JP7768698B2 - Medical image processing device, system and method - Google Patents

Description

The embodiments disclosed in this specification and drawings relate to medical image processing devices, systems, and methods.

Traditionally, technologies that present various types of information about blood flow in a subject's cardiac blood vessels based on medical images of the blood vessels have been known as technologies for supporting the diagnosis and formulation of treatment plans for cardiac diseases. For example, a technology that calculates and displays wall shear stress (WSS) at each position in a blood vessel as one type of information about blood flow is known.

Special Publication No. 2020-518362 JP 2011-62358 A Special table 2016-533815 publication

One of the problems that the embodiments disclosed in this specification and drawings attempt to solve is to reduce the effort required of users when diagnosing heart disease and formulating treatment plans. However, the problems that the embodiments disclosed in this specification and drawings attempt to solve are not limited to the above problem. Problems corresponding to the effects of each configuration shown in the embodiments described below can also be considered as other problems.

A medical image processing device according to an embodiment includes an acquisition unit, a display control unit, and an input operation reception unit. The acquisition unit acquires a three-dimensional image of a subject's blood vessels and the spatial distribution of wall shear stress values at each position in the blood vessels. The display control unit displays a display image in which the wall shear stress values are assigned to the three-dimensional image from any angle. The input operation reception unit receives an input operation to change the angle. The display control unit changes the display form of the display image in which the wall shear stress values are assigned to the three-dimensional image between a rotational display in which the display image is displayed while changing the angle over time, and a non-rotational display in which the angle is not changed.

FIG. 1 is a diagram showing an example of the configuration of a medical image processing system and a medical image processing apparatus according to the first embodiment. FIG. 2 is a flowchart showing the processing procedure of the processing performed by each processing function of the processing circuitry of the medical image processing apparatus according to the first embodiment. FIG. 3A is a diagram illustrating an example of a list according to the first embodiment. FIG. 3B is a diagram illustrating an example of a list according to the first embodiment. FIG. 4A is a diagram illustrating an example of a display image of the WSS according to the first embodiment. FIG. 4B is a diagram illustrating an example of a display image of the WSS according to the first embodiment. FIG. 5 is a diagram illustrating an example of switching the display mode of a display image according to the first embodiment. FIG. 6 is a diagram for explaining an example of speed adjustment of the rotation speed according to the first embodiment. FIG. 7 is a diagram illustrating an example of display control by the display control function according to the first embodiment. FIG. 8A is a diagram showing an example of display of additional information according to the first embodiment. FIG. 8B is a diagram for explaining an example of speed control of the rotation speed based on additional information according to the first embodiment. FIG. 9 is a diagram illustrating an example of information transfer by the control function according to the first embodiment. FIG. 10 is a flowchart showing the processing procedure of the processing performed by each processing function of the processing circuitry of the medical image processing apparatus according to the second embodiment. FIG. 11 is a diagram illustrating an example of display control by the display control function according to the third embodiment. FIG. 12 is a diagram illustrating an example of display control by the display control function according to the third embodiment.

Embodiments of a medical image processing device, system, and method are described in detail below with reference to the drawings. Note that the medical image processing device and medical image processing method according to the present application are not limited to the embodiments shown below. Furthermore, the embodiments can be combined with other embodiments or conventional technologies to the extent that no inconsistencies arise in the processing content.

(First embodiment)
FIG. 1 is a diagram showing an example of the configuration of a medical image processing system and a medical image processing apparatus according to the first embodiment.

For example, as shown in FIG. 1, the medical image processing system 100 according to this embodiment includes an X-ray CT (Computed Tomography) device 110, a medical image storage device 120, departmental systems 130, a medical information display device 140, and a medical image processing device 150. Here, each device and system is connected to each other so that they can communicate with each other via a network 160.

In addition to the X-ray CT scanner 110, the medical image processing system 100 may also include other medical image diagnostic devices such as a magnetic resonance imaging (MRI) device, an ultrasound diagnostic device, a PET (Positron Emission Tomography) device, or a SPECT (Single Photon Emission Computed Tomography) device.

The X-ray CT device 110 generates a CT image of the subject. Specifically, the X-ray CT device 110 collects projection data representing the distribution of X-rays that have passed through the subject by rotating the X-ray tube and X-ray detector on a circular orbit that surrounds the subject. The X-ray CT device 110 then generates a CT image based on the collected projection data.

The medical image storage device 120 stores various medical images related to subjects. Specifically, the medical image storage device 120 acquires CT images from the X-ray CT device 110 via the network 160 and stores the CT images in its own memory circuitry. For example, the medical image storage device 120 is implemented by computer equipment such as a server or workstation. Furthermore, for example, the medical image storage device 120 is implemented by a PACS (Picture Archiving and Communication System) or the like, and stores CT images in a format compliant with DICOM (Digital Imaging and Communications in Medicine).

Each department system 130 includes various systems such as a Hospital Information System (HIS), a Radiology Information System (RIS), a diagnostic report system, a Laboratory Information System (LIS), a rehabilitation department system, a dialysis department system, and a surgery department system. The medical image processing system 100 is connected to each of these systems and exchanges various information with them. For example, the medical image processing system 100 exchanges patient information, examination information, treatment information, information on analysis results, and the like with each system included in each department system 130.

The medical information display device 140 displays various medical information related to the subject. Specifically, the medical information display device 140 obtains medical information such as CT images and image processing results from the medical image storage device 120 via the network 160, and displays the medical information on its own display. For example, the medical information display device 140 is realized by computer equipment such as a workstation, personal computer, or tablet terminal.

The medical image processing device 150 performs various image processing operations on the subject. Specifically, the medical image processing device 150 acquires CT images from the X-ray CT device 110 or the medical image storage device 120 via the network 160, and performs various image processing operations using the CT images. The medical image processing device 150 also acquires various information from each department system 130 via the network 160 and performs various processes. For example, the medical image processing device 150 is realized by computer equipment such as a server or workstation.

For example, the medical image processing device 150 includes a network (NW) interface 151, a memory circuitry 152, an input interface 153, a display 154, and a processing circuitry 155.

The NW interface 151 controls the transmission and communication of various data sent and received between the medical image processing device 150 and other devices connected via the network 160. Specifically, the NW interface 151 is connected to the processing circuitry 155, and outputs data received from other devices to the processing circuitry 155, or transmits data output from the processing circuitry 155 to other devices. For example, the NW interface 151 is realized by a network card, network adapter, NIC (Network Interface Controller), etc.

The memory circuitry 152 stores various data and programs. Specifically, the memory circuitry 152 is connected to the processing circuitry 155 and stores data input from the processing circuitry 155, or reads stored data and outputs it to the processing circuitry 155. For example, the memory circuitry 152 is realized by a semiconductor memory element such as RAM (Random Access Memory) or flash memory, a hard disk, an optical disk, etc.

The input interface 153 accepts input operations of various instructions and information from the user. Specifically, the input interface 153 is connected to the processing circuit 155, converts the input operations received from the user into electrical signals, and outputs them to the processing circuit 155. For example, the input interface 153 may be realized by a trackball, switch buttons, a mouse, a keyboard, a touchpad that performs input operations by touching the operation surface, a touchscreen that integrates a display screen and a touchpad, a non-contact input interface that uses an optical sensor, a voice input interface, etc. Note that in this specification, the input interface 153 is not limited to those that have physical operating components such as a mouse and keyboard. For example, an electrical signal processing circuit that receives electrical signals corresponding to input operations from an external input device provided separately from the device and outputs these electrical signals to a control circuit is also included as an example of the input interface 153.

For example, the input interface 153 accepts an input operation to change the angle of a displayed image from any angle. The input interface 153 is an example of an input operation accepting unit.

