JP2016159117A - Image region mapping apparatus, 3d model generating apparatus, image region mapping method, and image region mapping program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image region mapping apparatus and method for mapping a plurality of image regions of a blood vessel captured in two directions, using one X-ray imaging apparatus.SOLUTION: An image region mapping apparatus: radiographs a blood vessel 1201 with a contrast medium held therein, at a first and a second position by an X-ray imaging apparatus 101A, 101B to capture a first and a second image in time series, respectively; acquires a first absorption quantity charge rate in a first image region of the first image; acquires second absorption quantity change rates in second image regions of the second image which are candidates for the correspondence to the first image region; and selects, from among the candidate regions, a region of which second absorption quantity change rate is close to the first absorption quantity change rate and maps the selected region to the first image region.SELECTED DRAWING: Figure 5

Description

  The present invention uses an image region association device and an image region association device that associate a plurality of image regions of an X-ray image of a blood vessel imaged from two directions using a single X-ray imaging device. The present invention relates to a three-dimensional model generation apparatus that generates a three-dimensional model, an image region association method, and an image region association program.

  As a test for examining a disease caused by stenosis or occlusion of a blood vessel, there is a catheter imaging test. In a catheter contrast examination, a contrast agent that is a radiopaque material is used. By injecting a contrast medium into a blood vessel and taking an X-ray image, it is possible to clearly distinguish the blood vessel from other portions.

  When X-ray imaging is performed from one direction, it is difficult for a person to grasp the shape of a blood vessel having a large number of branches such as a coronary artery.

  Therefore, a technique for generating a three-dimensional model by correlating blood vessels from two X-ray images taken from two directions has been researched and developed (see, for example, Patent Document 1 and Non-Patent Document 1). . Thereby, it becomes easy for a person to grasp the shape of a blood vessel.

JP-A-8-131429

Tadahiro Yoshida, Motohide Misaki, Hiroyasu Sato, Tsuneo Saito, “3D Extraction of Coronary Arteries from Cardiovascular Angiograms”, IEICE Transactions '89 / 3 Vol. J72-D-II No. 3, P433-441

  However, in the above-described conventional technique, a plurality of X-ray imaging apparatuses are necessary to associate blood vessels.

  In view of this, a non-limiting exemplary embodiment of the present disclosure is an image region association device that associates a plurality of image regions of an X-ray image of a blood vessel imaged from two directions using a single X-ray imaging device. A three-dimensional model generation device that generates a three-dimensional model of a blood vessel using an image region association device, an image region association method, and an image region association program are provided.

In order to solve the above problem, according to one aspect of the present invention, there is provided an image region association device that associates a plurality of image regions of a blood vessel having a branch,
A first image obtained by imaging the blood vessel in a state in which a contrast medium having a predetermined concentration is captured from a first position by an X-ray imaging apparatus is acquired in time series from the X-ray imaging apparatus, and further, the contrast medium having a predetermined concentration is acquired. An image acquisition unit that acquires, in a time series, the second image obtained by imaging the blood vessel in a state where the agent is held from a second position different from the first position with the X-ray imaging apparatus;
The X-ray absorption amount in the blood vessel is acquired at a predetermined time interval from the brightness of the contrast agent for the first image region corresponding to the branching blood vessel portion of the first image acquired by the image acquisition unit. A first X-ray absorption amount change rate acquisition unit that calculates a value in which the change rate of the acquired X-ray absorption amount is within the first threshold value or less;
For a plurality of second image regions that are candidate image regions corresponding to the first image region in the second image, the X-ray absorption amount in the blood vessel is determined at predetermined time intervals from the brightness of the contrast agent. A second X-ray absorption amount change rate acquisition unit that respectively obtains each of the acquired X-ray absorption amount change rates within a range equal to or less than the second threshold;
The change rate of the X-ray absorption amount acquired from the first X-ray absorption amount change rate acquisition unit and each of the change rates of the plurality of X-ray absorption amounts acquired from the second X-ray absorption amount acquisition unit. A similarity calculator for calculating the similarity,
The second image region with the closest similarity calculated by the similarity calculation unit or the second image region with the similarity smaller than a third threshold is a region corresponding to the first image region. A corresponding area determining unit that determines that
An image region associating device is provided.
These general and specific aspects may be realized by a system, a method, a computer program, and any combination of the system, method, and computer program.

  According to a non-limiting exemplary embodiment of the present disclosure, a single X-ray imaging apparatus is used to associate a plurality of image regions of blood vessel X-ray images taken from two directions at different times. There are provided an image region association device and method, an image region association program, and a three-dimensional model generation device that generates a three-dimensional model of a blood vessel using the image region association device.

Explanatory diagram for generating a 3D model of blood vessels Figure when there is one candidate point for the corresponding point Figure when there are 2 candidate points for corresponding points Illustration of the basic principle of the present invention The block diagram which shows the function structure of the three-dimensional model production | generation apparatus in 1st Embodiment. The flowchart which shows an example of the processing operation of the three-dimensional model production | generation apparatus in 1st Embodiment. The block diagram which shows the function structure of the shape restoration apparatus in 2nd Embodiment. Block diagram showing the configuration of the X-ray imaging unit The figure which shows the data structure of the imaging part information holding part in 2nd Embodiment. The figure which shows the data structure of the X-ray image holding part in 2nd Embodiment. The figure which shows the structure of the to-be-photographed object area | region acquisition part in 2nd Embodiment. The figure which shows an example of the binary image in 2nd Embodiment. The figure which shows an example of the thin line image in 2nd Embodiment Flowchart of the imaging object region acquisition unit in the second embodiment The figure which shows the data structure of the to-be-photographed object thinned image holding | maintenance part in 2nd Embodiment. The figure which shows the structure of the matching part in 2nd Embodiment. Flowchart of second image projection area acquisition unit in the second embodiment The figure which shows the epipolar line L2 in 2nd Embodiment The figure which shows the epipolar plane in 2nd Embodiment The figure which shows 2nd image projection area | region Qk (k = 1, 2) in 2nd Embodiment. The figure which shows an example of the data which the 2nd image projection area holding part in 2nd Embodiment hold | maintains. The figure which shows an example of the data which the 1st image projection area holding part in 2nd Embodiment hold | maintains. The figure which shows the epipolar plane in 2nd Embodiment The figure which shows the epipolar plane in 2nd Embodiment The graph which shows the absorption characteristic of 1st image projection point Pk and 2nd image projection area | region Qk_1-Qk_2 in 2nd Embodiment. The figure which shows the data structure of the absorption characteristic holding | maintenance part in 2nd Embodiment. Flowchart of association control unit in the second embodiment The figure which shows the data structure of the 2nd image projection area holding part in 2nd Embodiment. The figure which shows the data structure of the three-dimensional position holding part in 2nd Embodiment. The figure which shows the display screen which the display screen production | generation part in 2nd Embodiment produces | generates. Flowchart of shape restoration apparatus in second embodiment The graph which shows the quantity of the contrast agent which flows into the three-dimensional point J1 in 2nd Embodiment The figure which shows the epipolar plane in the modification 1 of 2nd Embodiment. The figure which shows the epipolar plane in the modification 1 of 2nd Embodiment. The figure which shows the epipolar plane in 3rd Embodiment A graph showing the absorption characteristics of the first image projection points Pk_1 and Pk_2, the sum of the first image projection points Pk_1 and Pk_2, and the corresponding point Qk_1 in the third embodiment. The figure which shows the epipolar plane in 3rd Embodiment The figure which shows the epipolar plane in 3rd Embodiment The figure which shows the epipolar plane in 3rd Embodiment The figure which shows the epipolar plane in 3rd Embodiment The figure which shows the epipolar plane in 3rd Embodiment The figure which shows the structure of the shape decompression | restoration apparatus in 3rd Embodiment. The figure which shows the structure of the matching part in 3rd Embodiment. The figure which shows an example of the grouping which the grouping acquisition part in 3rd Embodiment acquires The figure which shows the structure of the grouping acquisition part in 3rd Embodiment. The figure which shows an example of the grouping which the two grouping part in 3rd Embodiment performs The figure which shows the result of the grouping which the two-grouping part in 3rd Embodiment performs Flowchart of grouping main body in the third embodiment The figure which shows an example of the result of the grouping which the grouping part in 3rd Embodiment performs The figure which shows the structure of the grouping evaluation part in 3rd Embodiment. The flowchart of the process which the matching control part in 3rd Embodiment performs The figure which shows an example of the corresponding information added to the corresponding information holding | maintenance part in 3rd Embodiment. The figure which shows an example of the corresponding information added to the corresponding information holding | maintenance part in 3rd Embodiment.

Before continuing the description of the present invention, the same parts are denoted by the same reference numerals in the accompanying drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before the embodiments of the present invention are described in detail with reference to the drawings, the knowledge that forms the basis of the present invention will be described below.

(Knowledge 1 as the basis of the present invention)
FIG. 1 is an explanatory diagram for generating a three-dimensional model of a blood vessel.

  A first X-ray image 1101 and a second X-ray image 1102 are obtained by irradiating the blood vessel 1201 with X-rays from two different directions from the X-ray generation unit 1202A and the X-ray generation unit 1202B.

  A point Jk on the blood vessel 1201 corresponds to the point Pk on the first X-ray image 1101.

  Here, if the point Jk can be identified on the second X-ray image 1102, the three-dimensional position of the point Jk can be identified using the principle of triangulation. Similarly, a three-dimensional model of the blood vessel 1201 can be generated by specifying a three-dimensional position for each of a plurality of points on the blood vessel 1201.

  A method for obtaining a point on the second X-ray image 1102 corresponding to the point Jk will be described.

  First, an epipolar line L2 in the second X-ray image 1102 is obtained for the point Pk of the first X-ray image 1101. The epipolar line L2 is a linear range in which the corresponding point of the point Pk can appear on the second X-ray image 1102. The epipolar line L2 is determined from the geometrical positional relationship between the point Pk and the first X-ray image 1101 and the second X-ray image 1102. In FIG. 1, since the candidate point corresponding to the point Pk is only the point Qk, the corresponding point of the point Pk is the point Qk.

  FIG. 2 shows a diagram in the case where there is one corresponding candidate point.

  As shown in FIG. 2, in the second X-ray image 1102, when the intersection of the end point of the blood vessel 1201 and the epipolar line L2 is one point, the point Qk is determined as the corresponding point of the point Pk.

However, as shown in FIG. 3, when there are two intersections between the end point of the blood vessel 1201 and the epipolar line L2, it is determined which of the points Qk_1 and Qk_2 should be the corresponding point of the point Pk. I can't.
(Knowledge 2 as the basis of the present invention)
Here, blood vessel reconstruction in which blood vessels are simultaneously imaged from two directions using two X-ray imaging devices 1202A and 1202B will be described with reference to FIG.

  Since the blood vessel is roughly a cylinder, its cross section is roughly an ellipse as shown in FIG. Here, the case where the cross section is an ellipse will be described, but the same principle holds even when the cross section has a shape other than an ellipse.

  The first X-ray image 1101 (first projection image) is obtained by irradiating the blood vessel 1201 with X-rays from a first imaging angle by an X-ray imaging apparatus (hereinafter also referred to as an X-ray generation unit 1202A). The first image region Pk is a region on the first X-ray image 1101 and a region corresponding to the blood vessel 1201 imaged from the direction from the X-ray generation unit 1202A toward the blood vessel 1201. Since the first image region Pk absorbs X-rays from the contrast medium in the blood vessel 1201, the luminance is lower than the other regions on the first X-ray image 1101.

  The second X-ray image 1102 (second projection image) is obtained by irradiating the blood vessel 1201 with X-rays from a second imaging angle by an X-ray imaging apparatus (hereinafter also referred to as an X-ray generation unit 1202B). The second image region Qk is a region on the second X-ray image 1102 and a region corresponding to the blood vessel 1201 imaged from the direction from the X-ray generation unit 1202B toward the blood vessel 1201. In the second image region Qk, X-rays are absorbed by the contrast agent in the blood vessel 1201, and therefore the luminance is lower than other regions on the second X-ray image 1102. The first shooting angle and the second shooting angle are different from each other by 90 degrees in the drawing as an example. However, the present invention is not limited to this, and the angles may be different.

  Here, when the intensities of the X-rays irradiated by the X-ray generation unit 1202A and the X-ray generation unit 1202B are the same, the brightness of the first image region Pk is lower than that of the second image region Qk_2. . This is because the X-rays emitted from the X-ray generator 1202A pass through the width d2 of the blood vessel 1201, whereas the X-rays emitted from the X-ray generator 1202B are the width d1 of the blood vessel 1201 (where d1 <d2 This is because the amount of X-ray absorbed by the contrast medium in the blood vessel 1201 is small.

  However, the amount of X-rays irradiated to the blood vessel 1201 from the X-ray generation unit 1202A is absorbed by the contrast medium in the blood vessel 1201 and the X-rays irradiated to the blood vessel 1201 from the X-ray generation unit 1202B are in the blood vessel 1201. The amount absorbed by the contrast agent is equal. This is because, since the amount of X-ray absorption depends on the amount of contrast medium, the amount of X-ray absorption in a part of the blood vessel 1201 is constant regardless of the incident direction of the X-ray to the part of the blood vessel 1201. is there.

  Hereinafter, the above contents will be described using mathematical expressions.

The X-ray having the intensity I ₀ is attenuated to the intensity I when passing through the X-ray absorber having the thickness d. Here, when the linear attenuation coefficient indicating the degree of attenuation is μ, Equation 1 is established.

  Moreover, when the logarithm is taken for both sides of Equation 1, Equation 2 is obtained.

  Here, the amount of absorption of X-rays generated by the X-ray generator 1202A by the contrast medium in the blood vessel 1201 is the luminance of each pixel constituting the first image region Pk, that is, the intensity of X-rays at each pixel. Can be obtained using Specifically, it is calculated as follows.

The total sum of the intensities I _{pk —} n (n = 1, 2,..., N) of the pixels constituting the first image region Pk is obtained from Equation 3. However, N is an integer greater than or equal to 2, and is the maximum number of pixels constituting the first image region Pk.

Note that the thickness d2 of the blood vessel 1201 viewed from the direction of the X-ray generation unit 1202A is different in each pixel constituting the first image region Pk. Therefore, in Expression 3, the thickness d2 is set to the thickness d2 _{pk_n} (n = 1, 2,..., N).

  From Expression 3, the amount of absorption by which the X-ray generated from the X-ray generator 1202A is absorbed by the contrast agent in the blood vessel 1201 is expressed as Expression 4.

  Similarly, the amount of absorption by which the X-ray generated from the X-ray generation unit 1202B is absorbed by the contrast medium in the blood vessel 1201 is expressed as in Expression 5.

Note that the intensity of each pixel constituting the second image region Qk is I _{qk_m} (m = 1, 2,..., M), and the thickness of the blood vessel 1201 viewed from the direction of the X-ray generation unit 1202B is d1 _{qk_m} (m = 1, 2, ..., M). However, M is an integer greater than or equal to 2, and is the maximum number of pixels constituting the second image region Qk.

Therefore, as described above, the amount of X-rays irradiated to the blood vessel 1201 from the X-ray generation unit 1202A absorbed by the contrast medium in the blood vessel 1201 and the X-rays irradiated to the blood vessel 1201 from the X-ray generation unit 1202B are Since the amount of absorption absorbed by the contrast medium in the blood vessel 1201 is equal, Expression 4 and Expression 5 are equal.

By using the above principle, the correspondence between the first area on the first X-ray image 1101 and the second area on the second X-ray image 1102 can be determined. Thereby, a three-dimensional model of the blood vessel 1201 can be generated using two X-ray imaging apparatuses. Note that the above equation holds even when the linear attenuation coefficient μ is constant regardless of the location, and when the linear attenuation coefficient μ is a function depending on the location.
(Basic principle of the present invention)
As described above, blood vessels can be reconstructed by imaging blood vessels from two directions simultaneously using two X-ray imaging devices.
However, when only one X-ray imaging apparatus is used, blood vessels cannot be imaged simultaneously from two directions.
Therefore, in a first aspect of the present invention, there is provided an image region association device that associates a plurality of image regions of a blood vessel having a branch,
A first image obtained by imaging the blood vessel in a state in which a contrast medium having a predetermined concentration is captured from a first position by an X-ray imaging apparatus is acquired in time series from the X-ray imaging apparatus, and further, the contrast medium having a predetermined concentration is acquired. An image acquisition unit that acquires, in a time series, the second image obtained by imaging the blood vessel in a state where the agent is held from a second position different from the first position with the X-ray imaging apparatus;
The X-ray absorption amount in the blood vessel is acquired at a predetermined time interval from the brightness of the contrast agent for the first image region corresponding to the branching blood vessel portion of the first image acquired by the image acquisition unit. A first X-ray absorption amount change rate acquisition unit that calculates a value in which the change rate of the acquired X-ray absorption amount is within the first threshold value or less;
For a plurality of second image regions that are candidate image regions corresponding to the first image region in the second image, the X-ray absorption amount in the blood vessel is determined at predetermined time intervals from the brightness of the contrast agent. A second X-ray absorption amount change rate acquisition unit that respectively obtains each of the acquired X-ray absorption amount change rates within a range equal to or less than the second threshold;
The change rate of the X-ray absorption amount acquired from the first X-ray absorption amount change rate acquisition unit and each of the change rates of the plurality of X-ray absorption amounts acquired from the second X-ray absorption amount acquisition unit. A similarity calculator for calculating the similarity,
The second image region with the closest similarity calculated by the similarity calculation unit or the second image region with the similarity smaller than a third threshold is a region corresponding to the first image region. A corresponding area determining unit that determines that
An image region associating device is provided.

