and the embodiment does not limit the blood flow reserve fraction calculation device.

[0057] It can be understood that the three-dimensional blood vessel model is created according to angiographic image data of the blood vessel, the diseased blood vessel at two angles is labeled according to the angiographic image data at the two angles, and the three-dimensional blood vessel model of the blood vessel is reconstructed according to the imaging principle of graph theory, so that the blood vessel volume V of the blood vessel can be directly obtained. A blood vessel tree model can be created according to the three-dimensional blood vessel model of each blood vessel, and the blood flow reserve fraction of each blood vessel in the blood vessel tree model is calculated.

[0058] In a specific implementation, the center line of the blood vessel and the blood vessel diameter corresponding to each node on the center line are determined according to the three-dimensional blood vessel model of the blood vessel. Since the blood vessel is not strictly circular, the equivalent surface diameter of the cross section is taken as the blood vessel diameter, denoted as R_real, and it is ensured that each cross section is perpendicular to the center line.

[0059] Step S20: calculating the reference diameter of each node on the center line to determine the reference diameter of each node.

[0060] It should be noted that the reference tube diameter R_ref corresponding to each node on the center line of the blood vessel is calculated to determine the reference tube diameter of each node. To ensure that the reference tube diameter conforms to the blood vessel distribution, the calculation process of the reference tube diameter needs to meet certain constraints. Further, the calculation of the reference tube diameter of each node on the center line and the determination of the reference tube diameter of each node include: calculating the initial tube diameter of each node on the center line; verifying the initial tube diameter of each node according to the node position of each node on the center line to obtain a verification result; when the verification result is a qualified result, performing difference calculation according to the blood vessel diameter of each node and the initial tube diameter of each node; and when the difference result meets a preset condition, taking the initial tube diameter of each node as the reference tube diameter of each node.

[0061] It can be understood that the calculation of the reference tube diameter of each node on the center line and the determination of the initial tube diameter of each node, and the verification of the initial tube diameter of each node according to the node position of each node on the center line need to ensure that at any two positions of the blood vessel, the proximal reference tube diameter is greater than or equal to the distal reference tube diameter, so as to obtain a verification result of whether the reference tube diameter of each node meets the above condition. If the reference tube diameter of each node meets the above condition, the verification result is qualified, otherwise the verification result is unqualified.

[0062] In a specific implementation, when the verification result is a qualified result, difference calculation is performed according to the blood vessel diameter of each node and the initial tube diameter of each node, the difference result is , the preset condition is that the node on the center line needs to meet the minimum, and when the difference result meets the preset condition, the initial tube diameter of each node is taken as the reference tube diameter of each node. Through the above method, it can be found that in most non-stenosis regions, the reference tube diameter is the true tube diameter, and in the stenosis region, there is a significant difference between the two.

[0063] Step S30: determining a target stenosis segment in the blood vessel and a target stenosis rate corresponding to the target stenosis segment according to the blood vessel diameter of each node and the reference tube diameter of each node.

[0064] It should be noted that the target stenosis segment refers to a coronary stenosis in the blood vessel, and the target stenosis rate refers to a stenosis rate corresponding to the target stenosis segment. There can be more than one target stenosis segment on a blood vessel.

[0065] Step S40: determining the volume flow of the blood vessel according to the target stenosis rate corresponding to the target stenosis segment and the volume of the blood vessel, and determining the flow reserve fraction of the blood vessel based on the volume flow.

[0066] It should be noted that the volume flow of the blood vessel can be determined according to the target stenosis rate corresponding to the target stenosis segment and the volume of the blood vessel , in order to obtain accurate blood flow reserve fraction, further, the blood flow reserve fraction of the blood vessel is determined based on the volume flow rate, including: according to the volume flow rate, a preset viscous resistance coefficient and a preset inertial resistance coefficient, a pressure drop calculation is performed to obtain a target pressure drop; the blood flow reserve fraction of the blood vessel is determined according to the target pressure drop and the root pressure of the target blood vessel.

