Standard blood vessel generation device, blood vessel evaluation device, standard blood vessel generation program, blood vessel evaluation program, standard blood vessel generation method, and blood vessel evaluation method

Abstract

This standard blood vessel generation device executes: processing that specifies, for an image of each subject, a blood vessel region in which a blood vessel is rendered, derives feature lines along the blood vessel region that connect feature points included in a plurality of figures included in the blood vessel region, specifies a branch of the feature lines, disposes a division point that divides a line segment with the start point being one of two adjacent branches and the end point being the other branch, calculates a statistic amount of the coordinates for a set of division points for which the orders calculated from the start points are equal among a plurality of subjects, and determines a point with the coordinates being equal to the statistic amount to be a standard point; and processing of determining a dimension of a predetermined site of a figure included in the blood vessel region and including the standard point to be a standard diameter, for each set of division points. The standard blood vessel generation device generates a standard blood vessel that is a blood vessel along standard lines connecting a plurality of standard points and the diameter thereof at the standard point is the standard diameter.

Description

[Technical Field]

[0001] The present invention relates to a standard blood vessel generating device, a blood vessel evaluation device, a standard blood vessel generating program, a blood vessel evaluation program, a standard blood vessel generating method, and a blood vessel evaluation method. [Background technology]

[0002] The existence of diseases that change the shape of blood vessels and diseases caused by changes in blood flow due to changes in blood vessel shape has long been pointed out. In order to diagnose, prevent, and research these diseases, a technology that quantitatively evaluates the shape of blood vessels is required. One example of such a technology is a quantitative analysis device for blood vessel images disclosed in Patent Document 1.

[0003] This blood vessel image quantitative analysis device comprises a designation means, a division means, a profile direction determination means, a border extraction means, a center line determination means, and an analysis means. The designation means designates a blood vessel to be analyzed on a blood vessel image. The division means divides the blood vessel into a plurality of parts. The profile direction determination means determines a profile direction based on position information of the divided blood vessel. The border extraction means extracts the blood vessel border of the blood vessel to be analyzed based on the profile direction determined by the profile direction determination means. The center line determination means determines a center line from the blood vessel border extracted by the border extraction means. The analysis means performs quantitative analysis of the blood vessel to be analyzed based on data of the blood vessel border extracted by the border extraction means and the center line determined by the center line determination means. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 08-280655

[0005] However, although the above-mentioned quantitative analysis device for blood vessel images can identify the blood vessel image of an individual subject, it cannot identify the degree to which the shape of the blood vessels of the subject differs from the shape of the blood vessels of a healthy person. Furthermore, since blood vessel shapes vary from person to person, it is necessary to determine the blood vessels of a healthy person that can serve as a standard for identifying the degree of deviation, but the above-mentioned quantitative analysis device for blood vessel images does not identify the blood vessel image of an individual subject using such a standard. Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, the present invention aims to provide a standard blood vessel generation device, a standard blood vessel generation program, and a standard blood vessel generation method that can generate standard blood vessels, which are blood vessels that serve as suitable references for identifying the shape of blood vessels, and to provide a blood vessel evaluation device, a blood vessel evaluation program, and a blood vessel evaluation method that can use the standard blood vessels to more accurately evaluate the shape of a subject's blood vessels. [Means for solving the problem]

[0007] One aspect of the present invention is a system including: a vascular region specifying unit that executes, for each subject, a process of specifying a vascular region depicting the blood vessels of the subject in an image depicting the blood vessels of the subject; a feature line derivation unit that executes, for each subject, a process of deriving a feature line that connects feature points included in each of a plurality of figures included in the vascular region and that runs along the vascular region; a branch point specifying unit that executes, for each subject, a process of specifying a branch point of the feature line; and a process of arranging a division point that divides the line on a line that has one of two adjacent branch points on the feature line as a start point and the other as an end point. The standard blood vessel generation device includes a division point placement unit that is executed for each of the subjects, and a standard blood vessel generation unit that executes the following processes for each of the sets of division points: calculating coordinate statistics for sets of division points whose order of counting from the start point to the end point is the same among the plurality of subjects, and setting points whose coordinates are equal to the statistics as standard points; and setting the dimensions of a predetermined portion of a figure that includes the standard point and is included in the blood vessel region as a standard diameter; and generates data indicating standard blood vessels, which are virtual blood vessels that extend along a standard line connecting the plurality of standard points, with the diameter at the standard point being the standard diameter.

[0008] In the above-described standard blood vessel generation device, the blood vessel region identification unit may execute a process of identifying the blood vessel region depicting the blood vessels of the subject in the image registered with a reference image having a reference coordinate system.

[0009] In the above-described standard blood vessel generating device, the characteristic line deriving unit may execute a process of deriving the characteristic line connecting the centers of a plurality of spheres inscribed in the blood vessel region.

[0010] In the standard blood vessel generating device described above, the division point placement unit may execute a process of placing the division points on the line to equally divide the line.

[0011] In the above-described standard blood vessel generating device, the standard blood vessel generating unit may generate, as the standard blood vessel, data indicating a virtual blood vessel having a diameter at the standard point equal to the diameter of a sphere inscribed in the blood vessel region.

[0012] The above-mentioned standard blood vessel generation device further includes a feature line classification unit that executes, for each subject, a process of determining a category to which the connected structure of the feature lines depicted in the image belongs, based on the connection relationships between the branch points of the feature lines. The division point placement unit executes a process of placing the division points on the lines for at least two blood vessels determined by the feature line classification unit to belong to the same category, and the standard blood vessel generation unit executes a process of generating data indicating the standard blood vessels, based on the at least two blood vessels determined by the feature line classification unit to belong to the same category.

[0013] The above-mentioned standard blood vessel generation device further includes an endpoint identification unit that executes a process of identifying endpoints of the feature lines for each of the subjects, and the feature line classification unit executes a process of determining, for each of the subjects, a category to which the blood vessels depicted in the image belong, based on the connection relationship between the endpoints of the feature lines and the feature points.

[0014] One aspect of the present invention is Based on the standard line and standard diameter of the standard blood vessel generated by the standard blood vessel generating device, A blood vessel evaluation device for evaluating the blood vessels of a subject.