Display 154 displays various types of information and data. Specifically, display 154 is connected to processing circuit 155 and displays various types of information and data output from processing circuit 155. For example, display 154 may be implemented as a liquid crystal display, a CRT (Cathode Ray Tube) display, a touch panel, etc.

The processing circuitry 155 controls the entire medical image processing device 150. For example, the processing circuitry 155 performs various processes in response to input operations received from a user via the input interface 153. For example, the processing circuitry 155 inputs data transmitted from another device from the NW interface 151 and stores the input data in the memory circuitry 152. Also, for example, the processing circuitry 155 transmits data input from the memory circuitry 152 to another device by outputting the data to the NW interface 151. Also, for example, the processing circuitry 155 displays data input from the memory circuitry 152 on the display 154.

The above describes an example configuration of the medical image processing system 100 and medical image processing device 150 according to this embodiment. For example, the medical image processing system 100 and medical image processing device 150 according to this embodiment are installed in medical facilities such as hospitals and clinics, and support users such as doctors in diagnosing heart disease and formulating treatment plans.

Specifically, the medical image processing device 150 calculates and displays wall shear stress (WSS) at each position in the blood vessels based on medical images of the subject's cardiac blood vessels. The medical image processing device 150 automatically changes the display format, taking into account the cost of calculating WSS and the doctor's visibility, thereby reducing the user's effort when diagnosing cardiac disease and formulating treatment plans.

Since the calculation cost and accuracy of WSS vary depending on the calculation method, if it is not properly controlled taking into account the user's purpose, there is a risk of incurring unnecessary calculation costs or the WSS not being calculated with the accuracy required by the user. However, manually setting the calculation method while taking into account various circumstances is time-consuming for the user.

The medical image processing device 150 according to this embodiment is therefore configured to reduce the user's workload by appropriately controlling the calculation and display of the WSS, taking into account the user's intended use.

Specifically, the medical image processing device 150 changes the display format of the WSS depending on the display method of the WSS. For example, when displaying a 3D image of blood vessels showing the WSS, the medical image processing device 150 changes the display format depending on whether the image is rotated or not. A medical image processing device 150 with this configuration will be described in detail below. Note that the following describes an example in which a coronary artery CT image is used as a medical image related to blood vessels.

For example, as shown in FIG. 1, in this embodiment, the processing circuitry 155 of the medical image processing device 150 executes an acquisition function 155a, a determination function 155b, a calculation function 155c, a display information generation function 155d, a display control function 155e, and a control function 155f. Here, the acquisition function 155a is an example of an acquisition unit. The determination function 155b is an example of a determination unit. The calculation function 155c is an example of a calculation unit. The display information generation function 155d is an example of a generation unit. The display control function 155e is an example of a display control unit. The control function 155f is an example of a control unit.

The acquisition function 155a acquires coronary artery CT images of the subject from the X-ray CT scanner 110 or the medical image storage device 120 via the NW interface 151. Specifically, the acquisition function 155a acquires three-dimensional coronary artery CT images that can be used to calculate WSS. The acquisition function 155a can also acquire blood flow index values from devices connected to the medical image processing system 100 via the NW interface 151. That is, the acquisition function 155a can acquire blood flow index values calculated by devices connected to the medical image processing system 100. For example, the acquisition function 155a acquires WSS values and fractional flow reserve (FFR) values at each position of the coronary artery calculated by devices connected to the medical image processing system 100. Note that this embodiment describes a case in which the calculation function 155c calculates the above-mentioned blood flow index values using the three-dimensional coronary artery CT images acquired by the acquisition function 155a.

The judgment function 155b performs judgment processing regarding the WSS calculation target and calculation results. Specifically, the judgment function 155b performs judgment processing regarding the validity of the WSS calculation target and judgment processing regarding the validity of the WSS calculation results. The processing performed by the judgment function 155b will be described in detail later.

Calculation function 155c extracts the central lines of the coronary arteries contained in the coronary artery CT images of the subject acquired by acquisition function 155a. Calculation function 155c also calculates index values related to coronary artery blood flow based on the coronary artery CT images of the subject acquired by acquisition function 155a. For example, calculation function 155b calculates the WSS value and fractional flow reserve (FFR) at each position of the coronary arteries from the coronary artery CT images of the subject using known methods such as CFD (Computational Fluid Dynamics) and machine learning.

For example, when calculating index values using CFD, the calculation function 155c performs fluid analysis using analysis conditions such as blood physical properties (e.g., hematocrit, blood viscosity, density, etc.), vascular wall elasticity, iterative calculation conditions (maximum number of iterations in iterative calculation, relaxation coefficient, residual tolerance, etc.), and analysis initial values (blood flow rate, pressure, fluid resistance, initial values of pressure boundary, etc.) as well as vascular shape data to calculate index values related to blood flow in the target region of the blood vessel. As an example, the calculation function 155c calculates index values such as pressure, blood flow rate, blood flow velocity, vector, and wall shear stress for each position of the coronary artery.

The display information generation function 155d generates display information including various images and information for display. For example, the display information generation function 155d generates a three-dimensional image of the coronary artery by three-dimensionally reconstructing the vascular region of the coronary artery in a coronary artery CT image. As an example, the display information generation function 155d generates a VR (Volume Rendering) image, an SR (Surface Rendering) image, a CPR (Curved Planar Reconstruction) image, an MPR (Multi Planar Reconstruction) image, an SPR (Stretched Multi Planar Reconstruction) image, and the like.

Furthermore, for example, the display information generation function 155d generates various display information showing subject information, calculation results by the calculation function 155c, etc. The display information generated by the display information generation function 155d will be described in detail later.

The display control function 155e displays the display information generated by the display information generation function 155d on the display 154 and controls the display state. Specifically, the display control function 155e controls the display of a display image in which a WSS value is assigned to a three-dimensional image, displayed from any angle. For example, the display control function 155e controls the rotation of a display image showing the WSS calculated by the calculation function 155c. The processing performed by the display control function 155e will be described in detail later.

The control function 155f transfers the WSS calculation results to a specified destination and performs various processes. The processing performed by the control function 155f will be described in detail later.

The processing circuitry 155 described above is realized, for example, by a processor. In this case, each of the processing functions described above is stored in the memory circuitry 152 in the form of a program executable by a computer. The processing circuitry 155 then reads and executes each program stored in the memory circuitry 152 to realize the function corresponding to each program. In other words, when each program has been read, the processing circuitry 155 has each of the processing functions shown in FIG. 1.

The processing circuitry 155 may be configured by combining multiple independent processors, with each processor executing a program to realize each processing function. Furthermore, each processing function possessed by the processing circuitry 155 may be realized by being distributed or integrated as appropriate across a single or multiple processing circuits. Furthermore, each processing function possessed by the processing circuitry 155 may be realized by a combination of hardware and software, such as circuits. While an example in which programs corresponding to each processing function are stored in a single storage circuitry 152 has been described here, the embodiment is not limited to this. For example, the programs corresponding to each processing function may be stored in a distributed manner across multiple storage circuits, and the processing circuitry 155 may read and execute each program from each storage circuit.

As described above, when displaying a 3D image of blood vessels showing the WSS, the medical image processing device 150 changes the display format between rotated and non-rotated display. First, the processing procedure by the medical image processing device 150 will be explained using FIG. 2. FIG. 2 is a flowchart showing the processing procedure performed by each processing function of the processing circuitry 155 of the medical image processing device according to the first embodiment. Note that FIG. 2 shows an example in which the WSS is calculated in advance before receiving a WSS calculation instruction from the user.

For example, as shown in FIG. 2, in this embodiment, the acquisition function 155a acquires a coronary artery CT image of the subject from the X-ray CT device 110 or the medical image storage device 120 (step S101). For example, the acquisition function 155a acquires a coronary artery CT image each time the X-ray CT device 110 collects the coronary artery CT image or each time the coronary artery CT image is stored in the medical image storage device 120. This processing is realized, for example, by the processing circuitry 155 calling up and executing a program corresponding to the acquisition function 155a from the memory circuitry 152.

