Method and device for obtaining cross-sectional area based on 4D-CTA and CFD

Abstract

The present application relates to a method and device for obtaining cross-sectional area based on 4D-CTA and CFD, and relates to the field of medical technology. The method includes: obtaining 4D-CTA images, and generating a three-dimensional model of the local blood flow cavity according to the 4D-CTA images; performing CFD simulation analysis on the three-dimensional model of the local blood flow cavity to generate a simulation analysis result; according to the simulation analysis result, obtaining the blood flow velocity at the outflow tract corresponding to the cardiac output, and obtaining the blood flow velocity at the aortic valve corresponding to the cardiac output; according to the cardiac output and the blood flow velocity at the outflow tract, obtaining the cross-sectional area of the outflow tract, wherein the cross-sectional area of the outflow tract is used to evaluate the severity of left ventricular outflow tract obstruction; according to the cardiac output and the blood flow velocity at the aortic valve, obtaining the cross-sectional area at the aortic valve, wherein the cross-sectional area at the aortic valve is used to evaluate the severity of aortic valve stenosis. The present application is used to solve the problem that it is difficult to obtain parameter values or the parameter values are not accurate enough for evaluating left ventricular outflow tract obstruction and aortic valve stenosis at present.

Description

Technical Field

[0001] This application relates to the field of medical technology, and particularly to a method and device for obtaining cross-sectional area based on 4D-CTA and CFD. Background Art

[0002] Left ventricular outflow tract obstruction usually refers to the situation where the blood flow is blocked by the hypertrophic ventricular septal myocardium and the SAM (systolic anterior motion) of the mitral valve during the systolic ejection phase in patients with hypertrophic obstructive cardiomyopathy, and the heart cannot effectively pump out the blood. Aortic valve stenosis may also impede cardiac jet flow. When there is an obstruction in the left ventricular outflow tract of the human body, symptoms such as fatigue, dyspnea, exercise intolerance, palpitations, and syncope may occur, and in the most severe cases, it may even lead to sudden cardiac death.

[0003] Currently, the main clinical methods for quantitatively describing left ventricular outflow tract obstruction and aortic valve stenosis are the pressure differences calculated based on the maximum flow velocity measured by color Doppler ultrasound. There are also methods using catheters to measure the pressure difference between the left ventricular cavity and the aortic segment to judge the obstruction situation of patients.

[0004] Although color Doppler ultrasound technology has been widely used, it will produce obvious fluctuations when clinically applied to evaluate left ventricular outflow tract obstruction and aortic valve stenosis. Sometimes, the measurement results have a certain difference from the patient's image information and actual clinical manifestations. From the perspective of fluid mechanics, its pressure difference calculation formula is based on the Bernoulli equation under ideal conditions, and there are also certain simplifications in the derivation process. On the other hand, the ultrasonic beam inevitably has a certain angle with the measured blood flow direction, which may bring certain errors to the clinical diagnosis of patients with left ventricular outflow tract obstruction and aortic valve stenosis. In addition, due to invasiveness and cost reasons, the method of using catheters to measure pressure differences is less clinically applied than color Doppler ultrasound technology.

[0005] In summary, it is difficult to obtain the parameter values for evaluating left ventricular outflow tract obstruction and aortic valve stenosis currently, or the parameter values are not accurate enough. Summary of the Invention

[0006] This application provides a method and device for obtaining cross-sectional area based on 4D-CTA and CFD, so as to solve the problem that it is difficult to obtain the parameter values for evaluating left ventricular outflow tract obstruction and aortic valve stenosis currently, or the parameter values are not accurate enough.

[0007] In a first aspect, an embodiment of this application provides a method for obtaining cross-sectional area based on 4D-CTA and CFD, including:

[0008] Obtain a 4D-CTA image, and generate a three-dimensional model of the local blood flow cavity according to the 4D-CTA image;

[0009] Perform CFD simulation analysis on the three-dimensional model of the local blood flow cavity to generate simulation analysis results;

[0010] According to the simulation analysis results, obtain the blood flow velocity at the outflow tract corresponding to the cardiac output, and obtain the blood flow velocity at the aortic valve corresponding to the cardiac output;

[0011] According to the cardiac output and the blood flow velocity at the outflow tract, obtain the cross-sectional area of the outflow tract, where the cross-sectional area of the outflow tract is used to evaluate the severity of left ventricular outflow tract obstruction;

[0012] According to the cardiac output and the blood flow velocity at the aortic valve, obtain the cross-sectional area at the aortic valve, where the cross-sectional area at the aortic valve is used to evaluate the severity of aortic valve stenosis.

[0013] Optionally, the performing CFD simulation analysis on the three-dimensional model of the local blood flow cavity to generate simulation analysis results includes:

[0014] Obtain N cardiac outputs, where N is an integer greater than 1, the N cardiac outputs are set values, and the N cardiac outputs are different from each other;

[0015] Perform CFD simulation analysis on the three-dimensional model of the local blood flow cavity according to the N cardiac outputs to generate simulation analysis results.

[0016] Optionally, the obtaining the blood flow velocity at the outflow tract corresponding to the cardiac output according to the simulation analysis results includes:

[0017] According to the simulation analysis results, obtain the maximum blood flow velocity at the outflow tract corresponding to the cardiac output;

[0018] Take the maximum blood flow velocity at the outflow tract as the blood flow velocity at the outflow tract.

