JP2017158892A - Medical image processor and medical image processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medical image processor which allows an operator to easily grasp correspondence between an X-ray image and an OCT image.SOLUTION: A medical image processor 100 comprises: an X-ray image storage unit 31 for storing pieces of X-ray image information which are generated by imaging a blood vessel and sequentially acquired from an X-ray image measurement device 1; an OCT image storage unit 32 for storing pieces of OCT image information which are generated by imaging an inside of a blood vessel and sequentially acquired from an OCT image measurement device 2; and an image processing unit 33 for associating a position in an X-ray image based on the X-ray image information with a position in an OCT image based on the OCT image information, extracting a feature image included in the OCT image, and combining information related to the extracted feature image at an associated position in the X-ray image based on the X-ray image information sequentially acquired from the X-ray image measurement device 1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a medical image processing apparatus and a medical image processing method.

  2. Description of the Related Art Conventionally, an OCT (Optical Coherence Tomography) imaging system that generates an image in a blood vessel is known (see, for example, Patent Document 1).

  Patent Document 1 discloses an OCT imaging system that includes an OCT catheter for acquiring information in a blood vessel and an arithmetic unit that generates an OCT image in the blood vessel based on information from the OCT catheter.

Special table 2014-507201 gazette

  An X-ray image (angiographic image) obtained by an X-ray image measuring device when a catheter (for example, an OCT catheter) is inserted into a human body or stent treatment is performed in coronary intervention, which is one of the treatment methods for the circulatory organ. In addition, there is a case where an OCT image by an OCT imaging system as described in Patent Document 1 is used. In this case, since the X-ray image obtained by the X-ray image measurement apparatus and the OCT image obtained by the OCT imaging system are separate and independent images, the surgeon grasps the correspondence between the X-ray image and the OCT image. There is a problem that it is difficult.

  The present invention has been made to solve the above-described problems, and one object of the present invention is that an operator can easily grasp the correspondence between an X-ray image and an OCT image. A medical image processing apparatus and a medical image processing method are provided.

  In order to achieve the above object, a medical image processing apparatus according to a first aspect of the present invention includes an X-ray image storage unit that stores X-ray image information obtained by imaging blood vessels sequentially acquired from an X-ray image measurement apparatus; An OCT image storage unit for storing OCT image information obtained by imaging the inside of a blood vessel sequentially acquired from the OCT image measurement device, a position on the X-ray image based on the X-ray image information, and an OCT image based on the OCT image information The feature image included in the OCT image is extracted and the information about the extracted feature image is associated with the position on the X-ray image based on the X-ray image information sequentially acquired from the X-ray image measurement device. And an image processing unit for synthesizing at the position.

  In the medical image processing apparatus according to the first aspect of the present invention, an image processing unit having the above-described configuration is provided. Thereby, a composite image of the X-ray image and the OCT image can be generated in real time. As a result, the surgeon can easily grasp the correspondence between the X-ray image and the OCT image by confirming the generated composite image. In addition, the ability to generate a composite image in real time is particularly effective during surgery in which it is necessary to quickly make a decision in treatment.

  The medical image processing apparatus according to the first aspect preferably further includes an image display unit that sequentially displays composite images sequentially generated by the image processing unit. If comprised in this way, a synthesized image can be displayed in real time by the image display part of a medical image processing apparatus, without using an image display apparatus separately. As a result, the surgeon can perform the treatment while looking at the composite image, so that the treatment can be performed efficiently.

  In the medical image processing apparatus according to the first aspect described above, preferably, the image processing unit extracts an image of a portion showing a predetermined tissue property in the blood vessel as the feature image, and shows the predetermined tissue property in the extracted blood vessel. Information related to the image of the part is configured to be combined with the associated position on the X-ray image. If comprised in this way, an operator can grasp | ascertain easily the positional relationship of the position of the blood vessel and the position of the site | part which shows a predetermined | prescribed tissue property in the blood vessel by confirming the produced | generated synthesized image. . As a result, the surgeon can quickly and easily make decisions in the treatment of blood vessels.

  In this case, preferably, the image processing unit synthesizes the predetermined tissue properties so as to be visually identifiable in a state where the predetermined tissue properties are classified into lipid plaques, calcified plaques, fibrous plaques, or thrombus. It is configured. With this configuration, the surgeon confirms the generated composite image to determine whether the site exhibiting a predetermined tissue property in the blood vessel is a lipid plaque, a calcified plaque, a fibrous plaque, or a thrombus. Can be identified. As a result, the surgeon can appropriately make a decision in the treatment of the blood vessel according to the type of the tissue property of the blood vessel.

  In the medical image processing apparatus according to the first aspect described above, preferably, the image processing unit extracts an image of a stent inserted into a blood vessel as a feature image, and stores information regarding the extracted stent image as an X-ray image. It is comprised so that it may synthesize | combine to the upper matched position. If comprised in this way, the operator can grasp | ascertain easily the positional relationship of the position of the blood vessel and the position of the stent in the blood vessel by confirming the produced | generated synthesized image. As a result, the operator can quickly and easily grasp the position of the stent placed in the blood vessel, for example.

