Method for evaluating dynamic change of aortic valve open form based on 4D radiography

Abstract

The invention discloses a method for evaluating the dynamic change of the open form of an aortic valve based on 4D radiography, and the method comprises the following steps: 1, carrying out the three-dimensional modeling of the aortic valve based on a clinical image; 2, under the condition that it is guaranteed that morphological information of the three-dimensional model is not lost, the opening area AVA of the aortic valve under different time phases is obtained through a 4D image or the three-dimensional model; 3, according to the obtained AVA values in different time phases, drawing a systolic period AVA curve for describing open form change characteristics of the aortic valve in the systolic period, confirming an AV stable open period, and obtaining the average open area, the maximum open area and the minimum open area of the aortic valve in the AV stable open period; 4, calculating mutual differences according to the obtained average open area, the minimum open area and the maximum open area of the aortic valve in the AV stable open period; calculating the ratio of the open area to the maximum open area of the aortic valve under different time phases; 5, according to the result of the step 4, evaluating the opening degree change condition of the aortic valve in the systolic period.

Description

Technical Field

[0001] The present invention belongs to the field of aortic valve assessment, and in particular relates to a method for assessing dynamic changes in aortic valve opening morphology based on 4D angiography. Background Art

[0002] The opening of the aortic valve (AV) is often of great clinical concern. For patients with aortic valve disease, the opening of the aortic valve is generally described quantitatively using the AV opening area (AV area, AVA). Currently, the most commonly used method to measure AVA is to obtain AVA based on the continuity equation after obtaining the color Doppler ultrasound image results of the aortic valve. The principle is to obtain the blood flow velocity at the left ventricular outflow tract (LVOT), the blood flow velocity at the AV, and the cross-sectional area at the LVOT by ultrasound, and then calculate AVA through the continuity equation. Another AVA measurement method that is less common in clinical practice is to directly measure AVA through clinical images (Planimetry method).

[0003] For the two commonly used methods of measuring AVA in clinical practice, usually only a single AVA value is obtained to quantitatively describe the opening of the aortic valve. But in fact, the AV undergoes a dynamic process from closed to open and then closed during the systolic period. This dynamic process occurs continuously and cannot be effectively described by a single aortic valve opening area. Based on this, we can understand that the current clinical method of quantitatively evaluating the opening of the aortic valve mainly through a single AVA value obtained at a certain moment or based on time integration during the systolic period has defects. These common parameters that describe the characteristics of the opening of the aortic valve often do not pay attention to the changes of the aortic valve itself during the systolic period. Considering that the dynamic opening process of the patient's aortic valve contains more valuable clinical information, the method of simply evaluating the degree of aortic valve opening by a certain AVA value is not sufficient. Some morphological information that can effectively reflect the patient's aortic valve lesions may be ignored, and we cannot grasp the opening characteristics of the aortic valve throughout the cardiac cycle. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, we extract the opening of the patient's aortic valve at different phases of the systolic period based on the patient's 4D (4Dimensional) medical images, and quantitatively describe the opening characteristics of the aortic valve during the systolic period through a series of morphological parameters, obtain more morphological information related to the aortic valve, and describe the morphological dynamic characteristic changes of the aortic valve during the cardiac cycle from different angles, providing a new method for doctors to clinically grasp the situation of the patient's aortic valve. The technical solution adopted by the present invention is:

[0005] A method for evaluating the dynamic changes of aortic valve opening morphology based on 4D angiography comprises the following steps:

[0006] Step 1: 3D modeling of the aortic valve based on clinical images or 4D clinical images;

[0007] Step 2: Under the condition that the morphological information of the three-dimensional model is not lost, the opening area AVA of the aortic valve at different phases is obtained through 4D images or three-dimensional models;

[0008] Step 3: Based on the AVA values ​​obtained at different time phases, draw the systolic AVA curve to describe the opening morphological change characteristics of the aortic valve during systole, confirm the AV stable opening period and obtain the average opening area, maximum opening area, and minimum opening area of ​​the aortic valve during the AV stable opening period;

[0009] AVA max =max{AVA0,...AVA t-1 ,AVA t ,...AVA1}

[0010] In the above formula, t represents different phases, AVA t It represents the opening area of ​​the aortic valve at time phase t, AVA max is an area parameter greater than zero, in cm 2 , which can be used to quantitatively describe the maximum area that a patient can achieve when the aortic valve opens optimally during systole;