[0019] Optionally, the obtaining the cross-sectional area of the outflow tract according to the cardiac output and the blood flow velocity at the outflow tract includes:

[0020] Multiply the cardiac output by a first preset multiple to obtain the systolic blood flow volume;

[0021] Divide the systolic blood flow volume by the blood flow velocity at the outflow tract to obtain the cross-sectional area of the outflow tract;

[0022] The obtaining the cross-sectional area at the aortic valve according to the cardiac output and the blood flow velocity at the aortic valve includes:

[0023] Multiply the cardiac output by a first preset multiple to obtain the systolic blood flow volume;

[0024] Dividing the systolic blood flow volume by the blood flow velocity at the aortic valve to obtain the cross-sectional area at the aortic valve.

[0025] Optionally, the step of dividing the systolic blood flow volume by the blood flow velocity in the outflow tract to obtain the cross-sectional area of the outflow tract includes:

[0026] Multiplying the systolic blood flow volume by a second preset multiple to obtain the systolic blood flow volume after unit conversion, where the unit of the systolic blood flow volume is L / min and the unit of the systolic blood flow volume after unit conversion is cm 3 / s;

[0027] Multiplying the blood flow velocity in the outflow tract by a third preset multiple to obtain the blood flow velocity in the outflow tract after unit conversion, where the unit of the blood flow velocity in the outflow tract is m / s and the unit of the blood flow velocity in the outflow tract after unit conversion is cm / s;

[0028] Dividing the systolic blood flow volume after unit conversion by the blood flow velocity in the outflow tract after unit conversion to obtain the cross-sectional area of the outflow tract, where the unit of the cross-sectional area of the outflow tract is cm 2 ;

[0029] The step of dividing the systolic blood flow volume by the blood flow velocity at the aortic valve to obtain the cross-sectional area at the aortic valve includes:

[0030] Multiplying the systolic blood flow volume by a second preset multiple to obtain the systolic blood flow volume after unit conversion, where the unit of the systolic blood flow volume is L / min and the unit of the systolic blood flow volume after unit conversion is cm 3 / s;

[0031] Multiplying the blood flow velocity at the aortic valve by a third preset multiple to obtain the blood flow velocity at the aortic valve after unit conversion, where the unit of the blood flow velocity at the aortic valve is m / s and the unit of the blood flow velocity at the aortic valve after unit conversion is cm / s;

[0032] Dividing the systolic blood flow volume after unit conversion by the blood flow velocity at the aortic valve after unit conversion to obtain the cross-sectional area at the aortic valve, where the unit of the cross-sectional area at the aortic valve is cm 2 .

[0033] In a second aspect, an embodiment of the present application provides a cross-sectional area acquisition device based on 4D-CTA and CFD, including:

[0034] A first generation module, configured to acquire a 4D-CTA image and generate a three-dimensional model of a local blood flow cavity according to the 4D-CTA image;

[0035] A second generation module for performing CFD simulation analysis on the three-dimensional model of the local blood flow cavity to generate a simulation analysis result;

[0036] An acquisition module for obtaining the blood flow velocity at the outflow tract corresponding to the cardiac output and the blood flow velocity at the aortic valve corresponding to the cardiac output according to the simulation analysis result;

[0037] A first processing module for obtaining the cross-sectional area of the outflow tract according to the cardiac output and the blood flow velocity at the outflow tract, wherein the cross-sectional area of the outflow tract is used to evaluate the severity of left ventricular outflow tract obstruction;

[0038] A second processing module for obtaining the cross-sectional area at the aortic valve according to the cardiac output and the blood flow velocity at the aortic valve, wherein the cross-sectional area at the aortic valve is used to evaluate the severity of aortic valve stenosis.

[0039] Optionally, the second generation module includes:

[0040] A first acquisition sub-module for acquiring N cardiac outputs, where N is an integer greater than 1, the N cardiac outputs are set values, and the N cardiac outputs are different from each other;

[0041] A first processing sub-module for performing CFD simulation analysis on the three-dimensional model of the local blood flow cavity according to the N cardiac outputs to generate a simulation analysis result.

[0042] Optionally, the acquisition module includes:

[0043] A second acquisition sub-module for obtaining the maximum blood flow velocity at the outflow tract corresponding to the cardiac output according to the simulation analysis result;

[0044] A second processing sub-module for using the maximum blood flow velocity at the outflow tract as the blood flow velocity at the outflow tract.

[0045] Optionally, the first processing module includes:

[0046] A third processing sub-module for multiplying the cardiac output by a first preset multiple to obtain the systolic blood flow volume;

[0047] A fourth processing sub-module for dividing the systolic blood flow volume by the blood flow velocity at the outflow tract to obtain the cross-sectional area of the outflow tract;

[0048] The second processing module includes:

[0049] A fifth processing sub-module for multiplying the cardiac output by a first preset multiple to obtain the systolic blood flow volume;

[0050] The sixth processing sub-module is used to divide the systolic blood flow volume by the blood flow velocity at the aortic valve to obtain the cross-sectional area at the aortic valve.