[0015] In one aspect of the present invention, a computer is provided with a blood vessel region identifying function that executes, for each subject, a process of identifying a blood vessel region depicting the blood vessels of the subject in an image depicting the blood vessels of the subject; a feature line derivation function that executes, for each subject, a process of deriving a feature line that connects feature points included in each of a plurality of figures included in the blood vessel region and that runs along the blood vessel region; a branch point identifying function that executes, for each subject, a process of identifying a branch point of the feature line; and a process of arranging a division point that divides the line on a line that has one of two adjacent branch points on the feature line as a start point and the other as an end point. a standard blood vessel generation function that performs the following processes for each set of division points: a division point placement function that performs the above for each set of division points where the order of counting from the start point to the end point is the same among the plurality of subjects, calculates coordinate statistics for the set of division points, and sets the point whose coordinate is equal to the coordinate statistics as a standard point; and sets the dimension of a predetermined portion of a figure that includes the standard point and is included in the blood vessel region as a standard diameter for each set of division points; and generates data that indicates a standard blood vessel, which is a virtual blood vessel that follows a standard line connecting the plurality of standard points, and in which the diameter at the standard point is the standard diameter.

[0016] One aspect of the present invention is Based on the standard line and standard diameter of the standard blood vessel generated by the standard blood vessel generating device, A vascular evaluation program that evaluates the blood vessels of a subject.

[0017] One aspect of the present invention includes a vascular region specifying step for executing, for each subject, a process for specifying a vascular region depicting the blood vessels of the subject in an image depicting the blood vessels of the subject; a feature line deriving step for executing, for each subject, a process for deriving a feature line that connects feature points included in each of a plurality of figures included in the vascular region and that runs along the vascular region; a branch point specifying step for executing, for each subject, a process for specifying a branch point of the feature line; and a process for arranging a division point that divides the line on a line that has one of two adjacent branch points on the feature line as a start point and the other as an end point. a standard blood vessel generation step of performing the above process for each set of division points, the standard diameter being the diameter at the standard point, and generating data indicating a standard blood vessel that is a virtual blood vessel along a standard line connecting the plurality of standard points, the standard diameter being the diameter at the standard point, the standard diameter being the diameter at the standard point, the standard blood vessel being a virtual blood vessel along a standard line connecting the plurality of standard points, the standard diameter being the diameter at the standard point, the standard blood vessel being a virtual blood vessel along a standard line connecting the plurality of standard points, the standard blood vessel being a virtual blood vessel

[0018] One aspect of the present invention is Based on the standard line and standard diameter of the standard blood vessel generated by the standard blood vessel generating device, A blood vessel evaluation method for evaluating the blood vessels of a subject. [Effects of the Invention]

[0019] According to the present invention, a standard blood vessel, which is a blood vessel that serves as a suitable reference for identifying the shape of a blood vessel, can be generated, and the shape of the blood vessel of a subject can be evaluated more accurately using the standard blood vessel. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a diagram showing an example of the functional configuration of a standard blood vessel generation device and a blood vessel evaluation device according to an embodiment of the present invention. FIG. [Figure 2] FIG. 1 is a diagram showing an example of a blood vessel region according to an embodiment of the present invention. [Figure 3]FIG. 10 is a diagram illustrating an example of a plurality of spheres inscribed in a blood vessel region and characteristic lines connecting the centers of these spheres according to an embodiment of the present invention. [Figure 4] FIG. 10 is a diagram illustrating an example of values ​​assigned to branch point candidates according to the embodiment of the present invention. [Figure 5] FIG. 10 is a diagram showing an example of two branching points according to an embodiment of the present invention, a line connecting these two branching points, a plurality of division points arranged on the line, and a sphere centered on these division points and inscribed in a vascular region. [Figure 6] FIG. 1 is a diagram showing an example of a standard blood vessel according to an embodiment of the present invention. [Figure 7] FIG. 10 is a diagram showing an example of the results of evaluation of the center line of the internal carotid artery of a subject suffering from dorsal ectasia and the center line of the internal carotid artery of a healthy subject in the coronary plane using a vascular evaluation device according to an embodiment of the present invention. [Figure 8] FIG. 10 is a diagram showing an example of the results of evaluation of the center line of the internal carotid artery of a subject suffering from dorsal ectasia and the center line of the internal carotid artery of a healthy subject in the sagittal plane using a vascular evaluation device according to an embodiment of the present invention. [Figure 9] FIG. 10 is a diagram showing an example of the results of evaluation of the diameter of the internal carotid artery of a subject suffering from dorsal ectasia and the diameter of the internal carotid artery of a healthy subject using a vascular evaluation device according to an embodiment of the present invention, viewed from a direction perpendicular to the coronary plane. [Figure 10] FIG. 10 is a diagram showing an example of the results of evaluation of the diameter of the internal carotid artery of a subject suffering from dorsal carotid ectasia and the diameter of the internal carotid artery of a healthy subject using a vascular evaluation device according to an embodiment of the present invention, viewed from a direction perpendicular to the sagittal plane. [Figure 11] 10 is a flowchart illustrating an example of processing executed by a standard blood vessel generating device according to an embodiment of the present invention. [Figure 12] FIG. 10 is a diagram showing an example of the functional configuration of a standard blood vessel generating device according to another embodiment of the present invention. [Figure 13] FIG. 10 is a diagram showing an example of a blood vessel according to another embodiment of the present invention. [Figure 14] 14 is a diagram showing an example of a matrix indicating the connection relationship between branch points and end points on the characteristic lines of the blood vessels shown in FIG. 13. FIG. [Figure 15] FIG. 10 is a diagram showing an example of a blood vessel according to another embodiment of the present invention. [Figure 16] 16 is a diagram showing an example of a matrix indicating the connection relationship between branch points and end points on the characteristic lines of the blood vessels shown in FIG. 15. FIG. [Figure 17] FIG. 10 is a diagram showing an example of a blood vessel according to another embodiment of the present invention. [Figure 18] 18 is a diagram showing an example of a matrix indicating the connection relationship between branch points and end points on the characteristic lines of the blood vessels shown in FIG. 17. FIG. [Figure 19] FIG. 10 is a diagram showing an example of standard blood vessels generated based on the blood vessels of multiple subjects classified as left and right independent types when taking into account the posterior communicating artery by a standard blood vessel generation device according to another embodiment of the present invention. [Figure 20] FIG. 10 is a diagram showing an example of standard blood vessels generated based on the blood vessels of multiple subjects classified as bilaterally combined when the posterior communicating artery is taken into consideration by a standard blood vessel generation device according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] An example of a standard blood vessel generation device and a blood vessel evaluation device according to an embodiment will be described with reference to Figs. 1 to 10. Fig. 1 is a diagram showing the functional configuration of a standard blood vessel generation device and an example of a blood vessel evaluation device according to an embodiment of the present invention. Fig. 1 shows a standard blood vessel generation device 10, a blood vessel evaluation device 20, and a storage device 30. The standard blood vessel generation device 10, the blood vessel evaluation device 20, and the storage device 30 are connected to each other via a network NW in a manner that allows mutual communication. The network NW is, for example, an intranet, a LAN (Local Area Network), the Internet, or a WAN (Wide Area Network).

