Medical image processing device, medical image processing method, and medical image processing program

Abstract

To provide a recommended waiting time for a blood clot removal device in a subject's blood vessel according to a case.SOLUTION: A medical image processing device according to an embodiment includes a first calculation unit, a second calculation unit, a third calculation unit, and an output control unit. The first calculation unit calculates, from multiple medical X-ray fluoroscopy images, the size of a blood clot removal device placed in a subject's blood vessel and present in the medical X-ray fluoroscopy images. The second calculation unit calculates change information indicating a change in the size from the multiple medical X-ray fluoroscopy images. The third calculation unit calculates first time information indicating an amount of time for which the blood clot removal device is left in the subject on the basis of the change information. The output control unit performs control to output the first time information.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] An embodiment of the present invention relates to a medical image processing apparatus, a medical image processing method, and a medical image processing program. [Background technology]

[0002] Conventionally, there has been a thrombectomy therapy as a treatment for infarction, in which blood flow is hindered by a clot in a blood vessel, in which a catheter, a stent, or the like is inserted into the blood vessel to retrieve the clot. Infarction can occur in any part or organ of the human body, and one example of the thrombectomy therapy is a treatment for ischemic cerebral infarction, in which infarction occurs in a cerebral blood vessel, for example, in which a stent-type clot removal device such as a stent retriever is used to retrieve the clot.

[0003] A stent retriever is a stent intended for removing thrombus, which is deployed from a catheter to a site where a thrombus exists and retrieved into a guide catheter so as to entangle the thrombus. At this time, the stent retriever waits in the blood vessel for a predetermined recommended waiting time (for example, 5 minutes) after deployment in the blood vessel so as to sufficiently penetrate the thrombus, and then is retrieved.

[0004] The recommended waiting time when using a thrombus removal device is, for example, the time until the thrombus is sufficiently entangled and there is almost no possibility of further entanglement of the thrombus even if more time is allowed. The recommended waiting time differs depending on the case because the condition of the thrombus, such as the amount and shape, varies depending on the case. In order to perform thrombus removal at an appropriate waiting time depending on the case, it is preferable to estimate an appropriate waiting time from observation data specific to the case and present it to the surgeon as the recommended waiting time.

[0005] If it were possible to grasp the state of the thrombus from moment to moment as it is gradually removed during thrombectomy therapy, it would be easy to determine the recommended waiting time from the time-series data on the thrombus using existing techniques such as linear regression and nonlinear regression.

[0006] However, thrombi cannot be visualized in X-ray fluoroscopy images, and their amount and shape cannot be observed. In addition, if X-ray fluoroscopy is performed continuously throughout the recommended waiting time, only intermittent time-series data can be obtained due to the high radiation exposure to the subject. Therefore, it is not easy to estimate an appropriate waiting time from observation data specific to a case and present it to the surgeon as the recommended waiting time using existing technology. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2022-62169 A Summary of the Invention [Problem to be solved by the invention]

[0008] One of the problems that the embodiments disclosed in this specification and the drawings aim to solve is to provide a recommended waiting time for a thrombus removal device in a subject's blood vessel depending on the case. [Means for solving the problem]

[0009] A medical image processing apparatus according to an embodiment includes a first calculation unit, a second calculation unit, a third calculation unit, and an output control unit. The first calculation unit calculates a size of a thrombus removal device placed in a blood vessel of a subject and present in the medical X-ray fluoroscopy images from a plurality of medical X-ray fluoroscopy images. The second calculation unit calculates change information indicating a change in the size from the plurality of medical X-ray fluoroscopy images. The third calculation unit calculates first time information indicating a time for placing the thrombus removal device in the subject based on the change information. The output control unit performs control to output the first time information. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a medical image processing system according to an embodiment. [Diagram 2]FIG. 2 is a diagram illustrating an example of the configuration of a medical image processing apparatus according to an embodiment. [Diagram 3] FIG. 3 is a schematic diagram for explaining thrombus removal by the thrombus removal device according to the embodiment. [Figure 4] FIG. 4 is a schematic view showing an example for explaining the size of the thrombus removal device according to the embodiment. [Diagram 5] FIG. 5 is a graph showing an example of a change in size of a thrombus removal device according to an embodiment. [Figure 6] FIG. 6 is a flowchart showing an example of a processing procedure by the medical image processing apparatus according to the embodiment. [Figure 7] FIG. 7 is a graph showing an example of a change in size of the thrombus removal device according to the first modified example. [Figure 8] FIG. 8 is a diagram showing an example of the configuration of a medical image processing apparatus according to the second modified example. [Figure 9] FIG. 9 is a graph showing an example for explaining imaging timing according to the second modified example. [Figure 10] FIG. 10 is a diagram showing an example of the configuration of a medical image processing apparatus according to the third modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the medical image processing device, the medical image processing method, and the medical image processing program according to the present application will be described in detail with reference to the accompanying drawings. Note that the medical image processing device, the medical image processing method, and the medical image processing program according to the present application are not limited to the following embodiments.

