KR102000614B1 - Hemodynamics simulation method using partition of heart muscle volume - Google Patents

Abstract

The present invention relates to a hemodynamic simulation method using segmentation of myocardial volume, comprising the steps of: acquiring an image of at least a part of a heart and a coronary artery; A discretization step of discretizing an image acquired through the shooting step into a plurality of nodes; Dividing the heart into a myocardial region corresponding to at least one of the coronary arteries through the plurality of nodes; A volume calculating step of calculating a volume of the divided myocardial region through the dividing step; A blood flow volume calculation step of calculating a blood flow volume flowing to at least one of the coronary arteries using the divided myocardial region through the dividing step; And a modeling step of performing blood flow modeling using the blood flow volume in at least a part of the coronary artery branch tube calculated in the blood flow calculation step.

Description

HEMODYNAMICS SIMULATION METHOD USING PARTITION OF HEART MUSCLE VOLUME BACKGROUND OF THE INVENTION 1. Field of the Invention < RTI ID = 0.0 >

The present invention relates to a method for simulating hemodynamic volume using segmentation of myocardial volume, and more particularly, to a method for segmenting a volume of a myocardium into portions related to each coronary artery and dividing the myocardial volume by which the hemodynamic simulation can be performed The present invention relates to a method of simulating a blood flow using a blood vessel.

Coronary arteries are the main blood vessels supplying blood to the cardiac myocardium of the heart. Vascular stenosis caused by arteriosclerosis or the like can restrict blood supply and ultimately cause serious symptoms such as myocardial infarction.

For more accurate diagnosis of the severity of these lesions, information on hemodynamic functional diagnostic factors such as myocardial fractional flow reserve and wall shear stress plays an important role.

Non-invasive tests such as electrocardiogram, biopsy indicator, exercise electrocardiography, SPECT (Single Positron Emission Computed Tomography), and PET (Positron Emission Tomography) can be performed to secure this data. However, these methods do not provide a direct assessment of lesions, and furthermore, it is difficult to extract hemodynamic functionality information.

Therefore, we deduced the resistance of the microvascular vasculature of the coronary artery, and based on this, we derive the relationship between the blood flow volume fraction of each branch of the coronary artery and the coronary artery hemodynamic computer simulation based on this, and extract the hemodynamic function information A new way to do this is required.

Korean Registered Patent Publication No. 10-1524955

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to solve the above conventional problems, and it is an object of the present invention to provide a method and apparatus for calculating the blood flow volume by utilizing the volume of the myocardial muscle corresponding to each coronary artery branch tube and using the division of the myocardial volume And to provide a hemodynamic simulation method.

According to an aspect of the present invention, there is provided a method of imaging a heart, comprising: capturing an image of at least a part of a heart and a coronary artery; A discretization step of discretizing an image acquired through the shooting step into a plurality of nodes; Dividing the heart into a myocardial region corresponding to at least one of the coronary arteries through the plurality of nodes; A volume calculating step of calculating a volume of the myocardial region separated through the dividing step; And a modeling step of performing blood flow modeling using at least a part of the blood flow volume of the coronary artery branch tube calculated in the blood flow calculating step, and a method of simulating blood flow using the segmentation of the myocardial volume.

Herein, the coronary artery branch may include a left anterior descending coronary artery (LAD), a left circumflex artery (LCX), and a right coronary artery (RCA).

It is preferable that the imaging step is performed using a computed tomography (CT), a selective computed tomography (CT), or a magnetic resonance imaging (MRI).

In addition, the dividing step is preferably performed using a Voronoi diagram.

In addition, it is preferable that the blood flow rate determination step conforms to the following equation.

Here, Q is the blood flow in the coronary artery branch, and V is the volume of the myocardium corresponding to the coronary artery branch.

In addition, it is preferable that, after the modeling step, the blood flow modeling simulation is performed using the blood flow modeling data acquired through the image obtained through the imaging step and the modeling data.

According to another aspect of the present invention, there is provided a computer-readable recording medium storing a program for causing a computer to execute the method of claim 6.

According to the present invention, blood flow modeling with higher accuracy can be performed by being based on physiological theory in which the blood flow amount is determined in proportion to the total oxygen demand of the tissue.