[0022] As shown in FIG. 1, the standard blood vessel generating device 10 includes a blood vessel region specifying unit 11, a feature line deriving unit 12, a branch point specifying unit 13, a division point placing unit 14, and a standard blood vessel generating unit 15.

[0023] The vascular region specifying unit 11 executes a process for specifying, for each subject, a vascular region in which the subject's blood vessels are depicted in an image depicting the subject's blood vessels. The subject here refers to a part of a person's body depicted in a medical image used by the standard blood vessel generating device 10 for the purpose of generating data showing standard blood vessels (described later). In the following explanation, an example will be given in which the subject is a human head and the blood vessels are arteries in the brain.

[0024] The medical image may be, for example, an MRA (Magnetic Resonance Angiography) image taken by an angiography examination using a magnetic resonance imaging (MRI) device. Alternatively, the medical image may be a CTA (Computed Tomography Angiography) image taken by an examination using a computed tomography (CT) device. Alternatively, the medical image may be an angiography (Angiography) image taken by an examination using an angiography device, or an ultrasound image taken by an examination using an ultrasound diagnostic device. Furthermore, it is preferable that these medical images depict the subject's blood vessels and their surroundings in three dimensions. However, these medical images may also depict the subject's blood vessels and their surroundings in two dimensions.

[0025] Furthermore, it is preferable that the vascular region specifying unit executes a process of specifying a vascular region depicting the blood vessels of the subject in an image that has been registered with a reference image having a reference coordinate system. The registration referred to here is a process of using the image depicting the subject as a target image, and aligning the target image with the same coordinate system as the reference image by making the residual function between the reference image and an image obtained by performing a linear or nonlinear transformation on the target image as small as possible.

[0026] Linear transformation is a process of transforming at least a portion of a target image by performing transformation operations in the X, Y, and Z directions on a subject depicted in the target image. The transformation operations include translation, rotation, stretching, and shearing. On the other hand, nonlinear transformation is a process of transforming at least a portion of the target image by using B-spline curves to interpolate points in the target image that have predetermined X, Y, and Z coordinates.

[0027] The vascular region identifying unit 11 identifies a vascular region by, for example, applying binarization, region growing, or the like to a registered medical image. FIG. 2 is a diagram showing an example of a vascular region according to an embodiment of the present invention. The subject depicted in the medical image including the vascular region V1 shown in FIG. 2 and the subject depicted in the medical image including the vascular region V2 shown in FIG. 2 are different subjects. Furthermore, the vascular region V1 and the vascular region V2 are both three-dimensional regions depicting the blood vessels of the subject.

[0028] The feature line derivation unit 12 connects feature points included in each of the multiple figures included in the vascular region and executes a process for deriving feature lines along the vascular region for each subject. The figures included in the vascular region here are, for example, spheres or regular polyhedrons determined according to a certain rule for the vascular region. Furthermore, feature points are points determined according to a certain rule for the figures included in the vascular region. In the following explanation, a sphere inscribed in the vascular region will be used as an example of such a figure.

[0029] 3 is a diagram showing an example of a plurality of spheres inscribed in a blood vessel region and characteristic lines connecting the centers of these spheres according to an embodiment of the present invention. The plurality of spheres shown in FIG. 3 are an example of the plurality of figures described above.

[0030] For example, as shown in Fig. 3, the feature line derivation unit 12 determines spheres C101, C102, C103, C104, C105, C106, C107, C108, C109, C110, and C111 inscribed in the vascular region V1. Then, the feature line derivation unit 12 derives a feature line L1 connecting the centers of these spheres, which are indicated by black dots in Fig. 3. As shown in Fig. 3, the feature line L1 is a line that follows the vascular region V1, passes through the inside of the vascular region V1, and does not pass through the outside of the vascular region V1. Note that the centers of the spheres indicated by black dots in Fig. 3 are examples of the above-mentioned feature points.

[0031] Similarly, as shown in Fig. 3, the feature line derivation unit 12 determines spheres C201, C202, C203, C204, C205, C206, C207, C208, C209, C220, and C211 inscribed in the vascular region V2. Then, the feature line derivation unit 12 derives a feature line L2 connecting the centers of these spheres, which are indicated by black dots in Fig. 3. As shown in Fig. 3, the feature line L2 is a line that follows the vascular region V2, passes through the interior of the vascular region V2, and does not pass through the exterior of the vascular region V2. The centers of the spheres, indicated by black dots in Fig. 3, are examples of the above-mentioned feature points.

[0032] The branching point identification unit 13 performs a process of identifying branching points of characteristic lines for each subject. For example, the branching point identification unit 13 identifies the centers of the spheres C104 and C109 shown in Fig. 3 as branching points of the characteristic line L1. Similarly, the branching point identification unit 13 identifies the centers of the spheres C204 and C209 shown in Fig. 3 as branching points of the characteristic line L2.

[0033] Specifically, the branch point identification unit 13 sets voxels with equal side dimensions around at least a portion of the characteristic line, assigning a "1" to voxels through which the characteristic line passes and a "0" to voxels that the characteristic line does not pass through. Next, the branch point identification unit 13 sets, as branch point candidates, voxels to which a "1" is assigned and which have three or more adjacent voxels in the x, y, or z direction that are assigned a "1". Then, for each branch point candidate voxel, the branch point identification unit 13 assigns a value corresponding to the distance from the branch point candidate voxel to each of the other branch point candidate voxels located within a predetermined range.

[0034] 4 is a diagram illustrating an example of values ​​assigned to branch point candidates according to an embodiment of the present invention. For example, for voxel B of the branch point candidate shown in FIG. 4, the branch point identification unit 13 assigns the sum of a value according to the distance from voxel B to voxel B1 of another branch point candidate located within a predetermined range and a value according to the distance from voxel B to voxel B2 of the other branch point candidate.