[0012] (Embodiment) First, an embodiment will be described. In the embodiment, an example in which the technology disclosed in the present application is applied to a medical image processing device will be described. Note that, hereinafter, a medical image processing system including the medical image processing device will be described as an example.

[0013] Fig. 1 is a diagram showing an example of the configuration of a medical image processing system according to an embodiment. As shown in Fig. 1, the medical image processing system according to the embodiment includes a medical image diagnostic apparatus 100, an image storage apparatus 200, and a medical image processing apparatus 300.

[0014] For example, in a medical image processing system, a medical image processing apparatus 300 according to the embodiment is connected to a medical image diagnostic apparatus 100 and an image storage apparatus 200 via a network 400 as shown in FIG.

[0015] The medical image diagnostic apparatus 100 is a modality used in a procedure using a medical device, such as an X-ray diagnostic apparatus, an X-ray CT (Computed Tomography) apparatus, an ultrasound diagnostic apparatus, an MRI (Magnetic Resonance Imaging) apparatus, etc. For example, the medical image diagnostic apparatus 100 collects projection data by photographing a subject, and collects two-dimensional or three-dimensional medical image data based on the collected projection data.

[0016] The medical image diagnostic apparatus 100 can also collect two-dimensional or three-dimensional contrast image data by capturing an image of a subject injected with a contrast agent. For example, an X-ray CT apparatus as the medical image diagnostic apparatus 100 collects CTA (CT Angio) image data from a subject injected with a contrast agent as three-dimensional contrast image data. Also, for example, an X-ray diagnostic apparatus as the medical image diagnostic apparatus 100 collects X-ray image data from a subject injected with a contrast agent as two-dimensional contrast image data.

[0017] Furthermore, the medical image diagnostic apparatus 100 transmits the collected medical image data to the image storage apparatus 200 and the medical image processing apparatus 300. When transmitting the medical image data to the image storage apparatus 200 and the medical image processing apparatus 300, the medical image diagnostic apparatus 100 transmits, as additional information, for example, a patient ID for identifying a patient, an examination ID for identifying an examination, an apparatus ID for identifying the medical image diagnostic apparatus 100, a series ID for identifying one imaging operation by the medical image diagnostic apparatus 100, and the like.

[0018] The image storage device 200 stores medical image data collected by the medical image diagnostic device 100 via a network 400. For example, the image storage device 200 is realized by a computer device such as a server device. In this embodiment, the image storage device 200 acquires two-dimensional or three-dimensional medical image data from the medical image diagnostic device 100 via the network 400, and stores the acquired medical image data in a storage circuit provided inside or outside the device.

[0019] The medical image processing device 300 acquires medical image data from the medical image diagnostic device 100 or the image storage device 200 via the network 400, and processes the acquired medical image data. For example, the medical image processing device 300 is realized by a computer device such as a workstation.

[0020] In this embodiment, the medical image processing device 300 acquires medical image data from the medical image diagnostic device 100 or the image storage device 200 via the network 400, and performs various image processing on the acquired medical image data. Then, the medical image processing device 300 displays the medical image after the image processing, the analysis results obtained by the image processing, etc. on a display or the like.

[0021] Fig. 2 is a diagram showing an example of the configuration of a medical image processing device 300 according to the first embodiment. For example, as shown in Fig. 2, the medical image processing device 300 includes an I / F (interface) circuit 310, a storage circuit 320, an input interface 330, a display 340, and a processing circuit 350.

[0022] The I / F circuit 310 is connected to the processing circuit 350, and controls the transmission and communication of various data between the processing circuit 350 and the medical image diagnostic apparatus 100 or the image storage apparatus 200 connected via a network 400. For example, the I / F circuit 310 is realized by a network card, a network adapter, a NIC (Network Interface Controller), or the like.

[0023] In this embodiment, the I / F circuit 310 receives medical image data from the medical image diagnostic apparatus 100 or the image storage apparatus 200, and outputs the received medical image data to the processing circuit 350. Here, the I / F circuit 310 can also receive real-time medical image data collected by the medical image diagnostic apparatus 100, and output the medical image data to the processing circuit 350.

[0024] The memory circuitry 320 is connected to the processing circuitry 350 and stores various data. For example, the memory circuitry 320 is realized by a semiconductor memory element such as a RAM (Random Access Memory) or a flash memory, a hard disk, an optical disk, or the like. In this embodiment, the memory circuitry 320 stores medical image data received from the medical image diagnostic device 100 or the image storage device 200. For example, the memory circuitry 320 stores CT image data collected over time by an X-ray CT device, X-ray image data collected by an X-ray diagnostic device, ultrasound image data collected by an ultrasound diagnostic device, and the like. As an example, the memory circuitry 320 stores CTA image data collected by imaging a subject into which a contrast agent has been injected, X-ray image data, and the like.