[0011] AVA avg =avg{AVA a ,...AVA b-1 ,AVA b}

[0012] Phase a represents the beginning phase of the AV stable open period, and phase b represents the end phase of the AV stable open period. avg is an area parameter greater than or equal to zero, in cm 2 , which can be used to quantitatively describe the average area of ​​aortic valve opening in a patient during the AV stable opening period; similarly, we can obtain AVA min :

[0013] AVA min =min{AVA a ,...AVA b-1 ,AVA b}

[0014] Phase a represents the beginning phase of the AV stable open period, and phase b represents the end phase of the AV stable open period. min is an area parameter greater than or equal to zero, in cm 2 , which can be used to quantitatively describe the minimum area of ​​aortic valve opening in a patient during the AV stable opening period.

[0015] Step 4: Based on the results of step 3, calculate the change in aortic valve state during the AV stable open period.

[0016] Step 5: Based on the results of step 4, assess the changes in the degree of opening of the aortic valve during systole.

[0017] Further, the step 1: based on clinical images, a three-dimensional model of the aortic valve is performed; in the step 1, when modeling, based on the collected medical images at different time phases, a reconstructed three-dimensional model is obtained and relevant morphological parameters are extracted; images such as CTA, MRI, etc. are used to accurately reconstruct a three-dimensional model of the aortic valve region, such as Figure 1 As shown, we take the analysis results of the aortic valve of a normal person as an example. The medical images of this normal person at different phases are collected and a three-dimensional model is reconstructed. Figure 1 In the patent, we use phase 0 to represent the beginning of systole and phase 1 to represent the end of diastole. The 4D-CTA shown in this patent divides the entire cardiac cycle into 33 equal parts, and 0.06 represents a specific phase of systole.

[0018] Furthermore, the step 3: based on the acquired AVA values ​​at different time phases, a systolic AVA curve is drawn to describe the morphological change characteristics of the aortic valve during the systolic period.

[0019] AVA max Represents the maximum opening area of ​​the aortic valve during systole:

[0020] AVA max =max{AVA0,...AVA t-1 ,AVA t ,...AVA1}

[0021] In the above formula, t represents different phases, AVA t It represents the opening area of ​​the aortic valve at time phase t. max is an area parameter greater than zero, in cm 2 , which can be used to quantitatively describe the maximum area that a patient can achieve when the aortic valve opens optimally during systole.

[0022] AVA min Represents the minimum area of ​​the aortic valve opening during the AV stable opening phase:

[0023] AVA min =min{AVA a ,...AVA b-1 ,AVA b}

[0024] Phase a represents the beginning phase of the AV stable open period, and phase b represents the end phase of the AV stable open period. min is an area parameter greater than or equal to zero, in cm 2 , which can be used to quantitatively describe the minimum area of ​​aortic valve opening in a patient during the AV stable opening period.

[0025] Obtain the average opening area AVA during the stable AV opening period avg

[0026] AVA avg =avg{AVA a ,...AVA b-1 ,AVA b}

[0027] Compared with the traditional AVA value, the AVA described in the patent of this invention avg Based on 4D clinical images, the average value of the aortic valve opening area at different phases was taken into account to describe the opening of the aortic valve from another perspective.

[0028] We take the AVA collected based on 4D clinical images as an example, and draw the systolic AVA curve according to the AVA values ​​obtained at different time phases to describe the morphological changes of the aortic valve during systole. It can be seen that during systole, the aortic valve goes through three stages: rapid opening, stable opening, and rapid closure.

[0029] Furthermore, the step 4: according to the obtained average opening area of ​​the aortic valve in the AV stable opening period, the minimum opening area and the maximum opening area, the difference between them is calculated; according to the obtained aortic valve opening area and the maximum opening area at different time phases, the ratio between the two is calculated;

[0030]

[0031] RAVA avg,max is a dimensionless parameter greater than or equal to zero and less than or equal to 1.

[0032] Calculate the difference between the minimum and maximum aortic valve opening during the AV stable opening period:

[0033]

[0034] RAVA min,maxis a dimensionless parameter greater than or equal to zero and less than or equal to 1.

[0035] Furthermore, step 4 includes: obtaining the opening area AVA of the aortic valve at each different phase t Same as AVA max The ratio of AVA (RAVA) is used to quantitatively evaluate the difference between the degree of aortic valve opening and the maximum degree of opening at each time phase:

[0036]

[0037] RAVA t,max The aortic valve opening area at the representative time phase t is the same as AVA max The ratio of RAVA t,max is a dimensionless parameter greater than or equal to zero.