[0035] For voxel B1, the branch point identification unit 13 calculates the sum "8" of the following values: "2" obtained by subtracting "1" (the number of voxels distant from voxel B in the x direction) from "3", "3" obtained by subtracting "0" (the number of voxels distant from voxel B in the y direction) from "3", and "3" obtained by subtracting "0" (the number of voxels distant from voxel B in the z direction) from "3". For voxel B2, the branch point identification unit 13 calculates the sum "5" of the following values: "1" obtained by subtracting "2" (the number of voxels distant from voxel B in the x direction) from "3", "1" obtained by subtracting "2" (the number of voxels distant from voxel B in the y direction) from "3", and "3" obtained by subtracting "0" (the number of voxels distant from voxel B in the z direction) from "3". Then, the branch point identification unit 13 assigns the sum "13" of the sum "8" and the sum "5" to the voxel B.

[0036] The branch point identification unit 13 performs similar processing on other branch point candidate voxels such as voxel B1 and voxel B2, and determines the voxel with the largest sum of assigned values ​​as the voxel containing the branch point.

[0037] The division point placement unit 14 executes, for each subject, a process of placing division points on a line that has one of two adjacent branch points on the feature line as its start point and the other as its end point. Fig. 5 is a diagram showing an example of two branch points according to an embodiment of the present invention, a line connecting these two branch points, a plurality of division points placed on the line, and a sphere centered at these division points and inscribed in a blood vessel region.

[0038] For example, the division point placement unit 14 specifies a line R1 having a start point at point P104 shown in FIG. 5 and an end point at point P109 shown in FIG. 5. Here, point P104 coincides with the center of sphere C104 shown in FIG. 3. Similarly, point P109 coincides with the center of sphere C109 shown in FIG. 3. Furthermore, line R1 coincides with the line sandwiched between the centers of spheres C104 and C109 of characteristic line L1 shown in FIG. 3. Then, the division point placement unit 14 executes a process of placing division points on line R1 that divide line R1 into equal parts. The division points referred to here are points indicated by black circles on line R1 in FIG. 5, and may include at least one of a point coinciding with point P104 and a point coinciding with point P109, or may not include at least one of these two points. In the following explanation, a case where these two points are included in the division points will be described as an example.

[0039] Similarly, the division point placement unit 14 specifies a line R2 having point P204 shown in FIG. 5 as its start point and point P209 shown in FIG. 5 as its end point. Here, point P204 coincides with the center of sphere C204 shown in FIG. 3. Similarly, point P209 coincides with the center of sphere C209 shown in FIG. 3. Furthermore, line R2 coincides with the line sandwiched between the centers of sphere C204 and C209 of characteristic line L2 shown in FIG. 3. Then, the division point placement unit 14 executes a process of placing division points on line R2 that divide line R2 into equal parts. The division points referred to here are points indicated by black circles on line R2 in FIG. 5, and may include at least one of a point coinciding with point P204 and a point coinciding with point P209, or may not include at least one of these two points. In the following explanation, a case where these two points are included in the division points will be described as an example.

[0040] 6 is a diagram showing an example of a standard blood vessel according to an embodiment of the present invention. The standard blood vessel generating unit 15 generates data showing the standard blood vessel W shown in FIG.

[0041] The standard blood vessel generation unit 15 calculates the coordinate statistics for each set of division points whose order of counting from the start point to the end point is the same among multiple subjects, and performs a process for each set of division points in which the point whose coordinate is equal to the statistical value is set as the standard point. The statistical value here is, for example, the average value or the median value.

[0042] For example, the standard blood vessel generating unit 15 calculates the average coordinate value for a pair of a division point that coincides with point P104, which is the first point in the blood vessel region V1 when counted from the start point to the end point, and a division point that coincides with point P204, which is the first point in the blood vessel region V2 when counted from the start point to the end point.The standard blood vessel generating unit 15 then determines point P304, whose coordinate value is equal to the average coordinate value, as the standard point.

[0043] Furthermore, for example, the standard blood vessel generating unit 15 calculates the average value of coordinates for a pair of a division point that coincides with point P109, which is the sixth point in the blood vessel region V1 when counted from the start point to the end point, and a division point that coincides with point P209, which is the sixth point in the blood vessel region V2 when counted from the start point to the end point.The standard blood vessel generating unit 15 then determines point P309, whose coordinates are equal to the average value, as the standard point.

[0044] Similarly, the standard blood vessel generation unit 15 performs the same processing for a pair of a point whose order of counting from the start point to the end point matches a point that is neither the first nor the sixth in the blood vessel region V1, and a point whose order of counting from the start point to the end point matches a point that is neither the first nor the sixth in the blood vessel region V2.

[0045] Next, the standard blood vessel generating unit 15 executes a process for each set of division points to set the dimensions of a predetermined portion of a figure that includes the standard point and is included in the blood vessel region as the standard diameter at the standard point.

[0046] For example, the standard blood vessel generating unit 15 executes a process of setting the diameter of each of spheres D104, D105, D106, D107, D108, and D109 inscribed in the blood vessel region V1, centered on a standard point included in the blood vessel region V1, as the standard diameter. Similarly, the standard blood vessel generating unit 25 executes a process of setting the diameter of each of spheres D204, D205, D206, D207, D208, and D209 inscribed in the blood vessel region V2, centered on a standard point included in the blood vessel region V2, as the standard diameter.

[0047] The standard blood vessel generating unit 15 then generates data indicating a standard blood vessel, which is a virtual blood vessel whose diameter at the standard point is the standard diameter and which extends along a standard line connecting the multiple standard points.

[0048] The blood vessel evaluation device 20 evaluates the blood vessels of a subject based on standard blood vessels, which are included in an image depicting the subject's blood vessels and are determined by a standard line that runs along the vascular region depicting the subject's blood vessels and a standard diameter that includes points on the standard line and is the dimension of a predetermined portion of each of a plurality of figures included in the vascular region. The subject here refers to a person whose blood vessels are being evaluated. The blood vessel evaluation device 20 also acquires data representing the standard blood vessels and data representing the subject's blood vessels from the storage device 30 shown in FIG. 1.