[0067] It can be understood that the volume flow rate is applied to the pressure drop calculation formula or as a boundary condition to the simulation calculation to obtain the target pressure drop , wherein C1 and C2 are the preset viscous resistance coefficient and the preset inertial resistance coefficient, respectively.

[0068] In a specific implementation, the target blood vessel refers to a coronary artery, and the blood flow reserve fraction of the blood vessel is determined according to the target pressure drop and the root pressure of the target blood vessel , wherein is the root pressure of the target blood vessel.

[0069] It should be noted that in the prior art, the Ct-FFR technology: uses medical image data (mainly CTA) to reconstruct a coronary blood vessel model, the model includes the ascending aorta, left and right coronary arteries and important branches thereof; after grid discretization of the coronary model, the model is imported into a CFD solver for solving to obtain the velocity field and pressure field in the entire model, and then the average values of the pressures at the positions of the stenosis distal end and the coronary artery inlet aorta are extracted through post-processing, and the ratio of the two is the value of ctFFR. The QFR technology: QFR mainly uses coronary angiography image data to reconstruct a three-dimensional model, which has higher accuracy than CT data and is more accurate in identifying stenosis; the reconstruction of the three-dimensional model is generally based on two image data, and the three-dimensional model is reconstructed according to the related theories of computer graphics. Since the information of two angles cannot completely reflect the shape of the entire blood vessel, especially the shape characteristics of the stenosis part, part of the three-dimensional information is lost. The QFR technology model based on the angiography image generally only needs to reconstruct a single blood vessel, and then the blood flow time is obtained according to the TIMI frame method, and the volume flow rate is calculated by combining the model volume, so as to provide boundary conditions for subsequent simulation or numerical calculation, and finally the pressure drop and FFR are calculated. However, the current FFR calculation based on the angiography data ignores the nonlinear relationship between the flow rate and the blood vessel volume, which may cause the average volume flow rate to be too small. In addition, due to the existence of stenosis, the actual flow rate entering the blood vessel is affected by the degree of stenosis, that is, the higher the degree of stenosis, the lower the flow rate entering the blood vessel. Through the blood flow reserve fraction calculation method of the embodiment, the accuracy of FFR calculation can be effectively improved.

[0070] ​The embodiment obtains the vessel diameter of a plurality of nodes on the center line of the blood vessel and the vessel volume of the blood vessel according to the three-dimensional blood vessel model of the blood vessel; calculates the reference vessel diameter of each node on the center line to determine the reference vessel diameter of each node; determines the target stenosis segment in the blood vessel and the target stenosis rate corresponding to the target stenosis segment according to the vessel diameter of each node and the reference vessel diameter of each node; determines the volume flow of the blood vessel according to the target stenosis rate corresponding to the target stenosis segment and the vessel volume, and determines the flow reserve fraction of the blood vessel based on the volume flow. In the above manner, the target stenosis segment in the blood vessel and the target stenosis rate corresponding to the target stenosis segment are determined based on the vessel diameter of each node on the center line of the blood vessel and the reference vessel diameter of each node, the volume flow of the blood vessel is determined based on the target stenosis rate corresponding to the target stenosis segment and the vessel volume, and the flow reserve fraction is determined based on the volume flow. The volume flow is corrected, the accuracy of determining the volume flow is improved, and thus the accuracy of calculating the flow reserve fraction is effectively improved.

[0071] Reference Figure 3 , Figure 3 The flowchart of the second embodiment of the flow reserve fraction calculation method is shown.

[0072] Based on the above first embodiment, in the flow reserve fraction calculation method, the step S30 comprises the following steps.

[0073] Step S31: Difference calculation is performed on the vessel diameter of each node and the reference vessel diameter of each node to obtain the diameter difference R_diff of each node.

[0074] It should be noted that the difference calculation is performed on the vessel diameter of each node and the reference vessel diameter of each node to obtain the diameter difference R_diff of each node.

[0075] Step S32: When there is a diameter difference value that is not the preset value in the diameter difference values of each node, the suspected stenosis segment in the blood vessel is determined according to the node corresponding to the diameter difference value that is not the preset value.

