Information processing method, information processing device, and program

Abstract

To provide an information processing method, etc., capable of appropriately presenting the position of a guide wire in an intravascular image.SOLUTION: An information processing method causes a computer to execute processing for acquiring a transverse cross-section image imaging a cross section intersecting with a longitudinal direction of a blood vessel; detecting a surface of a guide wire inserted into the blood vessel from the transverse cross-section image; specifying a position away from the surface of the guide wire by a pre-stipulated radius of the guide wire on a straight line connecting the center of the transverse cross-section image and the surface of the guide wire as central coordinates of the guide wire; and displaying an object representing the guide wire on the transverse cross-section image in a superimposed manner on the basis of the central coordinates of the guide wire and the radius of the guide wire.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an information processing method, an information processing device, and a program. [Background technology]

[0002] There are technologies that support image diagnosis related to vascular treatments such as PCI (Percutaneous Coronary Intervention). For example, Patent Document 1 discloses a method for detecting a guide wire inserted into a blood vessel from an OCT (Optical Coherence Tomography) image of the blood vessel. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2018-520839 Summary of the Invention [Problem to be solved by the invention]

[0004] In one aspect, an object is to provide an information processing method and the like that can suitably present the position of a guidewire in an intravascular image. [Means for solving the problem]

[0005] In one aspect, (1) an information processing method includes a computer executing a process in which a cross-sectional image of a cross section of a blood vessel that intersects the longitudinal direction is acquired, the surface of a guide wire inserted into the blood vessel is detected from the cross-sectional image, a position on a line connecting the center of the cross-sectional image and the surface of the guide wire that is away from the surface of the guide wire by a predetermined radius of the guide wire is identified as the center coordinate of the guide wire, and an object representing the guide wire is superimposed on the cross-sectional image based on the center coordinate of the guide wire and the radius of the guide wire.

[0006] (2) The information processing method of (1) above further detects a shadow area caused by the guide wire from the cross-sectional image, identifies the radius of the guide wire based on the detection result of the shadow area, and changes the display size of the object based on the identified radius of the guide wire.

[0007] (3) The information processing method of (1) or (2) above further detects the lumen region of the blood vessel from the cross-sectional image, corrects the contour of the lumen region so that the object is displayed within the lumen region, and displays the cross-sectional image in which the object and the contour line of the lumen region are superimposed.

[0008] (4) The information processing method described in any one of (1) to (3) above acquires first and second cross-sectional images captured using different modalities, detects the surface of the guidewire from each of the first and second cross-sectional images to identify the center coordinates of the guidewire, and, if the center coordinates of the guidewire are located within a predetermined distance between the first and second cross-sectional images, displays the object in the same display mode on each of the first and second cross-sectional images.

[0009] (5) The information processing method described in any one of (1) to (4) above further detects the main trunk region and the side branch region of the blood vessel from the cross-sectional image, and identifies the blood vessel into which the guide wire is inserted depending on whether the center coordinates of the guide wire are located within the main trunk region or the side branch region.

[0010] (6) The information processing method described in any one of (1) to (5) above acquires multiple frames of cross-sectional images obtained by continuously capturing a cross section of the blood vessel intersecting the longitudinal direction along the longitudinal direction, detects the surface of the guidewire from the cross-sectional image of each frame to identify the center coordinates of the guidewire, and superimposes the object on the cross-sectional image of each frame based on the center coordinates of the guidewire and the radius of the guidewire.

[0011] (7) The information processing method of (6) above determines whether the center coordinates of the guide wires are located within a predetermined distance in adjacent frames, thereby grouping the guide wires whose center coordinates have been identified from the cross-sectional images of each frame, and when the objects are superimposed on the cross-sectional images of each frame, the objects corresponding to the guide wires in the same group are displayed in the same display manner.

[0012] (8) In the information processing method of (7) above, when there are multiple groups of guidewires separated by a frame in which the surface of the guidewire is not detected, the inclination of the trajectory of the guidewire in the non-detection frame is calculated based on the central coordinates of the guidewire in multiple frames before and after the non-detection frame, and based on the calculated inclination, it is determined whether the guidewires in each group located before and after the non-detection frame are the same guidewire.

[0013] (9) In the information processing method of (7) or (8) above, when multiple groups of guide wires intersect in one frame, the inclination of the trajectory of the guide wire in the one frame is calculated based on the central coordinates of the guide wire in multiple frames before and after the one frame, and based on the calculated inclination, it is determined whether the guide wires of each group located before and after the one frame are the same guide wire.

[0014] (10) The information processing method described in any of (6) to (9) above generates a diagram showing the trajectory of the guide wire along the longitudinal direction of the blood vessel based on the center coordinates of the guide wire identified from the cross-sectional image of each frame, and displays the generated diagram.

[0015] In one aspect, (11) an information processing device is an information processing device including a control unit, the control unit acquires a cross-sectional image of a cross section of a blood vessel that intersects the longitudinal direction, detects the surface of a guide wire inserted into the blood vessel from the cross-sectional image, identifies a position on a line connecting the center of the cross-sectional image and the surface of the guide wire that is away from the surface of the guide wire by a predetermined radius of the guide wire as the center coordinate of the guide wire, and superimposes an object representing the guide wire on the cross-sectional image based on the center coordinate of the guide wire and the radius of the guide wire.