[0049] For example, the blood vessel evaluation device 20 calculates the center line and diameter of each part of the blood vessels of a diseased subject and the center line and diameter of each part of the blood vessels of a healthy subject based on the standard line and standard diameter of the standard blood vessel generated by the standard blood vessel generation device 10, and compares the blood vessels of the diseased subject with the blood vessels of the healthy subject.

[0050] FIG. 7 shows an example of the results of evaluation of the center line of the internal carotid artery of a subject suffering from dolichoectasia and the center line of the internal carotid artery of a healthy subject in the coronary plane using a vascular evaluation device according to an embodiment of the present invention. The open circles in FIG. 7 represent points on the coronary plane where the center line of the internal carotid artery of the subject suffering from dolichoectasia passes. The black circles in FIG. 7 represent points on the coronary plane where the center line of the internal carotid artery of the healthy subject passes. Furthermore, the line segments in FIG. 7 represent the standard deviation of the coordinates of the points on the center line of the internal carotid artery of the healthy subject. FIG. 7 shows that, when projected onto the coronary plane, the center line of the internal carotid artery of the subject suffering from dolichoectasia deviates relatively significantly from the center line of the internal carotid artery of the healthy subject.

[0051] FIG. 8 shows an example of the results of evaluation of the center line of the internal carotid artery of a subject suffering from dolichoectasia and the center line of the internal carotid artery of a healthy subject in the sagittal plane using a vascular evaluation device according to an embodiment of the present invention. The open circles in FIG. 8 indicate points on the sagittal plane where the center line of the internal carotid artery of the subject suffering from dolichoectasia passes. The black circles in FIG. 8 indicate points on the sagittal plane where the center line of the internal carotid artery of the healthy subject passes. Furthermore, the line segments in FIG. 8 represent the standard deviation of the coordinates of the points on the center line of the internal carotid artery of the healthy subject. FIG. 8 shows that, when projected onto the sagittal plane, the center line of the internal carotid artery of the subject suffering from dolichoectasia deviates relatively significantly from the center line of the internal carotid artery of the healthy subject.

[0052] 9 is a diagram showing an example of the results of evaluation of the diameter of the internal carotid artery of a subject suffering from dolichoectasia and the diameter of the internal carotid artery of a healthy subject using a vascular evaluation device according to an embodiment of the present invention, viewed from a direction perpendicular to the coronary plane. Fig. 9 shows the diameter of the internal carotid artery E of the subject suffering from dolichoectasia and the diameter of the internal carotid artery H of the healthy subject, expressed as the diameter of each sphere. When viewed from a direction perpendicular to the coronary plane, Fig. 9 shows that the internal carotid artery E of the subject suffering from dolichoectasia is thicker overall than the internal carotid artery H of the healthy subject, and that a portion of the internal carotid artery E is enlarged.

[0053] 10 is a diagram showing an example of the results of evaluation of the diameter of the internal carotid artery of a subject suffering from dolichoectasia and the diameter of the internal carotid artery of a healthy subject using a vascular evaluation device according to an embodiment of the present invention, viewed from a direction perpendicular to the sagittal plane. Fig. 10 shows the diameter of the internal carotid artery E of the subject suffering from dolichoectasia and the diameter of the internal carotid artery H of the healthy subject, expressed as the diameter of each sphere. When viewed from a direction perpendicular to the sagittal plane, Fig. 10 shows that the internal carotid artery E of the subject suffering from dolichoectasia is thicker overall than the internal carotid artery H of the healthy subject, and that a portion of the internal carotid artery E is enlarged.

[0054] Next, an example of processing executed by the standard blood vessel generating device according to the embodiment will be described with reference to Fig. 11. Fig. 11 is a flowchart showing an example of processing executed by the standard blood vessel generating device according to the embodiment of the present invention.

[0055] In step S10, the vascular region specifying unit 11 executes, for each subject, a process of specifying a vascular region depicting the subject's blood vessels in an image depicting the subject's blood vessels.

[0056] In step S20, the feature line derivation unit 12 executes a process for deriving, for each subject, a feature line that connects feature points included in each of the plurality of figures included in the blood vessel region and that runs along the blood vessel region.

[0057] In step S30, the branch point identification unit 13 executes a process of identifying branch points of characteristic lines for each subject.

[0058] In step S40, the division point placement unit 14 executes, for each subject, a process of placing a division point on a line that divides a line, the line having one of two adjacent branch points on the characteristic line as a start point and the other as an end point.

[0059] In step S50, the standard blood vessel generation unit 15 calculates coordinate statistics for pairs of division points whose order of counting from the starting point to the end point is the same among multiple subjects, and performs a process for each pair of division points in which the point whose coordinates are equal to the statistics is set as the standard point.

[0060] In step S60, the standard blood vessel generating unit 15 performs a process for each set of division points to set the dimensions of a predetermined portion of a figure that includes the standard points and is included in the blood vessel region as the standard diameter.

[0061] In step S70, the standard blood vessel generating unit 15 generates data indicating a standard blood vessel, which is a virtual blood vessel whose diameter at the standard point is the standard diameter and which is along a standard line connecting a plurality of standard points.

[0062] The above describes the standard blood vessel generation device 10 and the blood vessel evaluation device 20 according to the embodiment. The standard blood vessel generation device 10 includes a blood vessel region identification unit 11, a feature line derivation unit 12, a branch point identification unit 13, a division point placement unit 14, and a standard blood vessel generation unit 15.

[0063] The vascular region identification unit 11 performs a process for each subject to identify a vascular region depicting the subject's blood vessels in an image depicting the subject's blood vessels. The feature line derivation unit 12 performs a process for each subject to derive a feature line that connects feature points included in each of multiple figures included in the vascular region and runs along the vascular region. The branch point identification unit 13 performs a process for each subject to identify branch points of the feature line. The division point placement unit 14 performs a process for each subject to place a division point that divides a line on a line that has one of two adjacent branch points on the feature line as its start point and the other as its end point.

[0064] The standard blood vessel generating unit 15 calculates coordinate statistics for pairs of division points whose counting order from the start point to the end point is the same among multiple subjects, and performs a process for each subject in which the points whose coordinates equal the statistics are set as standard points. Next, the standard blood vessel generating unit 15 performs a process for each pair of division points in which the dimensions of a predetermined portion of a figure that includes the standard point and is included in the blood vessel region are set as standard diameters. The standard blood vessel generating unit 15 then generates data representing standard blood vessels, which are virtual blood vessels whose diameters at the standard points are the standard diameters and that follow standard lines connecting multiple standard points.