[0076] It should be noted that the preset value is 0 in this embodiment, and the suspected narrow segment refers to a potential narrow segment in the blood vessel, which can be one or more. The suspected narrow segments in the blood vessel are recorded as S1, S2, …, Sn. The initial position and the end position of each suspected narrow segment can be determined according to whether R_diff is the preset value. For example, for the mth node, R_diff>0, and for the m-1th node, R_diff=0, the node is the starting point of Sn. For the mth to the m+kth node, R_diff>0, and for the m+k+1th node, R_diff=0, the m+kth node is the termination position of the nth potential narrow segment. Meanwhile, the distance between the mth to the m+kth node, that is, the length of Sn, can be calculated according to the center line.

[0077] Step S33: calculating the narrow rate of each node in the suspected narrow segment according to the pipe diameter difference of each node in the suspected narrow segment and the reference pipe diameter of each node.

[0078] It should be noted that the narrow rate of each node in the suspected narrow segment is calculated according to the pipe diameter difference of each node in the suspected narrow segment and the reference pipe diameter of each node, that is, (R_ref - R_real) / R_ref.

[0079] Step S34: determining the target narrow segment in the blood vessel and the target narrow rate corresponding to the target narrow segment according to the narrow rate of each node in the suspected narrow segment.

[0080] It should be noted that, in order to accurately obtain the target narrow segment in the blood vessel and the target narrow rate corresponding to the target narrow segment according to the narrow rate of each node in the suspected narrow segment, further, the determination of the target narrow segment in the blood vessel and the target narrow rate corresponding to the target narrow segment according to the narrow rate of each node in the suspected narrow segment comprises: sorting the narrow rates of the nodes in the suspected narrow segment, determining the target narrow rate corresponding to the suspected narrow segment according to the sorting result; comparing the target narrow rate corresponding to the suspected narrow segment with a narrow rate threshold; and when the target narrow rate corresponding to the suspected narrow segment is greater than the narrow rate threshold, regarding the suspected narrow segment as the target narrow segment.

[0081] It can be understood that the narrow rates of the nodes in the suspected narrow segment are sorted, and the maximum value of the narrow rates of the nodes in the suspected narrow segment, that is, (R_ref - R_real) / R_ref, is searched. The maximum value of the narrow rates is the target narrow rate of the suspected narrow segment.

[0082] In a specific implementation, the target stenosis rate corresponding to the suspected stenosis segment is compared with a stenosis rate threshold, and when the target stenosis rate corresponding to the suspected stenosis segment is greater than the stenosis rate threshold, the suspected stenosis segment is taken as the target stenosis segment. In this embodiment, the stenosis rate threshold is set to 0.1, and other values can also be set according to actual needs. The value of the stenosis rate threshold mainly considers that the error of the vessel reconstruction process itself will cause a certain fluctuation in the pipe diameter, but the fluctuation generally will not be too large. Therefore, the suspected stenosis segment is screened based on the set stenosis rate threshold, so as to ensure the accuracy of the determination of the stenosis segment.

[0083] It should be noted that, in order to accurately obtain the volume flow based on the target stenosis rate corresponding to the target stenosis segment and the volume of the blood vessel, further, the volume flow of the blood vessel is determined according to the target stenosis rate corresponding to the target stenosis segment and the volume of the blood vessel, comprising: when there are multiple target stenosis segments, the target stenosis rates corresponding to the multiple target stenosis segments are sorted, and an extreme value stenosis segment and a target stenosis rate corresponding to the extreme value stenosis segment are determined; the reagent flow time is determined according to the angiography data of the blood vessel; the volume flow of the blood vessel is determined by flow calculation according to the reagent flow time, the target stenosis rate corresponding to the extreme value stenosis segment, the volume of the blood vessel, and a preset volume coefficient.

[0084] It can be understood that when there are multiple target stenosis segments, the target stenosis rates corresponding to the multiple target stenosis segments are sorted, and a target stenosis segment with the largest target stenosis rate is determined. The target stenosis segment with the largest target stenosis rate is the extreme value stenosis segment, and the target stenosis rate corresponding to the extreme value stenosis segment is denoted as Max_SR.

