Information processing method, program, and information processing device

Abstract

To provide an information processing method and the like for automatically correcting the rotation of a tomographic image.SOLUTION: An information processing method causes a computer to execute processing of: determining whether or not a first rotation amount about a feature point of a hollow organ or a second rotation amount about an instrument used together with a catheter for image acquisition between a first tomographic image 411 acquired by using the catheter for image acquisition inserted to the hollow organ and a second tomographic image 412 acquired after the first tomographic image is equal to or greater than a prescribed first threshold; determining whether or not a difference between the first rotation amount and the second rotation amount is less than a prescribed second threshold when determining that the rotation amount is equal to or greater than the first threshold; and rotating a tomographic image 41 acquired after the second tomographic image 412 so as to cancel the first rotation amount when determining that the difference is less than the second threshold.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] A catheter system is used in which a diagnostic imaging catheter is inserted into a hollow organ such as a blood vessel to capture a tomographic image (Patent Document 1). The diagnostic imaging catheter disclosed in Patent Document 1 rotates a sensor inside a sheath to perform mechanical radial scanning. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2017 / 164071 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in areas where the hollow organ is bent or constricted, the rotation of the sensor may be temporarily inhibited and then released, causing the tomographic image to suddenly rotate significantly. When such a large rotation occurs, it becomes difficult to understand the positional relationship between the tomographic image and the actual organ.

[0005] In one aspect, an object of the present invention is to provide an information processing method or the like that automatically corrects the rotation of a tomographic image. [Means for solving the problem]

[0006] The information processing method includes a computer that determines whether a first rotation amount regarding a feature point of a tubular organ, or a second rotation amount regarding an instrument used with the image acquisition catheter, between a first tomographic image acquired using an image acquisition catheter inserted into the tubular organ and a second tomographic image acquired after the first tomographic image is greater than or equal to a predetermined first threshold, and if it is determined that the difference between the first rotation amount and the second rotation amount is less than a predetermined second threshold, rotates tomographic images acquired after the second tomographic image so as to cancel out the first rotation amount. [Effects of the Invention]

[0007] In one aspect, an information processing method or the like can be provided that automatically corrects the rotation of a tomographic image. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 10 is an explanatory diagram illustrating an outline of rotation correction processing. [Figure 2] FIG. 1 is an explanatory diagram illustrating the configuration of a catheter system. [Figure 3] FIG. 10 is an explanatory diagram illustrating an outline of a rotation detection process. [Figure 4] FIG. 10 is an explanatory diagram illustrating an outline of a rotation detection process. [Figure 5] FIG. 10 is an explanatory diagram illustrating an outline of a rotation detection process. [Figure 6] FIG. 10 is an explanatory diagram illustrating an outline of a rotation detection process. [Figure 7] FIG. 10 is an explanatory diagram illustrating an outline of a rotation correction process. [Figure 8] FIG. 1 is an explanatory diagram illustrating a classification model. [Figure 9] 10 is a flowchart illustrating the flow of processing of a program. [Figure 10] 10 is a flowchart illustrating a process flow of a feature point determination subroutine. [Figure 11] FIG. 10 is an explanatory diagram illustrating a characteristic feature of a modified example. [Figure 12] FIG. 2 is an explanatory diagram illustrating a rotational position estimation model. [Figure 13] FIG. 10 is an explanatory diagram illustrating the record layout of a rotational position training data DB. [Figure 14] FIG. 2 is an explanatory diagram illustrating a reference image. [Figure 15] 10 is a flowchart illustrating the flow of processing of a program according to the second embodiment. [Figure 16] FIG. 10 is an explanatory diagram illustrating the relationship between a constriction position and a rotation occurrence position. [Figure 17] 11 is a flowchart illustrating the flow of processing of a program according to the third embodiment. [Figure 18] 10 is a flowchart illustrating a process flow of a threshold calculation subroutine. [Figure 19] FIG. 1 is an explanatory diagram illustrating a configuration of an information processing device. [Figure 20] FIG. 10 is an explanatory diagram illustrating the record layout of a first tomographic image DB. [Figure 21] FIG. 10 is an explanatory diagram illustrating the record layout of a second tomographic image DB. [Figure 22] 10 is a flowchart illustrating the flow of processing of a program according to a fourth embodiment. [Figure 23] FIG. 13 is an explanatory diagram illustrating the configuration of an information processing device according to a fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Embodiment 1] FIG. 1 is an explanatory diagram outlining the rotation correction process. A radial scanning type imaging catheter 28 (see FIG. 2) is used to acquire a plurality of tomographic images 41 in time series. The center of FIG. 1 shows a schematic diagram in which the tomographic images 41 are arranged from left to right in the order in which they were acquired. Each tomographic image 41 may be acquired at the same location or at a different location.

[0010] The "no rotation" portion surrounded by dashed line A will be described. One first tomographic image 411 and one second tomographic image 412 will be selected from the multiple tomographic images 41 and described. The second tomographic image 412 is a tomographic image 41 acquired approximately one to five images after the first tomographic image 411. FIG. 1 illustrates an example in which a tomographic image 41 acquired three images after the first tomographic image 411 is used for the second tomographic image 412.

[0011] In each tomographic image 41, the circle in the center represents the image acquisition catheter 28 itself. In both the first tomographic image 411 and the second tomographic image 412, a guidewire image 48, indicated by a black dot, is visualized in the 3 o'clock direction. The shapes of the visualized images are also almost identical, and no rotation of the tomographic image 41 occurs between the first tomographic image 411 and the second tomographic image 412.

[0012] The following describes the "with rotation" portion surrounded by the dashed line B. As with the description regarding "without rotation," one first tomographic image 411 and one second tomographic image 412 are selected from the multiple tomographic images 41 and will be described.

[0013] In the first tomographic image 411, the guidewire image 48 is visualized in the 3 o'clock direction. In the second tomographic image 412, the guidewire image 48 is visualized in the 12 o'clock direction. The tomographic image 41 itself is rotated counterclockwise by approximately 60 degrees, just like the guidewire image 48. A counterclockwise rotation of approximately 60 degrees occurs between the first tomographic image 411 and the second tomographic image 412.

[0014] This rotation does not reflect the actual structure of the living body and is a type of artifact. If such an artifact occurs, the artifact can be removed by correcting the second tomographic image 412 by rotating it clockwise by approximately 60 degrees.

[0015] 2 is an explanatory diagram illustrating the configuration of the catheter system 10. The catheter system 10 includes an image processing device 210, a catheter control device 27, an MDU (Motor Driving Unit) 289, and an image acquisition catheter 28. The image acquisition catheter 28 is connected to the image processing device 210 via the MDU 289 and the catheter control device 27.