[0016] In one aspect, (12) the program causes a computer to perform a process of acquiring a cross-sectional image of a cross section of a blood vessel that intersects the longitudinal direction, detecting the surface of a guide wire inserted into the blood vessel from the cross-sectional image, identifying a position on a line connecting the center of the cross-sectional image and the surface of the guide wire that is away from the surface of the guide wire by a predetermined radius of the guide wire as the center coordinate of the guide wire, and superimposing an object representing the guide wire on the cross-sectional image based on the center coordinate of the guide wire and the radius of the guide wire. [Effects of the Invention]

[0017] In one aspect, the position of the guidewire in the intravascular image can be conveniently displayed. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of an imaging diagnostic apparatus. [Figure 2] FIG. 1 is a block diagram showing an example of the configuration of an imaging diagnostic apparatus. [Figure 3] FIG. 10 is an explanatory diagram relating to a target object detection process. [Figure 4] FIG. 10 is an explanatory diagram relating to the superimposition process of an object representing a guidewire. [Figure 5] FIG. 10 is a diagram showing an example of a display of a guidewire. [Figure 6] FIG. 10 is an explanatory diagram regarding a process of assigning a group number to a guidewire. [Figure 7] FIG. 2 is a diagram showing an example of a display screen of an imaging diagnostic apparatus. [Figure 8] FIG. 10 is a diagram showing another example of a trajectory diagram of a guide wire. [Figure 9] 10 is a flowchart illustrating an example of a processing procedure executed by the imaging diagnostic apparatus. [Figure 10] FIG. 10 is a diagram showing the trajectory of the guide wire when the trajectory is divided. [Figure 11] FIG. 10 is a trajectory diagram when there are multiple groups of guidewires. [Figure 12] FIG. 10 is a diagram showing the trajectory when multiple guide wires cross each other. [Figure 13] 10 is a flowchart showing an example of a processing procedure executed by the imaging diagnostic apparatus according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention will be described in detail below with reference to the drawings showing embodiments thereof. (Embodiment 1) Fig. 1 is a diagram showing an example of the configuration of an image diagnostic device 1. In this embodiment, an image diagnostic device 1 (information processing device) will be described that detects the surface of a guidewire from a cross-sectional image of a blood vessel, identifies the center coordinates of the guidewire, and displays a circular object (see Fig. 4, etc.) representing the guidewire superimposed on the cross-sectional image.

[0020] The diagnostic imaging device 1 is an imaging device that captures medical images of a patient's blood vessels, and is a device that has an IVUS (Intravascular Ultrasound) function that generates cross-sectional images of blood vessels by transmitting and receiving ultrasound, and an OCT function that generates cross-sectional images of blood vessels by transmitting and receiving light, using, for example, a catheter 101. The catheter 101 is a medical instrument that is inserted into a patient's blood vessels, and the tip of the catheter 101 is provided with an ultrasound transmitting and receiving unit that transmits and receives ultrasound, and an optical transmitting and receiving unit that transmits and receives light. The diagnostic imaging device 1 generates and displays IVUS images and OCT images based on the ultrasound and light received by the catheter 101.

[0021] In this embodiment, the diagnostic imaging device 1 is described as a device having both IVUS and OCT functions, but the diagnostic imaging device 1 may be a device having only one of the functions. Also, the cross-sectional images of blood vessels may be captured by a method other than IVUS or OCT.

[0022] In this embodiment, the diagnostic imaging device 1 detects various objects, including the surface of the guidewire, from a blood vessel cross-sectional image (transverse cross-sectional image) captured using the catheter 101. The diagnostic imaging device 1 then identifies the center coordinates of the guidewire from the detected surface of the guidewire, and displays an object representing the guidewire superimposed on the blood vessel cross-sectional image based on the center coordinates and a predetermined radius of the guidewire (see FIGS. 4, 5, etc.).

[0023] As will be described later, since only the surface of a guidewire is visualized in a vascular cross-sectional image, it is impossible to distinguish the guidewire without prior knowledge of image interpretation. Therefore, the image diagnostic device 1 visualizes a virtual guidewire in the vascular cross-sectional image to assist image interpretation.

[0024] 2 is a block diagram showing an example of the configuration of the diagnostic imaging device 1. The diagnostic imaging device 1 includes a control unit 11, a main memory unit 12, a communication unit 13, a display unit 14, an input unit 15, an image processing unit 16, and an auxiliary memory unit 17. The control unit 11 has one or more arithmetic processing devices such as a central processing unit (CPU), a micro-processing unit (MPU), a graphics processing unit (GPU), etc., and performs various information processing by reading and executing a program P stored in the auxiliary storage unit 17. The main storage unit 12 is a temporary storage area such as a static random access memory (SRAM) or a dynamic random access memory (DRAM), and temporarily stores data necessary for the control unit 11 to execute arithmetic processing. The communication unit 13 is a communication module for performing communication-related processing and transmits and receives information to and from the outside. The display unit 14 is a display screen such as a liquid crystal display and displays images. The input unit 15 is an operation interface such as a keyboard or mouse and receives operation input from the user. The image processing unit 16 is an image processing module that processes signals transmitted and received via the catheter 101 and generates a vascular cross-sectional image.