[0065] As a result, the standard blood vessel generating unit 15 can overcome the problem of individual differences in blood vessel shape and generate standard blood vessels that serve as a suitable standard for identifying blood vessel shapes. Furthermore, the standard blood vessels generated by the standard blood vessel generating device 10 serve as a common standard for evaluating blood vessel shapes, which vary considerably from person to person, and can therefore be utilized in research and development of medical devices, efficient disease prevention, diagnosis, and treatment, and the like. Furthermore, because the standard blood vessels generated by the standard blood vessel generating device 10 are determined by the above-described standard lines and standard diameters, they can serve as a clearer standard for identifying blood vessel shapes than the blood vessel existence probability distribution. Furthermore, because the data representing the standard blood vessels generated by the standard blood vessel generating device 10 differs from data relating to individual blood vessels, it is easy to handle from an ethical perspective.

[0066] The standard blood vessel generating device 10 may also perform a process to identify a blood vessel region depicting the subject's blood vessels in an image registered with a reference image having a reference coordinate system. This allows the standard blood vessel generating device 10 to unify the image used to generate the standard blood vessels with the coordinate system of the reference image, thereby generating data representing more accurate standard blood vessels.

[0067] The standard blood vessel generating device 10 may also perform processing to place division points on the line to divide the line into equal parts. This allows the standard blood vessel generating device 10 to use points that are likely to correspond between different subjects as reference points, thereby generating data indicating more accurate standard blood vessels.

[0068] Furthermore, the blood vessel evaluation device 20 evaluates the blood vessels of the subject based on a standard blood vessel, which is included in the image depicting the blood vessels of the subject and is determined by a standard line that is along the blood vessel region depicting the blood vessels of the subject and a standard diameter that includes points on the standard line and is the dimension of a predetermined portion of each of a plurality of figures included in the blood vessel region. This allows the blood vessel evaluation device 20 to perform not only a qualitative evaluation but also a quantitative evaluation of the blood vessels of the subject based on the standard blood vessel, which is a suitable standard for specifying the shape of the blood vessels.

[0069] Next, an example of a standard blood vessel generation device according to another embodiment will be described with reference to Fig. 12 to Fig. 20. Fig. 12 is a diagram showing an example of the functional configuration of a standard blood vessel generation device according to another embodiment of the present invention. In the following explanation, explanations of content that overlap with the above-mentioned embodiment will be omitted as appropriate.

[0070] As shown in FIG. 12, the standard blood vessel generating device 40 includes a blood vessel region specifying unit 11, a feature line derivation unit 12, a branch point specifying unit 13, a division point placing unit 14, and a standard blood vessel generating unit 15, as well as an end point specifying unit 131 and a feature line classification unit 132.

[0071] The endpoint identification unit 131 executes a process for identifying the endpoints of the characteristic lines for each subject. The endpoints referred to here include endpoints that occur when the blood vessel region becomes thinner than a certain thickness and the characteristic line cannot be determined, and endpoints that occur when the blood vessel region is interrupted at the edge of the image.

[0072] For example, the endpoint identification unit 131 sets voxels with equal side dimensions around at least a portion of the characteristic line, assigning a "1" to voxels that the characteristic line passes through and a "0" to voxels that the characteristic line does not pass through. Next, the endpoint identification unit 131 selects an arbitrary voxel assigned a "1" as a starting point in a three-dimensional space in which the x, y, and z directions are defined. Then, the endpoint identification unit 131 traces adjacent voxels in order from the selected voxel, and identifies a voxel at which it can no longer trace adjacent voxels in the three-dimensional space as an endpoint. Note that the term "adjacent voxel" used here refers to a voxel located one voxel away in at least one of the x, y, and z directions in the three-dimensional space.

[0073] The feature line classification unit 132 executes a process for determining, for each subject, a category to which the connected structure of the feature lines depicted in the image belongs, based on the connection relationships between branch points of the feature lines. The feature line classification unit 132 may also execute a process for determining, for each subject, a category to which the blood vessels depicted in the image belong, based not only on the connection relationships between branch points of the feature lines but also on the connection relationships between endpoints of the feature lines and feature points.

[0074] FIG. 13 is a diagram showing an example of a blood vessel according to another embodiment of the present invention. Specifically, FIG. 13 shows an example of a blood vessel in which the posterior communicating artery is not formed. When the blood vessel shown in FIG. 13 is depicted in an image, the branch point identifying unit 13 identifies, for example, points "1" and "5" circled in FIG. 13 as branch points of the characteristic line. When the blood vessel shown in FIG. 13 is depicted in an image, the endpoint identifying unit 131 identifies, for example, points "3" and "6" circled in FIG. 13 as endpoints of the characteristic line.

[0075] FIG. 14 is a diagram showing an example of a matrix indicating the connection relationships of branch points and end points on the characteristic lines of the blood vessels shown in FIG. 13. The numbers shown at the top and left end of FIG. 14 indicate the branch points or end points shown in FIG. 13. Furthermore, a white circle shown in FIG. 14 indicates that the point in the row and the point in the column in which the white circle is shown are connected by a characteristic line. For example, the white circle shown in the first row and third column of FIG. 14 indicates that branch point "1" and end point "3" shown in FIG. 13 are connected by a characteristic line. Furthermore, the white circle shown in the fourth row and sixth column of FIG. 14 indicates that branch point "5" and branch point "6" shown in FIG. 13 are connected by a characteristic line.

[0076] FIG. 15 is a diagram showing an example of a blood vessel according to another embodiment of the present invention. Specifically, FIG. 15 shows an example of a blood vessel published in a general anatomy textbook. When the blood vessel shown in FIG. 15 is depicted in an image, the branching point identifying unit 13 identifies, for example, points "1," "2," "4," and "5" circled in FIG. 15 as branching points of the characteristic line. When the blood vessel shown in FIG. 15 is depicted in an image, the end point identifying unit 131 identifies, for example, points "3" and "6" circled in FIG. 15 as end points of the characteristic line.

[0077] FIG. 16 is a diagram showing an example of a matrix indicating the connection relationships of branch points and endpoints on the characteristic lines of the blood vessels shown in FIG. 15. The numbers shown at the top and left end of FIG. 16 indicate the branch points or endpoints shown in FIG. 15. Furthermore, a white circle shown in FIG. 16 indicates that the point in the row and the point in the column in which the white circle is shown are connected by a characteristic line. For example, the white circle shown in the first row and second column of FIG. 16 indicates that branch point "1" and branch point "2" shown in FIG. 15 are connected by a characteristic line. Furthermore, the white circle shown in the fifth row and sixth column of FIG. 16 indicates that branch point "5" and endpoint "6" shown in FIG. 15 are connected by a characteristic line.