Next, the determination function 155b determines whether the conditions are met when the acquired coronary artery CT image is used as the target (step S102). Specifically, the determination function 155b determines whether the acquired coronary artery CT image is appropriate for use in calculating WSS. This process is realized, for example, by the processing circuitry 155 calling up and executing a program corresponding to the determination function 155b from the storage circuitry 152.

Here, if the determination function 155b determines that the condition is met (step S102, yes), the medical image processing device 150 proceeds to step S103. On the other hand, if the determination function 155b determines that the condition is not met (step S102, no), the medical image processing device 150 returns to step S101 and acquires image data.

Next, the calculation function 155c calculates an index value related to blood flow based on the coronary artery CT image of the subject acquired by the acquisition function 155a (step S103). For example, the calculation function 155c calculates WSS. This process is realized, for example, by the processing circuitry 155 retrieving and executing a program corresponding to the calculation function 155c from the memory circuitry 152.

Then, the determination function 155b determines the calculation result and stores the determination result in the memory circuitry 152 (step S104). Specifically, the determination function 155b determines whether the calculation result of WSS calculated by the calculation function 155c is valid. The determination function 155b then stores the determination result in the memory circuitry 152 in association with identification information for identifying the subject. This process is realized, for example, by the processing circuitry 155 calling up and executing a program corresponding to the determination function 155b from the memory circuitry 152.

Next, the display control function 155e determines whether a display operation for displaying index values has been received via the input interface 153 (step S105). If the display control function 155e has received a display operation (step S105, yes), the medical image processing apparatus 150 proceeds to step S106. On the other hand, if the display control function 155e has not received a display operation (step S105, no), the medical image processing apparatus 150 returns to step S101 and continues acquiring image data. This process is realized, for example, by the processing circuitry 155 calling up and executing a program corresponding to the display control function 155e from the memory circuitry 152.

Next, the display information generation function 155d generates a list showing the index values for each subject, and the display control function 155e displays the generated list on the display 154 (step S106). This process is realized, for example, by the processing circuitry 155 retrieving and executing a program corresponding to the display information generation function 155d and a program corresponding to the display control function 155e from the storage circuitry 152.

Next, the display control function 155e determines whether a selection operation on the list has been received via the input interface 153 (step S107). If the display control function 155e has received a selection operation (step S107, yes), the medical image processing device 150 proceeds to step S108. On the other hand, if the display control function 155e has not received a selection operation (step S107, no), the medical image processing device 150 continues displaying the list. This processing is realized, for example, by the processing circuitry 155 calling up and executing a program corresponding to the display control function 155e from the memory circuitry 152.

Next, the display information generation function 155d generates display information related to the selected information, and the display control function 155e displays the generated display information on the display 154 (step S108). This process is realized, for example, by the processing circuitry 155 retrieving and executing a program corresponding to the display information generation function 155d and a program corresponding to the display control function 155e from the storage circuitry 152.

Next, the display control function 155e switches between displaying a display image (1D-WSS) showing the spatial distribution of WSS values at each cross-sectional position of the blood vessel relative to the blood vessel's centerline on an image of the coronary artery and displaying a display image (3D-WSS) showing the spatial distribution of WSS values at each position within the blood vessel or on the blood vessel wall on an image of the coronary artery, depending on the display method (step S109). For example, the display control function 155e changes the display format so that 1D-WSS is displayed during rotational display, in which the display image is displayed while changing the angle over time, and 3D-WSS is displayed during non-rotational display, in which the angle is not changed. For example, when an operation to change the display angle of the display image is accepted by the input interface 153, the display control function 155e displays 1D-WSS. Furthermore, when an operation to change the display angle is not accepted, the display control function 155e displays 3D-WSS. This processing is realized, for example, by the processing circuitry 155 calling up and executing a program corresponding to the display control function 155e from the memory circuitry 152.

Next, the display control function 155e determines whether the display conditions have changed (step S110). For example, the display control function 155e determines whether the rotation conditions or display conditions have changed. For example, the display control function 155e determines whether the rotation conditions, including at least one of the number of rotations and the rotation speed, or the display conditions, including zooming in or out, have changed. If the display conditions have changed (step S110, Yes), the display control function 155e further changes the display form (step S111).

For example, when a 1D-WSS is displayed in a rotated display, if the rotation speed of the displayed image is reduced, the display control function 155e changes the displayed image from a 1D-WSS to a 3D-WSS. Furthermore, for example, when a 1D-WSS is displayed in a rotated display, if the displayed image is enlarged, the display control function 155e changes the type of image to be displayed as a WSS. On the other hand, if the display conditions have not changed (step S110: No), the display control function 155e proceeds to step S112. This processing is realized, for example, by the processing circuitry 155 retrieving and executing a program corresponding to the display control function 155e from the storage circuitry 152.

Next, the display control function 155e determines whether an end operation has been received via the input interface 153 (step S112). If an end operation has been received (step S112, yes), the medical image processing device 150 ends processing. On the other hand, if an end operation has not been received (step S112, no), the medical image processing device 150 returns to step S106 and displays the list again.

The following describes in detail each process performed by the medical image processing device 150.

(Determination process regarding calculation target)
2, the determination function 155b determines the validity of the calculation target in calculating WSS. Specifically, the determination function 155b determines the validity of the calculation target using preset conditions.

For example, the determination function 155b determines whether the WSS can be calculated for the coronary artery CT image acquired in step S101. As an example, the determination function 155b determines whether the coronary artery CT image satisfies the following four conditions: "1: The heart is included in the imaging range," "2: Contrast is used," "3: ECG-synchronized imaging is performed," and "4: Acquired at a heart rate of 70 or less."

In this case, the judgment function 155b may, for example, obtain information corresponding to the above four conditions from the DICOM header of the coronary artery CT image and perform the judgment process, or may obtain information corresponding to the above four conditions by communicating with each department system 130 and perform the judgment process.

The determination function 155b can also make a determination using image processing technology. For example, the determination function 155b can search for the anatomical structure of the heart from an image using image processing technology, and if the corresponding anatomical structure cannot be detected, determine that the condition "1: The heart is included in the imaging range" is not met. Similarly, the determination function 155b can determine that the condition "2: Contrast is present" is not met if the anatomical structure of the coronary artery cannot be detected from the image using image processing technology or if the pixel value at the position of the coronary artery is small.

The conditions for determining whether WSS can be calculated are not limited to the four conditions mentioned above, and various other conditions may also be used.

For example, the determination function 155b determines whether the WSS can be calculated by determining whether the protocol of the acquired CT image is included in the range of the recommended protocol for acquiring coronary artery CT images used to calculate index values related to blood flow. As one example, the determination function 155b determines whether the slice thickness and matrix size of the acquired CT image are within the range of the recommended protocol.

Furthermore, for example, the determination function 155b detects noise in the image due to subject movement during imaging or metal (stents or pacemakers), and determines whether the amount of detected noise exceeds a threshold, thereby determining whether WSS can be calculated. As one example, the determination function 155b calculates the S/N (signal-to-noise ratio) in the acquired coronary artery CT image, and compares the calculated S/N with a threshold to determine whether WSS can be calculated from the acquired coronary artery CT image.

Furthermore, for example, the determination function 155b can perform determination processing based on a combination of multiple conditions. For example, conditions are set for inconsistencies between the examination date and the imaging date, and the validity of the subject information. For example, if the examination date of the acquired coronary artery CT image is "2020" but the imaging date is "2019," the determination function 155b determines that it is not possible to calculate WSS using the coronary artery CT image. Also, for example, if the age is "30 years old" but the weight is "10 kg," the determination function 155b determines that the validity of the information about the subject is low and determines that it is not possible to calculate WSS.