[0025] The auxiliary storage unit 17 is a non-volatile storage area such as a hard disk or large-capacity memory, and stores a program P and other data required for the control unit 11 to execute processing. The auxiliary storage unit 17 also stores a detection model 50. The detection model 50 is a machine learning model that has learned predetermined training data, and is a model that uses a cross-sectional image of a blood vessel as input to detect the lumen of the main trunk of the blood vessel, the tunica media boundary, side branches, the surface of the guidewire, shadow areas caused by the guidewire, and the like.

[0026] The diagnostic imaging device 1 may include a reading unit that reads a portable storage medium 1a such as a CD (Compact Disk)-ROM or a DVD (Digital Versatile Disk)-ROM, and may read and execute the program P from the portable storage medium 1a.

[0027] Fig. 3 is an explanatory diagram of the object detection process. Fig. 3 illustrates how the lumen of the main trunk of the blood vessel, the media boundary, the surface of the guidewire, the shadow area caused by the guidewire, and the like are detected from a cross-sectional image captured of a cross section intersecting (perpendicular to) the longitudinal direction of the blood vessel. The media boundary includes the IEL (internal elastic lamina) located at the boundary between the intima and media of the blood vessel, the EEM (external elastic membrane) located at the boundary between the media and adventitia, and the EEL (external elastic lamina).

[0028] The diagnostic imaging device 1 acquires multiple frames of cross-sectional images captured continuously along the longitudinal direction of the blood vessel in accordance with the pull-back operation of the catheter 101. The diagnostic imaging device 1 inputs the cross-sectional image of each frame into the detection model 50, thereby detecting various objects such as the lumen (main trunk) of the blood vessel, the medial boundary, and the guide wire.

[0029] The detection model 50 is a machine learning model that has been trained on predetermined training data (a group of cross-sectional images), and is, for example, a CNN (Convolutional Neural Network) such as U-net that performs processing related to semantic segmentation. When a cross-sectional image is input, the detection model 50 identifies, on a pixel-by-pixel basis, image regions corresponding to various objects to be detected.

[0030] It should be noted that the image diagnostic device 1 is only required to be able to detect various objects from cross-sectional images, and the detection means is not limited to the machine learning model (detection model 50).

[0031] In this embodiment, the detection model 50 detects various objects including at least the surface of a guidewire. When a guidewire is present in the imaging range of the cross-sectional image (cross section of the blood vessel), the surface of the guidewire is observed as a high-luminance area, as shown in Fig. 3. The detection model 50 detects the surface of the guidewire from the cross-sectional image.

[0032] Furthermore, the detection model 50 detects the shadow area caused by the guidewire in addition to the surface of the guidewire. When a guidewire is present, the area behind the guidewire (far from the center of the image) is observed as a shadow, as shown in Fig. 3. The detection model 50 detects this shadow area from the cross-sectional image.

[0033] In addition, the detection model 50 detects the lumen region corresponding to the lumen of the main trunk of the blood vessel, the media boundary region corresponding to the media boundary, the side branch region corresponding to the side branch, the plaque region corresponding to plaque in the blood vessel wall, etc. Note that the lumen and media boundary are detected discontinuously in the areas that overlap with the shadow region created by the guidewire, but this area can be interpolated using a known method such as spline interpolation. Furthermore, the "main trunk" of the blood vessel refers to the blood vessel to be treated, into which the catheter 101 is inserted, and the "side branch" refers to the blood vessel that branches off from the main trunk.

[0034] As will be described later, the image diagnostic apparatus 1 presents the detection results of the lumen, etc. to the user by superimposing contour lines of the lumen, medial boundary, etc. on the cross-sectional image (see FIG. 7, etc.).

[0035] As described above, the diagnostic imaging device 1 captures cross-sectional images of different modalities, namely, an IVUS image (first cross-sectional image) and an OCT image (second cross-sectional image). The diagnostic imaging device 1 inputs the images of each modality to the detection model 50 and detects an object from each image.

[0036] Fig. 4 is an explanatory diagram regarding the superimposition process of an object representing a guidewire. Fig. 4 illustrates how the center coordinates of the guidewire are identified from the surface of the guidewire detected above, and a circular object representing the guidewire is superimposed and displayed based on the center coordinates.

[0037] As described above, the diagnostic imaging device 1 detects the surface of the guidewire from the cross-sectional image. Then, the diagnostic imaging device 1 identifies the center coordinates of the guidewire from the detected surface of the guidewire. Specifically, the diagnostic imaging device 1 identifies, as the center coordinates of the guidewire, a position on the straight line (A-Line) connecting the center of the cross-sectional image and the surface of the guidewire, that is spaced from the surface of the guidewire by a predetermined radius of the guidewire.

[0038] For example, the imaging diagnostic device 1 identifies a point on the surface of the guidewire that is closest to the center of the image. Next, the imaging diagnostic device 1 identifies a straight line connecting the point and the center of the image (a line that bisects the surface of the guidewire). Then, the imaging diagnostic device 1 identifies a position on the straight line that is away from the surface of the guidewire toward the outer edge of the image by the radius of the guidewire as the center coordinate of the guidewire.