  According to the first aspect, it is possible to appropriately associate a plurality of image regions of blood vessel X-ray images taken from two directions at different times using one X-ray imaging apparatus.

According to the second aspect of the present invention, the relative position information between the X-ray imaging apparatus that images the blood vessel from the first position and the X-ray imaging apparatus that images the blood vessel from the second position is retained. An imaging unit information holding unit,
An object area acquisition unit for acquiring position information of the object area from the first image and the second image of the X-ray imaging apparatus;
The X-ray image pickup device at the first position, the X-ray image pickup device at the second position, and the image pickup object from the position information respectively acquired from the image pickup unit information holding unit and the object region acquisition unit. An epipolar plane that is a plane composed of an object region is calculated, an epipolar line that is an intersection line of the calculated epipolar plane and the second image is calculated on the second image, and the plurality of second polarities are calculated. A second image projection area acquisition unit that acquires position information respectively located on the calculated epipolar line;
Further comprising
The second X-ray absorption amount change rate acquisition unit obtains the X-ray absorption amount at the position of the position information of the plurality of second image regions acquired by the second image projection region acquisition unit from the brightness of the contrast agent. , Each obtained at a predetermined time interval, and each obtained X-ray absorption amount change rate is calculated within a range below the second threshold value,
An image region association apparatus according to a first aspect is provided.

  According to the second aspect, a plurality of image areas are associated based on the absorption rate change rate from the corresponding candidate areas acquired based on the relative positional relationship between the first position and the second position of the X-ray imaging apparatus. Can be determined appropriately.

According to the third aspect of the present invention, it further includes an absorption amount acquisition unit that acquires X-ray absorption amounts in the first image region and the second image region,
The absorption amount acquisition unit includes a logarithm product of the number of pixels of the first image area and the intensity of X-rays emitted from the X-ray imaging device at the first position, and the first image area. The X-ray absorption amount in the first image region is acquired from the difference from the logarithmic sum of the intensity of the X-rays irradiated from the X-ray imaging device at the first position acquired at each pixel of
The first X-ray absorption amount change rate acquisition unit calculates a value in which the change rate of the X-ray absorption amount in the first image region acquired by the absorption amount acquisition unit is within the first threshold value or less. ,
The absorption amount acquisition unit, for each of the plurality of second image regions, includes the number of pixels in the second image region and the intensity of X-rays emitted from the X-ray imaging device at the second position. Based on the difference between the logarithm product and the logarithmic sum of the intensities of the X-rays emitted from the X-ray imaging device at the second position acquired at each pixel of the second image region, the second Obtain the amount of X-ray absorption in the image area,
The second X-ray absorption amount change rate acquisition unit calculates a value in which the change rate of the X-ray absorption amount in the second image region acquired by the absorption amount acquisition unit is within the second threshold value or less.
An image region association apparatus according to the first or second aspect is provided.

  According to the third aspect, the change rate of the absorption amount of the image region is calculated from the X-ray intensity of the image region captured by one X-ray imaging apparatus, and a plurality of change rates are calculated based on the calculated change rate of the absorption amount. The association of the image areas can be determined appropriately.

According to the fourth aspect of the present invention, it further includes an absorption amount acquisition unit that acquires X-ray absorption amounts in the first image region and the second image region,
The absorption amount acquisition unit calculates the product of the intensities of X-rays irradiated from the X-ray imaging device at the first position acquired by each pixel of the first image region as the first position. The X-ray absorption amount in the first image area is obtained from the value obtained by dividing the intensity of X-rays emitted from the X-ray imaging apparatus in FIG. By the value multiplied by the number of pixels in the first image area. And
The first X-ray absorption amount change rate acquisition unit calculates a value in which the change rate of the X-ray absorption amount in the first image region acquired by the absorption amount acquisition unit is within the first threshold value or less. ,
The absorption amount acquisition unit is configured to detect, for each of the plurality of second image regions, X-rays irradiated from the X-ray imaging device at the second position acquired at each pixel of the second image region. The value obtained by dividing the product of the intensities by the value obtained by multiplying the intensity of the X-rays irradiated from the X-ray imaging device at the second position by the number of pixels in the second image area. X-ray absorption amount in the image area of 2 is acquired,
The second X-ray absorption amount change rate acquisition unit calculates a value in which the change rate of the X-ray absorption amount in the second image region acquired by the absorption amount acquisition unit is within the second threshold value or less.
An image region association apparatus according to the first or second aspect is provided.

  According to the fourth aspect, it is possible to determine the correspondence between a plurality of image areas with high accuracy from the rate of change in the amount of absorption in a time-series image captured by one X-ray imaging apparatus.

According to the fifth aspect of the present invention, the apparatus further comprises an absorption amount acquisition unit that acquires X-ray absorption amounts in the first image region and the second image region,
The image acquisition unit acquires an image set composed of the first image and the second image for different first predetermined time and second predetermined time,
The absorption amount acquisition unit is a product of the intensities of the X-rays irradiated from the X-ray imaging device at the first position acquired at each pixel of the first image area at the first predetermined time. Divided by the product of the intensities of the X-rays emitted from the X-ray imaging apparatus at the first position acquired at each pixel of the first image area at the second predetermined time. To obtain the X-ray absorption amount in the first image region,
The first X-ray absorption amount change rate acquisition unit calculates a value in which the change rate of the X-ray absorption amount in the first image region acquired by the absorption amount acquisition unit is within the first threshold value or less. ,
The absorption amount acquisition unit acquires the X-ray imaging device at the second position acquired at each pixel of the second image area at the first predetermined time for each of the plurality of second image areas. X-rays irradiated from the X-ray imaging device at the second position acquired by the pixels of the second image area at the second predetermined time, the product of the intensity of the X-rays irradiated more From the value divided by the product of the line intensities, obtain the X-ray absorption amount in the second image area,
The second X-ray absorption amount change rate acquisition unit calculates a value in which the change rate of the X-ray absorption amount in the second image region acquired by the absorption amount acquisition unit is within the second threshold value or less.
An image region association apparatus according to the first or second aspect is provided.

  According to the fifth aspect, even in an X-ray image in which an object other than a blood vessel such as a bone or an organ is imaged together with the blood vessel, the association of a plurality of image regions for the blood vessel based on the rate of change in absorption amount Can be performed appropriately.

According to the sixth aspect of the present invention, the image processing apparatus further includes a grouping acquisition unit that generates a group in which the first image area and the second image area are combined.
The similarity calculation unit sets a sum of the change rates of the absorption amounts of all the first image regions included in the group generated by the grouping acquisition unit as a first sum, and the grouping acquisition unit The sum of the rate of change of the amount of absorption of all the second image regions included in the group generated by is used as the second sum, and the absolute value of the difference between the first sum and the second sum Calculating the similarity such that the similarity is high when the value is small and the similarity is low when the absolute value of the difference is large.
An image region association apparatus according to any one of the first to fifth aspects is provided.

  According to the sixth aspect, it is possible to calculate the change rate of the absorption amount by using a simple calculation and associate the image areas.

According to the seventh aspect of the present invention, the image acquisition unit acquires the first image in time series by photographing the blood vessel in which the contrast medium having the first predetermined concentration V1 is held as the predetermined concentration. And imaging the blood vessel in a state in which the contrast medium having the second predetermined concentration V2 is held as the predetermined concentration to acquire the second image in time series,
The first X-ray absorption amount change rate acquisition unit obtains a value obtained by multiplying a value by which the change rate of the acquired X-ray absorption amount is within the range of the first threshold value or less by (V2 / V1). The rate of change in linear absorption
An image region association apparatus according to any one of the first to sixth aspects is provided.

According to the eighth aspect of the present invention, the image acquisition unit acquires the first image in time series by photographing the blood vessel in which the contrast agent having the first predetermined concentration V1 is held as the predetermined concentration. And imaging the blood vessel in a state in which the contrast medium having the second predetermined concentration V2 is held as the predetermined concentration to acquire the second image in time series,
Whether the second X-ray absorption amount change rate acquisition unit sets, as the change rate of the X-ray absorption amount, a value obtained by multiplying the X-ray absorption amount when the X-ray absorption amount is maximum by (V1 / V2). Or, multiply the X-ray absorption amount when the X-ray absorption amount change rate when the X-ray absorption amount is acquired at a predetermined time interval is within the second threshold value or less by (V1 / V2). The value is the rate of change of the X-ray absorption amount,
An image region association apparatus according to any one of the first to sixth aspects is provided.
According to a ninth aspect of the present invention, a bed for carrying a patient having the blood vessel;
A mechanism that relatively moves the bed and the X-ray imaging apparatus;
The X-ray imaging device further acquiring the first image and the second image at the first position and the second position, respectively.
The first image is an image photographed by the X-ray imaging device when the X-ray imaging device is positioned at the first position, and the second image is captured by the mechanism unit with the bed and the X-ray. An image taken by the X-ray imaging apparatus after the X-ray imaging apparatus is moved from the first position to the second position by relatively moving with the X-ray imaging apparatus;
An image region association device according to any one of the first to eighth aspects is provided.
According to a tenth aspect of the present invention, there is provided a three-dimensional model generation device for generating a three-dimensional model of the blood vessel having the branch,
The image region association device according to any one of the first to ninth aspects;
A three-dimensional model generation unit that generates the three-dimensional model of the blood vessel using information determined by the corresponding region determination unit of the image region association device;
Is provided.
According to the tenth aspect, a three-dimensional model is generated by appropriately associating a plurality of image regions of blood vessels photographed from two directions at different times using one X-ray imaging apparatus. Can do. In particular, when generating a three-dimensional model using the principle of triangulation, an appropriate corresponding point can be determined even when there are a plurality of corresponding point candidates.

According to an eleventh aspect of the present invention, there is provided an image region association method for associating a plurality of image regions of a blood vessel having a branch,
A first image obtained by imaging the blood vessel in a state in which a contrast medium having a predetermined concentration is captured from a first position by an X-ray imaging apparatus is acquired in time series from the X-ray imaging apparatus, and further, the contrast medium having a predetermined concentration is acquired. A second image obtained by the X-ray imaging device is acquired in a time series from the second position different from the first position, and the blood vessel in a state where the agent is held is acquired in time series,
The X-ray absorption amount in the blood vessel is acquired at a predetermined time interval from the brightness of the contrast agent for the first image region corresponding to the branching blood vessel portion of the first image acquired by the image acquisition unit. The first X-ray absorption amount change rate acquisition unit calculates a value in which the change rate of the acquired X-ray absorption amount is within the first threshold value or less,
For a plurality of second image regions that are candidate image regions corresponding to the first image region in the second image, the X-ray absorption amount in the blood vessel is determined at predetermined time intervals from the brightness of the contrast agent, respectively. The obtained X-ray absorption amount change rate is calculated by the second X-ray absorption amount change rate acquisition unit so that the value is within the range of the second threshold value or less,
The change rate of the X-ray absorption amount acquired from the first X-ray absorption amount change rate acquisition unit and each of the change rates of the plurality of X-ray absorption amounts acquired from the second X-ray absorption amount acquisition unit. The similarity is calculated by the similarity calculator,
The second image region with the closest similarity calculated by the similarity calculation unit or the second image region with the similarity smaller than a third threshold is a region corresponding to the first image region. And determined by the corresponding area determination unit,
An image region matching method is provided.
According to the eleventh aspect, it is possible to appropriately associate a plurality of image regions of an X-ray image of a blood vessel taken from two directions at different times using one X-ray imaging apparatus.
According to a twelfth aspect of the present invention, in the image region associating method according to the eleventh aspect, after the corresponding region determining unit determines a region corresponding to the first image region,
A three-dimensional model generation method is provided in which a three-dimensional model generation unit generates a three-dimensional model of the blood vessel using information determined by the corresponding region determination unit.
According to the twelfth aspect, a three-dimensional model is generated by appropriately associating a plurality of image regions of blood vessels taken from two directions at different times using one X-ray imaging apparatus. Can do. In particular, when generating a three-dimensional model using the principle of triangulation, an appropriate corresponding point can be determined even when there are a plurality of corresponding point candidates.
According to a thirteenth aspect of the present invention, there is provided an image region association program that associates a plurality of image regions of a blood vessel having a branch.
Computer
A first image obtained by imaging the blood vessel in a state in which a contrast medium having a predetermined concentration is captured from a first position by an X-ray imaging apparatus is acquired in time series from the X-ray imaging apparatus, and further, the contrast medium having a predetermined concentration is acquired. An image acquisition unit that acquires, in a time series, the second image obtained by imaging the blood vessel in a state where the agent is held from a second position different from the first position with the X-ray imaging apparatus;
The X-ray absorption amount in the blood vessel is acquired at a predetermined time interval from the brightness of the contrast agent for the first image region corresponding to the branching blood vessel portion of the first image acquired by the image acquisition unit. A first X-ray absorption amount change rate acquisition unit that calculates a value in which the change rate of the acquired X-ray absorption amount is within the first threshold value or less;
For a plurality of second image regions that are candidate image regions corresponding to the first image region in the second image, the X-ray absorption amount in the blood vessel is determined at predetermined time intervals from the brightness of the contrast agent, respectively. A second X-ray absorption amount change rate acquisition unit that obtains and calculates a value in which each change rate of the acquired X-ray absorption amount is within a range equal to or less than a second threshold;
The change rate of the X-ray absorption amount acquired from the first X-ray absorption amount change rate acquisition unit and each of the change rates of the plurality of X-ray absorption amounts acquired from the second X-ray absorption amount acquisition unit. A similarity calculator for calculating the similarity,
The second image region with the closest similarity calculated by the similarity calculation unit or the second image region with the similarity smaller than a third threshold is a region corresponding to the first image region. A corresponding area determination unit for determining
A program for associating an image area is provided.
According to the thirteenth aspect, it is possible to appropriately associate a plurality of image regions of blood vessel X-ray images taken from two directions at different times using one X-ray imaging apparatus.

(First embodiment)
<Device configuration>
FIG. 5 shows a functional block diagram of the three-dimensional model generation apparatus 10 having the image region association apparatus 100 in the first embodiment of the present invention.

The three-dimensional model generation device 10 includes an image region association device 100 and a three-dimensional model generation unit 16.
The image region association apparatus 100 includes an X-ray image acquisition unit 11 and a first X-ray absorption amount constant value acquisition unit that functions as an example of a first X-ray absorption amount change rate acquisition unit (first X-ray absorption characteristic change rate acquisition unit). (First X-ray absorption characteristic constant value acquisition unit) 12 and a second X-ray absorption amount constant value acquisition unit (first X-ray absorption characteristic change rate acquisition unit) functioning as an example (second X-ray absorption characteristic change rate acquisition unit) 2 X-ray absorption characteristic constant value acquisition unit) 13, similarity calculation unit 14, and corresponding region determination unit 15.

<X-ray image acquisition unit 11>
The X-ray image acquisition unit 11 has different times at different positions (first position and second position, or first imaging position and second imaging position) depending on one X-ray imaging apparatus 101 described later. The two sets of time-series images taken at the time are acquired from the photographing start timing instructed by the input IF 114 to the photographing end timing (for example, every predetermined time). The first set of the two sets of time-series images is obtained by the X-ray imaging apparatus 101 after the operator injects a predetermined concentration of contrast medium into the blood vessel (with the predetermined concentration of contrast medium held in the blood vessel). It is the 1st image 1101 which image | photographed the said blood vessel in time series from the 1st imaging position (1st position or 1st imaging angle). The second set of the two sets of time series images moves the X-ray imaging apparatus 101 or the blood vessel after the first image 1101 is acquired, and then the operator again applies the predetermined concentration of the contrast agent to the blood vessel. After the injection (with the predetermined concentration of contrast medium held in the blood vessel), the blood vessel is time-sequentially measured from the second imaging position (second position or second imaging angle) by the X-ray imaging apparatus 101. It is the 2nd image 1102 image | photographed in FIG. The two sets of time-series images may be acquired only once at the timing instructed by the input IF 114, or from the start time instructed by the input IF 114 to the instructed end time.

<First X-ray absorption constant value acquisition unit 12>
The first X-ray absorption amount constant value acquisition unit 12 has a contrast medium brightness of the first image region Pk of the blood vessel 1201 in the first X-ray image (first image) 1101 acquired by the X-ray image acquisition unit 11. The X-ray absorption amount in the first image region Pk is acquired from the brightness of the contrast agent when the concentration becomes constant (in a state where the contrast agent of a predetermined concentration is held in the blood vessel). Thereafter, the first X-ray absorption amount constant value acquisition unit 12 acquires the change rate of the X-ray absorption amount from the acquired X-ray absorption amount, and from the acquired change rate, the absorption value constant value (absorption amount constant value or Get a constant absorption characteristic). Here, the constant amount of absorption (constant absorption characteristic value) is the brightness of the contrast agent for the first image region Pk corresponding to the blood vessel portion at the branch destination (portion ahead of the branch) of the first X-ray image 1101. The X-ray absorption amount (X-ray absorption characteristic) in the blood vessel is acquired at a predetermined time interval (for example, about 0.1 to 0.2 seconds), and the change rate of the acquired X-ray absorption amount is equal to or less than the first threshold value. Means a value within the range of

Note that the first image region Pk is a region including the blood vessel 1201.
Further, the determination of whether or not the brightness of the contrast medium has become constant by the first X-ray absorption amount constant value acquisition unit 12 is performed on the region included in the branch destination blood vessel 1201, and the absorption amount (an example of absorption characteristics). The first X-ray absorption amount constant value acquisition unit 12 may perform only the calculation of the constant value for the region including the branch destination blood vessel 1201.
For example, when the luminance at time t is L (t), the determination of whether or not the luminance has become constant by the first X-ray absorption amount constant value acquisition unit 12 (determination of whether or not there is a constant amount of absorption) is as follows.
| L (t) −L (t−1) |, | L (t) −L (t−2) |,..., | L (t) −L (t−N) |
When all of the values are equal to or less than the first threshold value, the first X-ray absorption amount constant value acquisition unit 12 determines that the luminance becomes constant at time t. Here, | X | indicates the absolute value of X. N is an integer of 2 or more. It is determined whether the brightness is continuously constant for N or more images out of the number of images captured in the first image area Pk.