  In the medical image processing apparatus according to the first aspect, preferably, the image processing unit acquires a correlation coefficient value between the X-ray image and the OCT image, and based on the acquired correlation coefficient value, the X-ray The position on the image and the position on the OCT image are associated with each other. If comprised in this way, the position on an X-ray image and the position on an OCT image can be matched with high precision using the correlation between an X-ray image and an OCT image.

  In this case, it is preferable that the image processing unit outputs a relative position between the OCT image and the X-ray image as the tomographic image of the surface along the axial direction of the blood vessel and the OCT image as the tomographic image of the surface along the axial direction of the blood vessel. A plurality of correlation coefficient values are obtained using at least a relative position of the cross-sectional angle as a variable, and a position on the X-ray image and a position on the OCT image are obtained based on the obtained plurality of correlation coefficient values. It is comprised so that it may match. If comprised in this way, in the combination of the X-ray image and OCT image with high correlation, the position on an X-ray image and the position on an OCT image can be matched easily. As a result, the position on the X-ray image and the position on the OCT image can be easily associated with high accuracy.

  In the medical image processing apparatus according to the first aspect described above, preferably, the image processing unit calculates a region near the X-ray contrast marker of the X-ray image based on the position of the X-ray contrast marker of the OCT catheter on the X-ray image. The region of interest is extracted as a region of interest, and the position on the X-ray image and the position on the OCT image are associated with each other based on the region of interest of the extracted X-ray image. With this configuration, the position on the X-ray image and the position on the OCT image are associated with each other only in a narrower region (region of interest in the X-ray image) than when the entire X-ray image is used. Therefore, it is possible to reduce the processing load related to the association.

  A medical image processing method according to a second aspect of the present invention stores X-ray image information obtained by imaging blood vessels sequentially acquired from an X-ray image measurement device, and images the inside of blood vessels sequentially acquired from an OCT image measurement device. The OCT image information is stored, the position on the X-ray image based on the X-ray image information is associated with the position on the OCT image based on the OCT image information, and the feature image included in the OCT image is extracted and extracted. The information related to the feature image is combined with the corresponding position on the X-ray image based on the X-ray image information sequentially acquired from the X-ray image measurement apparatus.

  In the medical image processing method according to the second aspect of the present invention, as described above, the information on the extracted feature image is handled on the X-ray image based on the X-ray image information sequentially acquired from the X-ray image measurement device. Composite at the attached position. Thereby, like the case of the medical image processing apparatus according to the first aspect, the correspondence relationship between the X-ray image and the OCT image can be easily grasped.

  According to the present invention, as described above, it is possible to provide a medical image processing apparatus and a medical image processing method that allow an operator to easily grasp the correspondence between an X-ray image and an OCT image.

1 is a block diagram illustrating an overall configuration of a medical image processing system including a medical image processing apparatus according to an embodiment of the present invention. It is a mimetic diagram showing the OCT catheter of the OCT image measuring device of one embodiment. It is a figure which shows the synthesized image produced | generated by the medical image processing apparatus of one Embodiment. It is a figure (A) and a figure (B) for explaining an extraction method of a region of interest of an X-ray image by a medical image processing device of one embodiment. It is a figure (A)-(C) for explaining the acquisition method of the correlation coefficient value between an X-ray image and an OCT image by the medical image processing device of one embodiment. It is a flowchart for demonstrating the image matching process by the medical image processing apparatus of one Embodiment. It is a flowchart for demonstrating the tissue property synthetic | combination process by the medical image processing apparatus of one Embodiment. It is a flowchart for demonstrating the stent synthetic | combination process by the medical image processing apparatus of one Embodiment.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings.

(Configuration of medical image processing system)
A configuration of a medical image processing system 100 including a medical image processing apparatus 3 according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

  As shown in FIG. 1, the medical image processing system 100 includes an X-ray image measurement device 1, an OCT image measurement device 2, and a medical image processing device 3.

  The X-ray image measurement apparatus 1 is an apparatus that acquires X-ray image information for imaging the inside of the subject T by irradiating X-rays from the outside of the subject T such as a human body.

  Specifically, the X-ray image measurement apparatus 1 includes an X-ray source 1a and an X-ray detector 1b. The X-ray image measurement apparatus 1 is configured to be able to irradiate X-rays from the X-ray source 1a toward the subject T so as to include a region of interest R1 (indicated by a broken line) of the subject T from the outside of the subject T. Yes. Further, the X-ray image measurement apparatus 1 is configured so that X-rays transmitted through the subject T can be detected by the X-ray detector 1b. The X-ray image measurement apparatus 1 is configured to acquire X-ray image information of the region of interest R1 based on the X-ray detection result by the X-ray detector 1b. The X-ray image measurement apparatus 1 is configured to transfer the acquired X-ray image information of the region of interest R1 to the medical image processing apparatus 3. The region of interest R1 is set so as to include a blood vessel into which a contrast medium has been injected.

  The OCT image measurement device 2 irradiates measurement light (near infrared light having a central wavelength of 1100 nm to 1300 nm) in the blood vessel of the subject T, thereby obtaining OCT image information for imaging the blood vessel in the subject T. It is a device to acquire. Specifically, the OCT image measurement apparatus 2 includes an OCT catheter 2a (see FIG. 2) and a light source (not shown) that generates measurement light emitted from the distal end portion of the OCT catheter 2a. As shown in FIG. 2, the OCT catheter 2a is provided with a light receiving portion 2b and an X-ray contrast marker 2c that absorbs X-rays.