[0039] The diagnostic imaging device 1 superimposes and displays a circular object based on the identified center coordinates of the guidewire and the radius of the guidewire. The object may be a circle filled with a specific color (see FIGS. 5, 7, etc.), may be only the outline of a circle, or may be a circle filled with a highly transparent color. The diagnostic imaging device 1 may be capable of switching between displaying and hiding the object in response to an operation input from the user. The diagnostic imaging device 1 may also be capable of allowing the user to correct the display position of the object (position of the guidewire).

[0040] The dimensions (radius) of the guidewire are generally set to 0.014 inches for coronary arteries and 0.018 inches or 0.035 inches for lower limbs. The diagnostic imaging device 1 may change the display size (radius) of the object according to settings made by the user.

[0041] Alternatively, the image diagnostic device 1 may identify the radius of the guidewire from the width of the shaded area caused by the guidewire and change the display size (radius) of the object. Note that the width of the shaded area may be measured, for example, as the length of the arc of the fan-shaped shaded area. This makes it possible to automatically change the display size according to the dimensions of the inserted guidewire.

[0042] Furthermore, since the guidewire does not cross the inner wall of the blood vessel, the contour of the lumen should naturally pass outside the circular object representing the guidewire. Therefore, the image diagnostic device 1 may correct the contour of the lumen region so that the object is displayed within the lumen region. This allows the contour of the lumen region to be correctly displayed when the contour of the lumen region is superimposed on the cross-sectional image as described below.

[0043] As described above, the image diagnostic device 1 detects an object such as the surface of the guidewire from each of the IVUS image (first cross-sectional image) and the OCT image (second cross-sectional image). The image diagnostic device 1 identifies the center coordinates of the guidewire from each of the IVUS image and the OCT image, and displays the object in a superimposed manner.

[0044] In this case, if the center coordinates of the guidewire are located within a predetermined distance between the IVUS image and the OCT image, the diagnostic imaging device 1 may consider the guidewire whose center coordinates are identified from each image to be the same, and may display the object in the same display mode (for example, the same display color) in both the IVUS image and the OCT image. This allows for mutual confirmation of erroneous determinations, etc.

[0045] The image diagnostic device 1 performs the above-described processing on each of the cross-sectional images of multiple frames captured in accordance with the pullback operation of the catheter 101, and identifies the center coordinates of the guidewire from the cross-sectional image of each frame. Here, the image diagnostic device 1 groups the guidewires by determining whether the center coordinates of the guidewires in adjacent frames are located within a predetermined distance, and displays objects corresponding to the guidewires in the same group in the same display mode (for example, the same display color).

[0046] Fig. 5 is a diagram showing an example of a guidewire display. Fig. 6 is an explanatory diagram regarding the process of assigning a group number to a guidewire. Fig. 5 schematically shows an image transition from a distal frame (the first frame captured) to a proximal frame (the last frame captured). Fig. 6 shows an example of an analysis result in which, for guidewires detected from each frame, the guidewire group number (hereinafter referred to as "GW group number") by which the guidewires are grouped is linked to the identification result of the blood vessel (main trunk or side branch) into which the guidewire is inserted.

[0047] For example, the diagnostic imaging device 1 processes frames sequentially, starting from the distal frame, to detect an object such as a guidewire and identify its center coordinates. The "center coordinates" of the guidewire referred to here may refer to the coordinate values ​​of the guidewire center, with the center of the image as the origin, or may refer to the coordinate values ​​of the guidewire center, with the center of gravity of the lumen or blood vessel (media boundary) as the origin. The diagnostic imaging device 1 compares the center coordinates of the guidewire detected in the previous frame with the center coordinates of the guidewire detected in the currently processed frame, and if the two are located within a predetermined distance, determines that they are the same guidewire. In this case, the diagnostic imaging device 1 assigns the same GW group number to the guidewire detected in the currently processed frame as the guidewire detected in the previous frame.

[0048] On the other hand, if the center coordinates of the guidewire in the previous frame are not within a predetermined distance from the center coordinates of the guidewire in the currently processed frame, it is determined that a new guidewire has appeared. In this case, the image diagnostic device 1 assigns a new GW group number to the guidewire detected in the currently processed frame.

[0049] The diagnostic imaging device 1 performs the above process for each frame and groups the guidewires whose center coordinates have been identified from each frame. When displaying the cross-sectional image of each frame, the diagnostic imaging device 1 displays the objects in the same display mode (display color) for guidewires assigned the same GW group number.

[0050] Furthermore, the image diagnostic device 1 identifies the blood vessel into which the guidewire is inserted depending on whether the center coordinates of the guidewire are located within the main trunk region (the lumen region of the main trunk) or within the side branch region. That is, when the center coordinates of the guidewire are located within the main trunk region in the frame currently being processed, the image diagnostic device 1 identifies the blood vessel into which the guidewire is inserted as the main trunk, and when the center coordinates of the guidewire are located within the side branch region, the image diagnostic device 1 identifies the blood vessel into which the guidewire is inserted as the side branch.