<Second X-ray absorption constant value acquisition unit 13>
The second X-ray absorption amount constant value acquisition unit 13 is an image region corresponding to the branch destination blood vessel 1201 in the second X-ray image (second image) 1102 and a candidate corresponding to the first image region Pk. When the brightness of the contrast medium becomes constant for a plurality of second image areas Qk_n (n = 1, 2,..., N) that are image areas of (candidate points for corresponding points) The X-ray absorption amount in the second image region Qk_n is obtained by calculating the X-ray intensity after passing through the branching vessel from the brightness of the contrast agent (in the state of being held in the blood vessel). Thereafter, the second X-ray absorption amount constant value acquisition unit 13 acquires the acquired X-ray absorption amount constant value (absorption amount constant value or absorption characteristic constant value). Here, the constant absorption amount (constant absorption characteristic value) is a plurality of second image regions Qk_n (n = 1, 2) that are candidate image regions corresponding to the first image region Pk in the second X-ray image 1102. ,..., N), the X-ray absorption amount (X-ray absorption characteristics) in the blood vessels is acquired at predetermined time intervals (for example, about 0.1 to 0.2 seconds) from the brightness of the contrast agent, and acquired respectively. It means that the change rate of the absorbed X-ray absorption amount is a value within the range of the second threshold value or less.

The second image region Qk_n is a region including the blood vessel 1201.
Further, the determination of whether or not the brightness of the contrast agent has become constant by the second X-ray absorption amount constant value acquisition unit 13 is performed on the region included in the branch destination blood vessel 1201, and the absorption amount (an example of absorption characteristics). The second X-ray absorption constant value acquisition unit 13 may perform only the calculation of the constant value for the region including the branch destination blood vessel 1201.

<Similarity calculation unit 14>
The similarity calculation unit 14 absorbs the X-ray absorption amount constant value acquired from the first X-ray absorption amount constant value acquisition unit 12 and the plurality of X-ray absorption values acquired from the second X-ray absorption amount constant value acquisition unit 13. The similarity with each of the fixed quantity values is calculated.

<Corresponding area determination unit 15>
The corresponding region determination unit 15 determines that the second image region Qk_n having the highest similarity among the plurality of similarities calculated by the similarity calculation unit 14 is a region corresponding to the first image region Pk. To do. The corresponding region determination unit 15 determines that the second image region Qk_n having a similarity calculated by the similarity calculation unit 14 smaller than the third threshold is a region corresponding to the first image region Pk. Also good.
Alternatively, the corresponding area determination unit 15 determines that the second image area Qk_n whose similarity is higher than the third threshold is an area corresponding to the first image area Pk. If there is a second image region Qk_n having a similarity higher than the third threshold, as an example, the second image region Qk_n first determined that the similarity is higher than the third threshold is used as the first image region Qk_n. Is determined to be an area corresponding to the image area Pk. By this determination, it is possible to determine the association between the second image region Qk_n and the first image region Pk.

<Three-dimensional model generation unit 16>
The three-dimensional model generation unit 16 generates a three-dimensional model of the blood vessel 1201 using the information determined by the corresponding region determination unit 15.

<Device operation>
FIG. 6 shows a processing operation flow of the image region association device 100 and the three-dimensional model generation device 10 in the first embodiment.

  First, when the surgeon injects a predetermined concentration of contrast medium into the blood vessel 1201, the X-ray image acquisition unit 11 images the blood vessel 1201 in time series from the first imaging position by the X-ray imaging apparatus 101. After moving the first image 1101 and the X-ray imaging apparatus 101 or the blood vessel 1201, the operator again injects a predetermined concentration of contrast medium into the blood vessel 1201. A second image 1102 taken in time series from the second shooting position is acquired (step S10).

  Next, the first X-ray absorption constant value acquisition unit 12 has the contrast agent brightness of the first image region Pk corresponding to the blood vessel 1201 portion in the first X-ray image 1101 acquired by the X-ray image acquisition unit 11. The amount of X-ray absorption in the first image region Pk is acquired from the brightness of the contrast agent when it becomes constant. Then, a value in which the change rate of the acquired X-ray absorption amount is within the first threshold value or less is acquired as the first X-ray absorption constant value (step S11).

  Next, the second X-ray absorption amount constant value acquisition unit 13 is an image area corresponding to the branch destination blood vessel 1201 in the second X-ray image 1102 and a candidate image corresponding to the first image area Pk. For a plurality of second image regions Qk_n (n = 1, 2,..., N) that are regions, the X-ray intensity after passing through the branching vessel from the contrast agent luminance when the contrast agent luminance becomes constant Are respectively obtained to acquire the X-ray absorption amount in the second image region Qk_n. Then, each value of the change rate of the acquired X-ray absorption amount within a range equal to or smaller than the second threshold is acquired as the second X-ray absorption constant value (step S12). Note that step S11 and step S12 may be performed simultaneously.

  Next, the similarity calculation unit 14 includes a plurality of first X-ray absorption amount fixed values acquired from the first X-ray absorption amount fixed value acquisition unit 12 and a plurality of first X-ray absorption amount fixed value acquisition units 13 acquired from the second X-ray absorption amount fixed value acquisition unit 13. The degree of similarity with each of the 2X-ray absorption amount constant values is calculated (step S13).

  Next, the corresponding region determination unit 15 selects the second image region Qk_n having the highest similarity among the plurality of similarities calculated by the similarity calculation unit 14 as a region corresponding to the first image region Pk. It is determined that there is (step S14). Up to this point, the processing operation of the image region association apparatus 100 has been described.

  Next, the three-dimensional model generation unit 16 generates a three-dimensional model of the blood vessel 1201 using the information determined by the corresponding region determination unit 15 (step S15).

<Effects of First Embodiment>
According to the image region association device 100 in the first embodiment, image regions are associated from two sets of image sequences of blood vessels 1201 photographed from two directions at different times using one X-ray imaging device 101. And a three-dimensional model of the blood vessel 1201 can be generated. That is, even when there are a plurality of second X-ray images 1102 for the first region on the first X-ray image 1101, the first region on the first X-ray image 1101 and the optimum second X-ray image 1102 are displayed. The corresponding area determination unit 15 can determine the correspondence with the second area. As a result, according to the three-dimensional model generation device 10, a three-dimensional model of the blood vessel 1201 can be generated based on the image region association result in the image region association device 100.
Here, the association of the blood vessel 1201 into which the contrast medium has been injected has been described, but the association can be performed in the same manner for general objects other than the blood vessel.

(Second Embodiment)
FIG. 7 is a diagram illustrating a configuration of a three-dimensional model generation device 1 (hereinafter, also referred to as a shape restoration device 1) having an image region association device 100B according to the second embodiment of the present invention. As an example, the shape restoration device 1 includes an image region association device 100B, a three-dimensional model generation unit 16B, and a display unit 112.
Furthermore, the image region association apparatus 100B includes, as an example, an X-ray image acquisition unit 113, an X-ray imaging unit (X-ray imaging device) 101, a movement instruction unit 102, an imaging unit information holding unit 104, and an input IF. (Interface) 114, X-ray image holding unit 103, imaged object region acquisition unit 105, imaged object thinned image holding unit 106, imaged object region image holding unit 1132, and association unit 107 Prepare. The X-ray image acquisition unit 113 corresponds to the X-ray image acquisition unit 11 of the first embodiment. The associating unit 107 includes a first X-ray absorption amount constant value acquisition unit 12 (an example of a first X-ray absorption characteristic constant value acquisition unit) and a second X-ray absorption amount constant value acquisition unit 13 (second X-ray absorption) of the first embodiment. An example of the constant characteristic value acquisition unit), the similarity calculation unit 14 of the first embodiment, and the corresponding region determination unit 15 correspond to examples.
The three-dimensional model generation unit 16B includes a correspondence information holding unit 108, a three-dimensional position acquisition unit 109, a three-dimensional position holding unit 110, and a display screen generation unit 111.

  The X-ray imaging unit 101 irradiates the imaging target region of the subject from different angles at different times, and takes an X-ray fluoroscopic image or a blood vessel imaged when a contrast agent is injected. A means for acquiring an image, for example, called an X-ray angiography apparatus or angiography. The X-ray imaging unit 101 in the second embodiment images a blood vessel 1201 that is an object to be imaged.

FIG. 8 shows the configuration of the X-ray imaging unit 101. The X-ray imaging unit 101 includes an X-ray generation unit 202, an X-ray detection unit 203, a mechanism unit 206, and a mechanism control unit 205.
The X-ray generation unit 202 includes an X-ray tube that generates X-rays using a high voltage, and an X-ray diaphragm that controls an irradiation field by shielding a part of the X-rays. The upper patient 200 is irradiated with X-rays.
The X-ray detection unit 203 is a camera that receives X-rays transmitted through the patient 200, records image information, and outputs the recorded image information. The X-ray detection unit 203 is configured as, for example, an FPD (Flat Panel Detector) that arranges an X-ray sensing layer, converts X-rays into digital data, and outputs the digital data. When the patient 200 is irradiated with X-rays from the X-ray generation unit 202, the X-ray detection unit 203 outputs image information indicating the irradiated X-ray image to the image acquisition unit 113.
The mechanism unit 206 includes a driving device such as a motor, and moves the arm 204 and the bed 201 based on an instruction from the mechanism control unit 205.
The mechanism control unit 205 controls the mechanism unit 206 based on the movement instruction from the movement instruction unit 102 and outputs the position of the X-ray generation unit 202 or the X-ray detection unit 203 to the imaging unit information holding unit 104. To do.
Here, the positions of the X-ray imaging unit 101 when imaging an image sequence for the first time and the X-ray imaging unit 101 when imaging the image sequence for the second time after moving the X-ray imaging unit 101 are distinguished. In this case, the X-ray imaging unit 101 at the former position is the X-ray imaging unit 101A, and the X-ray imaging unit 101 at the latter position is the X-ray imaging unit 101B. Similarly, when the position of the X-ray generation unit 202 of the X-ray imaging unit 101 is distinguished between when the first image sequence is captured and when the second image sequence is captured, the former is used. The X-ray generator 202 at the position is referred to as an X-ray generator 202A, and the X-ray generator 202 at the latter position is referred to as an X-ray generator 202B.

The movement instruction unit 102 drives and controls the mechanism control unit 205 to relatively move the X-ray detection unit 203, for example. Specifically, the movement instruction unit 102 sends an instruction to move the arm 204 (X-ray detection unit 203) or the bed 201 to the mechanism control unit 205.
The mechanism control unit 205 may be configured to control only the mechanism unit 206 to move only the arm 204, or to move only the bed 201, or to move both. In the case where only the bed 201 is moved, the apparatus can be made inexpensive by fixing the X-ray detection unit 203 and the X-ray generation unit 202.
The X-ray image acquisition unit 113 acquires X-ray images (radiation images) from the X-ray imaging unit 101 at different positions at different times, and stores the acquired X-ray images in the X-ray image holding unit 103, respectively. . The X-ray image acquisition unit 113 starts and ends image acquisition at a timing instructed by an input IF 114 described later.

  Specifically, the X-ray image acquisition unit 113 starts acquiring an image in response to an instruction from the input IF 114 and stores, for example, the image acquired from the X-ray imaging unit 101A in the X-ray image holding unit 115. Thereafter, the X-ray image acquisition unit 113 acquires an image from the X-ray imaging unit 101A at a timing instructed by the input IF 114 (for example, every predetermined time) until an instruction for termination is received from the input IF 114. Stored in the X-ray image holding unit 115. That is, the image acquired at the first position before the X-ray imaging unit 101 is moved by the movement instruction unit 102 (the image acquired by the X-ray imaging unit 101A) is stored in the X-ray image holding unit 115. Similarly, the X-ray image acquisition unit 113 acquires an image from the X-ray imaging unit 101B at the timing instructed by the input IF 114 (for example, every predetermined time), and the acquired image is stored in the X-ray image holding unit 103. Store. That is, the image acquired at the second position after the X-ray imaging unit 101 is moved by the movement instruction unit 102 (the image acquired by the X-ray imaging unit 101B) is stored in the X-ray image holding unit 115.

  The imaging unit information holding unit 104 is a unit that holds information regarding the X-ray imaging units 101A and 101B. Specifically, the imaging unit information holding unit 104 is realized by a storage device such as a CPU register, cache, RAM, or ROM, for example. Henceforth, the part which has a holding part in a name is implement | achieved by the same method.

  Specifically, the imaging unit information holding unit 104 holds the relative position information of the X-ray imaging units 101A and 101B and the internal parameter A of the camera of the X-ray imaging unit 101. FIG. 9 is a diagram illustrating an example of a data structure of the image capturing unit information holding unit 104. The imaging unit information holding unit 104 holds a translation vector T, a rotation vector R, and an internal parameter A.

  The translation vector T is a vector that indicates where the X-ray imaging unit 101B is located with reference to the position of the X-ray imaging unit 101A, and the position information (X-ray imaging device) of each of the X-ray imaging units 101A and 101B. 101A and positional information of the X-ray imaging apparatus 101B). The rotation vector R indicates the direction of the imaging direction of the X-ray imaging unit 101B with respect to the imaging direction of the X-ray imaging unit 101A. The internal parameter A is a parameter representing the positional relationship between the imaging lens provided in the camera of the X-ray imaging unit 101 and the imaging surface of the imaging element. In the X-ray imaging unit 101, the X-ray generation unit 202 and the X-ray detection unit 203 are used. Is a parameter representing the positional relationship between Here, to simplify the explanation, the position of the X-ray detection unit 203 with respect to the X-ray generation unit 202 is fixed, and the value of the internal parameter A is prepared in advance and stored in the imaging unit information holding unit 104. Shall be kept.

  Here, the relative position of the X-ray imaging apparatus 101B with respect to the X-ray imaging apparatus 101A is determined in advance, and the translation vector T and the rotation vector R are also held in the imaging unit information holding unit 104 in advance. . The imaging unit information holding unit 104 acquires the positions of the X-ray imaging apparatus 101A and the X-ray imaging apparatus 101B, and calculates the translation vector T and the rotation vector R from the acquired positions. It doesn't matter.

  The input IF 114 is a device by which an operator (operator) inputs an instruction to the shape restoration device 1. For example, the input IF 114 is realized by a button, a switch, a computer keyboard, a mouse, or the like. Here, the input IF 114 is used to give an instruction to start and end image acquisition to the X-ray image acquisition unit 113.

  The X-ray image holding unit 103 is a unit that holds the image acquired by the X-ray image acquisition unit 113. FIG. 10 is a diagram illustrating a data structure of the X-ray image holding unit 103. The time when the X-ray image acquisition unit 113 starts image acquisition is set to time 0, the time when image acquisition ends is set to time END, and the X-ray imaging units 101A to 101B are photographed at each time from image acquisition to start. Hold each image. That is, an image sequence (shown as an image sequence captured by the X-ray imaging unit 101A in FIG. 10) taken at a position before the X-ray imaging device 101 is moved by the movement instruction unit 102 and the X-ray imaging device 101. An image sequence (shown as an image sequence captured by the X-ray imaging unit 101B in FIG. 10) captured at a position after being moved by the movement instruction unit 102 is held. In the following description, an image captured at time n by the X-ray imaging unit 101A is referred to as an image 1_n, and an image captured at time n by the X-ray imaging unit 101B is referred to as an image 2_n. In addition, images 1_0 and 2_0 captured at time 0 by the X-ray imaging unit 101A and the X-ray imaging unit 101B are referred to as background images.

  The imaging object region acquisition unit 105 is a unit that acquires the region of the blood vessel 1201 into which a contrast agent has been introduced, from the image 1_END and the image 2_END. FIG. 11 is a diagram illustrating a configuration of the imaging object region acquisition unit 105. The object area acquisition unit 105 includes a difference image generation unit 1504, a difference image holding unit 1505, a binarization unit 1501, and a thinning unit 1503.

  The difference image generation unit 1504 acquires the image n_END and the image n_0 (background image) from the X-ray image holding unit 103, generates a difference image between them, and stores the generated difference image in the difference image holding unit 1505. (N = 1, 2).

  The difference image holding unit 1505 holds the difference image generated by the difference image generation unit 1504.

  The binarization unit 1501 acquires a difference image from the difference image holding unit 1505, binarizes the acquired difference image, and stores the binarized image in the captured object region image holding unit 1132. Here, the pixel value of the blood vessel region is “1”, and the pixel value of the other region is “0”.