  The OCT image measurement apparatus 2 is configured to be able to irradiate measurement light from the distal end portion of the OCT catheter 2a toward the blood vessel while rotating the OCT catheter 2a inserted into the blood vessel of the subject T. Further, the OCT image measurement device 2 is configured so that reflected light reflected from a living tissue such as a blood vessel or a stent can be received by the light receiving unit 2b (see FIG. 2). Further, the OCT image measurement device 2 is configured to acquire OCT image information based on an optical interference signal generated by the reflected light received by the light receiving unit 2b and the reference light previously divided from the measurement light. . The OCT image measuring device 2 is configured to transfer the acquired OCT image information to the medical image processing device 3. Note that the measurement by the OCT image measurement device 2 is performed in a blood vessel in the region of interest R1. Moreover, the OCT image measuring apparatus 2 can measure (image) a metal or resin stent.

(Configuration of medical image processing apparatus)
The medical image processing apparatus 3 acquires X-ray image information from the X-ray image measurement apparatus 1, acquires OCT image information from the OCT image measurement apparatus 2, and is based on the X-ray image based on the X-ray image information and the OCT image information. It is an apparatus for generating a composite image obtained by combining an OCT image.

  The medical image processing apparatus 3 includes an X-ray image storage unit 31, an OCT image storage unit 32, an image processing unit 33, and an image display unit 34. The X-ray image storage unit 31 and the OCT image storage unit 32 are configured by a storage medium such as a RAM or a ROM, for example. The image processing unit 33 is configured by an arithmetic device such as a CPU, for example.

  The X-ray image storage unit 31 is configured to store X-ray image information obtained by imaging blood vessels sequentially acquired (transferred) from the X-ray image measurement apparatus 1. During the operation of the subject T, X-ray image information transferred sequentially (in real time) from the X-ray image measurement apparatus 1 while the measurement (imaging) is performed by the X-ray image measurement apparatus 1 is performed as a medical image processing apparatus. 3 are obtained sequentially (in real time). The acquired X-ray image information is stored in the X-ray image storage unit 31 sequentially (in real time).

  The OCT image storage unit 32 is configured to store OCT image information of blood vessels sequentially acquired (transferred) from the OCT image measurement device 2. During the operation of the subject T, OCT image information transferred from the OCT image measurement device 2 is acquired by the medical image processing device 3 when measurement is performed by the OCT image measurement device 2. The acquired OCT image information is stored in the OCT image storage unit 32.

  Here, in the present embodiment, the image processing unit 33 generates X-ray images sequentially (in real time) based on X-ray image information acquired sequentially (in real time) from the X-ray image measurement apparatus 1. It is configured. The image processing unit 33 is configured to generate an OCT image based on the OCT image information acquired from the OCT image measurement device 2.

  In the present embodiment, the image processing unit 33 is configured to associate a position on the X-ray image based on the X-ray image information with a position on the OCT image based on the OCT image information. Then, as shown in FIGS. 1 and 3, the image processing unit 33 extracts and extracts feature images included in the OCT image (an image of a portion showing a predetermined tissue property or an image of a stent in a blood vessel described later). The information (image) related to the feature image is associated with the X-ray image sequentially generated (in real time) based on the X-ray image information sequentially acquired (in real time) from the X-ray image measurement apparatus 1. It is comprised so that it may synthesize | combine to a position.

  As shown in FIG. 1, the image processing unit 33 includes an X-ray image processing unit 33a, an OCT image processing unit 33b, a classification data storage unit 33c, and a composite image processing unit 33d.

  The X-ray image processing unit 33 a is configured to generate an X-ray image based on the X-ray image information stored in the X-ray image storage unit 31. The X-ray image processing unit 33a is configured to extract a blood vessel image and an image of the X-ray contrast marker 2c (see FIG. 2) of the OCT catheter 2a included in the X-ray image. The blood vessel image and the X-ray contrast marker 2c image included in the X-ray image can be extracted by using, for example, different pixel values (luminance values) and pixel value gradient information from other biological tissues. Is possible.

  Further, as shown in FIG. 4, the X-ray image processing unit 33 a determines a region near the X-ray contrast marker 2 c based on the position of the X-ray contrast marker 2 c of the OCT catheter 2 a on the X-ray image. The region of interest R2 is extracted. Note that the region of interest R2 of the X-ray image is extracted for alignment with the OCT image.

  A method for extracting the region of interest R2 will be described with reference to FIG. As shown in FIG. 4A, first, the X-ray image processing unit 33a has a radius L1 centered on the position of the image of the extracted X-ray contrast marker 2c in the X-ray image at the start of OCT image measurement. An intersection position X1 between the circle (indicated by a two-dot chain line) and the extracted blood vessel image is acquired. As shown in FIG. 2, the radius L1 is a distance between the light receiving unit 2b and the X-ray contrast marker 2c in the OCT catheter 2a. That is, the X-ray image processing unit 33a is configured to acquire the position estimated as the position of the light receiving unit 2b at the start of OCT image measurement on the X-ray image as the intersection position X1.