[0078] FIG. 17 is a diagram showing an example of a blood vessel according to another embodiment of the present invention. Specifically, FIG. 17 shows an example of a blood vessel in which the posterior communicating artery is longer than the posterior inferior cerebellar artery. When the blood vessel shown in FIG. 17 is depicted in an image, the branch point identifying unit 13 identifies, for example, points "1," "4," and "5" circled in FIG. 17 as branch points of the characteristic line. When the blood vessel shown in FIG. 17 is depicted in an image, the endpoint identifying unit 131 identifies, for example, points "3" and "6" circled in FIG. 17 as endpoints of the characteristic line.

[0079] FIG. 18 is a diagram showing an example of a matrix indicating the connection relationships of branch points and endpoints on the characteristic lines of the blood vessels shown in FIG. 17. The numbers shown at the top and left end of FIG. 18 indicate the branch points or endpoints shown in FIG. 17. Furthermore, a white circle shown in FIG. 18 indicates that the point in the row and the point in the column in which the white circle is shown are connected by a characteristic line. For example, the white circle shown in the third row and fourth column of FIG. 18 indicates that branch point "3" and branch point "4" shown in FIG. 17 are connected by a characteristic line. Furthermore, the white circle shown in the fifth row and sixth column of FIG. 18 indicates that branch point "5" and endpoint "6" shown in FIG. 17 are connected by a characteristic line.

[0080] The division point placement unit 14 performs a process of placing division points on a line that starts at one of two adjacent branch points on the characteristic line and ends at the other, for at least two characteristic line blood vessels determined to belong to the same category by the characteristic line classification unit 132. Then, the standard blood vessel generation unit 15 performs a process of generating data indicating standard blood vessels based on at least two characteristic lines determined to belong to the same category by the characteristic line classification unit 132.

[0081] The above describes a standard blood vessel generation device 40 according to another embodiment. The standard blood vessel generation device 40 includes an endpoint identification unit 131 and a feature line classification unit 132. The endpoint identification unit 131 performs a process of identifying the endpoints of feature lines for each subject. The feature line classification unit 132 performs a process of determining, for each subject, a category to which the connected structure of feature lines depicted in the image belongs, based on the connection relationships between branch points of the feature lines. The standard blood vessel generation device 40 then performs a process of arranging division points for at least two feature lines determined by the feature line classification unit 132 to belong to the same category, and generates data representing standard blood vessels.

[0082] This allows the standard blood vessel generating device 40 to generate more detailed standard blood vessels for each blood vessel category based on only at least two subjects having blood vessels that belong to the same category.

[0083] Furthermore, the feature line classification unit 132 performs a process for each subject to determine the category to which the connected structure of the feature lines depicted in the image belongs, based not only on the connection relationships between branch points of the feature lines but also on the connection relationships between endpoints of the feature lines and feature points.

[0084] This allows the standard blood vessel generation device 40 to further improve the accuracy of the process of determining the class to which the blood vessels depicted in the image belong.

[0085] Next, specific examples of the effects achieved by the standard blood vessel generating device according to another embodiment will be described with reference to FIGS.

[0086] 20 is a diagram showing an example of standard blood vessels generated by a standard blood vessel generation device according to another embodiment of the present invention based on the blood vessels of multiple subjects that are classified as left and right independent when the posterior communicating artery is taken into consideration. The average diameter of the standard blood vessels shown in FIG. 20 is 4.03±0.52 mm. The standard blood vessel generation device 40 can generate detailed standard blood vessels for each blood vessel category shown in FIG. 20 based only on subjects that have blood vessels that are classified as left and right independent when the posterior communicating artery is taken into consideration.

[0087] Fig. 21 is a diagram showing an example of standard blood vessels generated by a standard blood vessel generation device according to another embodiment of the present invention based on the blood vessels of multiple subjects that are classified as bilaterally combined when the posterior communicating artery is taken into consideration. The average diameter of the standard blood vessels shown in Fig. 21 is 3.45±0.49 mm. The standard blood vessel generation device 40 can generate detailed standard blood vessels for each blood vessel category shown in Fig. 21 based only on subjects that have blood vessels that are classified as bilaterally combined when the posterior communicating artery is taken into consideration.

[0088] In the above-described embodiment, the subject is a human head and the blood vessels are arteries in the brain, but the present invention is not limited to this. The subject may be a body part other than the human head, or a part of an animal's body. For example, examples of body parts other than the human head include the heart, limbs, and eyeballs. When the subject is a heart or limbs, the above-described medical image is preferably the above-described MRA image, CTA image, or ultrasound image. When the subject is an eyeball, the above-described medical image may be, for example, the above-described MRA image, CTA image, or ultrasound image, or may be a three-dimensional fundus image captured by an examination using an optical coherence tomography (OCT) device. Furthermore, the blood vessels may be veins.

[0089] In addition, at least a portion of the functions of the standard blood vessel generation device 10 and at least a portion of the functions of the blood vessel evaluation device 20 may be realized by hardware including circuitry such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit).

[0090] Furthermore, at least a portion of the functions of the standard blood vessel generation device 10 and at least a portion of the functions of the blood vessel evaluation device 20 may be realized by a combination of hardware and software. The software may be stored in, for example, a storage device having a non-transitory storage medium, and read and executed by the hardware. The storage device is, for example, a hard disk drive (HDD) or a solid state drive (SSD). Alternatively, the above-mentioned software may be stored in a storage device having a removable non-transitory storage medium, and read and executed by the above-mentioned hardware. The above-mentioned storage device is, for example, a DVD or a CD-ROM.

[0091] In the above-described embodiment, the standard blood vessel generating device 10 includes the blood vessel region identifying unit 11, the feature line deriving unit 12, the branch point identifying unit 13, the endpoint identifying unit 131, the feature line classification unit 132, the division point arrangement unit 14, and the standard blood vessel generating unit 15. However, the present invention is not limited to this. For example, some of the functions of the standard blood vessel generating device 10 may be realized by specific hardware, and other parts of the functions of the standard blood vessel generating device 10 may be realized by other hardware. For example, some of the functions of the standard blood vessel generating device 10 may be realized by specific hardware and software, and other parts of the functions of the standard blood vessel generating device 10 may be realized by other hardware and software.