  The thinning unit 1503 thins the binary image held by the imaging target region image holding unit 1132 and stores it in the imaging target thinned image holding unit 106. FIG. 13 shows a fine line image obtained by thinning the binary image shown in FIG. The binary image shown in FIG. 12 is an example of the imaged object region image, and the thin line image of FIG. 13 is an example of the thinned object region image.

<Flow of Process Performed by Object Captured Area Acquisition Unit 105>
FIG. 14 is a diagram illustrating a flowchart of processing for acquiring the imaging object region of the image 1_END imaged by the X-ray imaging unit 101A by the imaging object region acquisition unit 105.

  The to-be-photographed object area | region acquisition part 105 starts a process by step S801.

  In step S802, the difference image generation unit 1504 performs the process of the difference image generation unit 1504 described above. That is, the difference image generation unit 1504 acquires the image 1_0 and the image 1_END in the image sequence captured by the X-ray imaging unit 101A from the X-ray image holding unit 103, and calculates the difference between each pixel of the acquired image. The calculated difference image is generated and stored in the difference image holding unit 1505.

  Next, in step S803, the binarization unit 1501 performs the processing of the binarization unit 1501 described above. That is, the binarizing unit 1501 acquires the difference image as the captured object region image from the difference image holding unit 1505, binarizes the acquired difference image, and stores the captured object region in the captured object region image holding unit 1132. Store as an image.

  Next, the thinning unit 1503 performs the processing of the thinning unit 1503 described above in step S804. That is, the thinning unit 1503 thins the binary image held by the imaging target region image holding unit 1132 and stores the thinned image in the imaging target thinned image holding unit 106 as a thinned imaging target region image. .

  Next, the to-be-photographed object area | region acquisition part 105 complete | finishes a process by step S805. Through these processes, the imaging object region acquisition unit 105 acquires the imaging object region (position coordinates) of the image 1_END.

The captured object region acquisition unit 105 performs the same processing on the image 2_END captured by the X-ray imaging unit 101B, and acquires the captured object region (positional coordinates) of the image 2_END.
Here, a case is described in which the object area (position information, for example, position coordinates) is determined from the images 1_END and 2_END acquired at time END. However, an area in which the contrast agent is detected at any time from the start of imaging to the end of imaging may be used as a blood vessel area by the imaging object area acquiring unit 105. Specifically, a pixel having a time at which the luminance difference from the pixel brightness at the photographing start time is equal to or greater than the threshold for the object region is set as the object region by the object region acquisition unit 105, and any time In FIG. 5, pixels whose luminance difference from the luminance of the pixels at the shooting start time is less than the threshold for the imaging target area are excluded from the imaging target area by the imaging target area acquisition unit 105.

  The to-be-photographed object thinned image holding unit 106 is a unit that holds the to-be-photographed object region acquired by the to-be-photographed object region acquiring unit 105. FIG. 15 is a diagram illustrating a data structure of the object to be imaged thinned image holding unit 106. The to-be-photographed object thinned image holding unit 106 holds a first to-be-photographed object thinned image 1101T generated from the image 1_END and a second to-be-photographed object thinned image 1102T generated from the image 2_END.

  The captured object region image holding unit 1132 is a unit that stores the captured object region image acquired by the captured object region acquisition unit 105. The captured object area image holding unit 1132 holds a first captured object area image generated from the image 1_END and a second captured object area image generated from the image 2_END.

  The associating unit 107 performs the first object thinned image 1101T based on the first object thinned image 1101T and the second object thinned image 1102T held by the object thinned image holding unit 106. The position of the corresponding point on the second object to be imaged thinned image 1102T is acquired with respect to the black point. In the following description, each point of the first object thinned image 1101T is defined as a first image projection point Pk (k = 1, 2,..., K, where K is the first object thinned image 1101T in the first object thinned image 1101T. This is called the number of projection points for one image (see FIG. 18).

  FIG. 16 is a diagram illustrating a configuration of the association unit 107. The association unit 107 includes a first image projection region acquisition unit 1702C, a first image projection region holding unit 1703C, a second image projection region acquisition unit 1705, and a second image that function as an example of the object region acquisition unit. Constant absorption characteristic that functions as an example of the projection region holding unit 1706, the absorption characteristic acquisition unit 1707, the absorption characteristic holding unit 1708, the first X-ray absorption characteristic constant value acquisition unit 12, and the second X-ray absorption characteristic constant value acquisition unit 13. Value acquisition unit 1731, absorption characteristic constant value holding unit 1732, absorption characteristic evaluation unit 1709 functioning as an example of similarity calculation unit 14, absorption characteristic evaluation holding unit 1710, corresponding region determination unit 1711, and association control Part 1701.

  First, prior to the description of the second image projection region acquisition unit 1705, the epipolar lines and epipolar planes calculated and acquired by the second image projection region acquisition unit 1705 will be described with reference to FIG.

  In FIG. 18, 1201 is a blood vessel. The X-ray generated by the X-ray generation unit 202A of the X-ray imaging unit 101 and passing through the three-dimensional point Jk is the first image projection point Pk on the first object thinned image 1101T on the X-ray detection unit 203. Projected on.

  Although it is impossible to know the position of the three-dimensional point Jk only from the position of the first image projection point Pk, the three-dimensional point Jk is on a straight line 1231 connecting the X-ray generation unit 202A and the first image projection point Pk. Will exist somewhere.

  Now, the point on this straight line 1231 is projected onto the epipolar line L2 in FIG. 18 on the second object-thinned thinned image 1102T. Since the three-dimensional point Jk is a point on the straight line 1231, the projection point of the three-dimensional point Jk also appears somewhere on the epipolar line L2. Therefore, candidates for corresponding points of the three-dimensional point Jk can be narrowed down to projection points existing on the epipolar line L2.

  Next, a plane that passes through the X-ray generation unit 202B, the X-ray generation unit 202A, and the first image projection point Pk of the X-ray imaging unit 101 will be described. This plane is called the epipolar plane (relative to the first image projection point Pk).

  The three-dimensional points on the plane are not limited to Jk, and are all projected onto the epipolar line L2 on the second object thinned image 1102T. This is because all the straight lines connecting the X-ray generation unit 202B and the three-dimensional point are projected onto the epipolar L2.

  Further, all the three-dimensional points on this plane are projected on the epipolar line L1 on the first object thinned image 1101T. This is because all the straight lines connecting the X-ray generation unit 202A and the three-dimensional point are projected onto the epipolar L1.

  FIG. 19 is a diagram showing an epipolar plane. In the above description, one point on the blood vessel 1201 is described as a three-dimensional point Jk. However, in detail, the cross section of the blood vessel 1201 by the epipolar plane has a shape having an area such as an ellipse as shown in FIG. Therefore, in the following description, when utilizing the fact that there is an area, it is described as a three-dimensional region Jk. In addition, the first image projection point Pk and the second image projection point Qk, which are projection points of the three-dimensional region Jk, are actually line segments and have a shape having a length. Therefore, in the following description, when the fact that there is a length is used, it is described as a first image projection area (first image area) Pk and a second image projection area (second image area) Qk.

The second image projection area acquisition unit 1705 is a second image projection area Qk_n (n = 1, 2,...) That is a corresponding point candidate for a first image projection point Pk designated by the association control unit 1701 described later. N: where N is the number of second image projection areas).
A specific method for acquiring the position of the second image projection region Qk_n will be described with reference to a flowchart of processing performed by the imaging target region acquisition unit 105 in FIG.

  In step S1001, the second image projection area acquisition unit 1705 starts processing.

  Next, in step S <b> 1003, the second image projection area acquisition unit 1705 acquires the translation vector T, the rotation vector R, and the internal parameter A from the imaging unit information holding unit 104.

  Next, in step S1004, the second image projection area acquisition unit 1705 calculates an epipolar line L2 corresponding to the acquired first image projection area. The epipolar line L2 is a linear range in which the corresponding point of the first image projection point Pk can appear on the second screen. The position of the first image projection point Pk, the X-ray imaging unit 101A, and the X-ray imaging unit It is determined based on the geometric positional relationship of 101B.

  Epipolar line L2 is relative position information (translation vector T, rotation vector R) between the position of X-ray imaging unit 101 (X-ray generation unit 202A) and the position of X-ray imaging unit 101B (X-ray generation unit 202B); It is calculated from information (internal parameter A) indicating what kind of camera is used for photographing. Specifically, the second image projection area acquisition unit 1705 calculates the parameter l2 of the epipolar line L2 by performing the following expressions 6 and 7.

F = A− ^T [T] _x RA ⁻¹
... (Formula 6)

・・・・・（式７）

... (Formula 7)

In Equation 6, F is a matrix called a fundamental matrix, A− ^T represents a transposed matrix of an inverse matrix of the internal parameter A, and [T] _X represents a distortion symmetric matrix of the translation vector T. m indicates the position coordinates of the contrast point Pk.

  When the calculated parameter l2 of the epipolar line L2 is (a, b, c) T, the epipolar line L2 is ax + by + c = 0.

  Next, in step S <b> 1005, the second image projection area acquisition unit 1705 acquires the second object area image from the object area image holding unit 1132.

  Next, in step S1006, the second image projection area acquisition unit 1705 is a second image projection area Qk_n (n = 1, 2,..., N) that is an intersection with the epipolar line L2 in the second object area image. Where N is the number of second image projection areas). FIG. 20 is a diagram illustrating an example of the second image projection area Qk (k = 1, 2). In FIG. 20, reference numeral 8001 denotes an epipolar line L2. A thick line area in FIG. 20 indicates an object area in which the blood vessel 1201 is imaged in the image 2_END imaged by the X-ray imaging unit 101. In FIG. 20, each region where the object region (thick line region) and the epipolar line L2 intersect is the second image projection region Qk_n (n = 1, 2). In the case of FIG. 20, the area on the line segment connecting the points 8011 and 8012 is the second image projection area Qk_1, and the area on the line segment connecting the points 8012 and 8013 is the second image projection area. Qk_2. The second image projection area acquisition unit 1705 stores the coordinates of points belonging to the respective areas in the second image projection area holding unit 1706.

  Next, in step S1008, the second image projection area acquisition unit 1705 ends the process.

  The second image projection area holding unit 1706 is a part that holds the coordinates of the second image projection area Qk_n (n = 1, 2,..., N) acquired by the second image projection area acquisition unit 1705. In the case of FIG. 20, the coordinates of the second image projection areas Qk_1 and Qk_2 are acquired. FIG. 21 is a diagram illustrating an example of data held by the second image projection area holding unit 1706. The first row holds the coordinates of the points 8011 to 8012, and the second row holds the coordinates of the points 8013 to 8014. In the following description, each pixel constituting the second image projection area Qk_n is referred to as qk_n_an (an = 1, 2,..., An: where An is the number of pixels constituting the second image projection area Qk_n).

  The first image projection region acquisition unit 1702C acquires the position coordinates of the first image projection region Pk with respect to a first image projection point Pk designated by the association control unit 1701 described later.

A specific method for acquiring the position coordinates of the first image projection region Pk will be described.
First, the parameter l1 of the epipolar line L1 is calculated using Equation 8.

・・・・・（式８）

(Equation 8)

In Equation 8, F is the fundamental matrix F calculated in Equation 6, F ^T denotes a transposed matrix of the fundamental matrix F. m is a coordinate of one point of the arbitrary second image projection area Qk_n acquired by the first image projection area acquisition unit 1702C from the second image projection area holding unit 1706.

  When the parameter l1 of the calculated epipolar line L1 is (a, b, c) T, the epipolar line L1 is ax + by + c = 0. The method of acquiring the coordinates of the intersection point between the calculated epipolar line L1 and the first object thinned image 1011T is the same as in the case of the second image projection area acquisition unit 1705, and a description thereof will be omitted.

  The first image projection region holding unit 1703C is a unit that holds the coordinates of the first image projection region Pk acquired by the first image projection region acquisition unit 1702C. FIG. 22 shows an example of coordinates held by the first image projection area Pk. In the following description, each pixel constituting the first image projection area Pk is referred to as pk_b (b = 1, 2,..., B: where B is the number of pixels constituting the first image projection area Pk).

  Prior to describing the absorption characteristic acquisition unit 1707, the absorption characteristic will be described.

  In the epipolar plane shown in FIG. 19, since the brightness of the first image projection point Pk and the brightness of the second image projection point Qk_2 are different, the corresponding point of the first image projection point Pk cannot be determined using the brightness. . However, the total thickness of the three-dimensional region Jk_1 generated by the X-ray generation unit 202A and crossed by the X-rays reaching the first image projection region Pk (the total length of the thick lines in FIG. 23) and the X-ray generation unit The total thickness (the total length of the thick lines in FIG. 24) of the three-dimensional region Jk crossed by the X-rays generated in 202B and reaching the second image projection region Qk_2 is equal. Also, the sum of the amount of contrast agent (the amount of substance that absorbs X-rays) crossed by the X-rays generated by the X-ray generation unit 202A and reaching the first image projection region Pk (the amount of contrast agent on the thick line in FIG. 24) 23) and the amount of contrast agent (amount of substance that absorbs X-rays) crossed by the X-rays generated by the X-ray generator 202B and reaching the second image projection region Qk_2 (on the thick line in FIG. 23) The total amount of contrast agent) is equal. More precisely, the sum of the linear attenuation coefficients μ existing in the region crossed by the X-rays generated from the X-ray generation unit 202B and reaching the second image projection region Qk_2 is equal. In this method, using this relationship, the corresponding point of the first image projection region Pk is determined by the first image projection region acquisition unit 1702C.

  First, the reason why the association by luminance cannot be performed will be described. In the epipolar plane shown in FIG. 19, the thickness of the X-ray 8201 that passes through the X-ray generation unit 202A, passes through the three-dimensional region Jk, and reaches the first image projection point Pk through the blood vessel 1201 is 8211. . On the other hand, the thickness of the X-ray 8202 that passes through the X-ray generation unit 202B, passes through the three-dimensional region Jk, and reaches the second image projection point Qk_2 through the blood vessel 1201 is 8212.

  Since the thickness 8211 and the thickness 8212 are different, the luminance of the first image projection point Pk and the luminance of the second image projection point Qk_2 are different values. Therefore, it is difficult to determine the corresponding point of the first image projection point Pk based on the luminance.

  However, the area of the blood vessel 1201 that crosses until the X-ray reaching the range of the first image projection region Pk reaches the range of the second image projection region Pk and the X-rays reaching the second image projection region Qk_2 are The area of the blood vessel 1201 that traverses until reaching the range of the second image projection region Qk_2 is equal.

  This relationship will be described with reference to FIGS. FIG. 23 is a diagram illustrating the area of the blood vessel 1201 that crosses until the X-ray reaching the range of the first image projection region Pk reaches the range of the first image projection region Pk. In order to make the explanation easy to understand, the three-dimensional region Jk is described in a size and a position different from those in FIG. The area of the blood vessel 1201 that crosses until the X-ray reaching the range of the first image projection region Pk reaches the range of the second image projection region Pk can be approximated by the sum of the lengths of the thick lines in FIG.

  FIG. 24 is a diagram illustrating the area of the blood vessel 1201 that crosses the X-ray reaching the range of the second image projection region Qk_2 until it reaches the range of the second image projection region Qk_2. The area of the blood vessel 1201 that crosses until the X-ray reaching the range of the first image projection region Pk reaches the range of the second image projection region Pk can be approximated by the sum of the lengths of the thick lines in FIG. These areas are equal in both the case of FIG. 23 and the case of FIG. Further, the amount of the contrast agent present on the bold line is also the same in the case of FIG. 23 and the case of FIG. Further, since the amount of the contrast agent existing on the thick line is the same in the case of FIG. 23 and the case of FIG. 24, the amount of the substance that absorbs X-rays on the thick line is also the same as in FIG. This is the same as in the case of FIG.

  In the second embodiment of the present invention, an absorption characteristic acquisition unit 1707 is used to estimate the area or the total amount of X-rays absorbed by the substance in the area from the luminance of points belonging to the first imaged object region in the X-ray image. To do.

The principle will be described below. The X-ray having the intensity I ₀ attenuates to the intensity I when passing through an object having a thickness d [cm]. When the linear attenuation coefficient indicating the degree of attenuation is μ [cm ⁻¹ ], Equation 9 is established.

・・・・・（式９）

(Equation 9)

  Equation 8 also holds for each pixel pk_b that forms the first image projection region Pk. When the intensity of the X-ray acquired by the pixel pk_b (luminance of the pixel pk_b) is I_b and the thickness of the three-dimensional region Jk through which the X-ray reaching the pixel pk_b passes is d_b, Expression 10 is satisfied.

・・・・・（式１０）

(Equation 10)

  Taking the logarithm of both sides and calculating the sum of b = 1, 2,..., B (where B is the number of pixels constituting the first image projection region Pk as described above) by the absorption characteristic acquisition unit 1707, Equation 11 holds.

・・・・・（式１１）

... (Formula 11)

  When Expression 11 is transformed, Expression 12 is established.

・・・・・（式１２）

(Equation 12)

  Also, for each pixel qk_n_an constituting the second image projection region Qk_n, Expression 8 is established, where the intensity of the pixel qk_n_an is I_an, and the thickness of the three-dimensional region Jk through which X-rays reaching the pixel qk_n_an pass If d_an, then Equation 13 holds.