[0016] The image processing device 210 includes a control unit 211, a main memory device 212, an auxiliary memory device 213, a communication unit 214, a display unit 215, an input unit 216, and a bus. The control unit 211 is an arithmetic and control device that executes the program of this embodiment. The control unit 211 uses one or more CPUs, GPUs, multi-core CPUs, or the like. The control unit 211 is connected to each hardware unit that constitutes the image processing device 210 via the bus.

[0017] The main memory device 212 is a memory device such as an SRAM, a DRAM, a flash memory, etc. The main memory device 212 temporarily stores information required during the processing performed by the control unit 211 and programs currently being executed by the control unit 211.

[0018] The auxiliary storage device 213 is a storage device such as an SRAM, flash memory, hard disk, or magnetic tape. The auxiliary storage device 213 stores the classification model 62, the program to be executed by the control unit 211, and various data required for executing the program. The classification model 62 may be stored in an external mass storage device connected to the image processing device 210. The communication unit 214 is an interface for communication between the image processing device 210 and a network.

[0019] The display unit 215 is, for example, a liquid crystal display panel or an organic EL panel. The input unit 216 is, for example, a keyboard and a mouse. The input unit 216 may be stacked on the display unit 215 to form a touch panel. The display unit 215 may be a display device connected to the image processing device 210.

[0020] The image processing device 210 is a general-purpose personal computer, tablet, mainframe computer, or virtual machine running on a mainframe computer. The image processing device 210 may be configured with hardware such as multiple personal computers or mainframe computers that perform distributed processing. The image processing device 210 may also be configured with a cloud computing system. The image processing device 210 and the catheter control device 27 may be configured as integrated hardware.

[0021] The image acquisition catheter 28 has a sheath 281, a shaft 283 inserted inside the sheath 281, and a sensor 282 arranged at the tip of the shaft 283. The MDU 289 rotates and advances and retracts the shaft 283 and the sensor 282 inside the sheath 281.

[0022] Sensor 282 is, for example, an ultrasonic transducer that transmits and receives ultrasonic waves, or a transmitter / receiver for OCT (Optical Coherence Tomography) that emits near-infrared light and receives reflected light. In the following explanation, the image acquisition catheter 28 will be described as an example of an IVUS (Intravascular Ultrasound) catheter used to capture ultrasonic tomographic images from inside the circulatory system.

[0023] The catheter control device 27 creates one tomographic image 41 for each rotation of the sensor 282. As the MDU 289 rotates the sensor 282 while pulling or pushing it, the catheter control device 27 successively creates multiple tomographic images 41 that are approximately perpendicular to the sheath 281. The control unit 211 sequentially acquires the tomographic images 41 from the catheter control device 27. In this manner, so-called three-dimensional scanning is performed.

[0024] The advancing and retracting operation of the sensor 282 includes both an operation of advancing and retracting the entire image acquisition catheter 28 and an operation of advancing and retracting the sensor 282 inside the sheath 281. The advancing and retracting operation may be performed automatically at a predetermined speed by the MDU 289 or may be performed manually by the user.

[0025] The MDU 289 may rotate the sensor 282 at a fixed position without moving the sensor 282 back and forth. The user can observe the tomographic image 41 while inserting the image acquisition catheter 28 into or removing the image acquisition catheter 28 from the hollow organ. The user may also keep the image acquisition catheter 28 stationary and continuously observe the tomographic image 41 at a desired position.

[0026] The catheter system 10 is used when performing IVR (Interventional Radiology) such as PCI (Percutaneous Coronary Intervention). In IVR, which treats various organs while performing fluoroscopy using an imaging diagnostic device such as an X-ray fluoroscopy device, a doctor can accurately perform appropriate treatment procedures by referring in real time to a tomographic image 41 acquired using a sensor 282 placed near the area to be treated.

[0027] The reason why rotation of the tomographic image 41 occurs will be explained. When the image acquisition catheter 28 is inserted beyond a bent portion or a narrowed portion of a hollow organ, smooth rotation of the shaft 283 may be hindered, and the rotation of the MDU 289 may not be sufficiently transmitted to the sensor 282. However, the catheter control device 27 generates the tomographic image 41 based on the rotation of the MDU 289.

[0028] For example, if the sensor 282 rotates 359 degrees while the MDU 289 rotates once, i.e., 360 degrees, the imaging catheter 28 interprets the sound ray data for 359 degrees as sound ray data for 360 degrees, and generates the tomographic image 41. If such a phenomenon occurs continuously, each tomographic image 41 rotates by one degree.

[0029] Even if such slight rotations of the tomographic image 41 occur continuously, this does not hinder the user observing the tomographic image 41 from understanding the structure of the hollow organ. However, if the misalignment between the rotation of the MDU 289 and the rotation of the sensor 282 accumulates, some trigger may release the inhibition of rotation of the shaft 283, causing the sensor 282 to instantly rotate greatly.

[0030] Even if such a large rotation of the sensor 282 occurs, the catheter control device 27 continues to generate the tomographic image 41 based on the rotation of the MDU 289. Therefore, the tomographic image 41 suddenly rotates by a large amount.

[0031] A doctor or the like observing the tomographic image 41 must correct the relationship between the image of the X-ray fluoroscopy device or the like that they have previously grasped in their mind and the tomographic image 41 in accordance with the rotation of the tomographic image 41. However, it takes time to grasp the orientation of the new tomographic image 41 and reconstruct its positional relationship with the image of the X-ray fluoroscopy device or the like, which may adversely affect the progress of the treatment procedure.

[0032] In some cases, a medical technician, nurse, or other staff member manually rotates the tomographic image 41 to align it with its original orientation. However, interpreting the tomographic image 41 and rotating it correctly requires specialized knowledge and is time-consuming. In either case, doctors are unable to perform smooth diagnosis and treatment procedures for a while after the rotation occurs.

[0033] The catheter system 10 of this embodiment can support smooth diagnostic and therapeutic procedures by having the control unit 211 automatically detect the occurrence of large rotations and quickly correct them.

[0034] As described above, the image acquisition catheter 28 can also be used for three-dimensional scanning, in which images are acquired while the scanning plane is moved axially. However, if the tomographic image 41 rotates significantly during the three-dimensional scan, an appropriate three-dimensional image cannot be constructed. By using the appropriately rotated tomographic image 41 according to this embodiment, a catheter system 10 can be provided that can properly construct a three-dimensional image even if the tomographic image 41 rotates significantly during the three-dimensional scan.