Furthermore, for example, the determination function 155b can also perform determination processing based on information regarding the subject's medication history. For example, the determination function 155b obtains information regarding the subject's medication history from each department system 130, and determines that it is not possible to calculate WSS if aspirin or a vasodilator was administered immediately before imaging, since there is a high possibility that a calculation result that differs from normal will be calculated.

(Calculation process of index value)
2, the calculation function 155c calculates an index value related to blood flow. Specifically, the calculation function 155c calculates the WSS value at each position of the coronary artery.

For example, as described above, calculation function 155c calculates the WSS value in the acquired coronary artery CT image using known techniques such as CFD and machine learning. Here, calculation function 155c can calculate one-dimensional WSS (hereinafter referred to as 1D-WSS) and three-dimensional WSS (hereinafter referred to as 3D-WSS). Specifically, calculation function 155c calculates 1D-WSS, which indicates the WSS at each cross-sectional position of the blood vessel based on the center line of the blood vessel, and 3D-WSS, which indicates the WSS at each position within the blood vessel or on the blood vessel wall.

The calculation function 155c can also calculate index values related to blood flow other than WSS in one and three dimensions. For example, the calculation function 155c can calculate 1D-FFR, which indicates the FFR at each cross-sectional position of the blood vessel based on the center line of the blood vessel, and 3D-FFR, which indicates the FFR at each position within the blood vessel.

Here, 3D-FFR and 3D-WSS have the advantage of being able to provide more accurate information because they calculate WSS and FFR at local positions, but on the other hand, they have the disadvantage of high computational costs, such as calculation time, computer processing, and storage space usage. In contrast, 1D-FFR and 1D-WSS have the disadvantage of less accurate information than 3D-FFR and 3D-WSS, but on the other hand, they have the advantage of lower computational costs, such as calculation time, computer processing, and storage space usage.

In addition, when calculating index values using the calculation function 155c, the medical image processing device 150 can accept manual settings of CFD parameters via the input interface 153.

(Determination process regarding calculation results)
2, the determination function 155b determines the validity of the calculation result of WSS. Specifically, the determination function 155b determines the validity of the calculation result using preset conditions.

For example, when the calculation function 155c calculates WSS, if the calculation function 155c is unable to calculate WSS due to a calculation anomaly, or if the calculation result or calculation process deviates from a preset standard, the determination function 155b determines that the calculation result is invalid. As one example, the determination function 155b performs a determination process on the WSS calculation result for each coronary artery position or each blood vessel branch, and stores the determination result in association with the position or blood vessel branch.

In the process of assessing such calculation results, for example, a standard coronary artery shape model generated in advance using a large amount of image data, a preset WSS reference value, or the like is used. For example, the assessment function 155b calculates the degree of deviation between the coronary artery shape calculated in the WSS calculation process and the standard coronary artery shape model, and determines that the calculation result is invalid if the calculated degree of deviation exceeds a threshold. Furthermore, for example, the assessment function 155b calculates the degree of deviation between the calculated WSS value and the reference value, and determines that the calculation result is invalid if the calculated degree of deviation exceeds a threshold.

The determination function 155b can also make a determination using the calculated fluid. In such cases, the determination function 155b determines that the calculation results are invalid if there is a fluid distribution that is not possible in a normal subject, such as backflow occurring over a wide area of the blood vessels.

Furthermore, in the case of WSS, stress usually occurs in a direction corresponding to the direction in which blood vessels run. Therefore, the determination function 155b can determine that the calculation results are invalid if the WSS calculation results show that stress is occurring in the inward and outward directions of the blood vessels in a specified area or more.

The determination function 155b can also determine that the calculation results are invalid if there is a contradiction in the parameters manually set via the input interface 153 (for example, a mesh size of 50*50 and a mesh count of 100 for an image size of 100*100) or if the manually set parameters are invalid (for example, they are outside the range of the recommended protocol).

(List display processing)
As described in step S106 of FIG. 2 , when the display control function 155e receives a display operation from a user, it first displays a list summarizing the WSS calculation results for each subject. Specifically, the display information generation function 155d generates a list summarizing the WSS calculation results for each subject using the various calculation results calculated by the calculation function 155c and subject information. The display control function 155e displays the list generated by the display information generation function 155d on the display 154. FIGS. 3A and 3B are diagrams showing examples of a list according to the first embodiment.

For example, when the display control function 155e receives a display operation from a user, it displays on the display 154 a list associating "ID," "Patient name," "Average WSS," "Max WSS," "Min WSS," and "Calcium Score," as shown in FIG. 3A. Here, "ID" indicates an identifier for uniquely identifying the subject. "Patient name" indicates the name of the subject. "Average WSS" indicates the average value of the calculated WSS. "Max WSS" indicates the maximum value of the calculated WSS. "Min WSS" indicates the minimum value of the calculated WSS. "Calcium Score" indicates the calcium score of the blood vessel for which the WSS was calculated.

Here, the display control function 155e highlights results in the list that deviate from the reference value. Specifically, the display control function 155e compares a preset reference value with the value calculated by the calculation function 155c, and highlights results that deviate by more than the threshold. For example, as shown in Figure 3A, the display control function 155e highlights "Max WSS: 9" for "ID: 100001."

The display control function 155e can also display analysis results other than WSS in the list. For example, as shown in FIG. 3A, the display control function 155e displays calcium scores in addition to WSS values. Note that while the list shown in FIG. 3A shows only calcium scores as analysis results other than WSS, embodiments are not limited to this. For example, the presence or absence of plaque, FFR values, and the like may also be displayed in association with each other.

The display control function 155e can display various lists in addition to the list shown in Figure 3A. For example, when "Max WSS: 9" for "ID: 100001" highlighted in the list shown in Figure 3A is selected, the display control function 155e switches the display information to display a list showing details of the WSS for each vascular branch, as shown in Figure 3B.

The list shown in Figure 3B shows the "Average WSS," "Max WSS," and "Min WSS" for each of the coronary artery branches "RCA," "LAD," and "LCX." For example, as shown in Figure 3B, the display control function 155e displays "RCA," "LAD," and "LCX" as tabs, and displays a list including "Average WSS," "Max WSS," and "Min WSS" for the branch blood vessels included in the selected tab. Note that in Figure 3B, because "Max WSS: 9," highlighted in Figure 3A, was selected, the "RCA" tab, which includes the result for "Max WSS: 9," is automatically selected, and a list showing the "Average WSS," "Max WSS," and "Min WSS" for each of the branch blood vessels in the "RCA": "SN," "CB," "RVB," "AM," "AVN," and "PD."

Here, when the user selects the "LAD" or "LCX" tab, the display control function 155e displays a list showing the "Average WSS," "Max WSS," and "Min WSS" for the vascular branches included in the selected tab ("LAD" or "LCX").

(WSS display processing)
2, when a selection operation on the list is accepted, the display control function 155e controls the display of the WSS of the selected subject (or vascular branch). Specifically, the display information generation function 155d first generates a three-dimensional image of the blood vessel in which the wall shear stress value is calculated for each position of the blood vessel. Then, the display control function 155e displays a display image in which the wall shear stress value is reflected in the three-dimensional image.

For example, the display information generation function 155d generates a VR image of the coronary arteries of a selected subject. Then, the display control function 155e displays a color image in which colors corresponding to the WSS values are mapped onto the VR image of the coronary arteries. In such a case, the display control function 155e acquires the WSS values for all positions of the coronary arteries calculated by the calculation function 155c, and identifies the possible range of WSS from the maximum and minimum values of the acquired WSS values. Then, the display control function 155e sets a color array (color lookup table) for the identified range, and maps a color corresponding to the WSS value for each position to each position of the coronary artery.