[0038] Furthermore, the step 5: based on the result of step 4, the dynamic change of the opening degree of the aortic valve during the systolic period is evaluated.

[0039] When Rava avg,max The closer it is to 1, the more the aortic valve opens after reaching a stable opening during systole, indicating that the aortic valve opens well. avg,max The closer it is to 0, the more obvious the difference between the overall opening degree of the aortic valve after it reaches stable opening during contraction and the optimal opening degree, and the worse the overall opening degree of the aortic valve.

[0040] When Rava min,max The closer it is to 1, the closer the minimum opening degree of the aortic valve is to the optimal opening degree after the aortic valve reaches stable opening during systole, and the aortic valve opens well as a whole without obvious fluctuations. min,max The closer it is to 0, the more obvious the difference between the minimum opening degree and the optimal opening degree of the aortic valve after reaching the stable opening period, and the opening degree of the aortic valve has changed significantly.

[0041] Table 1: Summary of parameters describing aortic valve opening

[0042]

[0043] As shown in Table 1, it can be seen that the aortic valve opening area AVA obtained min , AVA avg With AVA max There are some differences. min,max With RAVA avg,max are all less than 1. However, for normal people, these values ​​are all greater than 0.7. It is not ruled out that for some specific patients, RAVAmin,max With RAVA avg,max Based on these parameters, we can further understand the opening characteristics of the aortic valve during systole. Surgeons can also use these parameters to judge the patient's condition and evaluate the difference between the patient's aortic valve opening and that of normal people, providing a reference for doctors' clinical diagnosis.

[0044] Further, in step 5, when AVA max The larger the aortic valve is, the larger the maximum opening area that the aortic valve can achieve during the entire cardiac cycle. max The smaller it is, the more likely the aortic valve's ability to open may be affected or limited;

[0045] When Rava t,max When RAVA is equal to 1, it indicates that the aortic valve opening is optimal. t,max When it is equal to 0, it means that the aortic valve is completely closed. t,max The larger the value, the better the aortic valve opening is at this time phase, and the closer it is to the optimal opening. t,max The smaller it is, the less fully the aortic valve opens at this time phase.

[0046] The beneficial effects of the present invention are:

[0047] First, the morphological analysis method presented in this patent has not been mentioned in related studies so far, and is used to describe the changes in the morphological characteristics of the aortic valve during the cardiac cycle.

[0048] Secondly, the acquisition of these parameters can be completely based on clinical imaging information, without increasing too much clinical measurement costs. It mainly involves reprocessing of clinically collected images, which will not significantly increase the burden on patients.

[0049] In addition, the measurement process of these morphological parameters is non-invasive and will not cause any impact on the patient's body. Finally, these morphological parameters describe the morphological information of the aortic valve from another perspective, focusing more on the morphological changes of the aortic valve during the cardiac cycle, and quantitatively describing the characteristics of the morphological changes of the aortic valve during the entire systolic period, providing valuable reference for doctors in clinical practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a three-dimensional model reconstruction based on 4D medical images in the present invention, which includes an AV model, an ECG diagram, and phase information. The phase is described by 0 to 1, where 0 represents the beginning of the systolic period and 1 represents the end of the diastolic period.

[0051] Figure 2Schematic diagram of the extraction of aortic valve opening area during systole in the present invention, (a) is based on image extraction, and (b) is based on three-dimensional model extraction.

[0052] Figure 3 is the AVA curve of the normal aortic valve systolic period in the present invention, wherein AVA max AVA represents the maximum opening area of ​​the aortic valve during systole. min It represents the minimum area of ​​the aortic valve opening during the AV stable open phase.

[0053] Figure 4 The AVA curve and RAVA curve of the aortic valve systolic period of normal people and patients with hypertrophic cardiomyopathy extracted by the present invention are t,max Curves, where (a) and (c) are the AVA curve and RAVA curve of normal people, respectively, and (b) and (d) are the AVA curve and RAVA curve of patients with hypertrophic cardiomyopathy, respectively. t,max curve. DETAILED DESCRIPTION

[0054] The present invention will be further described below with reference to the accompanying drawings and the accompanying drawings.