[0025] Furthermore, the storage circuitry 320 stores various information used in the processing of the processing circuitry 350, processing results by the processing circuitry 350, and the like. For example, the storage circuitry 320 stores correspondence information referenced by the processing circuitry 350. Details of the correspondence information will be described later.

[0026] The input interface 330 can be realized by a trackball for setting a specific area (e.g., a treatment target area), a switch button, a mouse, a keyboard, a touchpad for inputting operations by touching the operation surface, a touch screen in which the display screen and touchpad are integrated, a non-contact input circuit using an optical sensor, and a voice input circuit, as well as a foot switch for irradiating X-rays, etc.

[0027] The input interface 330 is connected to the processing circuit 350, and converts an input operation received from an operator into an electrical signal and outputs the electrical signal to the processing circuit 350. In this specification, the input interface 330 is not limited to an interface having physical operation parts such as a mouse and a keyboard. For example, an example of the input interface also includes an electrical signal processing circuit that receives an electrical signal corresponding to an input operation from an external input device provided separately from the device and outputs the electrical signal to a control circuit.

[0028] The display 340 is connected to the processing circuit 350 and displays various information and images output from the processing circuit 350. For example, the display 340 is realized by a liquid crystal monitor, a CRT (Cathode Ray Tube) monitor, a touch panel, etc. For example, the display 340 displays a GUI (Graphical User Interface) for receiving instructions from an operator, various images, and various processing results by the processing circuit 350.

[0029] The processing circuitry 350 controls each component of the medical image processing device 300 in response to an input operation received from an operator via the input interface 330. For example, the processing circuitry 350 is realized by a processor. In this embodiment, the processing circuitry 350 stores medical image data output from the I / F circuitry 310 in the storage circuitry 320. The processing circuitry 350 also reads out medical image data from the storage circuitry 320, and displays a medical image generated from the read out medical image data on the display 340. The processing circuitry 350 also executes various calculation processes on the medical image data, and displays the calculation results on the display 340.

[0030] With such a configuration, the medical image processing device 300 according to the present embodiment makes it possible to provide a recommended waiting time for the thrombus removal device in the blood vessel of the subject according to the case. Specifically, the medical image processing device 300 calculates the size of the thrombus removal device placed in the blood vessel of the subject from a plurality of medical X-ray fluoroscopic images and present in the medical X-ray fluoroscopic images, calculates change information indicating a change in size from the plurality of medical X-ray fluoroscopic images, calculates and outputs first time information indicating a time to retrieve the thrombus removal device from the subject based on the change information, thereby allowing the surgeon to grasp the recommended waiting time for the thrombus removal device in the blood vessel of the subject according to the case.

[0031] Here, a method for removing (recovering) a thrombus from a blood vessel of a subject by a thrombus removal device will be described. For more specific explanation, a stent retriever will be used as an example of the thrombus removal device, and cerebral blood vessels will be used as an example of the blood vessel of the subject. Fig. 3 is a schematic diagram for explaining thrombus removal by a thrombus removal device according to an embodiment.

[0032] 3 shows a first medical X-ray fluoroscopic image 31, a second medical X-ray fluoroscopic image 32, and a third medical X-ray fluoroscopic image 33. The first medical X-ray fluoroscopic image 31, the second medical X-ray fluoroscopic image 32, and the third medical X-ray fluoroscopic image 33 show a blood vessel 311, a thrombus 312 present in the blood vessel 311, a stent retriever 313 which is a medical device for removing the thrombus 312, a microcatheter 314 which is a medical device for placing the stent retriever 313 inside the blood vessel 311, and a guide catheter 315 which is a medical device for inserting the microcatheter 314 into the blood vessel 311.

[0033] First, in order to place the stent retriever 313 inside the blood vessel 311, the surgeon inserts a guide catheter 315 from the artery of the lower limb of the subject. Then, when the guide catheter 315 reaches the vicinity of the thrombus 312, the surgeon inserts a microcatheter 314 into the blood vessel 311 along a trajectory M1 toward the thrombus 312, and places the microcatheter 314 (see the first medical X-ray fluoroscopic image 31 in FIG. 3).

[0034] Next, after placing the microcatheter 314, the surgeon moves the microcatheter 314 along the trajectory M2 to the position of the guide catheter 315 (see the second medical X-ray fluoroscopic image 32 in FIG. 3). This allows the stent retriever 313 to place the thrombus 312.

[0035] Next, when the stent retriever 313 is deployed inside the blood vessel 311 and bites into the thrombus 312, the surgeon moves the stent retriever 313 along the trajectory M3 to the position of the guide catheter 315 in order to retrieve the stent retriever 313 entangled with the thrombus 312 (see the third medical X-ray fluoroscopic image 33 in FIG. 3). Then, the surgeon retrieves the guide catheter 315 from the artery of the lower limb of the subject. This makes it possible to retrieve the thrombus 312 present in the blood vessel 311 of the subject.