[0035] 3 to 6 are explanatory diagrams outlining the rotation detection process. FIG. 3 shows an example in which rotation of a tomographic image 41 has occurred. Using FIG. 3, processing of two tomographic images 41, a first tomographic image 411 and a second tomographic image 412, will be explained. Note that the center of the tomographic image 41 corresponds to the center of the image acquisition catheter 28.

[0036] The control unit 211 generates first classified data 511 by extracting the first guidewire region 581 and the first external elastic lamina region 521 based on the first tomographic image 411. Details of the first classified data 511 will be described later.

[0037] In Figure 3, the lumen region 55, which is the inside of the tubular organ into which the image acquisition catheter 28 and guide wire are inserted, is shown with hatching slanting downward to the left, the external elastic lamina region 52 is shown with a thick line, the biological tissue region 56 between the inner surface of the lumen region 55 and the external elastic lamina region 52 is shown with hatching slanting downward to the right, and the external region outside the external elastic lamina region 52 is shown with horizontal hatching.

[0038] The area inside the central circle is a catheter region 54 that indicates the image acquisition catheter 28 itself. In this embodiment, it is not necessary to distinguish between the lumen region 55 and the biological tissue region 56 and extract them, but for the sake of explanation, the boundary line between the lumen region 55 and the biological tissue region 56 is shown in the figure.

[0039] The control unit 211 calculates the first external elastic lamina center of gravity 531, which is the center of gravity of the first external elastic lamina region 521. Since the method for calculating the center of gravity is well known, detailed explanation will be omitted.

[0040] The control unit 211 generates second classified data 512 by extracting the second guidewire region 582 and the second external elastic lamina region 522 based on the second tomographic image 412. The control unit 211 calculates the second external elastic lamina centroid 532, which is the centroid of the second external elastic lamina region 522.

[0041] In the following description, when there is no need to particularly distinguish between "first" and "second," they may be referred to as the guidewire region 58, the external elastic lamina region 52, the classification data 51, and the external elastic lamina center of gravity 53. The guidewire region 58 is an example of an instrument region depicting an instrument used together with the image acquisition catheter 28. The instrument may be any instrument arranged approximately parallel to the image acquisition catheter 28, such as a balloon catheter or a Brockenbrough needle. The instrument may also be a marker attached to the patient's body surface.

[0042] The control unit 211 calculates the angle θG by which the guidewire region 58 has moved and the angle θB by which the external elastic lamina center of gravity 53 has moved, with the center of the image-acquiring catheter 28 as the reference point. θB is an example of a first rotation amount related to the feature point of the luminal organ. θG is an example of a second rotation amount related to the instrument used with the image-acquiring catheter 28.

[0043] When there is no change in the structure of the hollow organ depicted in the tomographic image 41 and no rotation of the tomographic image 41 has occurred, there is little change between the first tomographic image 411 and the second tomographic image 412, and θG and θB are approximately zero. In this way, when both θB and θG are less than the predetermined first threshold, the control unit 211 determines that rotation of the tomographic image 41 has not occurred.

[0044] However, in Fig. 3, rotation of the tomographic image 41 has occurred, and therefore θG and θB are equal to or greater than the first threshold. Furthermore, in Fig. 3, θG and θB are substantially the same value. If the difference between θG and θB is less than a predetermined second threshold, the control unit 211 determines that rotation of the tomographic image 41 has occurred. The control unit 211 rotates the entire tomographic image 41 by -θB to eliminate the effect of the rotation.

[0045] 4 shows an example in which the position of the guidewire has changed within the lumen region 55. Between the first tomographic image 411 and the second tomographic image 412, there is almost no change in the external elastic lamina region 52, but the guidewire region 58 has moved from the 3 o'clock direction to the 5 o'clock direction. This phenomenon occurs, for example, when a doctor pushes and pulls the guidewire.

[0046] When the first tomographic image 411 and the second tomographic image 412 are compared, θG is large but θB is small. If θG is equal to or greater than the first threshold value and the difference between θG and θB is equal to or greater than a predetermined second threshold value, the control unit 211 determines that rotation of the tomographic image 41 has not occurred.

[0047] 5 shows an example in which the sensor 282 moves longitudinally between the first tomographic image 411 and the second tomographic image 412 to depict different cross sections. Between the first tomographic image 411 and the second tomographic image 412, the positions of the external elastic lamina region 52 and the external elastic lamina center of gravity 53 change, but the position of the guidewire region 58 remains almost unchanged.

[0048] When the first tomographic image 411 and the second tomographic image 412 are compared, θG is small but θB is large. If θB is equal to or greater than the first threshold value and the difference between θG and θB is equal to or greater than the second threshold value, the control unit 211 determines that rotation of the tomographic image 41 has not occurred.

[0049] 6 shows an example in which the imaging catheter 28 and the guidewire are translated downward in the tomographic image 41 within the lumen region 55. Since the tomographic image 41 is visualized based on the imaging catheter 28, the lumen region 55 and the external elastic lamina region 52 are visualized in the second tomographic image 412 as having moved upward.

[0050] When the first tomographic image 411 and the second tomographic image 412 are compared, neither θG nor θB is zero and they do not match. If one or both of θG and θB is equal to or greater than the first threshold value and the difference between θG and θB is equal to or greater than the second threshold value, the control unit 211 determines that rotation of the tomographic image 41 has not occurred.

[0051] Fig. 7 is an explanatory diagram outlining the rotation correction process. The upper part of Fig. 7 schematically illustrates a case where the rotation correction process is not performed. A plurality of tomographic images 41 generated by the catheter control device 27 constitute a tomographic image set 43.

[0052] An example will be described in which a rotation of angle θ1 is detected in tomographic image 41F shown in the sixth image from the left, and a rotation of angle θ2 is detected in tomographic image 41N shown in the fourteenth image from the left. 41F is shown with hatching slanting downward to the left, and tomographic image 41N is shown with hatching slanting downward to the right.

[0053] The lower part of Figure 7 shows a schematic diagram of a case where rotational correction processing has been performed. Corrected tomographic image set 44 is composed of tomographic images 41 after rotational correction processing. Controller 211 rotates tomographic images 41 acquired after tomographic image 41F by θ1. The tomographic images 41 that have been rotated by θ1 are indicated by hatching slanting downward to the left. Controller 211 rotates tomographic images 41 acquired after tomographic image 41N by (θ1 + θ2). The tomographic images 41 that have been rotated by (θ1 + θ2) are indicated by hatching slanting downward to the right.