[0051] Furthermore, if a side branch region detected in the previous frame and a side branch region detected in the currently processed frame are located within a certain angle, the image diagnostic device 1 considers them to be the same side branch and assigns the same side branch group number to them. Note that the "angle" referred to here refers to the angle at which the center of gravity of the side branch region is located in the circumferential direction centered on the center of gravity of the blood vessel lumen.

[0052] By performing the above processing for each frame, the analysis result shown in Fig. 6 is generated. When displaying the cross-sectional image of each frame, the image diagnostic device 1 identifies each guidewire according to the GW group number assigned above and displays an object corresponding to each guidewire. As a result, for example, as shown in Fig. 5, when guidewires are inserted into a blood vessel to be treated (main trunk) and a side branch, representing the two guidewires in different display modes may lead to improved visibility in clinical practice.

[0053] 7 is a diagram showing an example of a display screen of the diagnostic imaging apparatus 1. The screen includes an OCT image display field 210, an IVUS image display field 220, a guidewire trajectory display field 230, and a longitudinal cross-sectional image display field 240.

[0054] The OCT image display field 210 and the IVUS image display field 220 are display fields that display OCT images and IVUS images (cross-sectional images) of blood vessels, respectively. The diagnostic imaging device 1 displays cross-sectional images at a position designated by a cursor 241 (described later) in the OCT image display field 210 and the IVUS image display field 220.

[0055] For example, the diagnostic imaging device 1 displays cross-sectional images on which the contours of the lumen region, the media boundary region, etc. detected by the detection model 50 are superimposed in the OCT image display field 210 and the IVUS image display field 220. Furthermore, the diagnostic imaging device 1 calculates the average diameters of the lumen and the media boundary, and displays the average diameter of the lumen as "L" (Lumen) and the average diameter of the media boundary as "V" (Vessel) next to the image.

[0056] Furthermore, the image diagnostic device 1 superimposes a circular object representing the guidewire on the cross-sectional image. As already described, the image diagnostic device 1 changes the display mode (display color) of the object according to the GW group number assigned by comparing the center coordinates of the guidewire in each frame.

[0057] The guidewire trajectory display field 230 is a display field that displays a trajectory diagram showing the trajectory of the guidewire along the longitudinal direction of the blood vessel. The horizontal axis (X-axis) of the trajectory diagram represents the position along the longitudinal direction of the blood vessel, and the vertical axis (Y-axis) represents the distance from the center of gravity of the lumen of the blood vessel to the center coordinates of the guidewire. The image diagnostic device 1 generates and displays a trajectory diagram based on the center coordinates of the guidewire identified from the cross-sectional image of each frame. By referring to the trajectory diagram, the position where the blood vessel is bent can be easily grasped.

[0058] FIG. 8 is a diagram showing another example of a guidewire trajectory diagram. In FIG. 7, the guidewire trajectory is expressed in a graph format, but this embodiment is not limited to this. For example, as shown in FIG. 8, the image diagnostic device 1 may generate a three-dimensional image of a blood vessel and superimpose the guidewire trajectory on the image. Specifically, the image diagnostic device 1 generates a three-dimensional image of the blood vessel based on the detection results of the lumen region, the medial boundary region, and the side branch region of the main trunk of the blood vessel in each frame. Then, the image diagnostic device 1 renders a line representing the guidewire trajectory based on the center coordinates of the guidewire in each frame and superimposes it on the three-dimensional image. This allows the trajectory of the guidewire to be grasped at a glance.

[0059] Although the trajectory of the guidewire is superimposed on a three-dimensional image of the blood vessel in FIG. 8, the trajectory of the guidewire may be superimposed on a two-dimensional image (longitudinal cross-sectional image).

[0060] Returning to FIG. 7 , the explanation will be continued. The longitudinal cross-sectional image display field 240 is a display field that displays a longitudinal cross-sectional image of a blood vessel. The diagnostic imaging device 1 generates a longitudinal cross-sectional image that schematically shows a longitudinal cross-section of the blood vessel based on the average diameter of the lumen-media boundary at each position (each frame) along the longitudinal direction of the blood vessel, and displays the image in the longitudinal cross-sectional image display field 240. For example, the diagnostic imaging device 1 displays a cursor 241 superimposed on the longitudinal cross-sectional image, and accepts an operation input to move the cursor 241 left and right (in the longitudinal direction of the blood vessel). The diagnostic imaging device 1 displays a cross-sectional image (frame) corresponding to the position of the cursor 241 in the OCT image display field 210 and the IVUS image display field 220.

[0061] In the longitudinal cross-sectional image of a blood vessel displayed in the longitudinal cross-sectional image display field 240, hatched regions of the blood vessel wall represent regions where the ratio of the plaque region to the cross section of the blood vessel is equal to or greater than a threshold. This ratio is calculated, for example, by (area of ​​the plaque region) / (area of ​​the plaque region + area of ​​the lumen region of the blood vessel). In addition, in the longitudinal cross-sectional image of a blood vessel displayed in the longitudinal cross-sectional image display field 240, punching bag-shaped objects placed inside the blood vessel represent the positions where side branches of the blood vessel exist.