[0051] Optionally, the fourth processing sub-module includes:

[0052] The first processing unit is used to multiply the systolic blood flow volume by a second preset multiple to obtain the systolic blood flow volume after unit conversion, where the unit of the systolic blood flow volume is L / min, and the unit of the systolic blood flow volume after unit conversion is cm 3 / s;

[0053] The second processing unit is used to multiply the outflow tract blood flow velocity by a third preset multiple to obtain the outflow tract blood flow velocity after unit conversion, where the unit of the outflow tract blood flow velocity is m / s, and the unit of the outflow tract blood flow velocity after unit conversion is cm / s;

[0054] The third processing unit is used to divide the systolic blood flow volume after unit conversion by the outflow tract blood flow velocity after unit conversion to obtain the cross-sectional area of the outflow tract, where the unit of the cross-sectional area of the outflow tract is cm 2 ;

[0055] The sixth processing sub-module includes:

[0056] The fourth processing unit is used to multiply the systolic blood flow volume by a second preset multiple to obtain the systolic blood flow volume after unit conversion, where the unit of the systolic blood flow volume is L / min, and the unit of the systolic blood flow volume after unit conversion is cm 3 / s;

[0057] The fifth processing unit is used to multiply the blood flow velocity at the aortic valve by a third preset multiple to obtain the blood flow velocity at the aortic valve after unit conversion, where the unit of the blood flow velocity at the aortic valve is m / s, and the unit of the blood flow velocity at the aortic valve after unit conversion is cm / s;

[0058] The sixth processing unit is used to divide the systolic blood flow volume after unit conversion by the blood flow velocity at the aortic valve after unit conversion to obtain the cross-sectional area at the aortic valve, where the unit of the cross-sectional area at the aortic valve is cm 2 .

[0059] The above technical solutions provided by the embodiments of the present application have the following advantages compared with the prior art: In the present application, based on 4D-CTA images and CFD simulation analysis, a simulation analysis result is generated. Compared with the prior art that uses a catheter to measure the pressure difference, it is non-invasive and has a lower cost. It can more conveniently obtain the outflow tract blood flow velocity corresponding to the cardiac output, and then obtain the cross-sectional area of the outflow tract to evaluate the severity of left ventricular outflow tract obstruction. It can also more conveniently obtain the blood flow velocity at the aortic valve corresponding to the cardiac output, and then obtain the cross-sectional area at the aortic valve to evaluate the severity of aortic valve stenosis, solving the problem that it is difficult to obtain the parameter values for evaluating left ventricular outflow tract obstruction and aortic valve stenosis currently. In addition, in the present application, based on 4D-CTA images and CFD simulation analysis, a simulation analysis result is generated. According to the simulation analysis result, the outflow tract blood flow velocity corresponding to the cardiac output and the blood flow velocity at the aortic valve corresponding to the cardiac output are obtained. According to the cardiac output and the outflow tract blood flow velocity, the cross-sectional area of the outflow tract is obtained. According to the cardiac output and the blood flow velocity at the aortic valve, the cross-sectional area at the aortic valve is obtained. Compared with the pressure difference calculated based on the maximum flow velocity measured by color Doppler ultrasound in the prior art, in the present application, directly according to the simulation analysis result, the outflow tract blood flow velocity corresponding to the cardiac output and the blood flow velocity at the aortic valve corresponding to the cardiac output are obtained, avoiding the error caused by the simplification of the pressure difference calculation formula, and also avoiding the error caused by a certain angle between the ultrasonic beam and the measured blood flow direction. The obtained outflow tract blood flow velocity and the blood flow velocity at the aortic valve are more accurate. Furthermore, the obtained cross-sectional area of the outflow tract and the cross-sectional area at the aortic valve are also more accurate, and can more accurately evaluate the severity of left ventricular outflow tract obstruction and aortic valve stenosis, solving the problem that the parameter values for evaluating left ventricular outflow tract obstruction and aortic valve stenosis are not accurate enough currently. Description of the Drawings

[0060] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present invention, and are used together with the specification to explain the principles of the present invention.

[0061] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0062] Figure 1 Schematic flow chart of the method for obtaining the cross-sectional area based on 4D-CTA and CFD in the embodiments of the present application;

[0063] Figure 2 Schematic diagram of a three-dimensional local blood flow cavity model from the left ventricular cavity to the aortic segment of a patient with hypertrophic cardiomyopathy in a specific embodiment of the present application;

[0064] Figure 3 A hemodynamic sketch drawn based on the three-dimensional model of the local blood flow cavity in a specific embodiment of the present application;

[0065] Figure 4 A schematic diagram of the three-dimensional model of the local blood flow cavity at the end-systole of a patient with hypertrophic obstructive cardiomyopathy before and after surgery generated according to 4D-CTA images in a specific embodiment of the present application;

[0066] Figure 5 A schematic diagram of the maximum blood flow velocity in the outflow tract under different cardiac outputs drawn according to the simulation analysis results of cases a, b, and c in a specific embodiment of the present application;

[0067] Figure 6 A schematic diagram of the maximum blood flow velocity in the outflow tract under different cardiac outputs drawn according to the simulation analysis results of cases d, e, and f in a specific embodiment of the present application;

[0068] Figure 7 A schematic structural diagram of a cross-sectional area acquisition device based on 4D-CTA and CFD in an embodiment of the present application. Detailed implementation manners

[0069] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0070] In the embodiments of the present application, a cross-sectional area acquisition method based on 4D-CTA and CFD is provided. As Figure 1 shown, the method flow for cross-sectional area acquisition based on 4D-CTA and CFD mainly includes:

[0071] Step 101: Obtain 4D-CTA images and generate a three-dimensional model of the local blood flow cavity according to the 4D-CTA images.

[0072] Among them, 4D-CTA (4-dimensions-computed tomography angiography, four-dimensional computed tomography angiography) is a dynamic CTA technology that adds a time dimension parameter on the basis of CTA.