[0054] As shown in FIG. 7, the rotation angle of the tomographic image 41 is accumulated every time a large rotation is detected, thereby maintaining continuity between the tomographic images 41.

[0055] The external elastic lamina centroid 53 is an example of a feature point related to a luminal organ that is visualized using the imaging catheter 28. Instead of the external elastic lamina centroid 53, for example, the centroid of the lumen region 55 may be used. Alternatively, any landmark extending in the longitudinal direction of the luminal organ may be used as a feature point.

[0056] Similarly, the guidewire region 58 is an example of a feature point related to an instrument used together with the image acquisition catheter 28. When the guidewire region 58 is depicted in a relatively large size in the tomographic image 41, the control unit 211 also calculates the center of gravity of the guidewire region 58 and uses it as a feature point. The control unit 211 may use the pixel with the highest brightness in the guidewire region 58 as a feature point.

[0057] The control unit 211 may accept a user instruction to correct the rotation angle. For example, the control unit 211 accepts a user instruction to correct the rotation angle after displaying an image based on the corrected tomographic image set 44 on the display unit 215. As described above, correction of the rotation angle by the user has been performed conventionally, and therefore detailed description thereof will be omitted.

[0058] 8 is an explanatory diagram illustrating the classification model 62. The classification model 62 receives the tomographic image 41, classifies each pixel constituting the tomographic image 41 into a plurality of regions including the external elastic lamina region 52, and outputs data associating the pixel position with a label indicating the classification result.

[0059] The classification model 62 is a trained model that performs semantic segmentation on, for example, the tomogram 41. The classification model 62 is a model generated by machine learning using training data that records a large number of pairs of the tomogram 41 and ground truth data in which an expert, such as a doctor, colors the tomogram 41 into multiple regions, including the external elastic lamina region 52. Since the generation of trained models that perform semantic segmentation has been performed in the past, detailed description will be omitted.

[0060] 8 schematically illustrates a classification model 62 that receives an XY-format tomographic image 41 and outputs XY-format classification data 51. The classification model 62 may be a trained model that is trained to receive an RT-format tomographic image 41 and output RT-format classification data 51. The method of conversion between the XY format and the RT format is well known, and therefore will not be described here.

[0061] A classified image can be created by color-coding the pixels corresponding to each label in the tomographic image 41. In Figures 3 to 6 and 8, the classified data 51 is schematically shown by classified images.

[0062] The classification data 51 in Figure 8 is an example. The classification model 62 may be a model that classifies each pixel that makes up the tomographic image 41 into the external elastic lamina region 52, the guidewire region 58, and other regions. The classification model 62 may be a model that classifies each pixel that makes up the tomographic image 41 into the external elastic lamina region 52 and other regions. If the classification model 62 does not classify the guidewire region 58, the control unit 211 extracts the guidewire region 58 without using the classification model 62. Specific examples will be described later.

[0063] Two classification models 62 may be used: one that classifies each pixel constituting the tomographic image 41 into the external elastic lamina region 52 and other regions, and the other that classifies each pixel constituting the tomographic image 41 into the guidewire region 58 and other regions. The classification model 62 may classify each pixel constituting the tomographic image 41 into any region such as the calcification region 57 (see FIG. 11 ), plaque region, or epicardial region in addition to the external elastic lamina region 52 and the guidewire region 58.

[0064] The classification model 62 may be a model that uses pattern matching to classify the external elastic lamina region 52 from other regions. For example, if the tomogram 41 is an ultrasound image, the external elastic lamina region 52 can be extracted by extracting a low-intensity closed curve that surrounds the image acquisition catheter 28. Similarly, the classification model 62 may be a model that uses pattern patching to classify the guidewire region 58 from other regions. For example, if the tomogram 41 is an ultrasound image, the guidewire region 58 can be extracted by extracting a high-intensity region of a predetermined dimension.

[0065] The classification model 62 may be a rule-based classifier. For example, if the tomogram 41 is an ultrasound image, each pixel can be classified into each region based on its brightness.

[0066] 9 is a flowchart illustrating the flow of processing of the program. The program described with reference to FIG. 9 is executed in real time while the tomographic image 41 is being acquired using the imaging catheter 28.

[0067] The control unit 211 sets the variable "rotation angle" to an initial value of 0 degrees (step S501). The control unit 211 acquires one tomographic image 41 from the catheter control device 27 (step S502). The control unit 211 starts a feature point determination subroutine (step S503). The feature point determination subroutine is a subroutine that determines feature points related to the luminal organ and feature points related to the instrument used together with the image acquisition catheter 28. The processing flow of the feature point determination subroutine will be described later.

[0068] The control unit 211 determines whether or not to determine whether or not tomogram 41 has been rotated (step S504). Specifically, when a tomogram 41 acquired n frames after the first tomogram 411 is used for the second tomogram 412, if the tomograms 41 acquired in step S502 are up to the nth frame, or if the tomograms 41 acquired in step S502 are up to the nth frame counting from the tomogram 41 for which the variable "rotation angle" has been updated in step S509 (described later), the control unit 211 determines not to determine whether or not tomogram 41 has been rotated.

[0069] If it is determined that rotation is to be performed (YES in step S504), the control unit 211 calculates the rotation angle θB of the luminal organ (step S505). Specifically, the control unit 211 calculates the rotation angle θB between the feature point of the luminal organ in the first tomographic image 411 and the feature point of the luminal organ in the second tomographic image 412.

[0070] The control unit 211 calculates the rotation angle θG of the guidewire (step S506). Specifically, the control unit 211 calculates the rotation angle θG between the feature point of the guidewire in the first tomographic image 411 and the feature point of the guidewire in the second tomographic image 412.

[0071] The control unit 211 determines whether the rotation angle θB or the rotation angle θG is equal to or greater than a predetermined first threshold value (step S507). The first threshold value is within a range in which the rotation of the tomographic image 41 can be substantially ignored, and is, for example, about 10 degrees.

[0072] If it is determined that either or both of the rotation angles θB and θG are equal to or greater than the first threshold (YES in step S507), the control unit 211 determines whether the rotation angles θB and θG are equivalent (step S508). Specifically, if the difference between the rotation angles θB and θG is less than the second threshold, the control unit 211 determines that the rotation angles θB and θG are equivalent. The second threshold is, for example, 10 degrees, the same as the first threshold.

[0073] The control unit 211 may determine whether the rotation angles θB and θG are equivalent based on the ratio between them. For example, if θB / θG is equal to or greater than 0.9 and less than 1.1, the control unit 211 determines that the rotation angles θB and θG are equivalent.