Figure 4A is a diagram showing an example of a WSS display image according to the first embodiment. For example, as shown in Figure 4A, the display control function 155e displays a color image in which colors corresponding to WSS values are mapped onto a VR image of the entire coronary arteries of a selected subject. Here, the display control function 155e can display a color image colorized based on the results of 1D-WSS and a color image colorized based on the results of 3D-WSS for the VR image of the coronary arteries.

For example, the display control function 155e extracts the centerlines of blood vessels and generates and displays a first display image (1D-WSS) in which one-dimensional information assigned to each centerline position is assigned to a three-dimensional image of the spatial distribution of wall shear stress values at each position of the blood vessel, and a second display image (3D-WSS) in which three-dimensional information assigned to each spatial position of the blood vessel is assigned to a three-dimensional image. That is, when displaying the 1D-WSS, the display control function 155e displays the spatial distribution of WSS, which is calculated by the 1D-WSS and has no direction dependency in the vascular axis direction, by color mapping it onto a three-dimensional blood vessel image. Furthermore, when displaying the 3D-WSS, the display control function 155e displays the spatial distribution of local WSS, which is calculated by the 3D-WSS and expressed in the form of a three-dimensional vector, by color mapping it onto a three-dimensional blood vessel image.

Here, the display state at the start of display can be set arbitrarily. Specifically, the display control function 155e starts displaying the display image at a preset angle, magnification, etc. at the start of display. For example, the display control function 155e starts displaying the display image at a display angle set based on the WSS calculation results and the characteristics of the blood vessels. As one example, the display control function 155e starts display at a display angle that displays the position where the WSS value is maximum or minimum.

The display control function 155e can also change the display format of the display image depending on the size of the display area in which the display image is displayed. Specifically, the display control function 155e can switch between 1D-WSS display and 3D-WSS display depending on the size of the display area in which the display image is displayed.

For example, if the size of the display area is larger than a predetermined size, the display control function 155e displays a color image colorized based on the results of 3D-WSS. On the other hand, if the size of the display area is smaller than a predetermined size, the display control function 155e displays a color image colorized based on the results of 1D-WSS.

The display control function 155e can also change the vascular image to be displayed depending on the size of the display area. For example, when the size of the display area is smaller than a predetermined size, the display control function 155e displays a color image that reflects the results of WSS in the CPR image for each vascular branch.

In such a case, the display information generation function 155d first generates a CPR image for each blood vessel branch using the coronary artery CT image. Then, the display control function 155e displays a display image in which the WSS value is reflected in the CPR image. As an example, as shown in FIG. 4B, the display control function 155e arranges the CPR images generated for each blood vessel branch in the coronary arteries "RCA," "LAD," and "LCX," and displays a display image in which the WSS value is reflected in the CPR image of each blood vessel branch.

The size of the display area may be the size of the area allocated to display the display image on the display, or the size of the display on which the display image is displayed. For example, when displaying on a medical information display device such as a tablet terminal or smartphone, the size of the display of each device may be used as the size of the display area.

(WSS rotation display processing)
As described in step S109 of FIG. 2, when the display image is displayed, the display control function 155e can switch between display using 1D-WSS and display using 3D-WSS depending on the display method of the display image.

For example, the display control function 155e switches between 1D-WSS display and 3D-WSS display in response to a user operation to change the display position of the display image (e.g., browsing, rotation, etc.). As an example, the display control function 155e displays the image using 1D-WSS when the display position of the display image is being changed, and displays the image using 3D-WSS when the display image is stationary.

For example, when the display image is rotated, the display control function 155e displays the spatial distribution of WSS values at each position of the blood vessel as 1D-WSS, which is one-dimensional information displayed on the image of the blood vessel, and when the display image is not rotated, the display control function 155e displays the spatial distribution of WSS values at each position of the blood vessel as 3D-WSS, which is three-dimensional information displayed on the image of the blood vessel.

Figure 5 is a diagram illustrating an example of switching the display mode of a display image according to the first embodiment. Here, Figure 5 shows a display mode when the display image is rotated and a display mode when the display image is not rotated. For example, as shown in the left diagram of Figure 5, the display control function 155e displays using 1D-WSS while the display position is being changed by a rotation operation performed by the user. That is, in response to the rotation operation performed by the user, the display control function 155e controls the sequential display of color images that reflect the results of 1D-WSS on a VR image of the coronary arteries rendered from a direction facing the user.

On the other hand, as shown in the right diagram of Figure 5, the display control function 155e performs 3D-WSS display while the color image remains stationary and no user operation is performed. In other words, the display control function 155e controls the display so that a color image that reflects the results of 3D-WSS is continuously displayed on the VR image of the coronary arteries rendered from a direction facing the user.

For example, while the display image is being manipulated, it is important to grasp the overall trend, but when it is stationary, detailed analysis is necessary. Therefore, by switching the display as described above, the display control function 155e can display an appropriate display image according to the situation, reducing the user's effort.

In addition, 3D-WSS displays generally involve a larger amount of data, which can result in slower drawing speeds. However, when operating the displayed image, it is necessary to switch the drawing quickly to improve usability. Therefore, as described above, the display control function 155e can prevent a decrease in drawing speed by displaying the image in 1D-WSS when operating the displayed image.

In the above example, we have described a case where the display format is switched in response to a user's operation on the displayed image, but the display control function 155e can also automatically rotate the display using a cine display, etc. For example, the display control function 155e starts the display in step S108 of FIG. 2 and simultaneously controls the start of a rotated display of a color image using 1D-WSS. Then, upon receiving an operation from the user to stop the rotated display, the display control function 155e stops the rotated display and switches to a color image display using 3D-WSS.

Here, the display control function 155e can change the display mode of the display image based on various conditions. Specifically, the display control function 155e can change the display mode of the display image in various ways based on the rotation conditions of the display image, the display conditions of the display image, or the WSS calculation results.

For example, when using the rotation condition of the display image, the display control function 155e switches between 1D-WSS display and 3D-WSS display depending on the number of rotations and rotation speed of the display image. To give one example, the display control function 155e performs 3D-WSS display when the number of rotations and rotation speed of the display image are equal to or less than a threshold. On the other hand, the display control function 155e performs 1D-WSS display when the number of rotations and rotation speed of the display image exceed a threshold.

Here, the display control function 155e can perform display control that combines control based on rotation/non-rotation and control based on the rotation conditions described above. For example, when displaying using 1D-WSS during rotated display, if the rotation speed is changed to below a threshold, the display control function 155e switches to 3D-WSS display. Furthermore, when displaying using 3D-WSS during non-rotated display, if the conditions are changed to start rotation at a rotation speed below a threshold, the display control function 155e continues displaying using 3D-WSS. Furthermore, for example, during rotated display, the display control function 155e can also change the type of medical image (e.g., CT image) used as the display image depending on the number of rotations and the rotation speed. For example, when at least one of the number of rotations and the rotation speed is below a threshold, the display control function 155e displays a display image using a predetermined type of medical image.

Furthermore, for example, during rotational display, the display control function 155e can switch between 1D-WSS display and 3D-WSS display depending on the rotation angle. To give one example, while rotating the coronary arteries, the display control function 155e displays the coronary arteries closest to the center of the display image using 3D-WSS, and the coronary arteries farther from the center of the display image using 1D-WSS. For example, the coronary arteries consist of three blood vessels: the LAD, LCX, and RCA, which run around the heart. Therefore, while rotating the coronary arteries, the display control function 155e displays one of the three blood vessels closest to the center of the display image using 3D-WSS, and the other blood vessels farther from the center of the display image using 1D-WSS. In other words, the display control function 155e switches to 3D-WSS display for each coronary artery blood vessel when it comes near the center of the displayed image as the image rotates, and switches to 1D-WSS display when it moves away from the center.