[0073] In a specific embodiment, as Figure 2 shown, it is a schematic diagram of the three-dimensional model of the local blood flow cavity from the left ventricular cavity to the aortic segment of a patient with hypertrophic cardiomyopathy. In a specific embodiment, asFigure 3 As shown, it is a hemodynamic sketch drawn based on a three-dimensional model of the local blood flow cavity. Among them, Figure 2 and Figure 3 The specific meanings of each parameter in are as follows: - Systolic blood flow volume, - Ascending aortic pressure, - Outflow tract pressure, - Left ventricular cavity pressure, - Ascending aortic blood flow velocity, - Outflow tract blood flow velocity, - Left ventricular cavity blood flow velocity, - Pressure difference between the left ventricular cavity and the outflow tract segment, - Pressure drop between the left ventricular cavity and the ascending aorta segment, AV - Aortic valve, MV - Mitral valve.

[0074] In a specific embodiment, as Figure 4 shown, it is a schematic diagram of a three-dimensional model of the local blood flow cavity at the end of systole of a patient with hypertrophic obstructive cardiomyopathy before and after surgery generated based on 4D-CTA images. Figure 4 shows schematic diagrams of three-dimensional models of the local blood flow cavity of six patients before and after surgery. The surgical measures taken by the patient with case number a are myectomy and mitral valvuloplasty. The surgical measures taken by the patient with case number b are myectomy and mitral valvuloplasty. The surgical measures taken by the patient with case number c are myectomy and mitral valvuloplasty. The surgical measures taken by the patient with case number d are myectomy, mitral valve formation, and mitral annuloplasty. The surgical measures taken by the patient with case number e are myectomy and mitral valvuloplasty. The surgical measures taken by the patient with case number f are myectomy and mitral valve replacement. From Figure 4 it can be seen that the six patients before surgery showed varying degrees of outflow tract obstruction, and the outflow tract obstruction was correspondingly eliminated after surgery.

[0075] Step 102, perform CFD simulation analysis on the three-dimensional model of the local blood flow cavity to generate simulation analysis results.

[0076] To quantitatively evaluate the severity of obstruction in each case and the improvement of obstruction after surgery, CFD (Computational Fluid Dynamics) simulation analysis was performed on the three-dimensional model of the local blood flow cavity to obtain relevant parameters. Among them, the pressure boundary condition refers to the clinically measured blood pressure of the patient, and the flow boundary condition is set to 3 L / min. The simulation analysis results include the computational domain, pressure distribution, blood flow velocity distribution, and wall shear stress distribution before and after surgery. According to the simulation analysis results, it is possible to intuitively observe the position where the outflow tract obstruction is most severe in the patient before surgery, where there is a significant increase in local blood flow velocity, which is relatively consistent with the measurement results of color Doppler ultrasound. At the same time, an abnormal pressure drop and an increase in wall shear stress at the stenosis occur locally, which helps to determine the main lesion area of the obstruction and locate the position of surgical myocardial resection. After surgery, as the outflow tract obstruction is eliminated, the distribution of local hemodynamic parameters also returns to normal.

[0077] In a specific embodiment, CFD simulation analysis is performed on the three-dimensional model of the local blood flow cavity to generate simulation analysis results, including: obtaining N cardiac outputs, where N is an integer greater than 1, the N cardiac outputs are set values, and the N cardiac outputs are different from each other; according to the N cardiac outputs, performing CFD simulation analysis on the three-dimensional model of the local blood flow cavity to generate simulation analysis results.

[0078] Due to the abnormal blood flow velocity at the obstruction, it is often difficult to obtain the cardiac output for patients with outflow tract obstruction or aortic valve stenosis at present. In this application, the setting of the cardiac output can be adjusted more conveniently in the CFD simulation analysis, which solves the problem of difficult acquisition of the cardiac output. Moreover, since the cardiac output of the patient is obtained by setting, the value of the cardiac output is also more accurate.

[0079] Step 103, according to the simulation analysis results, obtain the outflow tract blood flow velocity corresponding to the cardiac output, and obtain the blood flow velocity at the aortic valve corresponding to the cardiac output.

[0080] In a specific embodiment, according to the simulation analysis results, obtaining the outflow tract blood flow velocity corresponding to the cardiac output includes: according to the simulation analysis results, obtaining the maximum outflow tract blood flow velocity corresponding to the cardiac output; using the maximum outflow tract blood flow velocity as the outflow tract blood flow velocity.

[0081] In a specific embodiment, as Figure 5 shown, it is a schematic diagram of the maximum outflow tract blood flow velocity under different cardiac outputs drawn according to the simulation analysis results of cases a, b, and c. Figure 5 Among them, a1 represents before surgery in case a, a2 represents after surgery in case a, b1 represents before surgery in case b, b2 represents after surgery in case b, c1 represents before surgery in case c, and c2 represents after surgery in case c. In a specific embodiment, as Figure 6As shown, it is a schematic diagram of the maximum blood flow velocity in the outflow tract under different cardiac outputs drawn based on the simulation analysis results of cases d, e, and f. Figure 6 Among them, d1 represents before the operation of case d, d2 represents after the operation of case d, e1 represents before the operation of case e, e2 represents after the operation of case e, f1 represents before the operation of case f, and f2 represents after the operation of case f. Figure 5 and Figure 6 Among them, the abscissa is the cardiac output CO, with the unit of L / min, and the ordinate is the maximum blood flow velocity v max in the outflow tract, with the unit of m / s. Since the setting of the cardiac output can be adjusted relatively conveniently in the CFD simulation analysis, for the same three-dimensional model of the local blood flow cavity, eight different cardiac outputs of 3.0, 3.6, 4.2, 4.8, 5.4, 6.0, 6.6, and 7.2 L / min are respectively set for calculation, and then the maximum blood flow velocity v max in the outflow tract is statistically analyzed.