[0074] The user may be able to set the first threshold value and the second threshold value as appropriate. The first threshold value and the second threshold value may be set for each model of the image acquisition catheter 28 used. The first threshold value and the second threshold value may be set for each surgical procedure using the image acquisition catheter 28.

[0075] If it is determined that they are equivalent (YES in step S508), the control unit 211 updates the variable "rotation angle" by adding θB calculated in step S505 (step S509). If it is determined that the determination of whether or not rotation has occurred is not performed (NO in step S504), if it is determined that the rotation angle is less than the first threshold value (NO in step S507), if it is determined that the rotation angles are not equivalent values ​​(NO in step S508), or after the completion of step S509, the control unit 211 rotates the tomographic image 41 acquired in step S502 so as to cancel out the rotation corresponding to the variable "rotation angle" (step S510).

[0076] The control unit 211 displays the tomographic image 41 on the display unit 215 (step S511). The control unit 211 determines whether or not acquisition of the tomographic image 41 has been completed (step S512). If it is determined that acquisition has not been completed (NO in step S512), the control unit 211 returns to step S502. If it is determined that acquisition has been completed (YES in step S512), the control unit 211 ends the process.

[0077] 10 is a flowchart illustrating the processing flow of the feature point determination subroutine. The feature point determination subroutine is a subroutine for determining feature points related to the hollow organ and feature points related to the instrument used together with the image acquisition catheter 28.

[0078] The control unit 211 inputs the tomographic image 41 into the classification model 62 described using FIG. 8 to obtain classification data 51 (step S521). The control unit 211 extracts a determination region to be used for calculating feature points related to the luminal organ (step S522). For example, as described using FIGS. 3 to 6, if the center of gravity of the external elastic lamina region 52 is used as the feature point, the determination region extracted in step S522 is the external elastic lamina region 52. The control unit 211 calculates the center of gravity of the determination region (step S523). In this way, the feature points of the luminal organ are calculated.

[0079] The control unit 211 extracts the guidewire region 58 (step S524). The control unit 211 calculates the center of gravity of the guidewire region 58 (step S525). In this way, feature points related to the instrument used together with the image acquisition catheter 28 are calculated. Thereafter, the control unit 211 ends the process.

[0080] According to this embodiment, it is possible to provide a catheter system 10 that automatically corrects large rotations of the tomographic image 41. Therefore, it is possible to provide a catheter system 10 that supports smooth diagnostic and therapeutic procedures.

[0081] According to this embodiment, it is possible to provide a catheter system 10 that does not require staff to manually rotate the tomographic image 41 when the tomographic image 41 is rotated during a procedure. Appropriate diagnosis and treatment can be performed with a small number of staff.

[0082] According to this embodiment, it is possible to provide a catheter system 10 that corrects the orientation of the tomographic image 41 to a state suitable for constructing a three-dimensional image.

[0083] The tomographic image 41 may be acquired from inside the ventricle or atrium. With respect to the tomographic image 41 acquired from inside the ventricle or atrium, the center of the epicardial region, which is depicted as a substantially linear shape, can be used as a feature point related to the hollow organ.

[0084] When the image acquisition catheter 28 is inserted into a blood vessel in the lower limb, feature points related to the hollow organ may be determined based on other blood vessels that run parallel to the blood vessel into which the image acquisition catheter 28 is inserted.

[0085] According to this embodiment, by setting the first threshold value so as to ignore slight rotation of the tomographic image 41 caused by the patient's heartbeat or body movement, a catheter system 10 can be provided that is less likely to cause discomfort to doctors and others who are accustomed to conventional devices.

[0086] [Variations] 11 is an explanatory diagram illustrating feature points of a modified example. In the modified example, feature points relating to a hollow organ are calculated based on a plurality of regions in a tomographic image 41.

[0087] The control unit 211 creates classification data 51 based on the tomographic image 41. In Fig. 11, the classification data 51 includes the aforementioned external elastic lamina region 52, lumen region 55, and guidewire region 58, as well as a calcification region 57 indicated by thin, downward-sloping hatching.

[0088] The control unit 211 calculates the external elastic lamina centroid 53, which is the centroid of the external elastic lamina region 52, as well as the lumen region convex portion 558, which is the apex of the convex portion where the lumen region 55 protrudes, and the calcified region centroid 579, which is the centroid of the calcified region 57. In Fig. 11, the external elastic lamina centroid 53 is shown as a black triangle, the lumen region convex portion 558 as a black square, and the calcified region centroid 579 as a white triangle.

[0089] The control unit 211 calculates the center of gravity of the external elastic lamina 53, the luminal region convex portion 558, and the calcified region center of gravity 579. In FIG. 11, the three centers of gravity are indicated by black stars. The control unit 211 uses the calculated centers of gravity as feature points related to the luminal organ. The centers of gravity are an example of a definition for determining feature points. The control unit 211 may also calculate feature points of the luminal organ based on any other definition.

[0090] [Embodiment 2] This embodiment relates to a catheter system 10 that uses an extracorporeal imaging diagnostic device such as a three-dimensional CT (Computed Tomography) or MRI (Magnetic Resonance Imaging) to predict locations where image rotation is likely to occur and adjusts the first threshold based on the prediction. Explanation of parts common to the first embodiment will be omitted.

[0091] 12 is an explanatory diagram illustrating a rotational position estimation model 65. The rotational position estimation model 65 is a model that receives three-dimensional structure data 71 constructed using an extracorporeal imaging diagnostic device and outputs predicted rotational position data 72 that indicates positions where large rotation is likely to occur in the tomographic image 41. Here, the three-dimensional structure data 71 is data that represents the three-dimensional structure of a hollow organ or the like. In the predicted rotational position data 72 shown in FIG. 12, hatched portions indicate portions where rotation of the tomographic image 41 is likely to occur.

[0092] Generally, three-dimensional structural data 71 is constructed before surgery and is used to determine the necessity of surgery, decide on a surgical procedure, etc. Predicted rotational position data 72 using rotational position estimation model 65 is created by an extracorporeal imaging diagnostic device or a server computer connected to HIS (Hospital Information Systems), etc. The predicted rotational position data 72 may be created by image processing device 210.

[0093] 13 is an explanatory diagram illustrating the record layout of the rotational position training data DB 33. The rotational position training data DB 33 is data used to generate the rotational position estimation model 65 by machine learning.