[0036] In this way, the surgeon can use the thrombus removal device to retrieve the thrombus 312 present in the subject's blood vessel 311, but the time until the thrombus removal device is deployed (hereinafter also referred to as the recommended waiting time) varies depending on the case, and a method for determining an appropriate recommended waiting time has not been established. Therefore, the medical image processing device 300 according to this embodiment provides a recommended waiting time for the thrombus removal device in the subject's blood vessel according to the case.

[0037] Returning to FIG. 2, the processing circuitry 350 of the medical image processing apparatus 300 according to this embodiment executes an acquisition function 351, a detection function 352, a first calculation function 353, a second calculation function 354, a third calculation function 355 and an output control function 356.

[0038] The acquisition function 351 acquires a plurality of medical X-ray fluoroscopic images. The acquisition function 351 is an example of an acquisition unit. Specifically, the acquisition function 351 acquires a plurality of medical X-ray fluoroscopic images collected after the thrombus removal device is placed from the medical image diagnostic apparatus 100 or the image storage apparatus 200 via the I / F circuit 310.

[0039] The detection function 352 detects the thrombus removal device placed in the blood vessel of the subject and present in the medical X-ray fluoroscopy images from the multiple medical X-ray fluoroscopy images. The detection function 352 is an example of a detection unit. Specifically, the detection function 352 detects the thrombus removal device placed in the blood vessel of the subject and present in the medical X-ray fluoroscopy images from the multiple medical X-ray fluoroscopy images acquired by the acquisition function 351.

[0040] For example, when the thrombus removal device is a stent retriever, the stent retriever is made of a radiopaque material having a high X-ray absorption coefficient. For example, the detection function 352 performs threshold processing on the multiple medical X-ray fluoroscopic images by the acquisition function 351 to mask areas of the medical X-ray fluoroscopic images whose pixel values ​​are equal to or less than a certain value, generates multiple device mask images, and detects the stent retriever.

[0041] The first calculation function 353 calculates the size of the thrombus removal device placed in the blood vessel of the subject and present in the medical X-ray fluoroscopy images from a plurality of medical X-ray fluoroscopy images. The first calculation function 353 is an example of a first calculation unit. Specifically, the first calculation function 353 calculates the size of the thrombus removal device detected by the detection function 352. Here, the size of the thrombus removal device calculated by the first calculation function 353 will be described with reference to FIG. 4. FIG. 4 is a schematic diagram showing an example for explaining the size of the thrombus removal device according to an embodiment.

[0042] 4 shows the third medical X-ray fluoroscopic image 33 acquired by the acquisition function 351 and the device mask image 41 generated by the detection function 352. As described above, for example, the detection function 352 performs threshold processing on the multiple medical X-ray fluoroscopic images acquired by the acquisition function 351 to mask areas of the medical X-ray fluoroscopic images where the pixel values ​​are equal to or less than a certain value, generates the device mask image 41, and detects the stent retriever 313.

[0043] Then, the first calculation function 353 calculates the volume of a cylinder having a cross section projected onto the stent retriever 313 present in the detected device mask image. For example, the first calculation function 353 fits a Bezier curve 411 to the device mask image 41 shown in FIG.

[0044] In addition, first calculation function 353 sets points at equal intervals on Bezier curve 411, measures device length 412 in both directions normal to each point, and takes the average, which is the radius of the cylinder at each point. Then, first calculation function 353 calculates the volume of a cylinder having a radius at each point (the lumen volume of stent retriever 313) with Bezier curve 411 as the central axis.

[0045] It should be noted that the method is not limited to the above, and other methods may be used to detect the stent retriever 313 and calculate the lumen volume of the stent retriever 313. For example, a device mask image may be generated by a stent retriever detection model that has learned a combination of a medical X-ray fluoroscopic image in which the stent retriever is captured and position information of the stent retriever in the image.

[0046] Also, for example, the lumen volume of the stent retriever may be directly measured using a stent retriever detection model that has learned a combination of a medical X-ray fluoroscopic image showing the stent retriever and the lumen volume of the stent retriever in the image.

[0047] Although the size of the thrombus removal device has been described as the volume of the lumen of the stent retriever 313, the size is not limited to this. The size of the thrombus removal device may be, for example, the surface area of ​​the stent retriever 313 present in a medical X-ray fluoroscopic image.

[0048] Returning to Fig. 2, the second calculation function 354 calculates change information indicating a change in size of the thrombus removal device from a plurality of medical X-ray fluoroscopic images. The second calculation function 354 is an example of a second calculation unit. Specifically, the second calculation function 354 calculates change information indicating a change in size of the thrombus removal device, which corresponds to a change in size of the thrombus removal device over time, from the size of the thrombus removal device present in the medical X-ray fluoroscopic images calculated by the first calculation function 353.