・・・・・（式１３）

(Equation 13)

  In Expression 12, Σd_b is a cross-sectional area of the three-dimensional region Jk. When the second image projection area Qk_n is a corresponding point of the first image projection area Pk, in Expression 13, Σd_an is also a cross-sectional area of the three-dimensional area Jk, and the value of Expression 12 is equal to the value of Expression 13. Become. The three-dimensional region Jx is a substantially ellipse indicating the region of the blood vessel 1201 in the epipolar plane and the cross section of the blood vessel 1201, or a region in which a plurality of ellipses are arranged.

  Therefore, in the second embodiment of the present invention, in the second image projection area Qk_n (n = 1, 2,..., N), the second image projection area Qk_x in which the value of Expression 13 is closest to the value of Expression 12. Is determined as the corresponding point of the corresponding point in the first image projection area Pk by the corresponding area determination unit 1711. In the following description, the value of Expression 12 is referred to as an absorption characteristic λ_pk, and the value of Expression 13 is referred to as an absorption characteristic λ_qk_n.

  Note that the amount of X-ray absorption in the first image projection region Pk as an example of the absorption characteristic in the second embodiment is the number of pixels in the projection region (first image region Pk) and the X-rays at the first position. X-ray imaging at the first position acquired by the logarithm product of the intensity of the X-rays emitted from the X-ray generation unit 202A of the imaging apparatus 101A and each pixel of the projection area (first image area Pk) The absorption characteristic acquisition unit 1707 calculates the difference from the logarithmic sum of the intensities of the X-rays emitted from the apparatus 101A. Further, the amount of X-ray absorption in the second image region Qk as an example of the absorption characteristic in the second embodiment is the number of pixels in the projection region (second image region Qk) for each of the plurality of second image regions. And the logarithm product of the intensity of the X-rays irradiated from the X-ray generation unit 202B of the X-ray imaging apparatus 101B at the second position and each pixel of the projection area (second image area Qk). The absorption characteristic acquisition unit 1707 calculates the difference from the logarithmic sum of the intensities of the X-rays emitted from the X-ray imaging apparatus 101B at the second position.

  Here, the explanation is given for the case where μ is constant as the linear attenuation coefficient of the cross section of the three-dimensional region Jk. However, even when the linear attenuation coefficient value is different for each minute region in the cross section, the linear attenuation is performed. Since the sum of the coefficients is constant regardless of the shooting direction, the correlation can be performed by this method.

  The absorption characteristic acquisition unit 1707 is, for example, an absorption amount acquisition unit. The absorption characteristic acquisition unit 1707 acquires a value at each time of the absorption characteristic λ_Pk for the first image projection point Pk designated by the association control unit 1701. Further, the absorption characteristic acquisition unit 1707 acquires the value at each time of the absorption characteristic λ_Qk_n for the second image projection region Qk_n (n = 1, 2,..., N). In the following description, the absorption characteristic values at time t (t = 1, 2,..., END) are described as absorption characteristics λ_Pk_t and λ_Qk_n_t, respectively.

  FIG. 25 is a graph illustrating an example of the absorption characteristic acquired by the absorption characteristic acquisition unit 1707. In FIG. 25, a thick line 2301, a solid line 2302, and a dotted line 2303 indicate a change in the absorption characteristic of the first image projection area Pk, a change in the absorption characteristic of the second image projection area Qk_2, and a change in the absorption characteristic of the second image projection area Qk_2, respectively. Indicates. The horizontal axis of the graph is time, and one memory is 33 msec. The vertical axis of the graph is the absorption characteristic. This graph shows a change in absorption characteristics at a stage where the concentration of the contrast agent contained in the blood vessel 1201 increases as time passes (in other words, within a predetermined time) after the contrast agent is injected into the blood vessel 1201. ing.

  FIG. 26 is a diagram illustrating a data structure of absorption characteristics held by the absorption characteristic holding unit 1708. The absorption characteristic data acquired by the absorption characteristic acquisition unit 1707 includes the absorption characteristic λ_Pk_t (t = 0, 2,..., END) of the first image projection point Pk and the absorption characteristic λ_Qk_n (t) of the second image projection region Qk_n. (N = 1, 2,..., N, t = 0, 1,..., END). In other words, for the first image projection region Pk, the absorption characteristic acquisition unit 1707 absorbs the X-ray absorption amount change (absorption amount change rate) in the first image projection region Pk from the luminance of the contrast agent for a predetermined time. As a characteristic, the X-ray absorption amount change (absorption amount change rate) in the second image projection region Qk is determined for each of the plurality of second image projection regions Qk from the luminance of the contrast agent for a predetermined time. Get as.

  The absorption characteristic holding unit 1708 holds the time-series absorption characteristic (change in absorption characteristic) acquired by the absorption characteristic acquisition unit 1707. FIG. 26 is a diagram illustrating an absorption characteristic (absorption characteristic change) held by the absorption characteristic holding unit 1708 when there are two second image projection areas Qk_n.

When the change rate of the time-series absorption characteristic value held by the absorption characteristic holding unit 1708 is within a predetermined threshold value or less, the absorption characteristic constant value acquisition unit 1731 sets the value at that time as the constant value of the absorption characteristic. Get as. In the case of FIG. 25, the value of V2501 is obtained for the absorption characteristic λ_Pk, the value of V2502 is obtained for the absorption characteristic λ_Qk_1, and the value of V2503 is obtained for the absorption characteristic λ_Qk_2, respectively. To do.
The determination by the absorption characteristic constant value acquisition unit 1731 whether or not the luminance is constant (absorption characteristic constant value) is, for example,
| Λ_Pk (t) −λ_Pk (t−1) |, | λ_Pk (t) −λ_Pk (t−2) |,..., | Λ_Pk (t) −λ_Pk (t−P_TH) |
When all of the values are equal to or less than the threshold value, the absorption characteristic constant value acquisition unit 1731 determines that the luminance becomes constant at time t. Here, | X | indicates the absolute value of X. In addition, in the absorption characteristic constant value acquisition unit 1731, in order not to erroneously determine the time before the contrast agent is injected as the absorption amount constant value, when the absorption characteristic λ_Pk (t) is equal to or less than the threshold value, the constant absorption amount value Exclude from judgment.
The absorption characteristic constant value holding unit 1732 is a unit that stores the absorption characteristic constant value acquired by the absorption characteristic constant value acquisition unit 1731. In the case of FIG. 25, the values of V2501, V2502, and V2503 are stored.
The absorption characteristic evaluation unit 1709 is a unit that evaluates the constant absorption characteristic value of each second image projection region Qk_n (n = 1, 2,..., N) held by the constant absorption characteristic value holding unit 1732.

  That is, the absorption characteristic evaluation unit 1709 includes the first image and each of the plurality of absorption characteristic constant values in the second image projection region Qk_n (n = 1, 2,..., N) held by the absorption characteristic constant value holding unit 1732. The similarity between the projected point P and the constant absorption characteristic value is calculated. Specifically, the absolute value of the difference between the absorption characteristic constant value of the second image projection region Qk_n (n = 1, 2,..., N) and the absorption characteristic constant value of the first image projection point P is set as the first value. As an example of the similarity of the embodiment, the absorption characteristic evaluation unit 1709 calculates the similarity. Then, the absorption characteristic evaluation unit 1709 stores the calculated value in the absorption characteristic evaluation holding unit 1710 as the evaluation value H_n of the second image projection region Qk_n (n = 1, 2,..., N). Here, the lower the evaluation value H_n is, the higher the similarity is and indicates that the absorption characteristic constant value is similar. The higher the evaluation value H_n is, the lower the similarity is and the absorption characteristic constant value is similar. It shows no.

  The absorption characteristic evaluation holding unit 1710 has an evaluation value H_n (n = 1, 2) of the absorption characteristic of each second image projection region Qk_n (n = 1, 2,..., N) calculated and acquired by the absorption characteristic evaluation unit 1709. ,..., N). In the case where the constant values of the absorption characteristics are values indicated by V2502 and V2503 in FIG. 25, respectively, evaluation H_1 = | V2501-V2502 | and evaluation H_2 = | V2501-V2503 |.

  The corresponding area determination unit 1711 selects the smallest evaluation value among the evaluation values H_n (n = 1, 2,..., N) held by the absorption characteristic evaluation holding unit 1710. When the evaluation value selected by the corresponding area determination unit 1711 is H_x (where x is a value corresponding to the smallest evaluation value among n = 1, 2,..., N), the second image projection area Qk_x is The corresponding area determination unit 1711 determines the corresponding area Qk of the first image projection area Pk. When the constant value of the absorption characteristic is the value indicated by V2502 and V2503 in FIG. 25, H_1 which is a small value among the evaluation H_1 = | V2501-V2502 | and evaluation H_2 = | V2501-V2503 | The determination unit 1711 selects the second image projection region Qk_2, and the corresponding region determination unit 1711 determines the corresponding point Qk of the first image projection region Pk.

  The association control unit 1701 is a unit that performs control so that association is performed using each unit included in the association unit 107. FIG. 27 is a flowchart illustrating a flow of processing performed by the association control unit 1701.

  In step S1401, the association control unit 1701 starts processing.

  Next, in step S1402, the association control unit 1701 acquires the first captured object thinned image 1101T from the captured object thinned image holding unit 106.

  Next, the association control unit 1701 performs the processes of steps S1404 to S1415 on the black point of the imaged object region in the first imaged object thinned image 1101T acquired in step S1402. In the following description, the black point is referred to as a first image projection point Pk (k = 1, 2,..., K: where K is the number of black points).

  First, in step S1406, the association control unit 1701 uses the second image projection region acquisition unit 1705 to assign the second image projection region Qk_n (n = 1, 2,..., N) for the first image projection point Pk. The acquired coordinates of the acquired second image projection area Qk_n (n = 1, 2,..., N) are stored in the second image projection area holding unit 1706.

Next, in step S14061, the association control unit 1701 uses the first image projection region acquisition unit 1702C to acquire the first image projection region Pk for the first image projection point Pk, and acquires the acquired first image projection region. The coordinates of Pk are stored in the first image projection area holding unit 1703C.
Next, in step S1407, the association control unit 1701 uses the absorption characteristic acquisition unit 1707 to absorb the first image projection region Pk and the second image projection region Qk_n (n = 1, 2,..., N). Each characteristic is acquired and stored in the absorption characteristic holding unit 1708.

In step S1408, the association control unit 1701 uses the absorption characteristic constant value acquisition unit 1731 to absorb the absorption characteristics of the first image projection area Pk and the second image projection area Qk_n (n = 1, 2,..., N). Each constant value is acquired and stored in the absorption characteristic constant value holding unit 1732.
Next, in step S1409, the association control unit 1701 uses the absorption characteristic evaluation unit 1709 to evaluate the evaluation value (that is, the second image projection) of the second image projection region Qk_n (n = 1, 2,..., N). An absolute value of a difference between the absorption characteristic constant value of the region Qk_n (n = 1, 2,..., N) and the absorption characteristic constant value of the first image projection region Pk) is acquired as an evaluation value, and an absorption characteristic evaluation holding unit 1710 is stored.

  Next, in step S1410, the association control unit 1701 uses the corresponding region determination unit 1711 to determine the corresponding region Qk of the first image projection region Pk. That is, the corresponding region determination unit 1711 selects the second image projection region Qk_x having the lowest evaluation value among the evaluation values H_n held by the absorption characteristic evaluation holding unit 1710. In the corresponding area determination unit 1711, the lowest evaluation value Hk is set as the evaluation value of the corresponding area Qk.

Next, in step S1411, the association control unit 1701 stores the coordinates of the first image projection point Pk, the coordinates of the corresponding region Qk, and the evaluation value Hk of the corresponding region Qk in the correspondence information holding unit 108, The process started from step S1404 is terminated.
Next, in step S1499, the association control unit 1701 ends the process.

  The correspondence information holding unit 108 acquires the coordinates of the center of gravity of the first image projection region Pk (k = 1, 2,..., K: K is the number of first image projection points) acquired by the association unit 107, and the corresponding region. This is a unit for storing the coordinates of the center of gravity of Qk (k = 1, 2,..., K) and the evaluation value Hk (k = 1, 2,..., K) of the corresponding region Qk. FIG. 28 shows the data structure of the correspondence information holding unit 108. In the initial state, the number of combinations held by the correspondence information holding unit 108 is 0, but data is added line by line each time the process of step S1411 of the association control unit 1701 is performed.

  The three-dimensional position acquisition unit 109 performs triangulation using the coordinates of the center of gravity of the first image projection area Pk of each row held by the correspondence information holding unit 108 and the coordinates of the center of gravity of the corresponding area Qk of each row. Is used to calculate the coordinates of the three-dimensional position of the three-dimensional point Jk in three dimensions, and the calculated coordinates of the three-dimensional point Jk (k = 1, 2,..., K) to the three-dimensional position holding unit. Stored in 110.

  The three-dimensional position holding unit 110 holds the coordinates of the three-dimensional point Jk (k = 1, 2,..., K) restored by the three-dimensional position acquisition unit 109. FIG. 29 is a diagram illustrating a data structure of the three-dimensional position holding unit 110. In the Kth row (k = K), (JK_X, JK_Y, JK_Z) is held. JK_X, JK_Y, and JK indicate the X coordinate, Y coordinate, and Z coordinate of the three-dimensional point JK, respectively.

  Based on the three-dimensional position of the three-dimensional point Jk (k = 1, 2,..., K) held by the three-dimensional position holding unit 110, the display screen generating unit 111 is configured to display each three-dimensional point Jk (k = 1, 2). ,..., K) to generate a CG (computer graphics) screen. FIG. 30 is a diagram illustrating an example of a display screen generated by the display screen generation unit 111. In addition, although the three-dimensional display here shows the case where each three-dimensional point is displayed as a sphere as an example of the display method, other display methods may be used. For example, the three-dimensional points that precede and follow may be connected by a cylinder and displayed as a polygon.

  The display unit 112 displays the screen generated by the display screen generation unit 111. Specifically, an example of the display unit 112 is a display device or a display device such as a projector projection device.

<Processing Flow of Shape Restoration Apparatus 1>
FIG. 31 shows a flowchart of processing performed by the shape restoration device 1.

  First, in step S1901, the shape restoration apparatus 1 starts processing. That is, the operator uses the input IF 114 to give an instruction to start imaging to the shape restoration device 1 and starts injecting contrast medium into the blood vessel 1201.

Next, in step S1902, the X-ray image acquisition unit 113 acquires the first image 1101. That is, upon receiving an instruction from the input IF 114, the X-ray image acquisition unit 113 starts image acquisition. Specifically, the blood vessel 1201 is imaged in time series from the first imaging position (first position or first imaging angle) by the X-ray imaging apparatus 101, and the first image 1101 is acquired. Thereafter, after a predetermined time has elapsed from the start of acquisition, the operator instructs the shape restoration apparatus 1 to end imaging using the input IF 114, and the X-ray image acquisition unit 113 ends imaging. The acquired image is held in the X-ray image holding unit 103.
Next, in step S19021, the movement instruction unit 102 outputs an instruction to move the arm 204 or the bed 201 to the mechanism control unit 205. The mechanism control unit 205 controls the mechanism unit 206 based on the movement instruction from the movement instruction unit 102 to move the arm 204 or the bed 201 from the first imaging position to the second imaging position of the X-ray imaging apparatus 101. The relative movement is performed so that the shooting position becomes.
Next, in step S19022, the X-ray image acquisition unit 113 acquires the second image 1102. The acquisition method is the same as that in step S1902. Specifically, the blood vessel 1201 is imaged in time series from the second imaging position (second position or second imaging angle) by the X-ray imaging apparatus 101, and the second image 1102 is acquired. The acquired image is held in the X-ray image holding unit 103.

  Next, in step S1903, the captured object region acquisition unit 105 performs the processing of the captured object region acquisition unit 105 described above. That is, the imaging target region acquisition unit 105 acquires the first imaging target thinned image 1101T and the second imaging target thinned image 1102T based on the image held by the X-ray image holding unit 103, The object to be imaged is stored in the thinned image holding unit 106.

Next, in step S1904, the associating unit 107 performs the process of the associating unit 107 described above. That is, the associating unit 107 uses the first imaged object thinned image 1101T and the second imaged object thinned image 1102T held in the imaged object thinned image holding unit 106 to perform the first imaged object. The corresponding area Qk of each first image projection area Pk (k = 1, 2,..., K) of the thinned image 1101T is determined, and the corresponding information is stored in the corresponding information holding unit.
Next, in step S1905, the 3D position acquisition unit 109 performs the process of the 3D position acquisition unit 109 described above. That is, the three-dimensional position acquisition unit 109 applies the information stored in the correspondence information storage unit 108 to each first image projection region Pk (k = 1, 2,..., K) of the first captured object thinned image 1101T. On the other hand, the coordinates of the three-dimensional position of the three-dimensional point Jk are calculated and stored in the three-dimensional position holding unit 110.

  Next, in step S1906, the display screen generation unit 111 determines each three-dimensional point Jk (k = 1, 2,..., Based on the three-dimensional position of the three-dimensional point Jk held in the three-dimensional position holding unit 110. A CG screen displaying K) is generated.

Next, in step S1907, the display unit 112 displays the display screen generated by the display screen generation unit 111.
Thereafter, a series of processing ends in step S1908.

<Principle of processing performed by shape restoration device 1>
When a contrast agent is introduced into the blood vessel 1201, the amount of contrast agent present at the three-dimensional point Jk on the blood vessel 1201 changes with time. At that time, the absorption characteristics of the first image projection region Pk obtained by photographing the blood vessel cross section including the three-dimensional point Jk and the corresponding region Qk also change.