[0094] The rotational position training data DB33 stores a plurality of pieces of data that record positions of the tomographic image 41 where rotation of the tomographic image 41 has occurred in the three-dimensional structure data 71. The rotational position estimation model 65 is trained using the rotational position training data DB33 so as to output the probability that rotation of the tomographic image 41 will occur at each position of the hollow organ when the three-dimensional structure data 71 is input.

[0095] Instead of using the rotational position estimation model 65 generated by machine learning, a simulation using three-dimensional structural data 71 created for each patient may be performed to calculate positions where rotation of the tomographic image 41 is likely to occur, and predicted rotational position data 72 may be created.

[0096] FIG. 14 is an explanatory diagram illustrating a reference image 74. During an IVR procedure, the treatment site is generally photographed using an angiography system. In the following description, an image photographed by an angiography system will be referred to as an angioimage. The reference image 74 is an image that simulates an angioimage. The reference image 74 is created by projecting three-dimensional predicted rotational position data 72 onto a plane in accordance with the photographing direction of the angiography system.

[0097] 14, the hatched portions indicate areas where rotation of the tomographic image 41 is likely to occur. The reference image 74 is also generated by the in-vitro diagnostic device or a server computer connected to the HIS. The reference image 74 may be generated by the image processing device 210. The reference image 74 is generated before surgery and stored in the auxiliary storage device 213 or an external mass storage device.

[0098] 15 is a flowchart illustrating the flow of processing of the program according to embodiment 2. The control unit 211 acquires the reference image 74 (step S531). The control unit 211 sets the variable "rotation angle" to an initial value of 0 degrees (step S501).

[0099] The control unit 211 acquires one tomographic image 41 from the catheter control device 27 (step S502). The subsequent processing is the same as the processing flow of the program of the first embodiment described using FIG. 9, and therefore a description thereof will be omitted.

[0100] In parallel with the processing from step S502 to step S512, the control unit 211 acquires a real-time angio image (step S541).

[0101] The control unit 211 determines the position of the sensor 282 in the angio image (step S542). The determination is performed by, for example, pattern matching. The control unit 211 calculates a first threshold value based on the position of the sensor 282 in the reference image 74 (step S543). Thereafter, the control unit 211 returns to step S541.

[0102] 14, where the sensor 282 is located at a position where rotation of the tomographic image 41 is likely to occur, the control unit 211 changes the first threshold to a value smaller than that of embodiment 1. When the sensor 282 is located at any other position, the control unit 211 returns the first threshold to the value of embodiment 1. The control unit 211 may continuously change the first threshold based on the likelihood of rotation occurring.

[0103] In step S507, the control unit 211 uses the latest first threshold calculated in step S543 for the determination. Note that the processes of steps S541 to S543 may be executed by, for example, the angiography apparatus or a server computer connected to the HIS.

[0104] According to this embodiment, by setting the first threshold to a small value in a location where rotation of the tomographic image 41 is likely to occur, as determined based on a three-dimensional image created before surgery, a catheter system 10 can be provided that quickly corrects rotation if it occurs.

[0105] [Embodiment 3] This embodiment relates to a catheter system 10 that determines the likelihood of rotation of a tomographic image 41 based on the size of a lumen region 55. Explanation of parts common to the first embodiment will be omitted.

[0106] Figure 16 is an explanatory diagram illustrating the relationship between the stenosis position and the position where rotation occurs. The vertical axis of Figure 16 represents the position of the tomographic image 41 along the longitudinal direction of the imaging catheter 28. The vertical axis of Figure 16 represents the average lumen diameter in each tomographic image 41. Here, the average lumen diameter represents the diameter of a circle having the same area as the lumen region 55.

[0107] Region C indicated by the dashed line indicates a stenosis region where the average lumen diameter is smaller than other regions. Region D indicated by the solid line indicates a region where rotation is likely to occur in tomographic image 41. By performing various experiments or simulations, the relationship between the average lumen diameter and the likelihood of rotation occurring in tomographic image 41 can be determined, as shown in FIG. 16.

[0108] Fig. 17 is a flowchart illustrating the processing flow of the program according to embodiment 3. The processing flow from step S501 to step S506 is the same as the processing flow of the program according to embodiment 1 described using Fig. 9, and therefore the description thereof will be omitted.

[0109] The control unit 211 starts a subroutine for calculating a threshold value (step S551). The subroutine for calculating a threshold value is a subroutine for calculating a first threshold value for the tomographic image 41 being processed. The processing flow of the subroutine for calculating a threshold value will be described later.

[0110] The control unit 211 determines whether the rotation angle θB or the rotation angle θG is equal to or greater than the first threshold value (step S507). The subsequent processing is the same as the processing flow of the program in the first embodiment described with reference to FIG. 9, and therefore a description thereof will be omitted.

[0111] 18 is a flowchart illustrating the processing flow of the threshold calculation subroutine. The threshold calculation subroutine is a subroutine for calculating a first threshold value for the tomographic image 41 being processed.

[0112] The control unit 211 calculates the area of ​​the lumen region 55 based on the classification data 51 (step S561). Note that if the classification data 51 including the lumen region 55 extracted based on the tomographic image 41 is not recorded in the main storage device 212 or the auxiliary storage device 213, the control unit 211 inputs the tomographic image 41 to a classification model 62 capable of extracting the lumen region 55, and acquires the classification data 51.

[0113] The control unit 211 calculates the average lumen diameter based on the formula (1) (step S562).

[0114]

number

[0115] The control unit 211 determines the first threshold value based on the relationship between the average lumen diameter and the region where rotation of the tomographic image 41 is likely to occur, as explained using FIG. 16 (step S563).

[0116] Specifically, when the tomographic image 41 being processed is included in an area where rotation of the tomographic image 41 is likely to occur, which is shown as area D in Fig. 16, the control unit 211 changes the first threshold to a value smaller than that of embodiment 1. When a tomographic image 41 other than the above is being processed, the control unit 211 returns the first threshold to the value of embodiment 1.

[0117] More specifically, if the area of ​​lumen region 55 calculated in step S561 or the average lumen diameter calculated in step S562 is less than a predetermined threshold, control unit 211 changes the first threshold to a smaller value, and if it is equal to or greater than the predetermined threshold, returns it to the value in embodiment 1. Control unit 211 may continuously change the first threshold based on the likelihood of rotation occurring.

[0118] According to this embodiment, it is possible to provide a catheter system 10 that quickly corrects rotation when it occurs without using data acquired by an extracorporeal imaging diagnostic device.

[0119] [Embodiment 4] This embodiment relates to an information processing device 200 that processes a tomographic image set 43 recorded using an image acquisition catheter 28 for three-dimensional scanning to create a corrected tomographic image set 44. Explanation of parts common to the first embodiment will be omitted.