1 is a flowchart schematically illustrating a method of hemodynamic simulation using segmentation of myocardial volume according to an embodiment of the present invention,
FIG. 2 is a view schematically showing an image taken through an imaging step in a hemodynamic simulation method using segmentation of myocardial volume according to FIG. 1,
FIG. 3 is a view schematically showing a node set through a discretization step in a hemodynamic simulation method using segmentation of myocardial volume according to FIG. 1, and FIG.
FIG. 4 is a view schematically illustrating an image obtained by discretizing a heart in a voxel form in a hemodynamic simulation method using segmentation of myocardial volume according to FIG. 3,
FIG. 5 is a view schematically showing seed points set in the dividing step in the hemodynamic simulation method using the division of the myocardial volume according to FIG. 1,
FIG. 6 is a view schematically showing a state in which the myocardial region is divided through the dividing step in the hemodynamic simulation method using the segmentation of the myocardial volume according to FIG. 1. FIG.

Hereinafter, a hemodynamic simulation method using segmentation of myocardial volume according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Like reference symbols in the drawings denote like elements.

FIG. 1 is a flowchart schematically illustrating a hemodynamic simulation method using segmentation of myocardial volume according to an embodiment of the present invention.

Referring to FIG. 1, a hemodynamic simulation method (S100) using segmentation of myocardial volume according to an embodiment of the present invention calculates the volume of the myocardial region corresponding to at least one of the coronary artery branch tubes, (S110), a discretization step (S120), a segmentation step (S130), and a volume calculation step (S140) are performed in order to estimate the blood flow in the coronary artery and ultimately to perform blood flow modeling and simulation in the coronary artery branch tube. A blood flow calculation step S150, and a modeling step S160.

FIG. 2 is a view schematically showing an image taken through an imaging step in a hemodynamic simulation method using segmentation of myocardial volume according to FIG. 1;

Referring to FIG. 2, the photographing step S110 is a step of photographing at least a part of a heart and a coronary artery, and acquiring an image of at least a part of a heart and a coronary artery.

Here, the image of the heart and the image of the coronary artery may be photographed at the same time, and the image of the heart and the image of the coronary artery may be combined after they are respectively photographed.

Furthermore, the image for at least a portion of the heart and coronary arteries is preferably a three-dimensional image.

The right coronary artery (LCA) and the right coronary artery (RCA) can be divided into two groups: left anterior descending coronary artery (LAD), left anterior descending coronary artery Coronary artery (Left Circumplex Artery: LCX).

As a result, in one embodiment of the present invention, the coronary artery branch canal is divided into a left anterior descending coronary artery (LAD), a left circumflex artery (LCX), and a right coronary artery (RCA) . ≪ / RTI >

According to an exemplary embodiment of the present invention, the imaging step S110 may be performed using a computed tomography (CT), a selective computed tomography or a magnetic resonance imaging (MRI) .

Of course, it is not limited to this method, and images in the heart and coronary arteries can be acquired using a non-invasive imaging method such as ultrasound (US) or an invasive imaging method such as digital subtraction angiography (DSA).

Since the image acquiring method is a well-known technique, detailed description of each image acquiring method is omitted here.

FIG. 3 is a view schematically showing a node set through a discretization step in a hemodynamic simulation method using segmentation of the myocardial volume according to FIG. 1. FIG.

Referring to FIG. 3, the discretization step S120 is a step of discretizing the image obtained in the photographing step S110 into a plurality of nodes N. FIG.

In other words, the image acquired through the photographing step S110 is a three-dimensional image of a part or all of the heart and the coronary artery, and a plurality of nodes N can be set in the heart.

Here, each of the nodes N may be disposed on the surface area of the heart, respectively.

Further, the plurality of nodes N may be arranged at equal intervals, but is not limited thereto.

FIG. 4 is a diagram schematically illustrating an image obtained by discretizing a heart in a voxel form in a hemodynamic simulation method using segmentation of myocardial volume according to FIG. 3. FIG.

4, a plurality of nodes N may be discretized in a state connected to neighboring nodes N, and a shape in which a plurality of nodes N are connected may be in the form of a voxel or a tetrahedron.

Here, the size of the voxel or tetrahedron can be set differently considering the accuracy of the simulation.