First, the change in the absorption characteristics of the blood vessel cross section including the three-dimensional point Jk on the blood vessel 1201 will be described. FIG. 32 shows a change in absorption characteristics in a blood vessel cross section including a certain three-dimensional point Jk. Before the contrast agent is introduced into the blood vessel 1201 (time before time T2), the contrast agent does not flow into the blood vessel 1201. When the ejection of the contrast medium to the blood vessel 1201 is started at time T2, the contrast medium gradually starts to flow into the blood vessel 1201 from time T2. The absorption characteristic in the blood vessel near the position where the contrast agent is ejected has a small absorption characteristic at time T2, and the absorption characteristic in the blood vessel far from the position where the contrast medium is ejected has a large absorption characteristic at time T2. Eventually, the absorption characteristic becomes a constant value V34 at time T3. When the ejection of the contrast agent is stopped (or gradually decreased), the absorption characteristic gradually decreases from time T4, and the contrast agent does not flow into the blood vessel 1201 at time T5.
When the catheter is fixed at the same position in the blood vessel 1201 and the operation of injecting the contrast medium having the same concentration for a predetermined time is performed a plurality of times, the time T2 to T5 is different for each operation. This is because blood, which is a fluid, flows in the blood vessel 1201, and a contrast agent, which is a fluid, is mixed therein, so that it does not spread in the same manner every time. Further, it is conceivable that a change occurs due to the action of a living body such as pulsation. However, there is no significant change in the value of V34, that is, the value itself at which the absorption characteristic is constant. Therefore, the shape restoration device 1 is configured to obtain the absorption characteristics of the first image projection area Pk and the absorption characteristics of the second image projection area Qk_n (n = 1, 2,..., N) in time series, respectively. Obtained at 1707. Then, an absorption characteristic constant value that makes the absorption characteristic constant in each time-series absorption characteristic is acquired by the absorption characteristic constant value acquisition unit 1731. Then, the similarity between the absorption characteristic constant values is evaluated by the absorption characteristic evaluation unit 1709, and the corresponding region Qk is determined by the corresponding region determination unit 1711 from the second image projection region Qk_n.

<Effects of Second Embodiment>
In the image region association apparatus 100B and the three-dimensional model generation apparatuses 16 and 16B according to the present technique, only two X-ray imaging units 101 are used to capture the blood vessel 1201 using two captured images captured from two directions at different times. A three-dimensional reconstruction of the blood vessel 1201 can be performed by associating a plurality of image regions of the X-ray image.

(Modification 1 of 2nd Embodiment)
In the second embodiment, a case where only the blood vessel 1201 exists on the epipolar plane is described. In Modification 1 of the second embodiment, a case where an object that absorbs X-rays other than blood vessels exists on the epipolar plane will be described. 33 and 34 show an epipolar plane in which the object to be imaged Γ exists. FIG. 33 shows a state before the contrast agent is injected, and FIG. 34 shows a state after the contrast agent is injected.

In each pixel pk_b constituting the first image projection area Pk in FIG. 33, the intensity of the pixel pk_b and I_b_0, the thickness of the object to be imaged gamma and d _gamma _b passing the X-rays reaching the pixel pk_b, the object to be imaged When the linear attenuation coefficient of the object Γ is μ _Γ [cm ⁻¹ ], Expression 15 is established.

・・・・・（式１５）

(Equation 15)

  When the logarithm of both sides is taken and the sum of b = 1, 2,..., B is calculated by the absorption characteristic acquisition unit 1707, Expression 16 is established.

・・・・・（式１６）

(Equation 16)

  When the intensity of the pixel pk_b is I_b_t in each pixel pk_b constituting the first image projection region Pk in FIG. 34, Expression 17 is satisfied.

・・・・・（式１７）

(Equation 17)

  When the logarithm of both sides is taken and the sum of b = 1, 2,..., B is calculated by the absorption characteristic acquisition unit 1707, Expression 18 is established.

・・・・・（式１８）

(Equation 18)

  Using Expression 16, Expression 19 is established by replacing the first and second terms on the right side of Expression 18.

・・・・・（式１９）

(Equation 19)

  Equation 19 is transformed and Equation 20 is established.

・・・・・（式２０）

(Equation 20)

  The left side of Expression 20 is the definition of the absorption characteristic, and it can be understood that the absorption characteristic can be calculated by the absorption characteristic acquisition unit 1707 even if Expression 20 is used. The first term on the right side is calculated by the absorption characteristic acquisition unit 1707 as the sum of the logarithms of the luminance at time 0 of the points constituting the first image projection region Pk. Similarly, with respect to the second image projection region Qk, the absorption characteristic can be calculated by the absorption characteristic acquisition unit 1707 using Expression 21.

・・・・・（式２１）

... (Formula 21)

  Here, the case where there is no contrast agent in the three-dimensional region Jk at time 0 is described. However, even when there is a contrast agent, the amount of increase in the absorption characteristic from time 0 is expressed by Equation 20 and Equation 21 can be calculated by the absorption characteristic acquisition unit 1707.

  It should be noted that the absorption characteristic acquisition unit 1707 in the first modification example uses the logarithm of the intensity of the X-ray acquired at each pixel in the projection area (the first image area or each of the plurality of second image areas) at the first time. A value obtained by adding the values (logarithmic sum) and a value obtained by adding the logarithmic values of the X-ray intensities obtained at the respective pixels in the projection region at a second time different from the first time (logarithmic sum) The difference is calculated as the absorption characteristic of the projection area (the first image area or each of the plurality of second image areas). By using the apparatus of the first modification, blood vessels can be reconstructed even when an object that causes a change in luminance is captured in an X-ray image such as a bone in the captured image.

(Modification 2 of the second embodiment)
In the second embodiment, Expression 12 and Expression 13 are defined as the absorption characteristics, but in Modification 2 of the second embodiment, the absorption characteristics are defined by other methods.

When both sides of Expression 10 of the second embodiment are divided by the intensity I ₀ , Expression 22 is established.

・・・・・（式２２）

(Equation 22)

  Equation 22 is also established when b = 1, 2,..., B, and Equation 23 is established because the product of the left sides is equal to the product of the right sides.

・・・・・（式２３）

(Equation 23)

  Further, when Expression 23 is transformed, Expression 24 is established. Here, the symbol Π is an operator indicating the product of each element.

・・・・・（式２４）

(Equation 24)

  Further, Expression 21 holds for each pixel qk_n_an constituting the second image projection region Qk_n, where the intensity of the pixel qk_n_an is I_an, and the thickness of the three-dimensional region Jk through which the X-rays reaching the pixel qk_n_an pass is determined. If d_an, Equation 25 is similarly established.

・・・・・（式２５）

(Equation 25)

  In Expression 24, Σd_b is a cross-sectional area of the three-dimensional region Jk. When the second image projection area Qk_n is a corresponding point of the first image projection area Pk, in Expression 25, Σd_an is also a cross-sectional area of the three-dimensional area Jx, and the value of Expression 24 is equal to the value of Expression 25. Become.

  In the second modification, the value of Expression 24 is the absorption characteristic λ_pk, and the value of Expression 25 is λ_qk_n.

The absorption characteristic λ_pk is calculated by the absorption characteristic acquisition unit 1707 as a product of values obtained by dividing the luminance I_b in each pixel pk_b (b = 1, 2,..., B) of the first image projection region Pk by the intensity I ₀ .

Note that the absorption characteristic acquisition unit 1707 in the second modification is irradiated from the X-ray imaging apparatus 101A at the first position acquired in each pixel of the projection area (the first image area or each of the plurality of second image areas). A value obtained by dividing the product of the intensities of the generated X-rays by the X-ray intensity generated by the first or second X-ray generator 202A or 202B divided by the number of pixels in the projection region Based on the obtained value, the absorption amount as an example of the absorption characteristic of the projection region (the first image region or each of the plurality of second image regions) is determined.
(Modification 3 of 2nd Embodiment)
In the third modification of the second embodiment, as in the first modification, a case where an object that absorbs X-rays other than blood vessels exists in the epipolar plane will be described.

In each pixel pk_b constituting the first image projection area Pk in FIG. 33, the intensity of the pixel pk_b and I_b_0, the thickness of the object to be imaged gamma and d _gamma _b passing the X-rays reaching the pixel pk_b, the object to be imaged If the linear attenuation coefficient of the object Γ is μ _Γ [cm ⁻¹ ], Expression 26 is established.

・・・・・（式２６）

(Equation 26)

  When b = 1, 2,..., B, Equation 26 is established, and when the product of the left sides and the product of the right sides are calculated by the absorption characteristic acquisition unit 1707, Equation 27 is established.

・・・・・（式２７）

(Equation 27)

In the absorption characteristic acquisition unit 1707, assuming that the intensity of the pixel pk_b is I_b_t in each pixel pk_b constituting the first image projection region Pk in FIG. 34, Expression 17 is established, and both sides are divided by the intensity I ₀ , and b = 1 , 2,..., B, the equation 17 is established, and when the product of the left sides and the product of the right sides are calculated, the equation 28 is established.

・・・・・（式２８）

(Equation 28)

  From Expression 27 and Expression 28, Expression 29 is established.

・・・・・（式２９）

(Equation 29)

  The right side of Expression 29 is the definition of the absorption characteristic in Modification 1. It can be seen that the absorption characteristic can be calculated by the absorption characteristic acquisition unit 1707 even using Expression 29. The left side is calculated as the product of “the luminance at time t divided by the luminance at time 0” of the points pk_b (b = 1, 2,..., B) constituting the first image projection area Pk. That is, after the image acquisition unit 113 acquires an image set composed of the first image and the second image for the first predetermined time and the second predetermined time which are different from each other, the absorption characteristic acquisition unit 1707 Between the intensities of the X-rays irradiated from the X-ray imaging apparatus 101A at the first position acquired by each pixel of the projection area (the first image area or each of the plurality of second image areas) at a predetermined time. X-ray imaging apparatus at the first position or the second position obtained by obtaining the product at each pixel of the projection area (the first image area or the plurality of second image areas, respectively) at the second predetermined time The value divided by the product of the intensities of X-rays irradiated from 101A or 101B is obtained. The absorption characteristic acquisition unit 1707 can acquire the X-ray absorption amount in the projection region as the absorption characteristic from the divided value.

  Here, the case where there is no contrast agent in the three-dimensional region Jk at time 0 is described, but even in the case where there is a contrast agent, the amount of increase in the absorption characteristic from time 0 is expressed by Equation 20 and The absorption characteristic acquisition unit 1707 can be calculated using Equation 21.

  Note that the absorption characteristic acquisition unit 1707 in Modification 3 acquires the product of the X-ray intensity values acquired at each pixel in the projection area at the first time at each pixel in the projection area at the second time. The value divided by the product of the intensity values of X-rays is calculated to obtain absorption characteristics. By using the apparatus of the first modification, blood vessels can be reconstructed even when an object that causes a change in luminance is captured in an X-ray image such as a bone in the captured image.

The absorption characteristic constant value acquisition unit 1731 can also use the maximum value of the absorption characteristic as the absorption characteristic constant value instead of the value when the absorption characteristic (for example, the absorption amount) becomes constant. Here, the absorption characteristic (absorption amount) being constant is obtained by acquiring the X-ray absorption characteristic (X-ray absorption amount) of the blood vessel at intervals of about 0.1 to 0.2 seconds, which is a predetermined time as an example. This means an absorption characteristic (absorption amount) in which the change rate of the X-ray absorption characteristic (X-ray absorption amount) is constant (within a range equal to or less than the first threshold value or the second threshold value). In addition, the maximum value of the absorption characteristic means a value at which the absorption characteristic of the image area becomes the maximum value from when the image area is captured until the end of the imaging.
In the second embodiment, the concentration at which the contrast medium is injected into the blood vessel 1201 is the same concentration in the first time and the second time. Here, the ratio of the contrast agent concentration V1 injected for the first time to the contrast agent concentration V2 injected for the second time is V1: V2. When V1 <V2, the contrast agent concentration injected for the second time is higher.
Therefore, the second X-ray absorption amount change rate acquisition unit 13 multiplies the value (absorption amount change rate) by which the second X-ray absorption amount becomes constant (absorption amount change rate) by (V1 / V2), and the second absorption characteristic constant value (first value). 2X-ray absorption change rate).
Note that the first X-ray absorption amount change rate acquisition unit 12 multiplies the value (absorption amount change rate) by which the first X-ray absorption amount is constant (absorption amount change rate) by (V2 / V1). The first X-ray absorption amount change rate may be used.

(Third embodiment)
In the third embodiment, a shape restoration device 1C that restores the shape of a blood vessel 1201 when a plurality of blood vessels 1201 appear to overlap each other in an image taken by one X-ray imaging unit 101 (101A, 101B). Will be explained.

  FIG. 35 shows an epipolar cross section when two blood vessels 1201 appear to overlap each other in an image taken by the X-ray imaging unit 101 (101A, 101B). The X-ray generated by the X-ray generation unit 202B of the X-ray imaging unit 101B at the second position and having passed through the three-dimensional point Jk_1 of the blood vessel 1201 further passes through the three-dimensional point Jk_2 of another blood vessel 1201. The two-image projection area Qk_1 is reached. The X-ray generated by the X-ray generation unit 202B of the X-ray imaging unit 101B and passing through the three-dimensional point Jk_3 reaches the second image projection region Qk_2. On the other hand, the X-ray generated by the X-ray generation unit 202A of the X-ray imaging unit 101A at the first position and passing through the three-dimensional point Jk_1 is projected to the first image projection point Pk_1 on the captured image. The X-ray generated by the X-ray generator 202A and passing through the three-dimensional point Jk_2 is projected to the first image projection point Pk_2 on the captured image. The X-ray generated by the X-ray generation unit 202A of the X-ray imaging unit 101 and passing through the three-dimensional point Jk_3 is projected to the first image projection point Pk_3 on the captured image.

  FIG. 36 is a diagram showing the absorption characteristics of the first image projection areas Pk_1 and Pk_2 and the second image projection area Qk_1 in FIG. In FIG. 36, the horizontal axis of the graph is time, and one memory is 33 msec. The vertical axis of the graph is the absorption characteristic. In FIG. 36, an alternate long and short dash line 6204 is a graph of a change in absorption characteristics of the second image projection region Qk_1. A dotted line 6203 is a graph of the absorption characteristics of the first image projection region Pk_1. A thick line 6201 is a graph of the absorption characteristics of the first image projection region Pk_2. Since the blood vessel 1201 overlaps, the graph 6204 of the second image projection region Qk_1 has two constant values of absorption characteristics. Among them, the lower absorption constant value V4302 matches the absorption characteristic constant value V4303 of the first image projection region Pk_2, but the higher absorption constant value V4301 is the same as the constant absorption amount value of any image projection region. It does not match.

  However, the absorption characteristic constant value V4301 (which has a higher value) matches the sum of the absorption characteristic constant value V4303 and the absorption characteristic constant value V4304.

  Therefore, in the shape restoration device 1C according to the third embodiment, the sum of the absorption characteristic constant values of the plurality of first image projection areas and the (higher value) absorption characteristic constant value of the second image projection area are used as the absorption characteristics. The evaluation unit 1709 compares and compares them. In the case of FIG. 35, the absorption characteristic evaluation unit 1709 compares the sum of the fixed absorption characteristic values of the first image projection area Pk_1 and the first image projection area Pk_2 with the fixed absorption characteristic value of the second image projection area Qk_1. . In FIG. 36, a solid line 6202 is a graph of the total absorption characteristic obtained by adding the absorption characteristic value (graph 6201) of the first image projection region Pk_2 to the absorption characteristic value (graph 6203) of the first image projection region Pk_1. . The solid line 6202 tends to increase or decrease in the same manner as the alternate long and short dash line 6204. In addition, a value V4305 (a constant value of the absorption characteristic of the first image projection region Pk_1 in the graph 6203) and a value V4303 (a constant value of the absorption characteristic of the first image projection region Pk_2 in the graph 6201) are the value V4301 (the value V4301). The value is substantially equal to the absorption characteristic constant value at a later time of the second image projection area Qk_1.

  In the following description, in order to simplify the description, the absorption characteristic evaluation unit 1709 uses the total of the absorption characteristic constant values of the first image projection area Pk_x and the first image projection area Pk_y and the second image projection area. In the case where the absorption characteristic constant value of Qk_z is a comparison target, [{x, y}, {z}] is compared as a group.

  A blood vessel 1201 shown in FIG. 35 is an image captured by the X-ray imaging unit 101 and is projected on the first image projection areas Pk_1 to Pk_3. In the image captured by the X-ray imaging unit 101, the second image projection area is displayed. It is projected onto Qk_1 to Qk_2. In addition to the case of FIG. 35, a blood vessel whose projected position is the same as that of FIG. Specifically, when the three-dimensional points Jk_1 to Jk_3 are located at the positions shown in FIGS. 37 to 41, the first image projection area and the second image projection area appear at the same positions. (In actuality, there may be other special arrangements, but they are omitted here.) The shape restoration device 1C is a combination of corresponding points of the projection points of the blood vessel to be restored from these blood vessels. And the shape of the blood vessel can be correctly restored.