In this way, the coronary arteries close to the central position of interest are displayed in detailed 3D, and conversely, the coronary arteries displayed to the side are displayed in 1D rather than in detailed, allowing for a simplified and easy-to-understand view of the general trends, preventing oversight even when the distribution of values for the coronary arteries displayed to the side is unfavorable.

Furthermore, for example, when using the display conditions for the display image, the display control function 155e switches between 1D-WSS display and 3D-WSS display depending on whether the color image is enlarged or reduced. For example, if the color image is enlarged at a magnification rate exceeding the threshold, the display control function 155e displays it using 3D-WSS. On the other hand, if the color image is reduced at a reduction rate exceeding the threshold, the display control function 155e displays it using 1D-WSS.

Here, the display control function 155e can perform display control that combines control based on rotation/non-rotation and control based on the display conditions described above. For example, when displaying using 1D-WSS in rotated display mode, if the display image is enlarged at a magnification rate exceeding a threshold, the display control function 155e switches to 3D-WSS display. Furthermore, when displaying using 3D-WSS in non-rotated display mode, if the display image is reduced at a reduction rate exceeding a threshold, the display control function 155e switches to 1D-WSS display. Furthermore, for example, when the display image is enlarged or reduced in rotated display mode or non-rotated display mode, the display control function 155e can change the type of medical image (e.g., CT image) used for the display image. For example, when the display image is enlarged at a magnification rate exceeding a threshold or reduced at a reduction rate exceeding a threshold, the display control function 155e displays a display image using a predetermined type of medical image.

Furthermore, for example, when using the WSS calculation results, the display control function 155e uses 3D-WSS to display positions that are likely to be gazed upon by the user (positions with characteristic WSS or positions where plaque is present). For example, when performing rotational display using 1D-WSS, the display control function 155e switches to 3D-WSS display when a position where the WSS value is above a threshold or below the threshold approaches the front of the screen. Furthermore, for example, the display control function 155e identifies the position of plaque or calcification in a coronary artery, and switches to 3D-WSS display when the identified position approaches the front of the screen. The display control function 155e can appropriately use existing methods to identify the position of plaque or calcification in a coronary artery. For example, there are methods that use image processing based on the distribution of pixel values and machine learning.

(Rotational speed)
The rotation speed in the above-described rotation display can be changed as appropriate according to various conditions. Specifically, the display control function 155e can arbitrarily change the rotation speed during the rotation display based on the calculation result of WSS, the properties of blood vessels, etc.

For example, when using the WSS calculation results, the display control function 155e controls the rotation display so that the rotation speed is reduced at the timing when the position of the blood vessel for which the maximum and minimum WSS values were calculated is displayed. In other words, the display control function 155e slows the rotation speed when the position showing the characteristic WSS value approaches the front of the screen.

Figure 6 is a diagram illustrating an example of speed adjustment of the rotation speed according to the first embodiment. Here, Figure 6 shows a graph with the rotation speed on the vertical axis and the rotation angle on the horizontal axis. Also in Figure 6, curve L1 shows the rotation speed when the calculated spatial distribution of WSS includes a characteristic WSS value, and curve L2 shows the rotation speed when the calculated spatial distribution of WSS does not include a characteristic WSS value.

For example, as shown by curve L1 in Figure 6, the display control function 155e reduces the rotation speed as the position indicating the maximum WSS approaches the front of the screen, and increases the rotation speed as the position indicating the maximum WSS moves away from the front of the screen. Furthermore, as shown by curve L1 in Figure 6, the display control function 155e reduces the rotation speed as the position indicating the minimum WSS approaches the front of the screen, and increases the rotation speed as the position indicating the minimum WSS moves away from the front of the screen, thereby restoring the original speed.

The rotation speed adjustment described above may be performed at the maximum and minimum values for the entire coronary artery, or at the maximum and minimum values for each branch of the coronary artery. Furthermore, the rotation speed adjustment described above may be performed not only at the positions showing the maximum and minimum values, but also at positions showing WSS values above the threshold and positions showing WSS values below the threshold.

Furthermore, if the calculated spatial distribution of WSS does not include a characteristic WSS value, the display control function 155e rotates the display image at a constant rotation speed, as shown by curve L2 in Figure 6.

Furthermore, when using blood vessel characteristics, the display control function 155e controls the rotation display so that the rotation speed is reduced at the timing when the position of the vascular lesion is displayed. For example, the display control function 155e controls the rotation speed to slow down as the position where plaque or calcification is detected approaches the front of the screen, and to increase the rotation speed as the position where plaque or calcification is detected moves away from the front of the screen, and then to return to the original speed.

The display control function 155e can also perform control that combines the above-mentioned rotation speed adjustment with display mode switching (switching between 1D-WSS display and 3D-WSS display). Figure 7 is a diagram illustrating an example of display control by the display control function according to the first embodiment. Figure 7 shows a case in which speed adjustment on the curve L1 shown in Figure 6 is combined with display mode switching.

For example, as shown in Figure 7, a reference speed is set for the rotation speed. Here, the reference speed is set arbitrarily, for example, in advance for each user or each examination content. Then, the display control function 155e displays using 1D-WSS when the rotation speed is faster than the reference speed, and displays using 3D-WSS when the rotation speed is slower than the reference speed.

(Display direction control process)
In the above-described rotational display, the display direction can be changed as appropriate according to various conditions. Specifically, the display control function 155e can arbitrarily change the display direction of the display image during the rotational display based on the calculation result of the WSS, the properties of the blood vessels, etc.

For example, in a rotated display, as the positions of the blood vessels where the maximum and minimum WSS values are calculated or the positions of the vascular lesions approach the front of the screen, the display control function 155e adjusts the vertical direction of the rendering so that the direction of the blood vessels at those positions becomes approximately parallel to the screen.

(Display of additional information)
When displaying the display image described above, various additional information can be added to the image. Specifically, the display control function 155e can display a display image to which additional information related to the WSS calculation result has been added. More specifically, the display control function 155e displays a display image in which the WSS value at each position of the blood vessel is reflected in a three-dimensional image of the blood vessel, and adds information indicating the validity of the calculation result to positions where the validity of the calculation result is low.

For example, when calculating WSS, there may be cases where WSS cannot be calculated in parts of the image due to noise contained in the image or other factors. Therefore, the display control function 155e displays additional information indicating that WSS calculation failed at the position in the displayed image where WSS could not be calculated.

Figure 8A is a diagram showing an example of the display of additional information according to the first embodiment. For example, as shown in Figure 8A, the display control function 155e displays an "E" indicating an error at a position where the WSS could not be calculated.

Here, the display control function 155e can control the display of the above-mentioned additional information in combination with the rotational display. For example, when the display image is rotated, the display control function 155e displays an "E" indicating an error at positions where the WSS could not be calculated as the positions approach the front of the screen. Then, when the display image is rotated, the display control function 155e controls the display so that the "E" displayed at the positions where the WSS could not be calculated disappears as the positions move away from the front of the screen.

The display control function 155e can also control the display of the additional information described above in combination with the rotation speed. For example, when rotating the display image, the display control function 155e changes the rotation speed as the position where WSS could not be calculated approaches the front of the screen.

Figure 8B is a diagram illustrating an example of speed control of the rotation speed based on additional information according to the first embodiment. Here, Figure 8B shows a graph with the rotation speed on the vertical axis and the rotation angle on the horizontal axis. For example, the display control function 155e controls the rotation speed to increase as the position where the error exists approaches the front of the screen, and to decrease the rotation speed as the position where the error exists moves away from the front of the screen, so that the original speed is restored.

(Output of calculation results and judgment results)
The medical image processing apparatus 150 can output the calculation results and determination results of the index values described above to various output destinations. Specifically, the control function 155f transfers the calculation results and determination results of the index values to a predetermined transfer destination.