[0055] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0056] The terms “first”, “second”, “third”, etc. are only used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0057] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0058] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0059] Embodiment 1:

[0060] like Figure 1-3 As shown, a method for evaluating the dynamic changes of aortic valve opening morphology based on 4D angiography includes the following steps:

[0061] Step 1: 3D modeling of the aortic valve based on clinical images or 4D clinical images;

[0062] Step 2: Under the condition that the morphological information of the three-dimensional model is not lost, the opening area AVA of the aortic valve at different time phases is obtained through 4D images or three-dimensional models; Step 2 can be obtained based on the three-dimensional model or directly based on the 4D image;

[0063] Step 3: Based on the AVA values ​​obtained at different time phases, draw the systolic AVA curve to describe the opening morphological change characteristics of the aortic valve during systole, confirm the AV stable opening period and obtain the average opening area, maximum opening area, and minimum opening area of ​​the aortic valve during the AV stable opening period;

[0064] AVA max =max{AVA0,...AVA t-1 ,AVA t ,...AVA1}

[0065] In the above formula, t represents different phases, AVA t It represents the opening area of ​​the aortic valve at time phase t, AVA max is an area parameter greater than zero, in cm 2 , which can be used to quantitatively describe the maximum area that a patient can achieve when the aortic valve opens optimally during systole;

[0066] AVA avg =avg{AVA a ,...AVA b-1 ,AVA b}

[0067] Phase a represents the beginning phase of the AV stable open period, and phase b represents the end phase of the AV stable open period. avg is an area parameter greater than or equal to zero, in cm 2 , which can be used to quantitatively describe the average area of ​​aortic valve opening in a patient during the AV stable opening period; similarly, we can obtain AVA min :

[0068] AVA min =min{AVA a ,...AVA b-1 ,AVA b}

[0069] Phase a represents the beginning phase of the AV stable open period, and phase b represents the end phase of the AV stable open period. minis an area parameter greater than or equal to zero, in cm 2 , which can be used to quantitatively describe the minimum area of ​​aortic valve opening in a patient during the AV stable opening period.

[0070] Step 4: Based on the results of step 3, calculate the change in the aortic valve state during the AV stable open period;

[0071] Step 5: Based on the results of step 4, assess the changes in the degree of opening of the aortic valve during systole.

[0072] Embodiment 2:

[0073] On the basis of Example 1, the step 1: performs three-dimensional modeling of the aortic valve based on clinical images; in the step 1, medical images at different phases are collected during modeling.

[0074] Images such as CTA and MRI can be used to reconstruct an accurate three-dimensional model of the aortic valve area. Figure 1 As shown, we take the analysis results of the aortic valve of a normal person as an example. The medical images of this normal person at different phases are collected and a three-dimensional model is reconstructed. Figure 1 In the patent, we use phase 0 to represent the beginning of systole and phase 1 to represent the end of diastole. The 4D-CTA shown in this patent divides the entire cardiac cycle into 33 equal parts, and 0.06 represents a specific phase of systole.

[0075] Embodiment 3:

[0076] Based on Example 2, in step 3, AVA max Represents the maximum opening area of ​​the aortic valve during systole:

[0077] AVA max =max{AVA0,...AVA t-1 ,AVA t ,...AVA1}

[0078] In the above formula, t represents different phases, AVA t It represents the opening area of ​​the aortic valve at time phase t. max is an area parameter greater than zero, in cm 2 , which can be used to quantitatively describe the maximum area that a patient can achieve when the aortic valve opens optimally during systole.

[0079] AVA min Represents the minimum area of ​​the aortic valve opening during the AV stable opening phase:

[0080] AVA min =min{AVA a ,...AVAb-1 ,AVA b}

[0081] Phase a represents the beginning phase of the AV stable open period, and phase b represents the end phase of the AV stable open period. min is an area parameter greater than or equal to zero, in cm 2 , which can be used to quantitatively describe the minimum area of ​​aortic valve opening in a patient during the AV stable opening period.

[0082] Obtain the average opening area AVA during the stable AV opening period avg

[0083] AVA avg =avg{AVA a ,...AVA b-1 ,AVA b}

[0084] Compared with the traditional AVA value, the AVA described in the patent of this invention avg Based on 4D clinical images, the average value of the aortic valve opening area at different phases was taken into account to describe the opening of the aortic valve from another perspective.

[0085] We take AVA collected based on 4D clinical images as an example, and draw the systolic AVA curve according to the AVA values ​​obtained at different phases, as shown in the figure below: Figure 3 As shown in Figure 1, it is used to describe the morphological changes of the aortic valve during systole. It can be seen that during systole, the aortic valve undergoes three stages: rapid opening, stable opening, and rapid closure.