[0085] In a specific implementation, the reagent flow time refers to the time T that the contrast agent flows through the reconstructed blood vessel, and the preset volume coefficient refers to a coefficient preset in advance and , and the corresponding ranges are 0.5-1.5 and 0.7-0.95, respectively.

[0086] It should be noted that, according to the target stenosis rate Max_SR corresponding to the extreme value stenosis segment, a function is defined, wherein denotes the target stenosis rate Max_SR corresponding to the extreme value stenosis segment. The volume flow of the blood vessel is determined by flow calculation according to the reagent flow time, the function, the volume of the blood vessel, and the preset volume coefficient .

[0087] It can be understood that, in order to obtain an accurate reagent flow time, the determining the reagent flow time according to the angiography data of the blood vessel further comprises: determining a starting cross section of the blood vessel, a terminal cross section of the blood vessel and a filling state of the reagent in each angiography image according to the angiography data of the blood vessel; determining a reagent starting frame and a reagent terminal frame according to the starting cross section of the blood vessel, the terminal cross section of the blood vessel and the filling state of the reagent in each angiography image; and obtaining an actual flow time according to the reagent starting frame, the reagent terminal frame and a preset angiography frequency.

[0088] In a specific implementation, the starting cross section, the terminal cross section and the filling state of the contrast agent in each frame of the angiography image are determined according to the angiography data of the blood vessel and the starting position of the blood vessel, so as to determine the reagent starting frame and the reagent terminal frame. The reagent starting frame is determined according to the following constraints: 1) the contrast agent has a forward movement; and 2) the contrast agent fills the starting cross section. The reagent starting frame is recorded as N1. The reagent ending frame is determined by the following way: 1) the contrast agent has reached or passed the terminal cross section in the current frame, while the contrast agent has not reached the terminal cross section in the last frame. The reagent terminal frame is recorded as N2. The frame number N = N2 – N1 is obtained according to the above way, so as to obtain the reagent flow time T = N / fps, where fps is the preset angiography frequency, generally 15 frames / s or 30 frames / s.

[0089] It should be noted that when the target stenosis segment is only one, the target stenosis rate corresponding to the target stenosis segment is recorded as Max_SR, so as to define a function based on the formula to determine the volume flow of the blood vessel.

[0090] In the embodiment, when there is a pipe diameter difference value that is not the preset value in the pipe diameter difference values of the nodes, the suspected stenosis segment in the blood vessel is determined according to the node corresponding to the pipe diameter difference value that is not the preset value; the stenosis rate of each node in the suspected stenosis segment is calculated according to the pipe diameter difference value of each node in the suspected stenosis segment and the reference pipe diameter of each node; and the target stenosis segment in the blood vessel and the target stenosis rate corresponding to the target stenosis segment are determined according to the stenosis rate of each node in the suspected stenosis segment. In the above manner, the suspected stenosis segment in the blood vessel is determined according to the node corresponding to the pipe diameter difference value that is not the preset value, the stenosis rate of each node in the suspected stenosis segment is calculated based on the pipe diameter difference value of each node in the suspected stenosis segment and the reference pipe diameter of each node, and finally the target stenosis segment is determined in the suspected stenosis segment, thereby reducing the error rate in the determination process of the stenosis segment and ensuring the accuracy when the volume flow is calculated subsequently.

[0091] In addition, with reference to Figure 4 , the embodiment of the present application further provides a blood flow reserve fraction calculation device, which comprises:

[0092] The processing module 10 is configured to obtain the vessel diameter of each node on the centerline of the blood vessel and the volume of the blood vessel according to the three-dimensional blood vessel model of the blood vessel.

[0093] The calculation module 20 is configured to calculate the reference diameter of each node on the centerline to determine the reference diameter of each node.

[0094] The processing module 10 is further configured to determine the target stenosis segment in the blood vessel and the target stenosis rate corresponding to the target stenosis segment according to the vessel diameter of each node and the reference diameter of each node.

[0095] The processing module 10 is further configured to determine the volume flow of the blood vessel according to the target stenosis rate corresponding to the target stenosis segment and the volume of the blood vessel, and determine the flow reserve fraction of the blood vessel based on the volume flow.