[0082] From Figure 5 and Figure 6 it can be seen that for the six patients, the maximum blood flow velocity in the outflow tract before the operation is significantly higher than that after the operation, which can be used as a basis for clinically evaluating the severity of the obstruction and the effectiveness of the obstruction treatment for the patients after the operation.

[0083] Step 104, obtain the cross-sectional area of the outflow tract according to the cardiac output and the blood flow velocity in the outflow tract.

[0084] Among them, the cross-sectional area of the outflow tract is used to evaluate the severity of the left ventricular outflow tract obstruction.

[0085] The cross-sectional area of the outflow tract is mainly determined by the morphology of the patient's blood flow cavity, and will not be affected by other interferences, and can more accurately evaluate the severity of the left ventricular outflow tract obstruction. However, the cross-sectional area of the outflow tract requires clinically obtaining the blood flow velocity and cardiac output of the patient's outflow tract. Due to the abnormal blood flow velocity at the obstruction, it is often difficult to obtain the cardiac output for patients with outflow tract obstruction or aortic valve stenosis. In order to obtain the cross-sectional area of the outflow tract more conveniently and accurately, the relevant parameters are collected through 4D-CTA and CFD simulation technologies.

[0086] In a specific embodiment, obtaining the cross-sectional area of the outflow tract according to the cardiac output and the blood flow velocity in the outflow tract includes: multiplying the cardiac output by a first preset multiple to obtain the systolic blood flow volume; dividing the systolic blood flow volume by the blood flow velocity in the outflow tract to obtain the cross-sectional area of the outflow tract.

[0087] Considering that the systolic period often lasts for one-third of the cardiac cycle, we assume that the systolic blood flow volume is three times the cardiac output CO, that is = 3CO, that is, the first preset multiple can be set to 3.

[0088] According to Figure 5 and Figure 6 , the maximum blood flow velocity in the patient's outflow tract is significantly linearly positively correlated with the cardiac output, which can be explained by formula (1):

[0089] (1)

[0090] Wherein, - Blood flow velocity in the outflow tract, - Systolic blood flow volume, - Cross-sectional area of the outflow tract, CO - Cardiac output.

[0091] When the three-dimensional model of the local blood flow cavity at the outflow tract remains unchanged, that is, the cross-sectional area of the outflow tract remains unchanged, the blood flow velocity at the outflow tract is directly proportional to the cardiac output. Considering that the shape of the blood flow cavity at the outflow tract is often irregular, the cross-sectional area of the outflow tract can be calculated based on the simulation analysis results.

[0092] In a specific embodiment, the cross-sectional area of the outflow tract is obtained by dividing the systolic blood flow volume by the blood flow velocity in the outflow tract, including: multiplying the systolic blood flow volume by a second preset multiple to obtain the systolic blood flow volume after unit conversion, wherein the unit of the systolic blood flow volume is L / min, and the unit of the systolic blood flow volume after unit conversion is cm 3 / s; multiplying the blood flow velocity in the outflow tract by a third preset multiple to obtain the blood flow velocity in the outflow tract after unit conversion, wherein the unit of the blood flow velocity in the outflow tract is m / s, and the unit of the blood flow velocity in the outflow tract after unit conversion is cm / s; dividing the systolic blood flow volume after unit conversion by the blood flow velocity in the outflow tract after unit conversion to obtain the cross-sectional area of the outflow tract, wherein the unit of the cross-sectional area of the outflow tract is cm 2 .

[0093] The specific calculation process of the cross-sectional area of the outflow tract is shown in formula (2):

[0094] (2)

[0095] Wherein, the second preset multiple is , and the third preset multiple is 100.

[0096] Compared with clinically measuring the cardiac output, based on 4D-CTA and CFD simulation analysis, the blood flow velocity in the outflow tract can be obtained more conveniently and non-invasively, and since the cardiac output of the patient is set, the value of the cardiac output is also more accurate. Based on this, the calculated cross-sectional area of the outflow tract will be more reliable. This helps the effective application of relevant parameters in clinical practice.

[0097] Step 105, obtain the cross-sectional area at the aortic valve according to the cardiac output and the blood flow velocity at the aortic valve.

[0098] Among them, the cross-sectional area at the aortic valve is used to evaluate the severity of aortic valve stenosis.

[0099] The cross-sectional area at the aortic valve is mainly determined by the patient's blood flow cavity morphology and is not affected by other interferences, enabling a more accurate assessment of the severity of aortic valve stenosis. However, the cross-sectional area at the aortic valve requires clinically obtaining the blood flow velocity and cardiac output at the aortic valve of the patient. Due to the abnormal blood flow velocity at the obstruction site, it is often difficult to obtain the cardiac output for patients with outflow tract obstruction or aortic valve stenosis. To more conveniently and accurately obtain the cross-sectional area at the aortic valve, the collection of relevant parameters is achieved through 4D-CTA and CFD simulation technologies.

[0100] In a specific embodiment, according to the cardiac output and the blood flow velocity at the aortic valve, the cross-sectional area at the aortic valve is obtained, including: multiplying the cardiac output by a first preset multiple to obtain the systolic blood flow volume; dividing the systolic blood flow volume by the blood flow velocity at the aortic valve to obtain the cross-sectional area at the aortic valve.

[0101] Considering that the systolic period often lasts for one-third of the cardiac cycle, we assume that the systolic blood flow volume is three times the cardiac output CO, that is = 3CO, that is, the first preset multiple can be set to 3.

[0102] (3)

[0103] Among them, - Blood flow velocity at the aortic valve, - Systolic blood flow volume, - Cross-sectional area at the aortic valve, CO - Cardiac output.