[0086] Embodiment 4:

[0087] Based on Example 3, the step 4: according to the obtained average opening area of ​​the aortic valve in the AV stable opening period, the minimum opening area and the maximum opening area, the difference between them is calculated; according to the obtained aortic valve opening area and the maximum opening area in different time phases, the ratio between the two is calculated;

[0088]

[0089] RAVA avg,max is a dimensionless parameter greater than or equal to zero and less than or equal to 1;

[0090] Calculate the difference between the minimum and maximum aortic valve opening during the AV stable opening period:

[0091]

[0092] RAVA min,maxis a dimensionless parameter greater than or equal to zero and less than or equal to 1.

[0093] Embodiment 5:

[0094] Based on Example 4, when RAVA avg,max The closer it is to 1, the more the aortic valve opens after reaching a stable opening during systole, indicating that the aortic valve opens well. avg,max The closer it is to 0, the more obvious the difference between the overall opening degree of the aortic valve after it reaches stable opening during contraction and the optimal opening degree, and the worse the overall opening degree of the aortic valve.

[0095] When Rava min,max The closer it is to 1, the closer the minimum opening degree of the aortic valve is to the optimal opening degree after the aortic valve reaches stable opening during systole, and the aortic valve opens well as a whole without obvious fluctuations. min,max The closer it is to 0, the more obvious the difference between the minimum opening degree and the optimal opening degree of the aortic valve after reaching the stable opening period, and the opening degree of the aortic valve has changed significantly.

[0096] Embodiment 6:

[0097] Based on Example 1, we can obtain the following data:

[0098] Table 1: Summary of parameters describing aortic valve opening

[0099]

[0100] As shown in Table 1, it can be seen that the aortic valve opening area AVA obtained min , AVA avg With AVA max There are some differences. min,max With RAVA avg,max are all less than 1. However, for normal people, these values ​​are all greater than 0.7. It is not ruled out that for some specific patients, RAVA min,max With RAVA avg,max Based on these parameters, we can further understand the opening characteristics of the aortic valve during systole. Surgeons can also use these parameters to judge the patient's condition and evaluate the difference between the patient's aortic valve opening and that of normal people, providing a reference for doctors' clinical diagnosis.

[0101] Embodiment 7:

[0102] On the basis of Example 3, Figure 4 As shown, step 4 includes: obtaining the opening area AVA of the aortic valve at each different phase t Same as AVAmax The ratio of AVA (RAVA) is used to quantitatively evaluate the difference between the degree of aortic valve opening and the maximum degree of opening at each time phase:

[0103]

[0104] RAVA t,max The aortic valve opening area at the representative time phase t is the same as AVA max The ratio of RAVA t,max is a dimensionless parameter greater than or equal to zero.

[0105] Embodiment 8:

[0106] Based on Example 7, in step 5, when AVA max The larger the aortic valve is, the larger the maximum opening area that the aortic valve can achieve during the entire cardiac cycle. max The smaller it is, the more likely the aortic valve's ability to open may be affected or limited;

[0107] When Rava t,max When RAVA is equal to 1, it indicates that the aortic valve opening is optimal. t,max When it is equal to 0, it means that the aortic valve is completely closed. t,max The larger the value, the better the aortic valve opening is at this time phase, and the closer it is to the optimal opening. t,max The smaller the value, the less fully the aortic valve opens at this time phase. Figure 4 As shown in (c) and (d), it can be seen that for normal people, the aortic valve is stable for a period of time after opening during systole. Although RAVA has a slight decreasing trend, it is not obvious. The good opening of the aortic valve lasts for a period of time and then closes quickly. For patients with hypertrophic obstructive cardiomyopathy, the changes in RAVA values ​​show obvious differences. This may be due to the existence of outflow tract obstruction, which affects the heart's pumping process and thus affects the opening characteristics of the aortic valve during systole. For different types of patients, the aortic valve may show different opening characteristics during systole. Surgeons can also judge the patient's condition based on these parameters, evaluate the difference between the patient's aortic valve opening and that of normal people, and provide a reference for doctors' clinical diagnosis.

[0108] The present invention is not limited to the above-mentioned optional implementation modes. Anyone can derive other various forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, all technical solutions that fall within the scope defined by the claims of the present invention fall within the protection scope of the present invention.