For example, the control function 155f can transfer information about the WSS of a blood vessel position specified by the user to various destinations. Figure 9 is a diagram for explaining an example of information transfer by the control function 155f according to the first embodiment. Here, Figure 9 shows a case where the control function 155f transfers information about a blood vessel position specified by the user to an interpretation report.

For example, as shown in FIG. 9, the display control function 155e first displays a VR image on the display 154. Here, the display control function 155e displays a color image that reflects a color according to the WSS value on the VR image of the coronary arteries, for example, and performs the rotational display described above. Then, when the user performs a designation operation to designate a position on the color image via the input interface 153, the display control function 155e displays an enlarged image of the designated position (area).

Here, the display control function 155e displays a cross-sectional image of the original image (e.g., an MPR image in a CT image) corresponding to the specified position (area) alongside the enlarged image, as shown in Figure 9. In this way, the display control function 155e displays various information on the display 154 in response to various operations from the user.

When the user performs a transfer operation via the input interface 153, the information subject to the transfer operation is transferred to the transfer destination. For example, as shown in FIG. 9, the control function 155f outputs, for the radiology report, an enlarged image, a cross-sectional image, and information indicating the WSS value at the specified blood vessel position, such as "The maximum WSS at the RCE plaque position is 8 Pa."

Note that the information shown in FIG. 9 is merely an example, and the control function 155f can transfer various other information. For example, the control function 155f can transfer to the radiology report other characteristic WSS values (high WSS values, low WSS values, etc.) and information related to WSS obtained from coronary artery morphology information (e.g., the distance from the branching point of the coronary artery in the specified region, the distance from large calcifications, etc.).

The control function 155f can also transfer the calculated WSS and assessment results to the medical image storage device 120, each department system 130, and the medical information display device 140. For example, the control function 155f transfers the calculated WSS value to a viewer used by the user, a workstation, an electronic medical record system, etc. Each device stores the transferred WSS value in its own memory circuitry. The control function 155f may also transfer only characteristic values of the calculated WSS to each of the above-mentioned devices. Furthermore, if the location of plaque is known in advance or if plaque coordinate information has been recorded by determining it using existing technology, the control function 155f may transfer only the WSS at the location where plaque is present based on that information. Furthermore, for example, the control function 155f may also transfer the above-mentioned color image to a PACS.

Here, the control function 155f can also transfer the above-mentioned information separately for each vascular branch. For example, the control function 155f transmits the maximum and minimum WSS values for each coronary artery vascular branch to various devices on the network 160.

The control function 155f can also switch the transfer destination of the WSS calculation results depending on the index value related to blood flow in the blood vessel. In such cases, the calculation function 155c simultaneously calculates index values other than WSS (e.g., FFR). The control function 155f switches the device to which the WSS is transferred depending on the index value calculated at the same time.

For example, if the FFR value is greater than the threshold, the control function 155f transfers the WSS calculation result to the workstation used for interpretation. On the other hand, if the FFR value is less than the threshold, the control function 155f transfers the WSS calculation result to the electronic medical record, the doctor's mobile phone, email address, etc. This allows the control function 155f to quickly notify the doctor of the calculation result when the FFR value is small and the urgency is considered high.

The control function 155f can also transfer information related to the calculation of wall shear stress to the 3D printer. In such a case, for example, the 3D printer is connected to the network 160, and the control function 155f transmits the coronary artery morphology information calculated during the WSS calculation process and the WSS calculation results to the 3D printer. At this time, the control function 155f may determine and control whether to transfer the information to the 3D printer depending on the WSS value. For example, if the maximum WSS value is higher than a predetermined reference value, the information may be transferred to the 3D printer, and if it is lower, the control function 155f may not transfer the information to the 3D printer.

The 3D printer uses the received morphological information and the WSS calculation results to generate a coronary artery model specific to the subject. For example, the 3D printer generates a coronary artery model using a predetermined material (such as resin) based on the received morphological information. In doing so, the 3D printer generates the model using a material and color that corresponds to the WSS value. Note that the material and color that correspond to the WSS value are preset in the 3D printer.

The control function 155f also transfers the WSS calculation results to a medical imaging diagnostic device. For example, the control function 155f transfers the WSS calculation results to an intravascular imaging device using intravascular ultrasound (IVUS) or optical coherence tomography (OCT).

For example, the control function 155f monitors the registration information in each department system 130 to determine whether an IVUS or OCT has been scheduled. When an IVUS or OCT is scheduled, the control function 155f further determines whether information about the WSS has been saved for the subject for whom the appointment is scheduled. If WSS information has been saved for the subject, the control function 155f acquires the saved WSS information and transfers it to the intravascular imaging device.

In addition, the control function 155f can acquire images captured by an intravascular imaging device in response to user operations and display the acquired images with WSS information superimposed on them. In such cases, the control function 155f first acquires images from the intravascular imaging device and aligns them with the coronary artery CT image used to calculate the WSS. For example, the control function 155f performs alignment based on anatomical features contained in each image.

Then, based on the alignment results, the display control function 155e displays a display image in which the corresponding WSS value is superimposed on each position of the coronary artery in the image received from the intravascular imaging device. The control function 155f also transfers the display image with the WSS value superimposed to the intravascular imaging device. This allows the intravascular imaging device to display IVUS or OCT images showing the WSS values.

(Linkage with other devices)
For example, the medical image processing apparatus 150 can perform processing in cooperation with other devices on the network 160. For example, the control function 155f cooperates with the RIS to perform control so as to secure computational resources for calculating WSS at the scheduled time when a reservation for a coronary artery CT image is made in the RIS. The control function 155f may also accept input regarding the image size and various parameters at the time the reservation is made. The control function 155f can also estimate the calculation end time from the reservation information and return the estimated calculation end time to the user.

In addition, the control function 155f outputs a notification prompting the user to make a reservation for an examination device based on the calculated WSS results. For example, if the WSS value at the location where plaque is present is very high, the control function 155f assumes that the patient in the image is at high risk, and automatically makes a reservation for an intravascular OCT examination or an operating room reservation. In addition, for example, if the WSS value at the location where plaque is present is very high, the control function 155f sends a notification to the user prompting the user to make a reservation for an intravascular OCT examination.

In the above-described embodiment, the control function 155f transfers the WSS calculation result to an external device. However, the embodiment is not limited to this. For example, the control function 155f can also transfer the judgment result of the judgment function 155b along with the WSS calculation result. In other words, the control function 155f can transfer the judgment result of the validity of the calculation target and the judgment result of the validity of the WSS calculation result together with the WSS calculation result.

Furthermore, in the above-described embodiment, a case has been described in which the determination process is performed after image data has been acquired. However, the embodiment is not limited to this, and for example, the determination process may first be performed by acquiring image data of items that satisfy the conditions.

In such cases, when the target imaging test (e.g., CT) is performed, the X-ray CT device 110 transfers the imaging conditions for the captured image to the medical image processing device 150. Alternatively, the imaging conditions set on the RIS may be transferred to the medical image processing device 150. The determination function 155b compares the transferred imaging conditions with predetermined conditions to determine whether the conditions are met. Note that, depending on the conditions set, information may be obtained from the electronic medical record to make the determination. If it is determined that the imaging conditions satisfy the conditions, the acquisition function 155a requests the X-ray CT device 110 or the medical image storage device 120 to provide the corresponding image data.

As described above, according to the first embodiment, the display information generation function 155d generates a three-dimensional image of blood vessels that reflects the WSS value for each position in the blood vessel. The display control function 155e changes the display format of the display image, in which the WSS value is reflected in the three-dimensional image, between rotated and non-rotated display. Therefore, the medical image processing device 150 according to the first embodiment can appropriately display the display image depending on the situation, making it possible to reduce the effort required by the user when diagnosing heart disease, formulating treatment plans, etc.