[0049] The change in size of the thrombus removal device is a change in the lumen volume of the thrombus removal device. The change information includes a volume ratio of the thrombus removal device and a time corresponding to the volume ratio of the thrombus removal device. The change information also includes a difference in the volume ratio of the thrombus removal device between imaging, and a time corresponding to the difference in the volume ratio of the thrombus removal device between imaging.

[0050] Here, the change in size of the thrombus removal device will be described with reference to Fig. 5. Fig. 5 is a graph showing an example of the change in size of the thrombus removal device according to the embodiment. Fig. 5 shows a graph G1 with the horizontal axis representing time [s] and the vertical axis representing the volume ratio [%] of the stent retriever. Also shown is a graph G2 with the horizontal axis representing time [s] and the vertical axis representing the difference [%] in the volume ratio between images.

[0051] For example, a stent retriever placed in a subject's blood vessel is deployed into the vessel from a state where the lumen volume is close to 0 (zero)%, and then gradually expands while biting into the thrombus. The outward force that the stent retriever exerts due to the elasticity of its material is called the axial force. When the axial force is balanced with the force it receives from the thrombus or blood vessel wall, the deployment of the stent retriever stops completely.

[0052] Here, the known volume when the stent retriever is fully deployed in an obstacle-free space (a state in which there are no obstacles around the stent retriever) is set to 100%, and the volume ratio when the stent retriever is ideally fully folded and has a volume of 0 (zero)% is considered. When fluoroscopic imaging is intermittently repeated, the change in the volume ratio of the stent retriever penetrating into the thrombus and the change in the difference in volume ratio between imaging frames are obtained in the intermittent imaging sections from the start of imaging to the current time, as shown in graphs G1 and G2.

[0053] 2, the third calculation function 355 calculates first time information indicating the time for placing the thrombus removal device in the subject based on the change information. The third calculation function 355 is an example of a third calculation unit. Specifically, the third calculation function 35 calculates first time information indicating the time for placing the thrombus removal device in the subject based on the change information calculated by the second calculation function 354.

[0054] The first time information is information indicating a time from the time when the thrombus removal device is placed in the subject to the time when the axial force is balanced with the force from the thrombus or the vascular wall and the time when the deployment of the thrombus removal device is deemed to have completely stopped is the end point. The first time information is an example of a recommended waiting time.

[0055] For example, the third calculation function 355 calculates the recommended waiting time as the time from when the difference in the volume percentage of the stent retriever peaks to when the difference in the volume percentage of the stent retriever becomes 0 (zero) based on the slope of the difference in the volume percentage of the stent retriever.

[0056] Here, the recommended waiting time will be described with reference to Fig. 5. For example, in the imaging section S1 shown in Fig. 5, the third calculation function 355 does not calculate the recommended waiting time because the difference of the stent retriever is increasing. Also, in the imaging section S2 shown in Fig. 5, the third calculation function 355 calculates the recommended waiting time T1 from the slope of the difference using the latter observation time points 51 and 52 where the difference of the stent retriever is decreasing.

[0057] Furthermore, in the shooting section S2 shown in Figure 5, since the difference is decreasing throughout the stent retriever, the third calculation function 355 calculates the recommended waiting time T1 from the slope of the difference (graph G3 shown in Figure 5) using observation time points 51, 52, 53, and 54.

[0058] Note that, without being limited to the above-mentioned method, in order to improve the accuracy of the recommended waiting time T1, the third calculation function 355 may use observation data between the observation time points 51 and 52, or between the observation time points 53 and 54. Furthermore, the recommended waiting time T1 may be calculated by weighting more recently observed observation data (as an example, weighting in the order of observation time point 51<observation time point 52<observation time point 53<observation time point 54).

[0059] Furthermore, the third calculation function 355 may calculate a value related to the reliability of the calculated recommended waiting time T1. For example, the third calculation function 355 may calculate a prediction interval T2 of the time when the difference in the volume ratio becomes 0 (zero) by linear regression. Regarding the change in the difference, nonlinear regression or curve fitting may be performed instead of linear regression based only on the slope at multiple observation points. Alternatively, a model formula created in advance for the deployment of the stent retriever may be curve-fitted to the change in the volume ratio.

[0060] 2, the output control function 356 performs control so as to output the first time information. The output control function 356 is an example of an output control unit. Specifically, the output control function 356 performs control so as to output the first time information calculated by the third calculation function 355 to the display 340.

[0061] For example, after imaging of each imaging section is completed, if the third calculation function 355 calculates a recommended waiting time for that imaging section, the output control function 356 outputs the calculated recommended waiting time to the display 340. Thereafter, if the third calculation function 355 further calculates a recommended waiting time for another imaging section, the output control function 356 updates the recommended waiting time and outputs it to the display 340.