  As shown in FIG. 4B, the X-ray image processing unit 33a determines an intersection position X2 between a circle with a radius L2 (indicated by a two-dot chain line) centered on the intersection position X1 and the extracted blood vessel image. Is configured to get. Note that the radius L2 is the pullback length of the OCT catheter 2a during OCT image measurement, as shown in FIG. That is, the X-ray image processing unit 33a is configured to acquire the position estimated as the position of the light receiving unit 2b at the end of the OCT image measurement on the X-ray image as the intersection position X2.

  Further, as shown in FIG. 4B, the X-ray image processing unit 33a converts a predetermined region including an image of a blood vessel between the intersection position X1 and the intersection position X2 on the X-ray image into the X-ray image. The region of interest R2 is extracted. That is, the X-ray image processing unit 33a has a position estimated as the position of the light receiving unit 2b at the start of OCT image measurement on the X-ray image, and a position estimated as the position of the light receiving unit 2b at the end of OCT image measurement. The blood vessel region estimated to have been subjected to the OCT image measurement is extracted as the region of interest R2 of the X-ray image.

  As shown in FIG. 1, the OCT image processing unit 33 b is configured to generate an OCT image based on the OCT image information stored in the OCT image storage unit 32. Specifically, the OCT image processing unit 33b is configured to generate three-dimensional image data in the blood vessel based on the OCT image information. The three-dimensional image data is three-dimensional image data of blood vessels from the OCT image measurement start position to the OCT image measurement end position (that is, a position retracted by the pullback length L2 from the OCT image measurement start position). Further, the OCT image processing unit 33b is based on the generated three-dimensional image data, along with an OCT image (a so-called circular image) as a tomographic image of a plane orthogonal to the axial direction of the blood vessel, and the axial direction of the blood vessel. An OCT image is generated as a tomographic image of a surface.

  The OCT image processing unit 33b is configured to extract a blood vessel image and a stent image included in the OCT image. The blood vessel image and the stent image included in the OCT image can be extracted by using, for example, the fact that pixel values (luminance values) and gradient information of pixel values are different from other biological tissues. The image of the stent is an example of the “characteristic image” in the claims.

  In the first embodiment, the OCT image processing unit 33b is configured to extract an image of a part showing a predetermined tissue property in a blood vessel. An image of a portion showing a predetermined tissue property in a blood vessel is an example of a “characteristic image” in the claims.

  At this time, the OCT image processing unit 33b, based on the tissue property classification data stored in the classification data storage unit 33c, determines the tissue properties of a portion exhibiting a predetermined tissue property in the blood vessel, lipid plaque, calcified plaque, fiber It is configured to be classified as a plaque or thrombus.

  Organizational property classification data is stored in the classification data storage unit 33c. The tissue property classification data is data for classifying the tissue properties of blood vessels on the OCT image. Specifically, the tissue characterization data includes representative differential images (images having pixel value gradient information) and average pixel value information of lipid plaque, calcified plaque, fibrous plaque, or thrombus. Contains. Vascular tissue properties can be classified by taking advantage of the differences in the characteristics of differential images and average pixel values for each tissue property such as lipidic plaque, calcified plaque, fibrous plaque, or thrombus .

  The OCT image processing unit 33b compares the information on the differential image and average pixel value of the tissue property classification data with the information on the differential image and average pixel value of the OCT image acquired by OCT image measurement. The tissue characteristics of the site exhibiting the above-mentioned tissue characteristics are classified into lipid plaque, calcified plaque, fibrous plaque, or thrombus. For classification, for example, it is preferable to set an evaluation function for each tissue property such as lipidic plaque, calcified plaque, fibrous plaque, or thrombus. With this evaluation function, it is possible to easily compare the differential image and average pixel value information of the tissue property classification data with the differential image and average pixel value information of the OCT image acquired by OCT image measurement.

  The OCT image processing unit 33b is configured to extract an OCT image as a tomographic image of a surface along the axial direction of the blood vessel as a region of interest R3 (see FIG. 5) of the OCT image. At this time, if the orientation between the X-ray image and the OCT image is clear, the OCT image processing unit 33b determines a predetermined cross-sectional angle (a rotation around the axial direction formed by the cut surface of the OCT image and the reference surface). An OCT image as a tomographic image of a plane along the axial direction of the blood vessel at (angle) is extracted as a region of interest R3 of the OCT image. When the orientation between the X-ray image and the OCT image is unknown, the OCT image processing unit 33b converts the OCT image as a tomographic image of the surface along the axial direction of the blood vessel at an arbitrary cross-sectional angle to the interest of the OCT image. Extracted as region R3. Note that the region of interest R3 of the OCT line image is extracted for alignment with the X-ray image.

  As illustrated in FIGS. 5A to 5C, the composite image processing unit 33d (see FIG. 1) performs a phase between the image of the region of interest R2 of the X-ray image and the image of the region of interest R3 of the OCT image. While acquiring a relational numerical value, it is comprised so that the position on an X-ray image and the position on an OCT image may be matched based on the acquired correlation coefficient value.

  Specifically, the composite image processing unit 33d uses the relative position between the image of the region of interest R2 of the X-ray image and the image of the region of interest R3 of the OCT image, and the cross-sectional angle of the image of the region of interest R3 of the OCT image as variables. A plurality of correlation coefficient values are obtained.