FIG. 5 is a view schematically showing a seed point set in a dividing step in the hemodynamic simulation method using the segmentation of the myocardial volume according to FIG. 1. FIG. 6 is a view showing a blood flow FIG. 2 is a view schematically showing a state in which the myocardial region is divided through the dividing step in the dynamic simulation method. FIG.

5 and 6, the dividing step S 130 is a step of dividing the myocardial region corresponding to each of the coronary artery branch tubes using the plurality of nodes N in the image.

In one embodiment of the present invention, the segmentation step (S130) may employ a voronoi diagram technique for more objective segmentation of the myocardial region.

Here, the Voronoi diagram calculates a Euclidean distance from a set having n nodes (N) in space with an arbitrary seed point (S), and then calculates a set of adjacent nodes (N) Which is a method of dividing a space by using a space.

Accordingly, in an embodiment of the present invention, a seed point S for each of the coronary artery branches in the images of the heart and coronary arteries is designated, and a set of nodes N close to each seed point S is obtained It can be divided into three regions corresponding to the respective branch tubes.

Here, the seed point S in each of the branch tubes may be arranged on the center line of each of the coronary artery branch tubes as shown in Fig.

For example, it is possible to set the center line in each coronary artery branch tube in the three-dimensional image, and to set the seed point S so as to be arranged at predetermined intervals along the center line.

Here, the nodes N that are located relatively close to each seed point S are searched.

On the other hand, it is natural that the node N can be searched on the basis of the shape connected to the adjacent nodes N in the form of a voxel or tetrahedron, as described above.

The heart is divided into three myocardial regions. However, the present invention is not limited to this. It is divided into two myocardial regions related to the left coronary artery and the right coronary artery, and the right coronary artery- It is natural that it can be performed in such a manner that it is divided into related myocardial regions and finally three myocardial regions are acquired.

Here, when the retrieval of the nodes N is completed, the nodes N connected to the seed points S of the left anterior descending coronary artery, the left coronary artery, or the right coronary artery are connected. More specifically, the nodes N connected to the seed points S of the left anterior descending coronary artery are connected to each other, the nodes N connected to the seed points S of the left coronary artery are connected to each other , And the nodes (N) connected to the seed points (S) of the right coronary artery.

As a result, as shown in FIG. 6, the heart can be divided into three myocardial regions adjacent to each branch of the coronary artery.

The volume calculation step S140 is a step of calculating the volumes of the three myocardial regions obtained through the dividing step S130 described above.

The divided region through the division step S130 described above can be interpreted as a three-dimensional region, and the volume of the three-dimensional region can be easily calculated.

The blood flow calculation step S150 is a step of estimating a blood flow volume flowing into each of the coronary artery branch tubes using the volume of the myocardial region calculated through the volume calculation step S140 described above.

First, the blood flow volume flowing into each of the coronary artery branch tubes is given by the following equation.

Here, Q is the blood flow in the coronary artery branch, and V is the volume of the myocardium corresponding to the coronary artery branch.

That is, the blood flow flowing through each coronary artery branch tube is proportional to the volume of the myocardium corresponding to each coronary artery branch tube.

According to an embodiment of the present invention, the blood flow rate calculation step (S150) can obtain the ratio of the blood flow volume flowing to each of the coronary artery branch tubes. In other words, the volume of the myocardial region can be obtained through the volume calculation step (S140) described above, and the blood flow quantities of the respective coronary artery branch tubes can be deduced through the calculation.

Of course, it is of course possible to deduce the volume of the myocardial region corresponding to each coronary artery branch tube by calculating the volume of each myocardial region in the volume calculation step (S140).

On the other hand, since the blood flow rate is proportional to the volume, the ratio of the blood flow rate is also proportional to the volume ratio, and the volume ratio in each branch of the coronary artery can be regarded as a ratio of the blood flow to each branch of the coronary artery.

The modeling step (S160) is a step of performing blood flow modeling using the blood flow volume in the coronary artery branch tube calculated in the above-described blood flow calculation step (S150).

That is, the blood flow modeling can be performed by performing a numerical analysis using the blood flow volume in the coronary artery branch tube as a boundary condition.