<Configuration of Third Embodiment>
FIG. 42 is a diagram illustrating a configuration of a shape restoration device 1C according to the third embodiment. 107C of matching parts are used instead of the matching part 107 in 2nd Embodiment. FIG. 43 is a diagram illustrating a configuration of the association unit 107C.

  The association unit 107C includes a second image projection region acquisition unit 1705, a second image projection region holding unit 1706, a first image projection region acquisition unit 1702, a first image projection region holding unit 1703, and a grouping acquisition unit. 5203, a grouping holding unit 5204, a grouping evaluation unit 5207, a grouping evaluation holding unit 5208, and a corresponding area determination unit 5209.

  The first image projection area acquisition unit 1702 includes an epipolar plane passing through the first image projection point Pk of the first object thinned image 1101T held by the object thinning holding unit 106, and the first object thinning. The position of the first image projection area Pk_m (m = 1, 2,..., M) of the intersection line (epipolar line) with the image 1102T is acquired and stored in the first image projection area holding unit 1703. However, the first image projection point Pk_0 is the same as the first image projection point Pk.

  A specific method for the processing of the first image projection area acquisition unit 1702 will be described. First, the parameter l1 of the epipolar line L1 is calculated using Equation 30.

・・・・・（式３０）

(Equation 30)

In equation 30, F is a matrix called fundamental matrix calculated by Equation 6, F ^T denotes a transposed matrix of the fundamental matrix F. m is the coordinate of an arbitrary projection point (second image projection area) Qk_n acquired from the second image projection area holding unit 1706.

  When the parameter l1 of the calculated epipolar line L1 is (a, b, c) T, the epipolar line L1 is ax + by + c = 0. The method of acquiring the coordinates of the intersection point between the calculated epipolar line L1 and the first object thinned image 1011T is the same as in the case of the second image projection area acquisition unit 1705, and a description thereof will be omitted.

The first image projection region holding unit 1703 is a unit that holds the coordinates of the first image projection region Pk_m (m = 1, 2,..., M) acquired by the first image projection region acquisition unit 1702.
In the following description, each pixel constituting the first image projection area Pk_m is referred to as pk_b_bm (bm = 1, 2,..., Bm: where Bm is the number of pixels constituting the first image projection area Pk_m).

  The grouping acquisition unit 5203 generates a group G in which the first image projection area Pk_m (m = 1, 2,..., M) and the second image projection area Qk_n (n = 1, 2,..., N) are combined. Generate groupings to do. For example, when m = 3 and n = 2, the six groupings shown in FIG. 44 are generated. In the first column of FIG. 44, the grouping number (n = 1, 2,..., N), the second column is the grouping result, and the third column is the number of the corresponding epipolar section. Show.

  FIG. 45 is a diagram illustrating the configuration of the grouping acquisition unit 5203. The grouping acquisition unit 5203 includes a grouping control unit 7201, a grouping main body unit 7202, and a two grouping unit 7203.

  The two grouping unit 7203 generates a combination for dividing the group designated by the grouping main body unit 7202 into two groups, and outputs the combination to the grouping main body unit 7202.

  As a specific example, a two-grouping operation when the grouping main body 7202 gives a group G = {{F1, F2, F3}, {S1, S2}} to the two-grouping 7203 will be described. FIG. 46 shows a table of combinations divided into two groups (group G0 and group G1). Each row in the table of FIG. 46 shows one combination. Each column describes a numerical value indicating to which group each element of the set belongs. “0” indicates assignment to the group G0, and “1” indicates assignment to the group G1. For example, in the first row combination, S2 is the group G1, and other identifiers F1 to S1 are assigned to the group G0. Note that, as shown in FIG. 46, a group assigned to the first element of the set G is a group G0.

When the total number of elements is N, the combination of grouping is 2 ^ (N-1) -1, that is, 2 ^{(N-1) -1} and the number 1 to 2 ^ (N-1) -1 Number combinations up to are generated. Here, the operator “^” indicates a power operation. In the table of FIG. 46, the value in the U column from the right end is (number)% (2 ^ U).

  FIG. 47 is an example in which the group generated by grouping is divided into group 0 and group 1 and described for each element group.

  The grouping control unit 7201 acquires the number M of the first image projection regions held by the first image projection region holding unit 1703 and the number N of the projection regions held by the second image projection region holding unit 1706, and The grouping main body 7202 described later is executed with the 1 element group {1, 2,..., M} and the second element group {1, 2,. The grouping is stored in the grouping holding unit 5204.

  The grouping main body portion 7202 performs processing for grouping the designated first element group F {F_1, F_2,..., F_M} and the second element group S {S_1, S_2,. The grouping main body portion 7202 divides the designated elements into groups that satisfy the following conditions.

  Condition 1: One element always belongs to one group. One element does not belong to a plurality of groups.

  Condition 2: One group includes one or more elements of the first element group and one or more elements of the second element group.

  Condition 3: Each group has one element in the first element group or one element in the second element group.

  FIG. 48 is a flowchart showing the flow of processing performed by the grouping main body unit 7202.

  First, in step S5401, the grouping main body portion 7202 performs grouping for the designated first element group F {F_1, F_2,..., F_M} and the second element group S {S_1, S_2,. Start the separation process.

  Next, in step S5402, the grouping main body portion 7202 has the value of the number M of elements in the first element group being “0” or the number N of elements in the second element group is “0”. It is determined whether or not. If the grouping main body portion 7202 determines that either one is “0”, the process branches to step S5499, and the process ends. Otherwise, the process branches to step S5403.

  Next, in step S5403, the grouping main body 7202 determines that the value M of the number of elements in the first element group is “1” or the number N of elements in the second element group is “1”. It is determined whether or not. If it is determined that either one is “1”, the grouping main body portion 7202 branches to step S5404, and otherwise branches to step S5411.

  Next, in step S5404, the grouping main body portion 7202 determines that all elements {F_1, F_2, ..., F_M} of the first element group and all elements {S_1, S_2, ..., S_N} of the second element group. And a group. Then, the grouping main body 7202 outputs the group [{F_1, F_2,..., F_M} and {S_1, S_2,..., S_N}] as the processing result of the grouping main body 7202, and step S5499. End the process.

  For example, when the first element group F is {1, 2} and the second element group S is {1}, the grouping main body 7202 outputs the group [{1, 2}, {1}]. Further, for example, when the first element group F is {1} and the second element group S is {2}, the grouping main body unit 7202 outputs the group [{1}, {2}].

  In step S5411, the grouping main body unit 7202 executes the processing of the two grouping unit 7203. Specifically, for example, the grouping main body unit 7202 acquires the result of the two grouping of FIG.

  The grouping main body unit 7202 executes a loop process from step S5412 to step S5444 for each grouping result obtained by executing the two-grouping unit 7203. In the case of FIG. 47, the grouping main body portion 7202 performs the loop processing from step S5412 to step S5444 for the grouping of each row of FIG.

  Next, in step S5414, the grouping main body unit 7202 performs a condition determination on the group 0 generated by the two grouping. That is, the grouping main body 7202 determines whether or not the following condition is satisfied.

  Condition: The number M of elements in the first element group is “0”, or the number N of elements in the second element group is “0”.

  If the grouping main body unit 7202 determines that the condition of step S5414 is satisfied, the process branches to step S5444. If the grouping main body part 7202 determines that the condition of step S5414 is not satisfied, the process branches to step S5415.

  In the case of FIG. 47, when the number is “3, 7, 11, 15”, the grouping main body portion 7202 branches to step S5444 because the group 0 has an element group with the number of elements “0”. .

  In the case of FIG. 47, the grouping main body portion 7202 has an element group in which the number of elements is “0” in the group 1 when the number is “1, 2, (3), 4, 8, 12”. Therefore, the process branches to step S5444.

  In other cases, that is, in the case of “5, 6, 9, 10, 13, 14”, the grouping main body portion 7202 branches to step S5415.

  In step S5415, the grouping main body unit 7202 performs a condition determination on the group 0 generated by the two grouping. That is, the grouping main body unit 7202 determines whether or not the following condition is satisfied.

  Condition: The number M of elements in the first element group is “1”, or the number N of elements in the second element group is “1”.

  If the grouping main body unit 7202 determines that the condition is satisfied, the process branches to step S5418. If the grouping main body part 7202 determines that the condition is not satisfied, the process branches to step S5444.

  In the case of FIG. 47, the grouping main body portion 7202 branches to step S5418 when the numbers are all “5, 6, 9, 10, 13, 14”.

  In step S <b> 5418, the grouping main body unit 7202 generates grouping of the group 0 generated by the two grouping and stores it in the grouping holding unit 5204. Thereafter, after completing the loop process in step S5444, the process of the grouping main body unit 7202 is terminated in step S5499.

  49 shows the grouping generated in step S5418 in the case of “5, 6, 9, 10, 13, 14” in FIG.

  The above is the processing of the grouping main body unit 7202.

  The grouping holding unit 5204 holds a combination of grouping Gw (w = 1, 2,..., W: where W is the number of groupings) acquired by the grouping acquisition unit 5203. Each time step S5404 or step S5418 of the grouping main body portion 7202 is executed, one grouping is added.

  The grouping evaluation unit 5207 acquires and acquires the evaluation value Hw (w = 1, 2,..., W) for each grouping Gw (w = 1, 2,..., W) held by the grouping holding unit 5204. The evaluated value is stored in the grouping evaluation holding unit 5208. FIG. 50 is a diagram illustrating a configuration of the grouping evaluation unit 5207. The grouping evaluation unit 5207 includes an absorption characteristic constant value acquisition unit 7601, an absorption characteristic constant value holding unit 7602, and an evaluation acquisition unit 1709D that functions as an example of the similarity calculation unit 14.

  The absorption characteristic constant value acquisition unit 7601 is a constant absorption characteristic value of all areas belonging to the first image projection area Pk_m (m = 1, 2,..., M) belonging to the grouping Gw designated by the association control unit 5210. The total (first sum) Su1 of (absorption amount change rate) and all regions belonging to the second image projection region Qk_n (n = 1, 2,..., N) held by the second image projection region holding unit 1706. And the sum (second sum) Su2 of the absorption characteristic constant value (absorption amount change rate). Here, when there are a plurality of constant absorption characteristic values in one area, a higher absorption characteristic constant value is used. For example, in the case of the grouping G1 in FIG. 49, the sum of the constant absorption characteristic value of the first image projection area Pk_1 and the constant absorption characteristic value of the first image projection area Pk_2 is Su1, and the second image projection area Qk_2 The constant value of the absorption characteristic is Su2.

  The absorption characteristic constant value holding unit 7602 is a unit that holds the absorption characteristic constant value acquired by the absorption characteristic constant value acquisition unit 7601. Based on the absorption characteristic constant value held by the absorption characteristic constant value holding unit 7602, the evaluation acquisition unit 1709D performs the evaluation operation (evaluation calculation process) described below, and the evaluation value Hw (w = 1, 2,..., W). Is output to the grouping evaluation holding unit 5208.

The evaluation acquisition unit 1709D acquires the evaluation value Hw (w = 1, 2,..., W) for each grouping Gw (w = 1, 2,..., W) held by the grouping holding unit 5204 from Expression 31. The acquired evaluation value Hw is stored in the grouping evaluation holding unit 5208.
Hw = | Su1-Su2 | (Formula 31)
For example, in the case of the grouping G1 in FIG. 49, the absorption of the second image projection region Qk_2 is calculated from the sum Su1 of the constant absorption characteristic value of the first image projection region Pk_1 and the constant absorption property value of the first image projection region Pk_2. The absolute value | Su1-Su2 | of the value obtained by subtracting the constant characteristic value Su2 is the evaluation value Hw.
The grouping evaluation holding unit 5208 holds the evaluation value Hw (w = 1, 2,..., W) acquired by the grouping evaluation unit 5207.

The corresponding area determination unit 5209 has the smallest evaluation value Hx (x is the smallest evaluation value of w = 1, 2,..., W among the evaluation values held by the grouping evaluation holding unit 5208. Select the value corresponding to.
The association control unit 5210 controls to perform association using each unit of the association unit 107C. FIG. 51 is a flowchart showing the flow of processing performed by the association control unit 5210.

  First, in step S1401, the association control unit 5210 starts processing.

  Next, in step S1402, the association control unit 5210 acquires the first captured object thinned image 1101T from the captured object thinned image holding unit 106.

  The association control unit 5210 performs the processing from step S1404 to step S1415 on the black point of the imaged object region in the first imaged object thinned image 1101T acquired in step S1402. In the following description, the black point is defined as the first image projection point Pk (k = 1, 2,..., K: where K is the number of black points).

  Next, in step S1406, the association control unit 5210 uses the second image projection region acquisition unit 1705 to use the second image projection region Qk_n (n = 1, 2,..., N) for the first image projection point Pk. , And the coordinates of the acquired second image projection area Qk_n (n = 1, 2,..., N) are stored in the second image projection area holding unit 1706.

  Next, in step S14061, the association control unit 5210 uses the first image projection region acquisition unit 1702, and uses the first image projection region Pk_m (m = 1) existing on the same epipolar plane as the first image projection point Pk. , 2,..., M), and the coordinates of the acquired first image projection point Pk_m (m = 1, 2,..., M) are stored in the first image projection area holding unit 1703.

  Next, in step S14062, the association control unit 5210 performs processing of the grouping acquisition unit 5203. That is, the grouping acquisition unit 5203 performs grouping Gw between the first image projection point Pk_m (m = 1, 2,..., M) and the second image projection region Qk_n (n = 1, 2,..., N). (W = 1, 2,..., W) is generated.

  The association control unit 5210 performs the processing from step S14063 to step S1414 on the result of each grouping Gw (w = 1, 2,..., W) acquired in step S14062.

  In step S1407C, the association control unit 5210 performs the process of the absorption characteristic constant value acquisition unit 7601. That is, the sum of the absorption characteristic constant values of the first image projection points Pk_m (m = 1, 2,..., M) belonging to the grouping Gw and the second image projection area Qk_n (n = 1, 2) belonging to the grouping Gw. ,..., N) is acquired and stored in the absorption characteristic constant value holding unit 7602.

  Next, in step S1409, the association control unit 5210 performs the process of the evaluation acquisition unit 1709D. That is, the evaluation acquisition unit 1709D calculates a difference Hw between the total absorption characteristic constant value of the first image projection area Pk_m and the total absorption characteristic constant value of the second image projection area Qk_n as an evaluation value, and holds the grouping evaluation hold The data is stored in the unit 5208, and step S1414 is terminated.

  Next, in step S1410C, the association control unit 5210 performs processing of the corresponding region determination unit 5209. That is, the corresponding region determination unit 5209 obtains the smallest evaluation value Hα among the evaluation values Hw (w = 1, 2,..., W) held by the grouping evaluation holding unit 5208 by the corresponding region determination unit 5209. To do. Here, α is a grouping number of the selected evaluation value.

  Next, in step S1411C, the association control unit 5210 and the coordinates of the center of gravity of the first image projection area Pk_m (m = 1, 2,..., M) belonging to the grouping Gα and the second image projection area Qk_n (n = 1, 2,..., N) and the evaluation value Hα are stored in the correspondence information holding unit 108, and a series of processing ends in step S1415.

  FIG. 52 shows correspondence information to be added when there are a plurality of first image projection areas Pk_m in the grouping Gα. As illustrated in FIG. 52, the correspondence information holding unit 108 stores a row in which the corresponding region of each first image projection region Pk_m (m = 1, 2) is the corresponding point Qk_1. In FIG. 52, (Pk_m_X, Pk_m_Y) are the coordinates of the center of gravity of the first image projection region Pk_k. Further, (Qk_n_X, Qk_n_Y) is the coordinates of the center of gravity of the second image projection region Qk_k.

  FIG. 53 shows correspondence information to be added when there are a plurality of second image projection areas Qk_n in the grouping Gα. As shown in FIG. 53, the correspondence information holding unit 108 stores a row in which the corresponding region of the first image region Pk_1 is each second image region Qk_n (n = 1, 2).

  In step S1499, association control unit 5210 ends the process.

<Effect of the third embodiment>
In the third embodiment, the same effect as in the second embodiment can be obtained.

(Modification)
In the description of the first and second embodiments, an example of the flow of processing is shown, but the processing may be executed by changing the order or by parallelizing a plurality of processes (simultaneous parallel processing).

Although the present invention has been described based on the first to third embodiments and modifications, it is needless to say that the present invention is not limited to the first to third embodiments and modifications. The following cases are also included in the present invention.

  Part or all of the elements constituting the shape restoration devices 1 and 1C can be realized by a computer system including a microprocessor, a ROM, a RAM, a hard disk unit, a display unit, a keyboard, a mouse, and the like. The RAM or hard disk unit stores a computer program. That is, each part achieves its function by the microprocessor operating according to the computer program. Here, the computer program is configured by combining a plurality of instruction codes indicating instructions for the computer in order to achieve a predetermined function.

  Part or all of the elements constituting the shape restoration devices 1 and 1C may be configured by one system LSI (Large Scale Integration). The system LSI is an ultra-multifunctional LSI manufactured by integrating a plurality of components on a single chip. Specifically, the system LSI is a computer system including a microprocessor, a ROM, a RAM, and the like. is there. A computer program is stored in the RAM. That is, the system LSI achieves its functions by the microprocessor operating according to the computer program.

  Part or all of the elements constituting the shape restoration devices 1 and 1C may be constituted by an IC card that can be attached to and removed from each device or a single module. The IC card or module is a computer system including a microprocessor, ROM, RAM, and the like. The IC card or module may include the super multifunctional LSI. That is, the IC card or the module achieves its function by the microprocessor operating according to the computer program. This IC card or this module may have tamper resistance.