[0120] 19 is an explanatory diagram illustrating the configuration of an information processing device 200. The information processing device 200 includes a control unit 201, a main memory device 202, an auxiliary memory device 203, a communication unit 204, a display unit 205, an input unit 206, and a bus. The control unit 201 is an arithmetic and control device that executes the program of this embodiment. The control unit 201 uses one or more CPUs, GPUs, multi-core CPUs, or the like. The control unit 201 is connected to each hardware unit that constitutes the information processing device 200 via the bus.

[0121] The main memory device 202 is a memory device such as an SRAM, a DRAM, a flash memory, etc. The main memory device 202 temporarily stores information required during processing performed by the control unit 201 and programs currently being executed by the control unit 201.

[0122] The auxiliary storage device 203 is a storage device such as an SRAM, a flash memory, a hard disk, or a magnetic tape. The auxiliary storage device 203 stores the classification model 62, the first tomogram DB 31, the second tomogram DB 32, programs to be executed by the control unit 201, and various data required for executing the programs. The communication unit 204 is an interface that performs communication between the information processing device 200 and a network. The classification model 62, the first tomogram DB 31, and the second tomogram DB 32 may be stored in an external mass storage device connected to the information processing device 200.

[0123] The display unit 205 is, for example, a liquid crystal display panel or an organic EL panel. The input unit 206 is, for example, a keyboard and a mouse. The input unit 206 may be stacked on the display unit 205 to form a touch panel. The display unit 205 may be a display device connected to the information processing device 200.

[0124] The information processing device 200 is a general-purpose personal computer, a tablet, a mainframe computer, or a virtual machine running on a mainframe computer. The information processing device 200 may be configured with hardware such as multiple personal computers or mainframe computers that perform distributed processing. The information processing device 200 may also be configured with a cloud computing system.

[0125] 20 is an explanatory diagram illustrating the record layout of the first tomographic image DB 31. The first tomographic image DB 31 has a 3D scan ID field, a slice number field, and a tomographic image field.

[0126] The 3D scan ID field records a 3D scan ID assigned to each tomographic image set 43 obtained by one three-dimensional scan. The tomographic image number field records a number indicating the order of the tomographic image 41 in the tomographic image set 43. The tomographic image field records the tomographic image 41 acquired from the catheter control device 27. The first tomographic image DB 31 has one record for each tomographic image 41. The first tomographic image DB 31 records the tomographic image set 43 obtained by a three-dimensional scan performed in advance.

[0127] 21 is an explanatory diagram illustrating the record layout of the second tomogram DB 32. The second tomogram DB 32 is a database generated by the information processing device 200 of this embodiment based on the first tomogram DB 31. The second tomogram DB 32 has a 3D scan ID field, a slice number field, a pre-correction tomogram field, a rotation angle field, and a post-correction tomogram field.

[0128] The 3D scan ID field records a 3D scan ID. The tomographic number field records a number indicating the order of the tomographic image 41 in the tomographic image set 43. The pre-correction tomographic image field records the tomographic image 41 before rotation correction. The rotation angle field records the rotation angle of the tomographic image 41. The post-correction tomographic image field records the tomographic image 41 with the angle corrected. The second tomographic image DB 32 has one record for each tomographic image 41.

[0129] 22 is a flowchart illustrating the processing flow of the program of the fourth embodiment. The control unit 201 sets the variable "rotation angle" to an initial value of 0 degrees (step S601). The control unit 201 extracts one record from the first tomographic image DB 31 in ascending order of tomographic number, and acquires a tomographic image 41 from the tomographic image field (step S602). The tomographic image 41 acquired from the first tomographic image DB 31 is the tomographic image 41 before the rotation correction is performed.

[0130] The control unit 201 starts a feature point determination subroutine (step S603). The feature point determination subroutine is a subroutine that determines feature points related to the hollow organ and feature points related to the instrument used together with the image acquisition catheter 28. The processing flow of the feature point determination subroutine is similar to the processing flow of the subroutine described using FIG.

[0131] The control unit 201 determines whether or not to determine whether or not the tomographic image 41 acquired in step S602 has been rotated (step S604). If it is determined that the rotation has been determined (YES in step S604), the control unit 201 calculates the rotation angle θB of the luminal organ (step S605). The control unit 201 calculates the rotation angle θG of the guidewire (step S606).

[0132] The control unit 201 determines whether the rotation angle θB or the rotation angle θG is equal to or greater than a predetermined first threshold value (step S607). If it determines that one or both of the rotation angle θB and the rotation angle θG are equal to or greater than the first threshold value (YES in step S607), the control unit 201 determines whether the rotation angle θB and the rotation angle θG are equivalent to each other (step S608).

[0133] If it is determined that they are equivalent (YES in step S608), the control unit 201 updates the variable "rotation angle" by adding θB calculated in step S605 (step S609). If it is determined that the determination of whether or not rotation has occurred is not performed (NO in step S604), if it is determined that the rotation angle is less than the first threshold value (NO in step S607), if it is determined that the rotation angles are not equivalent values ​​(NO in step S608), or after the completion of step S609, the control unit 201 rotates the tomographic image 41 acquired in step S502 so as to cancel out the rotation corresponding to the variable "rotation angle" to generate a corrected tomographic image (step S610).

[0134] The control unit 201 creates a new record in the second tomographic image DB 32, and records the tomographic number in the tomographic image number field, the tomographic image 41 acquired in step S602 in the pre-correction tomographic image field, the variable "rotation angle" in the rotation angle field, and the corrected tomographic image generated in step S610 in the corrected tomographic image field (step S611). The control unit 201 determines whether processing of the tomographic images 41 included in one tomographic image set 43 has been completed (step S612).

[0135] If it is determined that the process has not ended (NO in step S612), the control unit 201 returns to step S602. If it is determined that the process has ended (YES in step S612), the control unit 201 ends the process.

[0136] According to this embodiment, it is possible to provide an information processing device 200 that corrects a tomographic image set 43 recorded by three-dimensional scanning and generates data that allows appropriate three-dimensional construction.

[0137] 2 may generate the second tomographic image DB32 in real time in parallel with the acquisition of the tomographic image 41. When the second tomographic image DB32 is generated in real time, the first tomographic image DB31 may not be recorded, and the control unit 211 may directly acquire the tomographic image 41 from the catheter control device 27 in step S602.