  For example, as illustrated in FIGS. 5A to 5C, the composite image processing unit 33d changes the position of the image of the region of interest R3 of the OCT image with respect to the image of the region of interest R2 of the X-ray image. Thereby, the correlation coefficient value in each relative position is acquired. The composite image processing unit 33d performs the same processing by changing the cross-sectional angle of the image of the region of interest R3 of the OCT image. Thereby, the correlation coefficient value in each cross-sectional angle is acquired. As a result, a plurality of correlation coefficient values corresponding to a plurality of relative positions for each cross-sectional angle are acquired.

  If the cross-sectional angle of the OCT image corresponding to the cross-section of the X-ray image is known in advance and the orientation between the X-ray image and the OCT image is clear, the cross-sectional angle is set as a predetermined cross-sectional angle and only the relative position is obtained. Variable. If the cross-sectional angle of the OCT image corresponding to the cross-section of the X-ray image is not known and the orientation between the X-ray image and the OCT image is unknown, as described above, both the cross-sectional angle and the relative position are set. Variable.

  The composite image processing unit 33d is configured to associate a position on the X-ray image with a position on the OCT image based on the plurality of acquired correlation coefficient values. Specifically, the composite image processing unit 33d combines the image of the region of interest R2 of the X-ray image having the highest correlation coefficient value among the plurality of acquired correlation coefficient values and the image of the region of interest R3 of the OCT image ( 5A to 5C, the positional information between images is associated with each other in the combination of correlation coefficient value = 0.9.

  Then, as shown in FIG. 3, the composite image processing unit 33 d converts the information about the image of the site showing the predetermined tissue property in the blood vessel extracted by the OCT image processing unit 33 b and the information about the image of the stent into an X-ray image. It is configured to generate a composite image by compositing at the corresponding position above.

  In the first embodiment, the composite image processing unit 33d visually classifies the tissue properties of a portion exhibiting a predetermined tissue property in a blood vessel into lipid plaques, calcified plaques, fibrous plaques, or thrombus. A composite image is generated so as to be identifiable.

  In FIG. 3, the tissue property of a site exhibiting a predetermined tissue property in a blood vessel is classified as a lipid plaque, and both the information related to the image of the site exhibiting the predetermined tissue property in the blood vessel and the information related to the image of the blood vessel are represented by X An example of synthesis at a corresponding position on a line image is shown. In FIG. 3, an image showing the shape (range) of the tissue property is synthesized at a predetermined position around the blood vessel wall on the X-ray image as information related to the image of the site showing the predetermined tissue property in the blood vessel. Note that the information related to the image of the region showing the predetermined tissue property in the blood vessel is not limited thereto, and for example, an image of a mark indicating the position of the tissue property may be used. In FIG. 3, an image indicating the shape (range) of the stent is synthesized as information on the stent image at a predetermined position in the blood vessel on the X-ray image. The information regarding the image of the stent is not limited to this, and for example, an image of a mark indicating the position of the stent may be used.

  For convenience of illustration, FIG. 3 shows a composite image in which both information related to an image of a region showing a predetermined tissue property in a blood vessel and information related to a stent image are combined. However, the composite image is not limited to this. I can't. Only the information related to the image of the part exhibiting the predetermined tissue property in the blood vessel may be synthesized, or only the information related to the image of the stent may be synthesized.

  As shown in FIG. 1, the image display unit 34 is configured to sequentially (in real time) display composite images generated sequentially (in real time) by the image processing unit 33. The image display unit 34 is configured to display an X-ray image and an OCT image in addition to the composite image.

(Image association processing)
Next, an image association process according to an embodiment will be described with reference to a flowchart with reference to FIG. The image association process is performed by the image processing unit 33.

  As shown in FIG. 6, first, in step S1, an image of a blood vessel included in the X-ray image is extracted by the X-ray image processing unit 33a.

  In step S2, an image of the X-ray contrast marker 2c included in the X-ray image is extracted by the X-ray image processing unit 33a.

  In step S3, the intersection position X1 between the circle of radius L1 centered on the position of the image of the X-ray contrast marker 2c extracted in step S2 and the blood vessel image extracted in step S1 is X-ray image processed. Acquired by the unit 33a.

  In step S4, the X-ray image processing unit 33a acquires the intersection position X2 between the circle having the radius L2 centered on the intersection position X1 acquired in step S3 and the blood vessel image extracted in step S1. .

  In step S5, based on the intersection position X1 and the intersection position X2, an area between the intersection position X1 and the intersection position X2, which is a vicinity area of the X-ray contrast marker 2c, is detected by the X-ray image processing unit 33a. It is extracted as the region of interest R2 of the line image.

  In step S6, an OCT image as a tomographic image of a surface along the axial direction of the blood vessel is extracted as a region of interest R3 of the OCT image by the OCT image processing unit 33b. At this time, if the orientation between the X-ray image and the OCT image is clear, an OCT image as a tomographic image of the surface along the axial direction of the blood vessel at a predetermined predetermined cross-sectional angle is obtained by the OCT image processing unit 33b. Extracted as a region of interest R3 of the OCT image. When the orientation between the X-ray image and the OCT image is unknown, an OCT image as a tomographic image of the surface along the axial direction of the blood vessel at an arbitrary cross-sectional angle is converted into a region of interest of the OCT image by the OCT image processing unit 33b. Extracted as R3.