[0096] The embodiment determines the target stenosis segment in the blood vessel and the target stenosis rate corresponding to the target stenosis segment based on the vessel diameter of each node on the centerline of the blood vessel and the reference diameter of each node, determines the volume flow of the blood vessel according to the target stenosis rate corresponding to the target stenosis segment and the volume of the blood vessel, and determines the flow reserve fraction of the blood vessel based on the volume flow. In this way, the target stenosis segment in the blood vessel and the target stenosis rate corresponding to the target stenosis segment are determined based on the vessel diameter of each node on the centerline of the blood vessel and the reference diameter of each node, the volume flow of the blood vessel is determined based on the target stenosis rate corresponding to the target stenosis segment and the volume of the blood vessel, and the flow reserve fraction is determined based on the volume flow. The volume flow is corrected, the accuracy of determining the volume flow is improved, and the accuracy of calculating the flow reserve fraction is effectively improved.

[0097] In an embodiment, the calculation module 20 is further configured to calculate the reference diameter of each node on the centerline to determine the initial diameter of each node.

[0098] The initial diameter of each node is verified according to the node position of each node on the centerline to obtain a verification result.

[0099] When the verification result is a qualified result, the difference between the vessel diameter of each node and the initial diameter of each node is calculated.

[0100] When the difference result meets a preset condition, the initial diameter of each node is taken as the reference diameter of each node.

[0101] In an embodiment, the processing module 10 is further configured to calculate a difference value of a vessel diameter of each node according to the vessel diameter of each node and a reference vessel diameter of each node;

[0102] When the difference value of the vessel diameter of each node is not the preset value, a suspected stenosis section in the blood vessel is determined according to the node corresponding to the difference value of the vessel diameter which is not the preset value;

[0103] A stenosis rate of each node in the suspected stenosis section is calculated according to the difference value of the vessel diameter of each node in the suspected stenosis section and the reference vessel diameter of each node;

[0104] A target stenosis section in the blood vessel and a target stenosis rate corresponding to the target stenosis section are determined according to the stenosis rate of each node in the suspected stenosis section.

[0105] In an embodiment, the processing module 10 is further configured to sort the stenosis rate of each node in the suspected stenosis section, and determine the target stenosis rate corresponding to the suspected stenosis section according to a sorting result;

[0106] The target stenosis rate corresponding to the suspected stenosis section is compared with a stenosis rate threshold value;

[0107] When the target stenosis rate corresponding to the suspected stenosis section is greater than the stenosis rate threshold value, the suspected stenosis section is taken as the target stenosis section.

[0108] In an embodiment, the processing module 10 is further configured to, when there are multiple target stenosis sections, sort the target stenosis rates corresponding to the multiple target stenosis sections, determine an extreme stenosis section and a target stenosis rate corresponding to the extreme stenosis section;

[0109] A reagent flow time is determined according to the angiography data of the blood vessel;

[0110] A volume flow rate of the blood vessel is determined by performing flow rate calculation according to the reagent flow time, the target stenosis rate corresponding to the extreme stenosis section, the volume of the blood vessel, and a preset volume coefficient.

[0111] In an embodiment, the processing module 10 is further configured to determine a starting cross section of the blood vessel, an ending cross section of the blood vessel, and a filling state of a reagent in each angiography image according to the angiography data of the blood vessel;

[0112] A reagent starting frame and a reagent ending frame are determined according to the starting cross section of the blood vessel, the ending cross section of the blood vessel, and the filling state of the reagent in each angiography image;

[0113] An actual flow time is obtained according to the reagent starting frame, the reagent ending frame, and a preset angiography frequency.

[0114] In an embodiment, the processing module 10 is further configured to calculate a pressure drop based on the volume flow, a preset viscous resistance coefficient and a preset inertial resistance coefficient, to obtain a target pressure drop.

[0115] The blood flow reserve fraction of the blood vessel is determined according to the target pressure drop and a root pressure of the target blood vessel.