[0062] This allows the operator to avoid unnecessary waiting by performing imaging again when the recommended waiting time approaches, checking the state of the stent retriever, and retrieving the stent retriever entangled with a thrombus, without waiting aimlessly. For example, if the ideal waiting time is the time when the shape change of the stent retriever completely stops, and it is assumed that the degree of shape change of the stent retriever gradually decreases before stopping, the recommended waiting time approaches the ideal waiting time each time it is updated by intermittently repeating imaging, and when it completely stops, it can be considered to match the ideal waiting time.

[0063] Next, a description will be given of processing executed by the medical image processing apparatus 300. Fig. 6 is a flowchart showing an example of a processing procedure by the medical image processing apparatus 300 according to the embodiment. In Fig. 6, the processing starts when an operator inserts a thrombus removal device into a subject and the thrombus removal device reaches a thrombus.

[0064] The acquisition function 351 acquires a plurality of medical X-ray fluoroscopic images (step S61). Next, the detection function 352 detects the thrombus removal device placed in the blood vessel of the subject and present in the medical X-ray fluoroscopic images from the plurality of medical X-ray fluoroscopic images (step S62). Next, the first calculation function 353 calculates the size of the thrombus removal device placed in the blood vessel of the subject and present in the medical X-ray fluoroscopic images from the plurality of medical X-ray fluoroscopic images (step S63). Next, the second calculation function 354 calculates change information indicating a change in size of the thrombus removal device from the plurality of medical X-ray fluoroscopic images (step S64).

[0065] Next, the third calculation function 355 calculates first time information indicating the time for placing the thrombus removal device in the subject based on the change information (step S65). Next, the output control function 356 performs control to output the first time information (step S66). Next, the acquisition function 351 determines whether imaging is continuing (step S67). Here, if the acquisition function 351 determines that imaging is continuing (step S67: Yes), the acquisition function 351 proceeds to step S61. On the other hand, if the acquisition function 351 determines that imaging is not continuing (step S67: No), the processing of the processing circuit 350 ends.

[0066] As described above, the medical image processing apparatus 300 according to the embodiment calculates the size of the thrombus removal device placed in the blood vessel of the subject from multiple medical X-ray fluoroscopy images and present in the medical X-ray fluoroscopy images, calculates change information indicating the change in size from the multiple medical X-ray fluoroscopy images, calculates first time information indicating the time for which the thrombus removal device is to be placed in the subject based on the change information, and outputs the first time information.

[0067] According to at least one of the embodiments described above, for example, when an operator uses a stent retriever to retrieve a thrombus present in a subject's blood vessel, the medical image processing device 300 provides the operator with a recommended waiting time based on changes in the size of a thrombus removal device present in a plurality of medical X-ray fluoroscopy images.

[0068] By knowing the recommended waiting time, the surgeon can perform imaging again when the recommended waiting time approaches and check the deployment state of the stent retriever without waiting aimlessly. This allows the surgeon to check the deployment state of the stent retriever before retrieving it, thereby reducing unnecessary waiting.

[0069] The above-described embodiment can be modified as appropriate by changing a part of the configuration or function of each device. Therefore, some modifications of the above-described embodiment will be described below as other embodiments. The following mainly describes the differences from the above-described embodiment, and the same reference numerals will be used to denote the common points with the contents already described, and detailed description will be omitted. The other embodiments described below may be implemented individually or in appropriate combination.

[0070] (First Modification) In the above embodiment, the third calculation function 355 of the processing circuit 350 calculates the first time information indicating the time for placing the thrombus removal device in the subject based on the change information, but the present invention is not limited to this. For example, the third calculation function 355 of the processing circuit 44 calculates the volume ratio at the time when the recommended waiting time has elapsed by accumulating the difference between the predicted volume ratios.

[0071] Fig. 7 is a graph showing an example of a change in size of the thrombus removal device according to the first modified example. In addition to the graph shown in Fig. 5, Fig. 7 shows a graph G4 showing the volume ratio [%] of the stent retriever based on the observation time point 51, and an integral V1 accumulating the difference in the expected volume ratio. Specifically, the third calculation function 355 calculates the difference in the volume ratio of the stent retriever between imaging, as the volume ratio at the time when the recommended waiting time T1 has elapsed.

[0072] 7, the third calculation function 355 calculates the volume ratio at the time when the recommended waiting time T1 has elapsed, which is the difference between the volume ratios of the stent retriever at the observation time points 51, 52, 53, and 54. This allows the surgeon to grasp the deployment state of the stent retriever.

[0073] (Second Modification) For example, the processing circuitry of the medical image processing device may calculate and output the next imaging timing suitable for the recommended waiting time calculated by the third calculation function 355. Fig. 8 is a diagram showing an example of the configuration of a medical image processing device 500 according to the second modified example. The processing circuitry 360 of the medical image processing device 500 according to the second modified example executes an acquisition function 351, a detection function 352, a first calculation function 353, a second calculation function 354, a third calculation function 355, an output control function 356, and a fourth calculation function 357.