  In step S7, the composite image processing unit 33d acquires a correlation coefficient value between the image of the region of interest R2 of the X-ray image and the image of the region of interest R3 of the OCT image. At this time, if the orientation between the X-ray image and the OCT image is clear, a plurality of correlation coefficient values are acquired by the composite image processing unit 33d using the cross-sectional angle as a predetermined cross-sectional angle and only the relative position as a variable. . When the orientation between the X-ray image and the OCT image is unknown, a plurality of correlation coefficient values are acquired by the composite image processing unit 33d using both the cross-sectional angle and the relative position as variables.

  In step S8, the composite image processing unit 33d associates the position on the X-ray image with the position on the OCT image based on the plurality of correlation coefficient values acquired in step S7. Specifically, in the combination of the image of the region of interest R2 of the X-ray image having the highest correlation coefficient value among the plurality of acquired correlation coefficient values and the image of the region of interest R3 of the OCT image, positional information between the images is obtained. Corresponding by the composite image processing unit 33d.

(Tissue properties synthesis process)
Next, with reference to FIG. 7, the tissue property synthesis process according to an embodiment will be described based on a flowchart. The tissue property synthesis process is performed by the image processing unit 33.

  As shown in FIG. 7, first, in step S11, the OCT image processing unit 33b acquires the differential image and average pixel value information of the OCT image acquired by the OCT image measurement.

  In step S12, the differential image and average pixel value information of the OCT image acquired in step S11 and the differential image and average pixel value information of the tissue property classification data stored in advance in the classification data storage unit 33c are obtained. Comparison is performed by the OCT image processing unit 33b.

  In step S13, based on the comparison result in step S12, the OCT image processing unit 33b determines that the tissue property of the site exhibiting the predetermined tissue property in the blood vessel is lipid plaque, calcified plaque, fibrous plaque, or thrombus. are categorized.

  In step S14, in the classified state, an image of a part showing a predetermined tissue property in the blood vessel included in the OCT image is extracted by the OCT image processing unit 33b.

  In step S15, the image association process shown in FIG. 6 is performed. As a result, the position on the X-ray image is associated with the position on the OCT image.

  In step S16, information related to an image of a part showing a predetermined tissue property in the blood vessel extracted in step S14 is synthesized by the synthesized image processing unit 33d at the associated position on the X-ray image. Thereby, a composite image is generated.

  In step S17, the composite image generated in step S16 is displayed on the image display unit 34. Then, based on the X-ray image information acquired sequentially (in real time) from the X-ray image measuring apparatus 1, a predetermined tissue in the blood vessel is placed at a corresponding position on the X-ray image generated sequentially (in real time). Information relating to the image of the part showing the property continues to be synthesized. As a result, the synthesized images generated sequentially (in real time) continue to be displayed on the image display unit 34 sequentially (in real time).

  A person (operator) who performs an operation on the subject T, for example, confirms a composite image when inserting the stent catheter into the blood vessel of the subject T. It is possible to easily grasp the positional relationship with the positions of the parts showing various tissue properties.

(Stent synthesis process)
Next, with reference to FIG. 8, the tissue property synthesis process according to an embodiment will be described based on a flowchart. The tissue property synthesis process is performed by the image processing unit 33.

  As shown in FIG. 8, first, in step S21, an image of a stent included in the OCT image is extracted by the OCT image processing unit 33b.

  In step S22, the image association process shown in FIG. 6 is performed. As a result, the position on the X-ray image is associated with the position on the OCT image.

  In step S23, the composite image processing unit 33d synthesizes information related to the stent image extracted in step S22 at the associated position on the X-ray image. Thereby, a composite image is generated. At this time, if the tissue property synthesis process shown in FIG. 7 has already been performed, information regarding an image of a region showing a predetermined tissue property in the blood vessel may be synthesized at the same time.

  In step S24, the composite image generated in step S23 is displayed on the image display unit 34. Then, based on the X-ray image information acquired sequentially (in real time) from the X-ray image measuring apparatus 1, information on the image of the stent at an associated position on the X-ray image generated sequentially (in real time). (And information relating to the image of the region showing a predetermined tissue property in the blood vessel) continue to be synthesized. As a result, the synthesized images generated sequentially (in real time) continue to be displayed on the image display unit 34 sequentially (in real time).

  For example, when confirming the placement position of the stent in the blood vessel, the person (operator) performing the operation on the subject T confirms the position of the stent and the position of the tissue property such as lipid plaque by confirming the composite image. It is possible to easily grasp the positional relationship.

(Effect of this embodiment)
In the present embodiment, the following effects can be obtained.

  In the present embodiment, as described above, the position on the X-ray image based on the X-ray image information is associated with the position on the OCT image based on the OCT image information, and the feature image included in the OCT image is extracted. An image processing unit 33 is provided that synthesizes the information related to the extracted feature image at an associated position on the X-ray image based on the X-ray image information sequentially acquired from the X-ray image measurement apparatus 1. Thereby, a composite image of the X-ray image and the OCT image can be generated in real time. As a result, the surgeon can easily grasp the correspondence between the X-ray image and the OCT image by confirming the generated composite image. In addition, the ability to generate a composite image in real time is particularly effective during surgery in which it is necessary to quickly make a decision in treatment.