[0104] In a specific embodiment, dividing the systolic blood flow volume by the blood flow velocity at the aortic valve to obtain the cross-sectional area at the aortic valve includes: multiplying the systolic blood flow volume by a second preset multiple to obtain the systolic blood flow volume after unit conversion, where the unit of the systolic blood flow volume is L / min and the unit of the systolic blood flow volume after unit conversion is cm 3 / s; multiplying the blood flow velocity at the aortic valve by a third preset multiple to obtain the blood flow velocity at the aortic valve after unit conversion, where the unit of the blood flow velocity at the aortic valve is m / s and the unit of the blood flow velocity at the aortic valve after unit conversion is cm / s; dividing the systolic blood flow volume after unit conversion by the blood flow velocity at the aortic valve after unit conversion to obtain the cross-sectional area at the aortic valve, where the unit of the cross-sectional area at the aortic valve is cm 2 .

[0105] The specific calculation process of the cross-sectional area at the aortic valve is shown in Equation (4):

[0106] (4)

[0107] wherein, the second preset multiple is , and the third preset multiple is 100.

[0108] Compared with clinically measuring cardiac output, based on 4D-CTA and CFD simulation analysis, the blood flow velocity at the aortic valve can be obtained more conveniently and non-invasively. Moreover, since the patient's cardiac output is obtained by setting, the value of the cardiac output is also more accurate. Based on this, the cross-sectional area at the aortic valve calculated will be more reliable. This helps the effective application of relevant parameters in clinical practice.

[0109] In summary, in this application, based on 4D-CTA images and CFD simulation analysis, a simulation analysis result is generated. Compared with the prior art of measuring pressure difference using a catheter, it is non-invasive and has a lower cost. It can more conveniently obtain the outflow tract blood flow velocity corresponding to the cardiac output, and then obtain the cross-sectional area of the outflow tract to evaluate the severity of left ventricular outflow tract obstruction. It can also more conveniently obtain the blood flow velocity at the aortic valve corresponding to the cardiac output, and then obtain the cross-sectional area of the aortic valve to evaluate the severity of aortic valve stenosis, solving the problem of difficult acquisition of parameter values for evaluating left ventricular outflow tract obstruction and aortic valve stenosis currently. In addition, in this application, based on 4D-CTA images and CFD simulation analysis, a simulation analysis result is generated. According to the simulation analysis result, the outflow tract blood flow velocity corresponding to the cardiac output and the blood flow velocity at the aortic valve corresponding to the cardiac output are obtained. According to the cardiac output and the outflow tract blood flow velocity, the cross-sectional area of the outflow tract is obtained. According to the cardiac output and the blood flow velocity at the aortic valve, the cross-sectional area of the aortic valve is obtained. Compared with the pressure difference calculated based on the maximum flow velocity measured by color Doppler ultrasound in the prior art, in this application, directly according to the simulation analysis result, the outflow tract blood flow velocity corresponding to the cardiac output and the blood flow velocity at the aortic valve corresponding to the cardiac output are obtained, avoiding the error caused by the simplification of the pressure difference calculation formula, and also avoiding the error caused by a certain angle between the ultrasonic beam and the measured blood flow direction. The obtained outflow tract blood flow velocity and blood flow velocity at the aortic valve are more accurate, and thus the obtained cross-sectional area of the outflow tract and cross-sectional area of the aortic valve are also more accurate, and can more accurately evaluate the severity of left ventricular outflow tract obstruction and aortic valve stenosis, solving the problem that the parameter values for evaluating left ventricular outflow tract obstruction and aortic valve stenosis are not accurate enough currently.

[0110] Based on the same concept, in an embodiment of this application, a cross-sectional area acquisition device based on 4D-CTA and CFD is provided. For the specific implementation of this device, reference can be made to the description in the method embodiment part, and the repeated parts will not be elaborated again. As Figure 7 shown, this device mainly includes:

[0111] The first generation module 701 is configured to obtain a 4D-CTA image and generate a three-dimensional model of the local blood flow cavity based on the 4D-CTA image;

[0112] The second generation module 702 is configured to perform CFD simulation analysis on the three-dimensional model of the local blood flow cavity to generate a simulation analysis result;

[0113] The acquisition module 703 is configured to obtain the outflow tract blood flow velocity corresponding to the cardiac output and the blood flow velocity at the aortic valve corresponding to the cardiac output according to the simulation analysis result;

[0114] The first processing module 704 is configured to obtain the cross-sectional area of the outflow tract according to the cardiac output and the outflow tract blood flow velocity, wherein the cross-sectional area of the outflow tract is used to evaluate the severity of left ventricular outflow tract obstruction;

[0115] The second processing module 705 is configured to obtain the cross-sectional area at the aortic valve according to the cardiac output and the blood flow velocity at the aortic valve, wherein the cross-sectional area at the aortic valve is used to evaluate the severity of aortic valve stenosis.

[0116] In a specific embodiment, the second generation module includes:

[0117] The first acquisition sub-module is configured to acquire N cardiac outputs, where N is an integer greater than 1, the N cardiac outputs are set values, and the N cardiac outputs are different from each other;

[0118] The first processing sub-module is configured to perform CFD simulation analysis on the three-dimensional model of the local blood flow cavity according to the N cardiac outputs to generate a simulation analysis result.

[0119] In a specific embodiment, the acquisition module includes:

[0120] The second acquisition sub-module is configured to obtain the maximum blood flow velocity of the outflow tract corresponding to the cardiac output according to the simulation analysis result;

[0121] The second processing sub-module is configured to use the maximum blood flow velocity of the outflow tract as the outflow tract blood flow velocity.