[0062] As described above, according to this embodiment, the surface of the guidewire is detected from the cross-sectional image of the blood vessel, the center coordinates of the guidewire are identified, and an object representing the guidewire is superimposed on the cross-sectional image, thereby notifying the user of the presence of the guidewire and assisting in image interpretation.

[0063] 9 is a flowchart showing an example of a processing procedure executed by the diagnostic imaging apparatus 1. The processing contents executed by the diagnostic imaging apparatus 1 will be described with reference to FIG. The control unit 11 of the image diagnostic apparatus 1 acquires cross-sectional images of a cross section of a blood vessel that intersects the blood vessel in the longitudinal direction (step S11) by using the catheter 101. Specifically, the control unit 11 acquires multiple frames of cross-sectional images that are successively captured along the blood vessel in the longitudinal direction in accordance with the pull-back operation of the catheter 101.

[0064] The control unit 11 selects a frame to be processed from the multiple frames of cross-sectional images acquired in step S11 (step S12). For example, the control unit 11 selects frames in order, starting from the distal frame (the frame captured first). The control unit 11 inputs the cross-sectional images of the selected frames into the detection model 50, thereby detecting various objects including the surface of the guidewire (step S13). For example, in addition to the surface of the guidewire, the control unit 11 detects a shadow area caused by the guidewire, the lumen area of ​​the main trunk of the blood vessel, the area within the boundary of the tunica media of the main trunk, the side branch area, etc.

[0065] The control unit 11 specifies a position on a straight line (A-Line) connecting the center of the cross-sectional image and the surface of the guidewire that is spaced from the surface of the guidewire by a predetermined radius of the guidewire as the center coordinate of the guidewire (step S14). For example, the control unit 11 specifies a point on the surface of the guidewire that is closest to the center of the image, and specifies a straight line connecting that point and the center of the image (a line that bisects the surface of the guidewire). The control unit 11 specifies a position on that straight line that is spaced from the surface of the guidewire toward the outer edge of the image by the radius of the guidewire as the center coordinate of the guidewire.

[0066] The control unit 11 determines whether the center coordinates of the guidewire in the currently processed frame and the center coordinates of the guidewire in the immediately previous frame are located within a predetermined distance, and assigns a GW group number to the guidewire whose center coordinates have been identified (step S15). That is, if the center coordinates of the guidewire in the currently processed frame are located within a predetermined distance from the center coordinates of the guidewire in the immediately previous frame, the control unit 11 considers them to be the same guidewire and assigns the same GW group number. On the other hand, if the center coordinates of the guidewire in the immediately previous frame are not present within the predetermined distance from the center coordinates of the guidewire in the currently processed frame, the control unit 11 considers that a new guidewire has appeared and assigns a new GW group number.

[0067] The control unit 11 identifies the blood vessel into which the guidewire is inserted by determining whether the center coordinates of the guidewire are located within the main trunk region (the lumen region of the main trunk) or the side branch region (step S16).When the control unit 11 detects a side branch region from the currently processed frame, the control unit 11 assigns a side branch group number to the side branch region depending on whether the side branch region is within a certain angle in the previous frame (step S17).

[0068] The control unit 11 determines whether the processes of steps S13 to S17 have been performed on all frames acquired in step S11 (step S18). If it is determined that there are frames for which the processes have not been performed (S18: NO), the control unit 11 returns the process to step S12. In this case, the control unit 11 selects the next frame (step S12) and performs the processes of steps S13 to S17.

[0069] If it is determined that processing has been performed on all frames (S18: YES), the control unit 11 displays the analysis results of the cross-sectional image (step S19). Specifically, as shown in FIG. 7, the control unit 11 displays the cross-sectional image on which the contours of the lumen and medial boundary are superimposed, as well as a circular object representing the guidewire. The control unit 11 also displays a trajectory diagram of the guidewire along the longitudinal direction of the blood vessel, based on the center coordinates of the guidewire identified from each frame. The control unit 11 then terminates the series of processes.

[0070] As described above, according to the first embodiment, the position of the guidewire in the intravascular image can be suitably displayed.

[0071] (Embodiment 2) In this embodiment, when a guidewire is not detected (overlooked), crosses, etc., it is determined whether the guidewires classified into each group are the same, and the trajectory of the guidewire is interpolated. Note that the same reference numerals are used to designate the same contents as in the first embodiment, and the description thereof will be omitted.

[0072] Figure 10 is a diagram of the trajectory of a guidewire when the trajectory is segmented. Figure 10 illustrates the trajectory of the guidewire along the longitudinal direction of the blood vessel when the guidewire is overlooked (not detected). In Figure 10, the horizontal direction represents the position along the longitudinal direction of the blood vessel, and the vertical direction represents the distance from the center of gravity of the lumen of the blood vessel to the center coordinates of the guidewire.

[0073] Here, we consider a case where the surface of the guidewire is not detected in a certain frame and the guidewire is overlooked. In this case, as shown in Figure 10, even though it is actually the same guidewire, a new GW group number is assigned at the boundary of the non-detected frame.

[0074] In such a case, the image diagnostic device 1 interpolates the trajectory of the guidewire based on the center coordinates of the guidewire in several frames before and after. As shown in Fig. 10, when there is only one guidewire in each of the frames before and after a frame in which the guidewire is not detected, the image diagnostic device 1 performs spline interpolation to interpolate the center coordinates of the guidewire in the non-detection frame.