  In the present embodiment, as described above, the medical image processing apparatus 3 is provided with the image display unit 34 that sequentially displays the composite images sequentially generated by the image processing unit 33. Accordingly, the composite image can be displayed in real time by the image display unit 34 of the medical image processing apparatus without using a separate image display apparatus. As a result, the surgeon can perform the treatment while looking at the composite image, so that the treatment can be performed efficiently.

  Further, in the present embodiment, as described above, an image of a portion showing a predetermined tissue property in a blood vessel is extracted as a feature image, and information on an image of a portion showing a predetermined tissue property in the extracted blood vessel is expressed as X. The image processing unit 33 is configured to synthesize at a corresponding position on the line image. As a result, the operator can easily grasp the positional relationship between the position of the blood vessel and the position of the portion exhibiting a predetermined tissue property in the blood vessel by confirming the generated composite image. As a result, the surgeon can quickly and easily make decisions in the treatment of blood vessels.

  In the present embodiment, as described above, the predetermined tissue properties are classified into lipidic plaques, calcified plaques, fibrous plaques, or thrombus so that each can be visually identified. The image processing unit 33 is configured as described above. Thereby, the operator can identify whether the site showing the predetermined tissue property in the blood vessel is a lipid plaque, a calcified plaque, a fibrous plaque, or a thrombus by checking the generated composite image. it can. As a result, the surgeon can appropriately make a decision in the treatment of the blood vessel according to the type of the tissue property of the blood vessel.

  In the present embodiment, as described above, an image of a stent inserted into a blood vessel is extracted as a feature image, and information regarding the extracted stent image is placed in an associated position on the X-ray image. The image processing unit 33 is configured to synthesize. Thereby, the surgeon can easily grasp the positional relationship between the position of the blood vessel and the position of the stent in the blood vessel by confirming the generated composite image. As a result, the operator can quickly and easily grasp the position of the stent placed in the blood vessel, for example. In addition, since OCT image measurement can clearly measure (imaging) not only a metal stent but also a resin stent (for example, BVS (Bioregulatable Vascular Scaffolding)), this is necessary when performing treatment using a stent. It is particularly effective to synthesize an OCT image and an X-ray image as in the embodiment.

  In the present embodiment, as described above, the correlation coefficient value between the X-ray image and the OCT image is acquired, and based on the acquired correlation coefficient value, the position on the X-ray image, and the OCT image The image processing unit 33 is configured to associate with the upper position. Thereby, the position on the X-ray image and the position on the OCT image can be associated with high accuracy using the correlation between the X-ray image and the OCT image.

  In the present embodiment, as described above, the relative position between the OCT image and the X-ray image as a tomographic image of the surface along the axial direction of the blood vessel, and the OCT image as the tomographic image of the surface along the axial direction of the blood vessel. A plurality of correlation coefficient values are obtained using at least the relative position of the cross-sectional angle as a variable, and based on the acquired plurality of correlation coefficient values, a position on the X-ray image, a position on the OCT image, and The image processing unit 33 is configured to associate them with each other. Thereby, in the combination of an X-ray image and an OCT image with high correlation, the position on the X-ray image and the position on the OCT image can be easily associated with each other. As a result, the position on the X-ray image and the position on the OCT image can be easily associated with high accuracy.

  Further, in the present embodiment, as described above, based on the position of the X-ray contrast marker of the OCT catheter on the X-ray image, a region near the X-ray contrast marker is extracted as the region of interest R2 of the X-ray image, Based on the region of interest R2 of the extracted X-ray image, the image processing unit 33 is configured to associate the position on the X-ray image with the position on the OCT image. As a result, the position on the X-ray image and the position on the OCT image can be associated with each other only in a narrower region (region of interest R2 of the X-ray image) than when the entire X-ray image is used. Therefore, it is possible to reduce the processing load related to the association.

[Modification]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiment but by the scope of claims for patent, and further includes all modifications (modifications) within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the above-described embodiment, an example in which the X-ray image measurement device, the OCT image measurement device, and the medical image processing device are separately provided has been described, but the present invention is not limited to this. In the present invention, the X-ray image measurement device, the OCT image measurement device, and the medical image processing device may be provided integrally (as a single device), or the X-ray image measurement device and the medical image processing device. May be provided integrally. Further, the OCT image measurement device and the medical image processing device may be provided integrally.

  Moreover, although the example which extracted the image of the site | part which shows the predetermined | prescribed tissue property in the blood vessel, and the image of a stent was shown as said characteristic image in the said embodiment, this invention is not limited to this. In the present invention, a feature image other than an image of a region showing a predetermined tissue property in a blood vessel and an image of a stent may be extracted.

  Moreover, although the example which provided the image display part in the medical image processing apparatus was shown in the said embodiment, this invention is not limited to this. In the present invention, it is not necessary to provide an image display unit in the medical image processing apparatus. In this case, an image such as a composite image may be displayed on an image display device separate from the medical image processing device.

  In the above-described embodiment, an example is shown in which the tissue properties of a portion exhibiting a predetermined tissue property in a blood vessel are classified into lipid plaques, calcified plaques, fibrous plaques, or thrombus, but the present invention is not limited thereto. I can't. In the present invention, the tissue properties of a site exhibiting a predetermined tissue property in a blood vessel may be classified into a type other than lipid plaque, calcified plaque, fibrous plaque, or thrombus. Moreover, you may classify | categorize into two or three types among any four types, lipidic plaque, calcified plaque, fibrous plaque, or thrombus.