[0116] Since the device adopts all the technical solutions of the above embodiments, it has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0117] In addition, the embodiment of the present application further provides a storage medium, and the storage medium stores a blood flow reserve fraction calculation program. When the blood flow reserve fraction calculation program is executed by a processor, the steps of the blood flow reserve fraction calculation method described above are implemented.

[0118] Since the storage medium adopts all the technical solutions of the above embodiments, it has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0119] It should be noted that the above-described workflow is only illustrative and does not limit the scope of protection of the present application. In actual applications, a person skilled in the art can select part or all of them to achieve the purpose of the embodiment according to actual needs, which is not limited here.

[0120] In addition, technical details not described in detail in the embodiment can be referred to the blood flow reserve fraction calculation method provided by any embodiment of the present application, which will not be repeated here.

[0121] In addition, it should be noted that in this paper, the term "includes", "contains" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or system including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such process, method, article or system. Without more limitations, the element defined by the sentence "includes a" does not exclude the presence of other identical elements in the process, method, article or system including the element.

[0122] The above-mentioned embodiment numbers of the present application are only for description, not representing the advantages and disadvantages of the embodiments.

[0123] Those skilled in the art can clearly understand the above-mentioned example method can be realized by means of software and the necessary general hardware platform, of course, also can be through hardware, but in many cases the former is a better implementation. Based on such understanding, the technical solutions of the present application essentially or say the part of the prior art contribution can be embodied in the form of software products, the computer software product is stored in a storage medium (such as read only memory (Read Only Memory, ROM) / RAM, disk, optical disk), including a number of instructions to make a terminal device (may be a mobile phone, computer, server, or network equipment, etc.) executes the method described in various embodiments of the present application.

[0124] The above is only the preferred embodiment of the present application, not therefore limit the patent scope of the present application, any equivalent structure or equivalent process transformation using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method of calculating a fractional flow reserve, characterized by, The blood flow reserve fraction calculation method comprises: obtaining the vessel diameter of a plurality of nodes on the centerline of the blood vessel and the blood vessel volume of the blood vessel according to the three-dimensional blood vessel model of the blood vessel; calculating the reference vessel diameter of each node on the centerline to determine the reference vessel diameter of each node; determining the target stenosis segment in the blood vessel and the target stenosis rate corresponding to the target stenosis segment according to the vessel diameter of each node and the reference vessel diameter of each node; determining the volume flow of the blood vessel according to the target stenosis rate corresponding to the target stenosis segment and the blood vessel volume, and determining the blood flow reserve fraction of the blood vessel based on the volume flow; the determination of the volume flow of the blood vessel according to the target stenosis rate corresponding to the target stenosis segment and the blood vessel volume comprises: when there are a plurality of target stenosis segments, sorting the target stenosis rates corresponding to the plurality of target stenosis segments to determine the extreme value stenosis segment and the target stenosis rate corresponding to the extreme value stenosis segment; determining the reagent flow time according to the angiographic data of the blood vessel; determining the volume flow of the blood vessel through flow calculation according to the reagent flow time, the target stenosis rate corresponding to the extreme value stenosis segment, the blood vessel volume, and a preset volume coefficient; the determination of the blood flow reserve fraction of the blood vessel based on the volume flow comprises: performing pressure drop calculation according to the volume flow, a preset viscous resistance coefficient, and a preset inertial resistance coefficient to obtain a target pressure drop; determining the blood flow reserve fraction of the blood vessel according to the target pressure drop and the root pressure of the target blood vessel.

2. The method of flow reserve fraction calculation of claim 1, wherein, the calculation of the reference vessel diameter of each node on the centerline to determine the reference vessel diameter of each node comprises: calculating the reference vessel diameter of each node on the centerline to determine the initial vessel diameter of each node; performing vessel diameter verification on the initial vessel diameter of each node according to the node position of each node on the centerline to obtain a verification result; when the verification result is a qualified result, performing difference calculation on the vessel diameter of each node and the initial vessel diameter of each node; when the difference result meets a preset condition, taking the initial vessel diameter of each node as the reference vessel diameter of each node.