[0075] Fig. 11 is a diagram of a trajectory when there are multiple groups of guidewires. Fig. 11 illustrates a case where there is one group of guidewires before the non-detected frame and two groups after it. In such a case, the image diagnostic device 1 compares the groups before and after the separation and determines whether the guidewires in each group are the same guidewire.

[0076] Specifically, the diagnostic imaging device 1 calculates the gradient of the guidewire's trajectory from the center coordinates of the guidewire in several frames before (or after) the frame in which the guidewire is not detected. Note that the "gradient" here refers to the amount of displacement of the center coordinates of the guidewire per unit length along the longitudinal direction of the blood vessel. The diagnostic imaging device 1 performs linear extrapolation based on the calculated gradient to determine whether the guidewire in the group located before the non-detection frame and the guidewire in the group located after the non-detection frame are the same guidewire.

[0077] In the above, whether the guidewires in each group are the same or not is determined based on the inclination of the guidewire trajectory, but this embodiment is not limited to this, and whether the guidewires are the same or not may be determined based on criteria other than inclination.

[0078] If it is determined that the guidewires are the same, the image diagnostic device 1 assigns the same GW group number to the two groups determined to be the same. As in Fig. 10, the image diagnostic device 1 performs spline interpolation from the center coordinates of the guidewire in several frames before and after the non-detection frame to interpolate the trajectory (center coordinates) of the guidewire in the non-detection frame.

[0079] In contrast, guidewire groups that have no connections even after interpolation up to the proximal frame are removed as noise.

[0080] Fig. 12 is a diagram showing the trajectories of a case where multiple guide wires cross each other, in which two guide wires cross each other in one frame (hereinafter also referred to as a "crossing frame").

[0081] When guidewires of multiple groups intersect, the diagnostic imaging apparatus 1 divides the groups at the intersecting frame as a boundary, and then determines whether the guidewires of each group are the same guidewire.

[0082] Specifically, as in the case of the above-described division, the imaging diagnostic device 1 calculates the inclination of the guidewire trajectory in the crossing frame from the center coordinates of the guidewire in several frames before and after the crossing frame. Based on the calculated inclination, the imaging diagnostic device 1 determines whether the guidewires in each group located before and after the crossing frame are the same. If it determines that the guidewires are the same, the imaging diagnostic device 1 assigns the same GW group number to the two groups determined to be the same.

[0083] 13 is a flowchart showing an example of a processing procedure executed by the imaging diagnostic apparatus 1 according to Embodiment 2. When it is determined that processing has been performed on all frames (S18: YES), the imaging diagnostic apparatus 1 executes the following processing. The control unit 11 of the image diagnostic apparatus 1 determines whether the guidewire is divided into multiple groups based on the presence of a frame in which the surface of the guidewire is not detected (step S201). If it is determined that the guidewire is not divided into multiple groups (S201: NO), the control unit 11 proceeds to step S205.

[0084] If it is determined that the frame is divided into multiple groups (S201: YES), the control unit 11 determines whether the guidewires of the groups located before and after the non-detection frame are the same guidewire (step S202). Specifically, the control unit 11 calculates the inclination of the guidewire trajectory in the non-detection frame based on the center coordinates of the guidewires in multiple frames before and after (before or after) the non-detection frame. Based on the calculated inclination, the control unit 11 determines whether the guidewire of the group located before the non-detection frame and the guidewire of the group located after the non-detection frame are the same guidewire. The control unit 11 interpolates the trajectories (center coordinates) of the guidewires between the groups determined to be the same guidewire (step S203). Furthermore, the control unit 11 deletes the guidewires of the groups that are not connected up to the proximal frame as noise (step S204).

[0085] The control unit 11 determines whether or not guidewires of multiple groups cross each other in one frame (crossing frame) (step S205). If it is determined that they do not cross each other (S205: NO), the control unit 11 proceeds to step S19.

[0086] If it is determined that they intersect (S205: YES), the control unit 11 divides the group at the crossing frame (step S206). The control unit 11 determines whether the guidewires in each divided group are the same guidewire (step S207). Specifically, the control unit 11 calculates the inclination of the guidewire trajectory in the crossing frame based on the center coordinates of the guidewire in multiple frames before and after the crossing frame. Based on the calculated inclination, the control unit 11 determines whether the guidewire of the group located before the crossing frame and the guidewire of the group located after the crossing frame are the same guidewire. The control unit 11 transitions the process to step S19.

[0087] In this embodiment, if a guidewire is overlooked (the trajectory of the guidewire is interrupted), this is automatically interpolated, but the user may also be able to interpolate the trajectory of the guidewire (center coordinates).

[0088] Also, if a guidewire is erroneously detected, the user may be able to delete it.

[0089] Furthermore, if the grouping of the guidewires is incorrect, the user may be able to correct this to the correct group number.

[0090] As described above, according to the second embodiment, when the trajectory of the guidewire is broken, crossed, or the like, it is possible to suitably determine whether the guidewires in each group are the same or not.