[0074] The fourth calculation function 357 calculates the next imaging timing suitable for the recommended waiting time. The fourth calculation function 357 is an example of a fourth calculation unit. Specifically, the fourth calculation function 357 calculates the next imaging timing suitable for the recommended waiting time calculated by the third calculation function 355.

[0075] Here, the imaging timing will be described with reference to FIG. 9. FIG. 9 is a graph showing an example for explaining the imaging timing according to the second modified example. FIG. 9 shows a graph G11 with the horizontal axis representing time [s] and the vertical axis representing the volume ratio [%] of the stent retriever. Also, FIG. 9 shows a graph G21 with the horizontal axis representing time [s] and the vertical axis representing the difference [%] in the volume ratio between images. Furthermore, a recommended waiting time T3 calculated by the third calculation function 355 is shown.

[0076] The fourth calculation function 357 calculates the time at which the difference in volume ratio reaches a rapid value (+2%, as an example) as a change in the stent retriever from the results of the observation time 91 and the observation time 92 in the graph G21 in the imaging section S11, and calculates imaging timing 93 so as to recommend imaging in the imaging section S12 from the calculated time. Then, the output control function 356 performs control so as to output the imaging timing 93 calculated by the fourth calculation function 357 to the display 340.

[0077] Further, the fourth calculation function 357 calculates the time when the difference in the volume ratio reaches the prediction interval T2 from the results of the observation time point 94 and the observation time point 95 in the graph G21 in the imaging section S12, and calculates the imaging timing 96 so as to recommend imaging in the imaging section S13 from the calculated time. Then, the output control function 356 performs control so as to output the imaging timing 96 calculated by the fourth calculation function 357 to the display 340. This allows the operator to reduce the radiation exposure to the subject by knowing the imaging timing.

[0078] (Third Modification) For example, the processing circuitry of the medical image processing device may detect the thrombus removal device placed in the blood vessel of the subject from the acquired multiple medical X-ray fluoroscopic images and present in the medical X-ray fluoroscopic images, and calculate and output second time information indicating the time for placing the thrombus removal device in the subject. Fig. 10 is a diagram showing an example of the configuration of a medical image processing device 600 according to the third modified example. The processing circuitry 370 of the medical image processing device 600 according to the third modified example executes an acquisition function 351, a detection function 352, an output control function 356, and an estimation function 358.

[0079] The estimation function 358 estimates second time information indicating a time for placing the thrombus removal device placed in the blood vessel of the subject and present in the medical X-ray fluoroscopy images from the multiple medical X-ray fluoroscopy images. The estimation function 358 is an example of an estimation unit. Specifically, when the detection function 352 detects the thrombus removal device placed in the blood vessel of the subject and present in the medical X-ray fluoroscopy images from the multiple medical X-ray fluoroscopy images acquired by the acquisition function 351, the estimation function 358 estimates the size of the thrombus removal device.

[0080] The estimation function 358 also estimates change information indicating a change in size of the thrombus removal device, which corresponds to a change in size of the thrombus removal device over time. Furthermore, the estimation function 358 estimates second time information indicating a time for placing the thrombus removal device in the subject, based on the estimated change information.

[0081] Then, the output control function 3578 performs control so as to output the second time information. The second time information is information indicating a time, starting from the timing when the thrombus removal device is placed in the subject, and ending from the timing when the axial force is balanced with the force from the thrombus or the vascular wall and the deployment of the thrombus removal device is deemed to have completely stopped. The second time information is an example of a recommended waiting time.

[0082] According to at least one of the above-described embodiments, for example, when an operator uses a thrombus removal device to retrieve a thrombus present in a blood vessel of a subject, the medical image processing apparatus 500 estimates and outputs a recommended waiting time indicating the time for which the thrombus removal device present in the medical X-ray fluoroscopy images is placed in the blood vessel of the subject from a plurality of medical X-ray fluoroscopy images. By knowing the recommended waiting time, the operator can perform imaging again when the recommended waiting time approaches and check the deployment state of the stent retriever without waiting aimlessly. This allows the operator to check the deployment state of the stent retriever and retrieve it, thereby reducing unnecessary waiting.

[0083] (Application to lower limb arteries) Although the blood vessels described in the above embodiment are cerebral blood vessels of the subject, the present invention is not limited thereto and can also be applied to thrombus in lower limb arteries. In other words, the operator can know the timing to retrieve thrombus in the lower limb arteries by using the recommended waiting time calculated by the processing circuit of the medical image processing device.