3. The method of flow reserve fraction calculation of claim 1, wherein, the determination of the target stenosis segment in the blood vessel and the target stenosis rate corresponding to the target stenosis segment according to the vessel diameter of each node and the reference vessel diameter of each node comprises: performing difference calculation on the vessel diameter of each node and the reference vessel diameter of each node to obtain the vessel diameter difference of each node; when there is a vessel diameter difference that is not a preset value in the vessel diameter difference of each node, determining a suspected stenosis segment in the blood vessel according to the node corresponding to the vessel diameter difference that is not the preset value; calculating the stenosis rate of each node in the suspected stenosis segment according to the vessel diameter difference of each node in the suspected stenosis segment and the reference vessel diameter of each node; determining the target stenosis segment in the blood vessel and the target stenosis rate corresponding to the target stenosis segment according to the stenosis rate of each node in the suspected stenosis segment.

4. The method for calculating a flow reserve fraction according to claim 3, characterized in that, the determination of the target stenosis segment in the blood vessel and the target stenosis rate corresponding to the target stenosis segment according to the stenosis rate of each node in the suspected stenosis segment comprises: sorting the stenosis rates of each node in the suspected stenosis segment to determine the target stenosis rate corresponding to the suspected stenosis segment according to the sorting result; The target stenosis rate corresponding to the suspected stenosis segment is compared with a stenosis rate threshold value; When the target stenosis rate corresponding to the suspected stenosis segment is greater than the stenosis rate threshold value, the suspected stenosis segment is taken as a target stenosis segment.

5. The method of flow reserve fraction calculation of claim 1, wherein, The reagent flow time is determined according to the angiography data of the blood vessel, including: The starting cross section of the blood vessel, the ending cross section of the blood vessel and the filling state of the reagent in each angiography image are determined according to the angiography data of the blood vessel; The reagent starting frame and the reagent ending frame are determined according to the starting cross section of the blood vessel, the ending cross section of the blood vessel and the filling state of the reagent in each angiography image; The actual flow time is obtained according to the reagent starting frame, the reagent ending frame and a preset angiography frequency.

6. A blood flow reserve fraction calculating apparatus characterized by comprising: The blood flow reserve fraction calculation device includes: The processing module is configured to obtain the vessel diameter of a plurality of nodes on the centerline of the blood vessel and the vessel volume of the blood vessel according to the three-dimensional blood vessel model of the blood vessel; The calculation module is configured to calculate the reference diameter of each node on the centerline to determine the reference diameter of each node. The processing module is further configured to determine the target stenosis segment in the blood vessel and the target stenosis rate corresponding to the target stenosis segment according to the vessel diameter of each node and the reference diameter of each node. The processing module is further configured to determine the volume flow of the blood vessel according to the target stenosis rate corresponding to the target stenosis segment and the vessel volume of the blood vessel, and determine the blood flow reserve fraction of the blood vessel based on the volume flow. The processing module is further configured to sort the target stenosis rates corresponding to a plurality of target stenosis segments when there are a plurality of target stenosis segments, determine the extreme value stenosis segment and the target stenosis rate corresponding to the extreme value stenosis segment, determine the reagent flow time according to the angiography data of the blood vessel, and perform flow calculation according to the reagent flow time, the target stenosis rate corresponding to the extreme value stenosis segment, the vessel volume of the blood vessel and a preset volume coefficient to determine the volume flow of the blood vessel. The processing module is further configured to perform pressure drop calculation according to the volume flow, a preset viscous resistance coefficient and a preset inertial resistance coefficient to obtain a target pressure drop, and determine the blood flow reserve fraction of the blood vessel according to the target pressure drop and the root pressure of the target blood vessel.

7. A blood flow reserve fraction calculating device characterized by comprising: The device includes a memory, a processor and a blood flow reserve fraction calculation program stored on the memory and executable on the processor, and the blood flow reserve fraction calculation program is configured to implement the blood flow reserve fraction calculation method of any one of claims 1 to 5.

8. A storage medium, characterized by The storage medium stores a blood flow reserve fraction calculation program, and the blood flow reserve fraction calculation program is executed by the processor to implement the blood flow reserve fraction calculation method of any one of claims 1 to 5.

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