  In the above embodiment, an example is shown in which the relative position and the cross-sectional angle are used as variables for acquiring the correlation coefficient value, but the present invention is not limited to this. In the present invention, a variable other than the relative position and the cross-sectional angle may be used as a variable for obtaining the correlation coefficient value.

  In the above embodiment, an example in which positional information between images is associated with a combination of an X-ray image and an OCT image having the highest correlation coefficient value among a plurality of acquired correlation coefficient values is shown. The invention is not limited to this. In the present invention, when a correlation coefficient value equal to or greater than a threshold value is acquired, positional information between images may be associated in a combination of an X-ray image having a correlation coefficient value equal to or greater than the threshold value and an OCT image. Good.

  In the above embodiment, an example is shown in which a predetermined region including other than the blood vessel image is extracted as a region of interest in the X-ray image, and a region including other than the blood vessel image is extracted as the region of interest in the OCT image. The invention is not limited to this. In the present invention, a blood vessel image (extracted blood vessel image) between the intersection position X1 and the intersection position X2 on the X-ray image is extracted as a region of interest of the X-ray image, and the surface along the axial direction of the blood vessel A blood vessel image (extracted blood vessel image) of an OCT image as a tomographic image may be extracted as a region of interest of the OCT image. If comprised in this way, since the image of the blood vessel can be compared, it is possible to acquire a correlation coefficient value more accurately.

  In the above-described embodiment, for convenience of explanation, the processing of the image processing unit has been described using a flow-driven flow that performs processing in order along the processing flow. However, the present invention is not limited to this. In the present invention, the processing of the image processing unit may be performed by event-driven (event-driven) processing that executes processing in units of events. In this case, it may be performed by a complete event drive type or a combination of event drive and flow drive.

DESCRIPTION OF SYMBOLS 1 X-ray image measuring device 2 OCT image measuring device 3 Medical image processing device 31 X-ray image memory | storage part 32 OCT image memory | storage part 33 Image processing part 34 Image display part 100 Medical image processing system

Claims (9)

An X-ray image storage unit for storing X-ray image information obtained by imaging blood vessels sequentially acquired from the X-ray image measurement device;
An OCT image storage unit for storing OCT image information obtained by imaging the inside of the blood vessel sequentially obtained from an OCT image measurement device;
The position on the X-ray image based on the X-ray image information is associated with the position on the OCT image based on the OCT image information, and a feature image included in the OCT image is extracted, and the extracted feature image A medical image processing apparatus comprising: an image processing unit that synthesizes information related to an associated position on the X-ray image based on the X-ray image information sequentially acquired from the X-ray image measurement apparatus.   The medical image processing apparatus according to claim 1, further comprising an image display unit that sequentially displays composite images sequentially generated by the image processing unit.   The image processing unit extracts an image of a part exhibiting a predetermined tissue property in the blood vessel as the feature image, and information on the extracted image of a part exhibiting a predetermined tissue property in the blood vessel is used as the X-ray image. The medical image processing apparatus according to claim 1, wherein the medical image processing apparatus is configured to synthesize at an upper associated position.   The image processing unit is configured to synthesize the predetermined tissue properties so as to be visually identifiable in a state where the predetermined tissue properties are classified into lipid plaque, calcified plaque, fibrous plaque, or thrombus. The medical image processing apparatus according to claim 3.   The image processing unit extracts a stent image inserted into the blood vessel as the feature image, and synthesizes information regarding the extracted stent image at a corresponding position on the X-ray image. The medical image processing apparatus according to claim 1, configured as described above.   The image processing unit acquires a correlation coefficient value between the X-ray image and the OCT image, and on the basis of the acquired correlation coefficient value, the position on the X-ray image and the OCT image The medical image processing apparatus according to any one of claims 1 to 5, wherein the medical image processing apparatus is configured so as to be associated with each other position.   The image processing unit includes a relative position between the OCT image as a tomographic image of a plane along the axial direction of the blood vessel and the X-ray image, and the OCT image as a tomographic image of a plane along the axial direction of the blood vessel. A plurality of the correlation coefficient values are acquired using at least the relative position of the cross-sectional angle as a variable, and the position on the X-ray image and the OCT image are obtained based on the acquired plurality of correlation coefficient values. The medical image processing apparatus according to claim 6, configured to associate with an upper position.   The image processing unit extracts a region near the X-ray contrast marker as a region of interest of the X-ray image based on the position of the X-ray contrast marker of the OCT catheter on the X-ray image, and extracts the extracted The medical image according to any one of claims 1 to 7, wherein the medical image is configured to associate a position on the X-ray image with a position on the OCT image based on a region of interest of the X-ray image. Processing equipment. Storing X-ray image information obtained by imaging blood vessels sequentially acquired from the X-ray image measurement device;
Storing OCT image information obtained by imaging the inside of the blood vessel sequentially obtained from the OCT image measuring device;
A position on the X-ray image based on the X-ray image information is associated with a position on the OCT image based on the OCT image information;
Extracting a feature image included in the OCT image;
A medical image processing method for synthesizing the extracted information related to the feature image at an associated position on the X-ray image based on the X-ray image information sequentially acquired from the X-ray image measurement apparatus.

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