  Part or all of the elements constituting the shape restoration devices 1 and 1C are also realized as a method for acquiring the shape of the tube. The present invention is also realized as a computer program that causes a computer to acquire the shape of a tube by these methods, or as a digital signal composed of a computer program.

  Part or all of the elements constituting the shape restoration device 1 or 1C is a computer-readable recording medium such as a flexible disk, a hard disk, a CD-ROM, an MO, a DVD, or a DVD-ROM. , DVD-RAM, BD (Blu-ray (registered trademark) Disc), or recorded on a semiconductor memory or the like. Further, it is also realized as a digital signal recorded on these recording media.

  Part or all of the elements constituting the shape restoration devices 1 and 1C are transmitted via an electric communication line, a wireless communication line, a wired communication line, a network typified by the Internet, or data broadcasting, etc. Also realized as a computer program or a digital signal.

  Part or all of the elements constituting the shape restoration devices 1 and 1C are also realized as a computer system including a microprocessor and a memory. In this case, the memory stores the above-described computer program, and the microprocessor operates according to the computer program.

The processing of the present invention can be performed by another independent computer system by recording the computer program or digital signal on a recording medium and transferring it, or by transferring the computer program or digital signal via a network or the like. You may implement.
Further, the computer that executes this program may be singular or plural. That is, centralized processing may be performed, or distributed processing may be performed.
In addition, it can be made to show the effect which each has by combining arbitrary embodiment or modification of the said various embodiment or modification suitably. In addition, combinations of the embodiments, combinations of the examples, or combinations of the embodiments and examples are possible, and combinations of features in different embodiments or examples are also possible.

  An image region association device, a three-dimensional model generation device, an image region association method, and an image region association program according to one aspect of the present invention are provided for correspondence between a plurality of image regions of a blood vessel X-ray image captured from two directions. Since a three-dimensional model can be generated using the result, it is useful for catheter treatment.

DESCRIPTION OF SYMBOLS 1,1C Shape restoration apparatus 10 3D model production | generation apparatus 11 X-ray image acquisition part 12 1st X-ray absorption amount fixed value acquisition part 13 2nd X-ray absorption amount fixed value acquisition part 14 Similarity calculation part 15 Corresponding area | region determination part 16, 16B 3D model generation unit 100, 100B Image region association device 101 X-ray imaging unit (X-ray imaging device)
101A, 101B X-ray imaging unit 102 when taking an image sequence for the first time and the second time 102 Movement instruction unit 103 X-ray image holding unit 104 Imaging unit information holding unit 105 Target object region acquisition unit 106 Target object thin line Converted image holding unit 107, 107C associating unit 108 correspondence information holding unit 109 three-dimensional position acquisition unit 110 three-dimensional position holding unit 111 display screen generation unit 112 display device 113 X-ray image acquisition unit 114 input IF (interface)
200 patient 201 bed 202 X-ray generation unit 202A, 202B X-ray generation unit when taking an image sequence for the first time and the second time 203 X-ray detection unit 204 arm 205 mechanism control unit 206 mechanism unit 1101 first X-ray image (First image, first projection image)
1101T 1st to-be-photographed object thinning image 1102 2nd X-ray image (2nd image, 2nd projection image)
1102T Second object thinned image 1132 Object region image holding unit 1201 Blood vessel 1202A, 1202B X-ray generation unit 1231 Straight line 1501 Binarization unit 1503 Thinning unit 1504 Difference image generation unit 1505 Difference image holding unit 1701 Correlation Control unit 1702, 1702C First image projection region acquisition unit 1703, 1703C First image projection region holding unit 1705 Second image projection region acquisition unit 1706 Second image projection region holding unit 1707 Absorption characteristic acquisition unit 1708 Absorption characteristic holding unit 1709 Absorption Characteristic evaluation unit 1709D Evaluation acquisition unit 1710 Absorption characteristic evaluation holding unit 1711 Corresponding region determination unit 1731 Absorption characteristic constant value acquisition unit 1732 Absorption characteristic constant value holding unit 2301 Thick line 2302 Solid line 2303 Dotted line 5203 Grouping acquisition unit 5204 Holding unit 5207 Grouping evaluation unit 5208 Grouping evaluation holding unit 5209 Corresponding area determination unit 7201 Grouping control unit 7202 Grouping main body unit 7203 Two grouping unit 7601 Absorption characteristic constant value acquisition unit 7602 Absorption characteristic constant value holding unit 8001 Epipolar line 8011, 8012, 8013, 8014 Point 8202 X-ray 8211, 8212 Thickness Pk First image area Qk_n Second image area

Claims (13)

An image region association device that associates a plurality of image regions of a blood vessel having a branch,
A first image obtained by imaging the blood vessel in a state in which a contrast medium having a predetermined concentration is captured from a first position by an X-ray imaging apparatus is acquired in time series from the X-ray imaging apparatus, and further, the contrast medium having a predetermined concentration is acquired. An image acquisition unit that acquires, in a time series, the second image obtained by imaging the blood vessel in a state where the agent is held from a second position different from the first position with the X-ray imaging apparatus;
The X-ray absorption amount in the blood vessel is acquired at a predetermined time interval from the brightness of the contrast agent for the first image region corresponding to the branching blood vessel portion of the first image acquired by the image acquisition unit. A first X-ray absorption amount change rate acquisition unit that calculates a value in which the change rate of the acquired X-ray absorption amount is within the first threshold value or less;
For a plurality of second image regions that are candidate image regions corresponding to the first image region in the second image, the X-ray absorption amount in the blood vessel is determined at predetermined time intervals from the brightness of the contrast agent. A second X-ray absorption amount change rate acquisition unit that respectively obtains each of the acquired X-ray absorption amount change rates within a range equal to or less than the second threshold;
The change rate of the X-ray absorption amount acquired from the first X-ray absorption amount change rate acquisition unit and each of the change rates of the plurality of X-ray absorption amounts acquired from the second X-ray absorption amount acquisition unit. A similarity calculator for calculating the similarity,
The second image region with the closest similarity calculated by the similarity calculation unit or the second image region with the similarity smaller than a third threshold is a region corresponding to the first image region. A corresponding area determining unit that determines that
An image region association device comprising: An imaging unit information holding unit that holds relative position information between the X-ray imaging device that images the blood vessel from the first position and the X-ray imaging device that images the blood vessel from the second position;
An object area acquisition unit for acquiring position information of the object area from the first image and the second image of the X-ray imaging apparatus;
The X-ray image pickup device at the first position, the X-ray image pickup device at the second position, and the image pickup object from the position information respectively acquired from the image pickup unit information holding unit and the object region acquisition unit. An epipolar plane that is a plane composed of an object region is calculated, an epipolar line that is an intersection line of the calculated epipolar plane and the second image is calculated on the second image, and the plurality of second polarities are calculated. A second image projection area acquisition unit that acquires position information respectively located on the calculated epipolar line;
Further comprising
The second X-ray absorption amount change rate acquisition unit obtains the X-ray absorption amount at the position of the position information of the plurality of second image regions acquired by the second image projection region acquisition unit from the brightness of the contrast agent. , Each obtained at a predetermined time interval, and each obtained X-ray absorption amount change rate is calculated within a range below the second threshold value,
The image area matching apparatus according to claim 1. Furthermore, an absorption amount acquisition unit that acquires X-ray absorption amounts in the first image region and the second image region, respectively,
The absorption amount acquisition unit includes a logarithm product of the number of pixels of the first image area and the intensity of X-rays emitted from the X-ray imaging device at the first position, and the first image area. The X-ray absorption amount in the first image region is acquired from the difference from the logarithmic sum of the intensity of the X-rays irradiated from the X-ray imaging device at the first position acquired at each pixel of
The first X-ray absorption amount change rate acquisition unit calculates a value in which the change rate of the X-ray absorption amount in the first image region acquired by the absorption amount acquisition unit is within the first threshold value or less. ,
The absorption amount acquisition unit, for each of the plurality of second image regions, includes the number of pixels in the second image region and the intensity of X-rays emitted from the X-ray imaging device at the second position. Based on the difference between the logarithm product and the logarithmic sum of the intensities of the X-rays emitted from the X-ray imaging device at the second position acquired at each pixel of the second image region, the second Obtain the amount of X-ray absorption in the image area,
The second X-ray absorption amount change rate acquisition unit calculates a value in which the change rate of the X-ray absorption amount in the second image region acquired by the absorption amount acquisition unit is within the second threshold value or less.
The image area matching apparatus according to claim 1 or 2. Furthermore, an absorption amount acquisition unit that acquires X-ray absorption amounts in the first image region and the second image region, respectively,
The absorption amount acquisition unit calculates the product of the intensities of X-rays irradiated from the X-ray imaging device at the first position acquired by each pixel of the first image region as the first position. The X-ray absorption amount in the first image area is obtained from the value obtained by dividing the intensity of X-rays emitted from the X-ray imaging apparatus in FIG. By the value multiplied by the number of pixels in the first image area. And
The first X-ray absorption amount change rate acquisition unit calculates a value in which the change rate of the X-ray absorption amount in the first image region acquired by the absorption amount acquisition unit is within the first threshold value or less. ,
The absorption amount acquisition unit is configured to detect, for each of the plurality of second image regions, X-rays irradiated from the X-ray imaging device at the second position acquired at each pixel of the second image region. The value obtained by dividing the product of the intensities by the value obtained by multiplying the intensity of the X-rays irradiated from the X-ray imaging device at the second position by the number of pixels in the second image area. X-ray absorption amount in the image area of 2 is acquired,
The second X-ray absorption amount change rate acquisition unit calculates a value in which the change rate of the X-ray absorption amount in the second image region acquired by the absorption amount acquisition unit is within the second threshold value or less.
The image area matching apparatus according to claim 1 or 2. Furthermore, an absorption amount acquisition unit that acquires X-ray absorption amounts in the first image region and the second image region, respectively,
The image acquisition unit acquires an image set composed of the first image and the second image for different first predetermined time and second predetermined time,
The absorption amount acquisition unit is a product of the intensities of the X-rays irradiated from the X-ray imaging device at the first position acquired at each pixel of the first image area at the first predetermined time. Divided by the product of the intensities of the X-rays emitted from the X-ray imaging apparatus at the first position acquired at each pixel of the first image area at the second predetermined time. To obtain the X-ray absorption amount in the first image region,
The first X-ray absorption amount change rate acquisition unit calculates a value in which the change rate of the X-ray absorption amount in the first image region acquired by the absorption amount acquisition unit is within the first threshold value or less. ,
The absorption amount acquisition unit acquires the X-ray imaging device at the second position acquired at each pixel of the second image area at the first predetermined time for each of the plurality of second image areas. X-rays irradiated from the X-ray imaging device at the second position acquired by the pixels of the second image area at the second predetermined time, the product of the intensity of the X-rays irradiated more From the value divided by the product of the line intensities, obtain the X-ray absorption amount in the second image area,
The second X-ray absorption amount change rate acquisition unit calculates a value in which the change rate of the X-ray absorption amount in the second image region acquired by the absorption amount acquisition unit is within the second threshold value or less.
The image area matching apparatus according to claim 1 or 2. And a grouping acquisition unit that generates a group in which the first image area and the second image area are combined.
The similarity calculation unit sets a sum of the change rates of the absorption amounts of all the first image regions included in the group generated by the grouping acquisition unit as a first sum, and the grouping acquisition unit The sum of the rate of change of the amount of absorption of all the second image regions included in the group generated by is used as the second sum, and the absolute value of the difference between the first sum and the second sum Calculating the similarity such that the similarity is high when the value is small and the similarity is low when the absolute value of the difference is large.
The image area matching apparatus according to any one of claims 1 to 5. The image acquisition unit acquires the first image in time series by photographing the blood vessel in which the contrast medium having the first predetermined concentration V1 is held as the predetermined concentration, and the second predetermined concentration as the predetermined concentration. The second image is acquired in time series by photographing the blood vessel in a state where the contrast medium of V2 is held,
The first X-ray absorption amount change rate acquisition unit obtains a value obtained by multiplying a value by which the change rate of the acquired X-ray absorption amount is within the range of the first threshold value or less by (V2 / V1). The rate of change in linear absorption
The image area matching apparatus according to any one of claims 1 to 6. The image acquisition unit acquires the first image in time series by photographing the blood vessel in which the contrast medium having the first predetermined concentration V1 is held as the predetermined concentration, and the second predetermined concentration as the predetermined concentration. The second image is acquired in time series by photographing the blood vessel in a state where the contrast medium of V2 is held,
Whether the second X-ray absorption amount change rate acquisition unit sets, as the change rate of the X-ray absorption amount, a value obtained by multiplying the X-ray absorption amount when the X-ray absorption amount is maximum by (V1 / V2). Or, multiply the X-ray absorption amount when the X-ray absorption amount change rate when the X-ray absorption amount is acquired at a predetermined time interval is within the second threshold value or less by (V1 / V2). The value is the rate of change of the X-ray absorption amount,
The image area matching apparatus according to any one of claims 1 to 6. A bed for carrying a patient having the blood vessel;
A mechanism that relatively moves the bed and the X-ray imaging apparatus;
The X-ray imaging device further acquiring the first image and the second image at the first position and the second position, respectively.
The first image is an image photographed by the X-ray imaging device when the X-ray imaging device is positioned at the first position, and the second image is captured by the mechanism unit with the bed and the X-ray. An image taken by the X-ray imaging apparatus after the X-ray imaging apparatus is moved from the first position to the second position by relatively moving with the X-ray imaging apparatus;
The image area matching device according to claim 1. A three-dimensional model generation device for generating a three-dimensional model of the blood vessel having the branch,
The image region association device according to any one of claims 1 to 9,
A three-dimensional model generation unit that generates the three-dimensional model of the blood vessel using information determined by the corresponding region determination unit of the image region association device;
A three-dimensional model generation device comprising: An image region association method for associating a plurality of image regions of a blood vessel having a branch,
A first image obtained by imaging the blood vessel in a state in which a contrast medium having a predetermined concentration is captured from a first position by an X-ray imaging apparatus is acquired in time series from the X-ray imaging apparatus, and further, the contrast medium having a predetermined concentration is acquired. A second image obtained by the X-ray imaging device is acquired in a time series from the second position different from the first position, and the blood vessel in a state where the agent is held is acquired in time series,
The X-ray absorption amount in the blood vessel is acquired at a predetermined time interval from the brightness of the contrast agent for the first image region corresponding to the branching blood vessel portion of the first image acquired by the image acquisition unit. The first X-ray absorption amount change rate acquisition unit calculates a value in which the change rate of the acquired X-ray absorption amount is within the first threshold value or less,
For a plurality of second image regions that are candidate image regions corresponding to the first image region in the second image, the X-ray absorption amount in the blood vessel is determined at predetermined time intervals from the brightness of the contrast agent, respectively. The obtained X-ray absorption amount change rate is calculated by the second X-ray absorption amount change rate acquisition unit so that the value is within the range of the second threshold value or less,
The change rate of the X-ray absorption amount acquired from the first X-ray absorption amount change rate acquisition unit and each of the change rates of the plurality of X-ray absorption amounts acquired from the second X-ray absorption amount acquisition unit. The similarity is calculated by the similarity calculator,
The second image region with the closest similarity calculated by the similarity calculation unit or the second image region with the similarity smaller than a third threshold is a region corresponding to the first image region. And determined by the corresponding area determination unit,
Image area matching method. 12. The image region association method according to claim 11, wherein after the region corresponding to the first image region is determined by the corresponding region determination unit,
A three-dimensional model generation method in which a three-dimensional model generation unit generates a three-dimensional model of the blood vessel using information determined by the corresponding region determination unit. An image region association program that associates a plurality of image regions of a blood vessel having a branch,
Computer
A first image obtained by imaging the blood vessel in a state in which a contrast medium having a predetermined concentration is captured from a first position by an X-ray imaging apparatus is acquired in time series from the X-ray imaging apparatus, and further, the contrast medium having a predetermined concentration is acquired. An image acquisition unit that acquires, in a time series, the second image obtained by imaging the blood vessel in a state where the agent is held from a second position different from the first position with the X-ray imaging apparatus;
The X-ray absorption amount in the blood vessel is acquired at a predetermined time interval from the brightness of the contrast agent for the first image region corresponding to the branching blood vessel portion of the first image acquired by the image acquisition unit. A first X-ray absorption amount change rate acquisition unit that calculates a value in which the change rate of the acquired X-ray absorption amount is within the first threshold value or less;
For a plurality of second image regions that are candidate image regions corresponding to the first image region in the second image, the X-ray absorption amount in the blood vessel is determined at predetermined time intervals from the brightness of the contrast agent, respectively. A second X-ray absorption amount change rate acquisition unit that obtains and calculates a value in which each change rate of the acquired X-ray absorption amount is within a range equal to or less than a second threshold;
The change rate of the X-ray absorption amount acquired from the first X-ray absorption amount change rate acquisition unit and each of the change rates of the plurality of X-ray absorption amounts acquired from the second X-ray absorption amount acquisition unit. A similarity calculator for calculating the similarity,
The second image region with the closest similarity calculated by the similarity calculation unit or the second image region with the similarity smaller than a third threshold is a region corresponding to the first image region. A corresponding area determination unit for determining
Program for associating image areas to function as

Images