Claims

1. A method for evaluating the dynamic changes of aortic valve opening morphology based on 4D angiography, characterized by: The following steps are involved: Step 1: 3D modeling of the aortic valve based on clinical images or 4D clinical images; Step 2: Under the condition that the morphological information of the three-dimensional model is not lost, the opening area AVA of the aortic valve at different phases is obtained through 4D images or three-dimensional models; Step 3: Based on the AVA values ​​obtained at different time phases, draw the systolic AVA curve to describe the opening morphological change characteristics of the aortic valve during systole, confirm the AV stable opening period and obtain the average opening area, maximum opening area, and minimum opening area of ​​the aortic valve during the AV stable opening period; AVA max =max{AVA0,...AVA t-1 ,AVA t ,...AVA1} In the above formula, t represents different phases, AVA t It represents the opening area of ​​the aortic valve at time phase t, AVA max is an area parameter greater than zero, in cm 2 , which can be used to quantitatively describe the maximum area that a patient can achieve when the aortic valve opens optimally during systole; AVA avg =avg{AVA a ,...AVA b-1 ,AVA b } Phase a represents the beginning phase of the AV stable open period, and phase b represents the end phase of the AV stable open period. avg is an area parameter greater than or equal to zero, in cm 2 , which can be used to quantitatively describe the average area of ​​aortic valve opening in a patient during the AV stable opening period; Similarly, we can get AVA min : AVA min =min{AVA a ,...AVA b-1 ,AVA b } Phase a represents the beginning phase of the AV stable open period, and phase b represents the end phase of the AV stable open period. min is an area parameter greater than or equal to zero, in cm 2 , which can be used to quantitatively describe the minimum area of ​​aortic valve opening in a patient during the AV stable opening period; Step 4: Based on the results of step 3, calculate the change in the aortic valve state during the AV stable open period; Step 5: Based on the results of step 4, assess the changes in the degree of opening of the aortic valve during systole.

2. The method for evaluating the dynamic changes of aortic valve opening morphology based on 4D angiography according to claim 1, characterized in that: In the step 1, based on the collected medical images at different time phases, a reconstructed three-dimensional model is obtained and relevant morphological parameters are extracted.

3. The method for evaluating the dynamic changes of aortic valve opening morphology based on 4D angiography according to claim 1, characterized in that: The step 4 comprises: calculating the difference between the average opening area, the minimum opening area and the maximum opening area of ​​the aortic valve during the AV stable opening period; calculating the ratio between the opening area and the maximum opening area of ​​the aortic valve at different time phases; Calculate the difference between the minimum and maximum aortic valve opening during the AV stable opening period:

4. The method for evaluating the dynamic changes of aortic valve opening morphology based on 4D angiography according to claim 1, characterized in that: The step 4 comprises: obtaining the opening area AVA of the aortic valve at each different phase t Same as AVA max The ratio of AVA (RAVA) is used to quantitatively evaluate the difference between the degree of aortic valve opening and the maximum degree of opening at each time phase: RAVA t,max The aortic valve opening area at the representative time phase t is the same as AVA max The ratio of RAVA t,max is a dimensionless parameter greater than or equal to zero.

5. The method for evaluating the dynamic changes of aortic valve opening morphology based on 4D angiography according to claim 3, characterized in that: In step 5, when RAVA avg,max The closer it is to 1, the more the aortic valve opens after reaching a stable opening during systole, indicating that the aortic valve opens well. avg,max The closer it is to 0, the more obvious the difference between the overall opening degree of the aortic valve after it reaches stable opening during contraction and the optimal opening degree, and the worse the overall opening degree of the aortic valve; When Rava min,max The closer it is to 1, the closer the minimum opening degree of the aortic valve is to the optimal opening degree after the aortic valve reaches stable opening during systole, and the aortic valve opens well as a whole without obvious fluctuations. min,max The closer it is to 0, the more obvious the difference between the minimum opening degree and the optimal opening degree of the aortic valve after reaching the stable opening period, and the opening degree of the aortic valve has changed significantly.

6. The morphological evaluation method for the dynamic opening characteristics of the aortic valve according to claim 4, characterized in that: In step 5, when RAVA t,max When RAVA is equal to 1, it indicates that the aortic valve opening is optimal at this phase. t,max When it is equal to 0, it means that the aortic valve is completely closed; when a certain phase RAVA t,max The larger the value, the better the aortic valve opening is at this time phase, and the closer it is to the optimal opening. t,max The smaller it is, the less fully the aortic valve opens at this time phase.

Images