In the past, blood flow modeling was performed using the blood flow in the coronary artery branch tube. However, since there was no method for estimating the blood flow, the Murray rule, which is a well-known theory, was generally applied. The Murray's law means that the blood flow (Q _d ) has a proportional relationship with the power formula of the diameter (d) of the blood vessel, and can be expressed by the following equation.

Here, d is the diameter of the blood vessel, and a is a power constant value usually set to 1.5 to 3 and is not precisely defined.

However, since the power constant value is not exactly determined in the coronary artery region, there is a difficulty in determining the representative blood vessel diameter because the blood vessel diameter continuously changes along the longitudinal direction.

In contrast, the blood flow calculation step S150 according to an embodiment of the present invention can calculate the volume of the myocardial muscle corresponding to each coronary artery branch tube, thereby estimating the blood flow volume flowing into each branch of the coronary artery Therefore, more accurate simulation can be performed in the modeling step S160 according to the embodiment of the present invention.

According to an embodiment of the present invention, a simulation step of performing hemodynamic computer simulation using the image obtained through the photographing step S110 and the blood flow modeling data obtained through the modeling step S160 S170).

By performing computer simulation through the simulation step (S170), information on the coronary arterial blood flow of the patient's body, such as pressure, velocity, FFR, etc., can be obtained and output to the outside.

In other words, the simulation step (S170) can analyze the three-dimensional equation of blood flow using a computer system, and use a numerical solution method or the like. In this simulation step S170, a coronary artery, more specifically, a left anterior descending coronary artery (LAD), a left circumflex coronary artery (LCX), and a right coronary artery (RCA) Various blood flow characteristics, parameters, etc. including blood flow and blood pressure in the subject can be calculated.

Furthermore, the calculated characteristics or parameters can be displayed externally to an angiographic image or the like.

Meanwhile, one embodiment of the present invention described above can be realized in a general-purpose digital computer that can be created as a program that can be executed in a computer and operates the program using a computer-readable recording medium.

Computer readable media can be any available media that can be accessed by a computer and includes both volatile and nonvolatile media, removable and non-removable media. In addition, the computer-readable medium may include both computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Communication media typically includes computer readable instructions, data structures, program modules, and may include any information delivery media.

It is to be understood that the scope of the present invention is not limited to the above embodiments and that various changes and modifications may be made without departing from the spirit and scope of the present invention, I will see.

S100: Hemodynamic simulation method using segmentation of myocardial volume
S110: photographing step S120: discretization step
S130: Split step S140: Volumet calculation step
S150: blood flow calculation step S160: modeling step
S170: Simulation step

Claims (7)

An imaging step of acquiring images of at least a part of a heart and a coronary artery;
A discretization step of discretizing an image acquired through the shooting step into a plurality of nodes;
Dividing the heart into a myocardial region corresponding to at least one of the coronary arteries through the plurality of nodes;
A volume calculating step of calculating a volume of the divided myocardial region through the dividing step;
A blood flow volume calculation step of calculating a blood flow volume flowing to at least one of the coronary arteries using the volume of the myocardial region acquired through the volume calculation step;
And a modeling step of performing blood flow modeling using at least a part of the blood flow in the coronary artery branch tube calculated in the blood flow calculating step. The method according to claim 1,
The coronary artery branch was used for segmentation of the myocardial volume including left anterior descending coronary artery (LAD), left circumflex coronary artery (LCX) and right coronary artery (RCA) Method of hemodynamic simulation. The method according to claim 1,
The imaging step may be performed by a hemodynamic simulation method using segmentation of myocardial volume performed using a computed tomography (CT), a selective computed tomography (MRI) or a magnetic resonance imaging (MRI) . The method according to claim 1,
Wherein the dividing step is performed using a voronoi diagram. The method according to claim 1,
Wherein the blood flow calculation step is a hemodynamic simulation method using segmentation of myocardial volume according to the following equation.

Here, Q is the blood flow in the coronary artery branch, and V is the volume of the myocardium corresponding to the coronary artery branch. 6. The method according to any one of claims 1 to 5,
And performing hemodynamic simulation using blood flow modeling data acquired through the image and modeling data acquired through the imaging step after the modeling step. A computer-readable recording medium storing a program for causing a computer to execute the method of claim 6.

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