[0122] In a specific embodiment, the first processing module includes:

[0123] The third processing sub-module is configured to multiply the cardiac output by a first preset multiple to obtain the systolic blood flow volume;

[0124] The fourth processing sub-module is configured to divide the systolic blood flow volume by the outflow tract blood flow velocity to obtain the cross-sectional area of the outflow tract;

[0125] The second processing module includes:

[0126] The fifth processing sub-module is used to multiply the cardiac output by a first preset multiple to obtain the systolic blood flow volume;

[0127] The sixth processing sub-module is used to divide the systolic blood flow volume by the blood flow velocity at the aortic valve to obtain the cross-sectional area at the aortic valve.

[0128] In a specific embodiment, the fourth processing sub-module includes:

[0129] The first processing unit is used to multiply the systolic blood flow volume by a second preset multiple to obtain the systolic blood flow volume after unit conversion, where the unit of the systolic blood flow volume is L / min, and the unit of the systolic blood flow volume after unit conversion is cm 3 / s;

[0130] The second processing unit is used to multiply the outflow tract blood flow velocity by a third preset multiple to obtain the outflow tract blood flow velocity after unit conversion, where the unit of the outflow tract blood flow velocity is m / s, and the unit of the outflow tract blood flow velocity after unit conversion is cm / s;

[0131] The third processing unit is used to divide the systolic blood flow volume after unit conversion by the outflow tract blood flow velocity after unit conversion to obtain the cross-sectional area of the outflow tract, where the unit of the cross-sectional area of the outflow tract is cm 2 ;

[0132] The sixth processing sub-module includes:

[0133] The fourth processing unit is used to multiply the systolic blood flow volume by a second preset multiple to obtain the systolic blood flow volume after unit conversion, where the unit of the systolic blood flow volume is L / min, and the unit of the systolic blood flow volume after unit conversion is cm 3 / s;

[0134] The fifth processing unit is used to multiply the blood flow velocity at the aortic valve by a third preset multiple to obtain the blood flow velocity at the aortic valve after unit conversion, where the unit of the blood flow velocity at the aortic valve is m / s, and the unit of the blood flow velocity at the aortic valve after unit conversion is cm / s;

[0135] The sixth processing unit is used to divide the systolic blood flow volume after unit conversion by the blood flow velocity at the aortic valve after unit conversion to obtain the cross-sectional area at the aortic valve, where the unit of the cross-sectional area at the aortic valve is cm 2 .

[0136] It should be noted that in this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising said element.

[0137] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for obtaining cross-sectional area based on 4D-CTA and CFD, characterized in that, Comprising: Obtaining a 4D-CTA image and generating a three-dimensional model of the local blood flow cavity based on the 4D-CTA image; Performing CFD simulation analysis on the three-dimensional model of the local blood flow cavity to generate a simulation analysis result; Based on the simulation analysis result, obtaining the blood flow velocity at the outflow tract corresponding to the cardiac output and obtaining the blood flow velocity at the aortic valve corresponding to the cardiac output; Based on the cardiac output and the blood flow velocity at the outflow tract, obtaining the cross-sectional area of the outflow tract, wherein the cross-sectional area of the outflow tract is used to evaluate the severity of left ventricular outflow tract obstruction; Based on the cardiac output and the blood flow velocity at the aortic valve, obtaining the cross-sectional area at the aortic valve, wherein the cross-sectional area at the aortic valve is used to evaluate the severity of aortic valve stenosis.

2. The cross-sectional area acquisition method based on 4D-CTA and CFD according to claim 1, wherein The performing CFD simulation analysis on the three-dimensional model of the local blood flow cavity to generate a simulation analysis result includes: Obtaining N cardiac outputs, where N is an integer greater than 1, the N cardiac outputs are set values, and the N cardiac outputs are different from each other; Performing CFD simulation analysis on the three-dimensional model of the local blood flow cavity according to the N cardiac outputs to generate a simulation analysis result.

3. The cross-sectional area acquisition method based on 4D-CTA and CFD according to claim 2, wherein The obtaining the blood flow velocity at the outflow tract corresponding to the cardiac output based on the simulation analysis result includes: Based on the simulation analysis result, obtaining the maximum blood flow velocity at the outflow tract corresponding to the cardiac output; Taking the maximum blood flow velocity at the outflow tract as the blood flow velocity at the outflow tract.

4. The cross-sectional area acquisition method based on 4D-CTA and CFD according to claim 3, wherein The obtaining the cross-sectional area of the outflow tract based on the cardiac output and the blood flow velocity at the outflow tract includes: Multiplying the cardiac output by a first preset multiple to obtain the systolic blood flow volume; Dividing the systolic blood flow volume by the blood flow velocity at the outflow tract to obtain the cross-sectional area of the outflow tract; The obtaining the cross-sectional area at the aortic valve based on the cardiac output and the blood flow velocity at the aortic valve includes: Multiplying the cardiac output by a first preset multiple to obtain the systolic blood flow volume; Dividing the systolic blood flow volume by the blood flow velocity at the aortic valve to obtain the cross-sectional area at the aortic valve.