[0138] [Embodiment 5] 23 is an explanatory diagram illustrating the configuration of an information processing device 200 according to a fifth embodiment. This embodiment relates to a form in which the information processing device 200 according to this embodiment is realized by combining and operating a general-purpose computer 90 and a program 97. Explanations of parts common to the third embodiment will be omitted.

[0139] The computer 90 includes a reading unit 209 in addition to the control unit 201, main memory unit 202, auxiliary memory unit 203, communication unit 204, display unit 205, input unit 206, and bus.

[0140] The program 97 is recorded on the portable recording medium 96. The control unit 201 reads the program 97 via the reading unit 209 and stores it in the auxiliary storage device 203. The control unit 201 may also read the program 97 stored in a semiconductor memory 98, such as a flash memory, implemented in the computer 90. Furthermore, the control unit 201 may download the program 97 from another server computer (not shown) connected via the communication unit 204 and a network (not shown) and store it in the auxiliary storage device 203.

[0141] The program 97 is installed as a control program for the computer 90, and is loaded into the main storage device 202 and executed. In this way, the information processing device 200 described in the third embodiment is realized. The program 97 in this embodiment is an example of a program product.

[0142] The technical features (constituent elements) described in each embodiment can be combined with each other, and by combining them, new technical features can be formed. The embodiments disclosed herein are illustrative in all respects and should not be considered as 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. [Explanation of symbols]

[0143] 10 Catheter System 200 Information processing device 201 Control Unit 202 Main storage 203 Auxiliary storage device 204 Communications Department 205 Display section 206 Input section 209 Reading unit 210 Image processing device 211 Control Unit 212 Main storage 213 Auxiliary storage 214 Communications Department 215 Display section 216 Input section 27 Catheter control device 28 Imaging catheter 281 Sheath 282 Sensors 283 Shaft 289 MDU 31 First Tomographic Image DB 32 Second Tomographic Image DB 33 Rotation position training data DB 41 Tomographic image 411 First tomographic image 412 Second tomographic image 43 Tomographic Image Set 44 Corrected tomogram set 48 Guidewire image 51 Classification Data 511 Class 1 Data 512 Class 2 Data 52 Outer elastic plate area 521 First outer elastic plate area 522 Second outer elastic plate area 53 Center of gravity of external elastic plate 531 First outer elastic plate center of gravity 532 Second outer elastic plate center of gravity 54 Catheter Area 55 Luminal area 558 Lumen area convex part 56 Biological Tissue Area 57 Calcified area 579 Calcified area centroid 58 Guidewire Area 581 First guidewire region 582 Second guidewire region 62 Classification Models 65 Rotational position estimation model 71 Three-dimensional structural data 72 Predicted rotation position data 74 Reference Images 90 Computer 96 Portable recording media 97 Programs 98 Semiconductor Memory

Claims

1. determining whether a first rotation amount of a feature point of the luminal organ or a second rotation amount of an instrument used together with the image-acquiring catheter between a first tomographic image acquired using the image-acquiring catheter inserted into the luminal organ and a second tomographic image acquired after the first tomographic image is equal to or greater than a predetermined first threshold value; If it is determined that the difference is equal to or greater than the first threshold, it is determined whether or not the difference between the first rotation amount and the second rotation amount is less than a predetermined second threshold; If it is determined that the value is less than the second threshold value, the tomographic images acquired after the second tomographic image are rotated so as to cancel out the first rotation amount. An information processing method in which processing is performed by a computer.

2. The hollow organ is a blood vessel, and the characteristic point is the center of gravity of the external elastic lamina. The information processing method according to claim 1 .

3. The feature point is the center of gravity of the lumen area into which the imaging catheter is inserted. The information processing method according to claim 1 .

4. The feature point is a convex portion of the lumen area into which the imaging catheter is inserted. The information processing method according to claim 1 .

5. The hollow organ is a blood vessel, and the feature point is a center of gravity of the external elastic lamina, a feature point of the lumen region into which the image acquisition catheter is inserted, and a feature point of the calcified region existing between the external elastic lamina and the lumen region. The information processing method according to claim 1 .

6. The first tomogram and the second tomogram are input to a trained model that outputs classification data in which each region of the tomogram is classified into a predetermined region when the tomogram is input, and the first rotation amount is calculated based on the acquired first classification data and second classification data.

6. The information processing method according to claim 1.

7. The trained model outputs an instrument domain for an instrument used with the imaging catheter; and The second rotation amount is calculated based on the appliance area included in the first classification data and the appliance area included in the second classification data. The information processing method according to claim 6.

8. The external elastic lamina is extracted from each of the first tomographic image and the second tomographic image by pattern matching. The information processing method according to claim 3 .

9. acquiring a region in which rotation is likely to occur in a tomographic image acquired using the imaging catheter, the region being determined based on the three-dimensional structure of the hollow organ; When the second tomographic image is acquired within the region, the first threshold is set to a smaller value than when the second tomographic image is acquired outside the region.

9. The information processing method according to claim 1.

10. Calculating an area of ​​the lumen region into which the imaging catheter is inserted in the second tomographic image; When the area is less than a predetermined threshold, the first threshold is set to a smaller value than when the area is equal to or greater than the predetermined threshold.

10. The information processing method according to claim 1.

11. The imaging catheter is an imaging catheter for three-dimensional scanning that performs radial scanning while moving the scanning plane in the axial direction.

11. The information processing method according to claim 1.

12. determining whether a first rotation amount of a feature point related to the hollow organ or a second rotation amount related to an instrument used together with the image acquisition catheter between a first tomographic image acquired using an image acquisition catheter inserted into the hollow organ and a second tomographic image acquired after the first tomographic image is equal to or greater than a predetermined first threshold value; If it is determined that the difference is equal to or greater than the first threshold, it is determined whether or not the difference between the first rotation amount and the second rotation amount is less than a predetermined second threshold; If it is determined that the value is less than the second threshold value, the tomographic images acquired after the second tomographic image are rotated so as to cancel out the first rotation amount. A program that causes a computer to perform a process.

13. An information processing device including a control unit, The control unit determining whether a first rotation amount of a feature point related to the hollow organ or a second rotation amount related to an instrument used together with the image acquisition catheter between a first tomographic image acquired using an image acquisition catheter inserted into the hollow organ and a second tomographic image acquired after the first tomographic image is equal to or greater than a predetermined first threshold value; If it is determined that the difference is equal to or greater than the first threshold, it is determined whether or not the difference between the first rotation amount and the second rotation amount is less than a predetermined second threshold; If it is determined that the value is less than the second threshold value, the tomographic images acquired after the second tomographic image are rotated so as to cancel out the first rotation amount. Information processing device.

Images