[0092] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the embodiments of the present invention are not limited to the above-described forms, and various modifications, substitutions, and / or design changes may be made without departing from the spirit of the present invention. [Explanation of symbols]

[0093] 10, 40...standard blood vessel generation device, 11...vascular region identification unit, 12...characteristic line derivation unit, 13...branch point identification unit, 131...end point identification unit, 132...characteristic line classification unit, 14...division point placement unit, 15...standard blood vessel generation unit, 20...blood vessel evaluation device, 30...storage device, NW...network

Claims

1. a vascular region specifying unit that executes a process for specifying a vascular region in which the blood vessels of the subject are depicted in an image depicting the blood vessels of the subject for each of the subjects; a feature line derivation unit that executes, for each subject, a process of deriving a feature line that connects feature points included in each of a plurality of figures included in the blood vessel region and that runs along the blood vessel region; a branch point identification unit that executes a process of identifying a branch point of the characteristic line for each of the subjects; a division point placement unit that executes, for each of the subjects, a process of placing a division point on a line that has one of the two adjacent branch points on the characteristic line as a start point and the other as an end point, to divide the line; a standard blood vessel generating unit that calculates a coordinate statistic for a set of division points that are counted from the start point to the end point in the same order among the plurality of subjects, and performs the following process for each set of division points: calculating a coordinate statistic for a set of division points that are counted from the start point to the end point in the same order; setting a point whose coordinate is equal to the statistic as a standard point; and setting a dimension of a predetermined portion of a figure that includes the standard point and is included in the blood vessel region as a standard diameter; and generates data indicating a standard blood vessel that is a virtual blood vessel along a standard line that connects the plurality of standard points, the diameter at the standard point being the standard diameter; A standard blood vessel generation device comprising:

2. the vascular region specifying unit executes a process of specifying the vascular region depicting the blood vessels of the subject in the image registered with a reference image having a reference coordinate system.

10. The standard blood vessel generation device of claim 1.

3. the feature line derivation unit executes a process of deriving the feature line connecting the centers of a plurality of spheres inscribed in the blood vessel region.

3. The standard blood vessel generating device according to claim 1 or 2.

4. the division point placement unit executes a process of placing the division points on the line to equally divide the line; 4. The standard blood vessel generating device according to claim 1.

5. the standard blood vessel generation unit generates, as the standard blood vessel, data indicating a virtual blood vessel having a diameter at the standard point equal to a diameter of a sphere inscribed in the blood vessel region; 5. The standard blood vessel generating device according to claim 1.

6. a feature line classification unit that executes, for each of the subjects, a process of determining a category to which a connection structure of the feature lines depicted in the image belongs, based on a connection relationship between the branch points of the feature lines; the division point placement unit executes the process of placing the division points on the line for at least two blood vessels determined by the characteristic line classification unit to belong to the same category; the standard blood vessel generating unit executes a process of generating data representing the standard blood vessel based on at least two blood vessels determined by the feature line classifying unit to belong to the same category; 6. The standard blood vessel generating device according to claim 1.

7. an end point specifying unit that executes a process of specifying end points of the characteristic lines for each of the objects; the feature line classification unit executes, for each of the subjects, a process of determining a category to which a blood vessel depicted in the image belongs, based on a connection relationship between the endpoints of the feature line and the feature points.

7. The standard blood vessel generating device of claim 6.

8. A vascular evaluation device that evaluates the blood vessels of a subject based on the standard lines and standard diameters of standard blood vessels generated by the standard blood vessel generation device described in claim 1.

9. On the computer, a vascular region identifying function that executes, for each subject, a process of identifying a vascular region in which the blood vessels of the subject are depicted in an image depicting the blood vessels of the subject; a feature line derivation function that executes, for each subject, a process of deriving a feature line that connects feature points included in each of a plurality of figures included in the blood vessel region and that runs along the blood vessel region; a branch point identification function that executes a process of identifying a branch point of the characteristic line for each of the subjects; a division point placement function that executes, for each of the subjects, a process of placing a division point on a line that has one of the two adjacent branch points on the characteristic line as a start point and the other as an end point, the division point dividing the line; a standard blood vessel generation function that calculates a coordinate statistic for a set of division points that are counted from the start point to the end point in the same order among the plurality of subjects, and performs the following process for each set of division points: calculating a coordinate statistic for a set of division points that are counted from the start point to the end point in the same order; and setting a point whose coordinate is equal to the statistic as a standard point; and setting a dimension of a predetermined portion of a figure that includes the standard point and is included in the blood vessel region as a standard diameter; and generates data indicating a standard blood vessel that is a virtual blood vessel along a standard line that connects the plurality of standard points, the diameter at the standard point being the standard diameter; A standard blood vessel generation program that achieves this.

10. A vascular evaluation program that evaluates the blood vessels of a subject based on the standard lines and standard diameters of standard blood vessels generated by the standard blood vessel generation device described in claim 1.

11. a vascular region specifying step of executing, for each subject, a process of specifying a vascular region in which the blood vessels of the subject are depicted in an image depicting the blood vessels of the subject; a feature line deriving step of executing, for each subject, a process of deriving a feature line that connects feature points included in each of a plurality of figures included in the blood vessel region and that runs along the blood vessel region; a branch point specifying step of executing a process of specifying a branch point of the characteristic line for each of the objects; a division point arrangement step of performing, for each of the subjects, a process of arranging a division point on a line that has one of the two adjacent branch points on the characteristic line as a start point and the other as an end point, the division point dividing the line; a standard blood vessel generating step of calculating a coordinate statistic for a set of division points that are counted from the start point to the end point in the same order among the plurality of subjects, and setting a point whose coordinate is equal to the statistic as a standard point, and setting a dimension of a predetermined portion of a figure that includes the standard point and is included in the blood vessel region as a standard diameter for each set of division points, and generating data indicating a standard blood vessel that is a virtual blood vessel along a standard line that connects the plurality of standard points, the diameter at the standard point being the standard diameter; Standard vascular generation methods including:

12. A vascular evaluation method for evaluating the blood vessels of a subject based on the standard lines and standard diameters of standard blood vessels generated by the standard blood vessel generation device described in claim 1.

Images