5. The cross-sectional area acquisition method based on 4D-CTA and CFD according to claim 4, wherein The dividing the systolic blood flow volume by the blood flow velocity at the outflow tract to obtain the cross-sectional area of the outflow tract includes: Multiply the systolic blood flow by a second preset multiple to obtain the systolic blood flow after unit conversion, where the unit of the systolic blood flow is L / min, and the unit of the systolic blood flow after unit conversion is cm 3 / s; Multiplying the blood flow velocity at the outflow tract by a third preset multiple to obtain the blood flow velocity at the outflow tract after unit conversion, wherein the unit of the blood flow velocity at the outflow tract is m / s, and the unit of the blood flow velocity at the outflow tract after unit conversion is cm / s; Dividing the converted systolic blood flow volume by the converted outflow tract blood flow velocity to obtain the cross-sectional area of the outflow tract, where the unit of the cross-sectional area of the outflow tract is cm 2 ; The dividing the systolic blood flow volume by the blood flow velocity at the aortic valve to obtain the cross-sectional area at the aortic valve includes: Multiply the systolic blood flow by a second preset multiple to obtain the systolic blood flow after unit conversion, where the unit of the systolic blood flow is L / min, and the unit of the systolic blood flow after unit conversion is cm 3 / s; Multiplying the blood flow velocity at the aortic valve by a third preset multiple to obtain the blood flow velocity at the aortic valve after unit conversion, wherein the unit of the blood flow velocity at the aortic valve is m / s, and the unit of the blood flow velocity at the aortic valve after unit conversion is cm / s; Divide the systolic blood flow volume after the unit conversion by the blood flow velocity at the aortic valve after the unit conversion to obtain the cross-sectional area at the aortic valve, where the unit of the cross-sectional area at the aortic valve is cm 2 .

6. A cross-sectional area acquisition device based on 4D-CTA and CFD, characterized in that Comprising: A first generation module for obtaining a 4D-CTA image and generating a three-dimensional model of the local blood flow cavity based on the 4D-CTA image; A second generation module for performing CFD simulation analysis on the three-dimensional model of the local blood flow cavity to generate a simulation analysis result; An acquisition module, configured to obtain the outflow tract blood flow velocity corresponding to the cardiac output and the blood flow velocity at the aortic valve corresponding to the cardiac output according to the simulation analysis result; A first processing module, configured to obtain the cross-sectional area of the outflow tract according to the cardiac output and the outflow tract blood flow velocity, wherein the cross-sectional area of the outflow tract is used to evaluate the severity of left ventricular outflow tract obstruction; A second processing module, configured to obtain the cross-sectional area at the aortic valve according to the cardiac output and the blood flow velocity at the aortic valve, wherein the cross-sectional area at the aortic valve is used to evaluate the severity of aortic valve stenosis.

7. The cross-sectional area acquisition device based on 4D-CTA and CFD according to claim 6, wherein The second generation module includes: A first acquisition sub-module, configured to acquire N cardiac outputs, where N is an integer greater than 1, the N cardiac outputs are set values, and the N cardiac outputs are different from each other; A first processing sub-module, configured to perform CFD simulation analysis on the three-dimensional model of the local blood flow cavity according to the N cardiac outputs to generate a simulation analysis result.

8. The cross-sectional area acquisition device based on 4D-CTA and CFD according to claim 7, characterized in that, The acquisition module includes: A second acquisition sub-module, configured to obtain the maximum blood flow velocity of the outflow tract corresponding to the cardiac output according to the simulation analysis result; A second processing sub-module, configured to use the maximum blood flow velocity of the outflow tract as the outflow tract blood flow velocity.

9. The cross-sectional area acquisition device based on 4D-CTA and CFD according to claim 8, wherein The first processing module includes: A third processing sub-module, configured to multiply the cardiac output by a first preset multiple to obtain the systolic blood flow volume; A fourth processing sub-module, configured to divide the systolic blood flow volume by the outflow tract blood flow velocity to obtain the cross-sectional area of the outflow tract; The second processing module includes: A fifth processing sub-module, configured to multiply the cardiac output by a first preset multiple to obtain the systolic blood flow volume; A sixth processing sub-module, configured to divide the systolic blood flow volume by the blood flow velocity at the aortic valve to obtain the cross-sectional area at the aortic valve.

10. The cross-sectional area acquisition device based on 4D-CTA and CFD according to claim 9, wherein The fourth processing sub-module includes: A first processing unit, configured to multiply the systolic blood flow by a second preset multiple to obtain the systolic blood flow after unit conversion, where the unit of the systolic blood flow is L / min, and the unit of the systolic blood flow after unit conversion is cm 3 / s; A second processing unit, configured to multiply the outflow tract blood flow velocity by a third preset multiple to obtain the outflow tract blood flow velocity after unit conversion, wherein the unit of the outflow tract blood flow velocity is m / s, and the unit of the outflow tract blood flow velocity after unit conversion is cm / s; A third processing unit, configured to divide the systolic blood flow volume after the unit conversion by the outflow tract blood flow velocity after the unit conversion to obtain the cross-sectional area of the outflow tract, where the unit of the cross-sectional area of the outflow tract is cm 2 ; The sixth processing sub-module includes: A fourth processing unit, configured to multiply the systolic blood flow by a second preset multiple to obtain the systolic blood flow after unit conversion, where the unit of the systolic blood flow is L / min, and the unit of the systolic blood flow after unit conversion is cm 3 / s; A fifth processing unit, configured to multiply the blood flow velocity at the aortic valve by a third preset multiple to obtain the blood flow velocity at the aortic valve after unit conversion, wherein the unit of the blood flow velocity at the aortic valve is m / s, and the unit of the blood flow velocity at the aortic valve after unit conversion is cm / s; A sixth processing unit, configured to divide the unit-converted systolic blood flow volume by the unit-converted blood flow velocity at the aortic valve to obtain the cross-sectional area at the aortic valve, where the unit of the cross-sectional area at the aortic valve is cm 2 .

Images