[0084] In the above-described embodiment, an example has been described in which each processing function is realized by a single processing circuit (processing circuit 350, processing circuit 360, and processing circuit 370), but the embodiment is not limited to this. For example, the processing circuits 350, processing circuit 360, and processing circuit 370 may be configured by combining multiple independent processors, and each processor may execute each program to realize each processing function. Furthermore, each processing function possessed by the processing circuits 350, processing circuit 360, and processing circuit 370 may be realized by being appropriately distributed or integrated into a single or multiple processing circuits.

[0085] When the technical idea of ​​this embodiment is realized in a medical image processing method, the medical image processing method includes the steps of: calculating the size of a thrombus removal device placed in a blood vessel of a subject and present in the medical X-ray fluoroscopy images from a plurality of medical X-ray fluoroscopy images; calculating change information indicating a change in size from the plurality of medical X-ray fluoroscopy images; calculating first time information indicating a time to retrieve the thrombus removal device from the subject based on the change information; and controlling to output the first time information. The processing procedure and effects of the medical image processing method are similar to those of the embodiment, and therefore description thereof will be omitted.

[0086] When the technical idea of ​​the present embodiment is realized by a medical image processing program, the medical image processing program causes a computer to calculate the size of a thrombus removal device placed in a blood vessel of a subject and present in the medical X-ray fluoroscopy images from a plurality of medical X-ray fluoroscopy images, calculate change information showing a change in size from the plurality of medical X-ray fluoroscopy images, calculate first time information showing the time to retrieve the thrombus removal device from the subject based on the change information, and control the computer to output the first time information. The processing procedure and effects of the medical image processing program are similar to those of the embodiment, and therefore will not be described.

[0087] The term "processor" used in the description of each of the above-mentioned embodiments means, for example, a circuit such as a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a programmable logic device (for example, a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA)). Here, instead of storing a program in a memory circuit, the program may be directly built into the circuit of the processor. In this case, the processor realizes its function by reading and executing the program built into the circuit. Furthermore, each processor in the present embodiment is not limited to being configured as a single circuit for each processor, and may be configured as a single processor by combining multiple independent circuits to realize its function.

[0088] Here, the program executed by the processor is provided by being pre-installed in a ROM (Read Only Memory), a storage unit, etc. This program may be provided by being stored in a computer-readable storage medium such as a CD (Compact Disk)-ROM, a FD (Flexible Disk), a CD-R (Recordable), or a DVD (Digital Versatile Disk) in a format that can be installed in these devices or in a format that can be executed.

[0089] This program may also be provided or distributed by being stored on a computer connected to a network such as the Internet and downloaded via the network. For example, this program is composed of modules including each of the functional units described below. In terms of actual hardware, a CPU reads out the program from a storage medium such as a ROM and executes it, whereby each module is loaded into a main storage device and generated on the main storage device.

[0090] According to at least one of the embodiments described above, a recommended waiting time for a thrombus removal device in a blood vessel of a subject can be provided according to a case.

[0091] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0092] 100 Medical imaging diagnostic equipment 200 Image Archiver 300, 500, 600 Medical image processing equipment 310 I / F circuit 320 Memory circuit 330 Input Interface 340 Display 350, 360, 370 Processing circuit 351 Acquisition Function 352 Detection Function 353 First calculation function 354 Second calculation function 355 3rd calculation function 356 Output Control Function 357 4th calculation function 358 Estimation Function

Claims

1. a first calculation unit that calculates a size of a blood clot removal device placed in a blood vessel of a subject and present in the medical X-ray fluoroscopy images from a plurality of medical X-ray fluoroscopy images; a second calculation unit that calculates change information indicating a change in the size from the plurality of medical X-ray fluoroscopic images; a third calculation unit that calculates first time information indicating a time for which the thrombus removal device is to be placed in the subject based on the change information; an output control unit that performs control so as to output the first time information; A medical image processing device comprising:

2. The change in size is a change in the lumen volume of the thrombus removal device. The medical image processing device according to claim 1 .

3. the first time information is information indicating a time from a timing when the thrombus removal device is placed in the subject to a timing when the thrombus removal device is considered to have completely stopped being deployed as an end point; The medical image processing device according to claim 1 .

4. Calculating the size of a blood clot removal device placed in a blood vessel of a subject and present in the medical X-ray fluoroscopy images from a plurality of medical X-ray fluoroscopy images; calculating change information indicating a change in the size from the plurality of medical X-ray fluoroscopic images; calculating first time information indicating a time to retrieve the thrombus removal device from the subject based on the change information; and performing control to output the first time information. A medical image processing method comprising:

5. On the computer, Calculating the size of a blood clot removal device placed in a blood vessel of a subject and present in the medical X-ray fluoroscopy images from a plurality of medical X-ray fluoroscopy images; calculating change information indicating a change in the size from the plurality of medical X-ray fluoroscopic images; calculating first time information indicating a time to retrieve the thrombus removal device from the subject based on the change information; and performing control to output the first time information. A medical image processing program that makes this possible.

Images