[0091] The embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is defined by the claims, not by the above meaning, and is intended to include all modifications within the meaning and scope of the claims.

[0092] The matters described in each embodiment can be combined with each other. Furthermore, the independent claims and dependent claims described in the claims can be combined with each other in any combination, regardless of the reference format. Furthermore, although the claims use a format in which a claim references two or more other claims (multi-claim format), this is not limited to this format. A format in which multiple claims (multi-multi-claims) that reference at least one other multiple claim may also be used. [Explanation of symbols]

[0093] 1. Diagnostic imaging equipment (information processing equipment) 11 Control section 12 Main memory 13 Communications Department 14 Display section 15 Input section 16 Image processing section 17 Auxiliary storage P Program 50 detection models

Claims

1. A cross-sectional image of a cross section intersecting the longitudinal direction of the blood vessel is obtained. detecting a surface of a guidewire inserted into the blood vessel from the cross-sectional image; specifying, on a line connecting the center of the cross-sectional image and the surface of the guidewire, a position that is separated from the surface of the guidewire by a predetermined radius of the guidewire as the center coordinate of the guidewire; An object representing the guidewire is superimposed on the cross-sectional image based on the center coordinates of the guidewire and the radius of the guidewire. An information processing method in which processing is performed by a computer.

2. Further, a shadow region caused by the guide wire is detected from the cross-sectional image; Identifying a radius of the guidewire based on the detection of the shadowed region; The display size of the object is changed based on the identified radius of the guidewire. The information processing method according to claim 1 .

3. Further detecting a lumen region of the blood vessel from the cross-sectional image; correcting the contour of the lumen region so that the object is displayed within the lumen region; and displaying the cross-sectional image with the object and the contour line of the lumen region superimposed thereon. The information processing method according to claim 1 .

4. acquiring first and second cross-sectional images taken with different modalities; detecting a surface of the guidewire from each of the first and second cross-sectional images to identify a center coordinate of the guidewire; When the center coordinates of the guidewire are located within a predetermined distance between the first and second cross-sectional images, the object is displayed in the same display mode on each of the first and second cross-sectional images. The information processing method according to claim 1 .

5. Further, a main trunk region and a side branch region of the blood vessel are detected from the cross-sectional image; The blood vessel into which the guide wire is inserted is identified depending on whether the center coordinates of the guide wire are located within the trunk region or the side branch region. The information processing method according to claim 1 .

6. acquiring a plurality of frames of cross-sectional images by successively capturing images of a cross section intersecting the longitudinal direction of the blood vessel along the longitudinal direction; detecting a surface of the guidewire from the cross-sectional image of each frame to identify the center coordinates of the guidewire; The object is superimposed on the cross-sectional image of each frame based on the center coordinates of the guide wire and the radius of the guide wire. The information processing method according to claim 1 .

7. determining whether the center coordinates of the guide wires are located within a predetermined distance in adjacent frames, and grouping the guide wires whose center coordinates are identified from the cross-sectional images of each frame; When the objects are superimposed on the cross-sectional image of each frame, the objects corresponding to the guide wires of the same group are displayed in the same display mode. The information processing method according to claim 6.

8. When there are a plurality of groups of guidewires with a frame in which the surface of the guidewire is not detected as a boundary, a gradient of the trajectory of the guidewire in the frame in which the surface of the guidewire is not detected is calculated based on the center coordinates of the guidewire in a plurality of frames before and after the frame in which the surface of the guidewire is not detected; Based on the calculated gradient, it is determined whether the guidewires in each group located before and after the non-detected frame are the same guidewire. The information processing method according to claim 7.

9. When a plurality of groups of the guide wires cross each other in one frame, the inclination of the trajectory of the guide wire in the one frame is calculated based on the center coordinates of the guide wires in a plurality of frames before and after the one frame; Based on the calculated gradient, it is determined whether the guide wires in each group located before and after the one frame are the same guide wire. The information processing method according to claim 7.

10. generating a diagram showing a trajectory of the guidewire along the longitudinal direction of the blood vessel based on the center coordinates of the guidewire identified from the cross-sectional image of each frame; View the generated diagram The information processing method according to claim 6.

11. An information processing device including a control unit, The control unit A cross-sectional image of a cross section intersecting the longitudinal direction of the blood vessel is obtained. detecting a surface of a guidewire inserted into the blood vessel from the cross-sectional image; specifying, on a line connecting the center of the cross-sectional image and the surface of the guidewire, a position that is separated from the surface of the guidewire by a predetermined radius of the guidewire as the center coordinate of the guidewire; An object representing the guidewire is superimposed on the cross-sectional image based on the center coordinates of the guidewire and the radius of the guidewire. Information processing device.

12. A cross-sectional image of a cross section intersecting the longitudinal direction of the blood vessel is obtained. detecting a surface of a guidewire inserted into the blood vessel from the cross-sectional image; specifying, on a line connecting the center of the cross-sectional image and the surface of the guidewire, a position that is separated from the surface of the guidewire by a predetermined radius of the guidewire as the center coordinate of the guidewire; An object representing the guidewire is superimposed on the cross-sectional image based on the center coordinates of the guidewire and the radius of the guidewire. A program that causes a computer to perform a process.

Images