Furthermore, according to the first embodiment, when the display image is rotated, the display control function 155e displays a 1D-WSS on the image of the blood vessel, showing the spatial distribution of WSS values at each cross-sectional position of the blood vessel relative to the blood vessel's centerline, and when the display image is not rotated, it displays a 3D-WSS on the image of the blood vessel, showing the spatial distribution of WSS values at each position within the blood vessel or on the blood vessel wall. Therefore, the medical image processing device 150 according to the first embodiment makes it possible to automatically perform appropriate display when rotated and when not rotated.

Furthermore, according to the first embodiment, the display control function 155e further changes the display format of the display image depending on the rotation conditions of the display image. Therefore, the medical image processing apparatus 150 according to the first embodiment enables more appropriate display.

Furthermore, according to the first embodiment, the display control function 155e further changes the display format of the display image depending on the display conditions of the display image. Therefore, the medical image processing apparatus 150 according to the first embodiment enables more appropriate display.

Furthermore, according to the first embodiment, the display control function 155e further changes the display format of the display image depending on the size of the display area in which the display image is displayed. Therefore, the medical image processing apparatus 150 according to the first embodiment enables more appropriate display.

Furthermore, according to the first embodiment, the display control function 155e changes the rotation speed of the displayed image based on the WSS calculation results. Therefore, the medical image processing apparatus 150 according to the first embodiment enables a rotated display that is easier to observe.

Furthermore, according to the first embodiment, the display control function 155e controls the rotational display so that the rotation speed is reduced at the timing when the position of the blood vessel for which the maximum and minimum WSS values are calculated is displayed. Therefore, the medical image processing device 150 according to the first embodiment makes it possible to display the position to be focused on at a rotation speed that makes it easy to observe.

Furthermore, according to the first embodiment, the display control function 155e controls the rotation display so that the rotation speed is increased at the timing when the position of a blood vessel for which the WSS calculation result is incorrect is displayed. Therefore, the medical image processing device 150 according to the first embodiment makes it possible to pass through positions where observation should be omitted at a high rotation speed.

Furthermore, according to the first embodiment, the display control function 155e changes the rotation speed of the displayed image based on the characteristics of the blood vessels. Therefore, the medical image processing device 150 according to the first embodiment makes it possible to switch the rotation speed at the position to be focused on.

Furthermore, according to the first embodiment, the display control function 155e controls the rotation display so that the rotation speed is reduced at the timing when the position of the vascular lesion is displayed. Therefore, the medical image processing device 150 according to the first embodiment makes it possible to appropriately observe the lesion that requires attention.

Furthermore, according to the first embodiment, the determination function 155b determines the validity of the calculation target when calculating WSS. The display control function 155e displays the validity determination results. Therefore, the medical image processing apparatus 150 according to the first embodiment makes it possible to select only highly reliable targets as calculation targets.

Furthermore, according to the first embodiment, the determination function 155b determines the validity of the calculation results when calculating WSS. The display control function 155e displays the determination result of the validity of the calculation results. Therefore, the medical image processing apparatus 150 according to the first embodiment makes it possible to target only highly reliable results.

Furthermore, according to the first embodiment, the display control function 155e displays a list of WSS calculation results for each subject, and highlights results in the list that deviate from the reference value. Therefore, the medical image processing apparatus 150 according to the first embodiment makes it possible to make a diagnosis based on the results with the highest priority.

Furthermore, according to the first embodiment, the display control function 155e also displays analysis results other than WSS in the list. Therefore, the medical image processing device 150 according to the first embodiment enables comprehensive diagnosis.

Furthermore, according to the first embodiment, the display control function 155e displays a three-dimensional image of the blood vessel in which the WSS values at each position of the blood vessel are reflected, and adds information indicating the validity of the calculation results to positions where the validity of the calculation results is low. Therefore, the medical image processing device 150 according to the first embodiment makes it possible to grasp at a glance the positions of results with low reliability.

Furthermore, according to the first embodiment, the calculation function 155c calculates the WSS value at each position in the blood vessel. The control function 155f transfers the WSS calculation results to a predetermined destination. Therefore, the medical image processing apparatus 150 according to the first embodiment makes it possible to transfer the WSS results to various destinations.

Furthermore, according to the first embodiment, the control function 155f transfers the WSS calculation results to the medical report. Therefore, the medical image processing device 150 according to the first embodiment makes it possible to reduce the effort required to create the medical report.

Furthermore, according to the first embodiment, the control function 155f transfers information related to the WSS calculation to the 3D printer. Therefore, the medical image processing device 150 according to the first embodiment makes it possible to easily generate a model based on the WSS results.

Furthermore, according to the first embodiment, the control function 155f transfers the WSS calculation results to the medical image diagnostic device. Therefore, the medical image processing device 150 according to the first embodiment makes it possible to reflect the WSS results in the medical image.

Furthermore, according to the first embodiment, the control function 155f switches the transfer destination of the WSS calculation results depending on the index value related to blood flow in the blood vessel. Therefore, the medical image processing apparatus 150 according to the first embodiment makes it possible to transfer the WSS results to an appropriate transfer destination depending on the index value.

Furthermore, according to the first embodiment, the control function 155f reserves an examination device or outputs a notification prompting the reservation of an examination device based on the WSS calculation results. Therefore, the medical image processing device 150 according to the first embodiment makes it possible to reliably make the necessary subsequent arrangements based on the WSS results.

Furthermore, according to the first embodiment, the control function 155f controls the allocation of computational resources to be used for calculating WSS in accordance with the reservation for medical image data collection used for calculating WSS. Therefore, the medical image processing apparatus 150 according to the first embodiment enables smooth scheduling of WSS calculations.

Second Embodiment
In the first embodiment described above, the WSS is calculated in advance each time image data is collected. In the second embodiment, the WSS is calculated in response to a user instruction. The medical image processing apparatus 150 according to the second embodiment differs from the first embodiment in the processing performed by the display control function 155e. This point will be mainly described below.

First, the processing procedure by the medical image processing apparatus 150 according to the second embodiment will be described using FIG. 10. FIG. 10 is a flowchart showing the processing procedure performed by each processing function of the processing circuitry 155 of the medical image processing apparatus according to the second embodiment. Note that FIG. 10 shows an example in which WSS is calculated in response to a WSS calculation instruction from the user.

For example, as shown in FIG. 10, in this embodiment, when a start operation is received via the input interface 153 (step S201, yes), the acquisition function 155a acquires coronary artery CT images of the specified subject from the X-ray CT scanner 110 or medical image storage device 120 (step S202). This process is realized, for example, by the processing circuitry 155 calling up and executing a program corresponding to the acquisition function 155a from the memory circuitry 152. Note that the system remains in a standby state until a start operation is received via the input interface 153 (step S201, no).

Next, the determination function 155b determines whether the conditions are met when the acquired coronary artery CT image is used as the target (step S203). Specifically, the determination function 155b determines whether the acquired coronary artery CT image is appropriate for use in calculating WSS. This process is realized, for example, by the processing circuitry 155 retrieving and executing a program corresponding to the determination function 155b from the storage circuitry 152.

Here, if the determination function 155b determines that the condition is met (step S203, yes), the medical image processing device 150 proceeds to step S204. On the other hand, if the determination function 155b determines that the condition is not met (step S203, no), the medical image processing device 150 proceeds to step S205.

When the process proceeds to step S205, the display control function 155e outputs a warning (step S205). For example, the display control function 155e causes the display 154 to display a warning indicating that the acquired coronary artery CT image is not appropriate for use in calculating WSS. This process is realized, for example, by the processing circuitry 155 calling up and executing a program corresponding to the display control function 155e from the memory circuitry 152.

Next, the calculation function 155c determines whether to continue processing (step S206). For example, the calculation function 155c determines whether it has been instructed to continue or to stop processing via the input interface 153. This processing is realized, for example, by the processing circuitry 155 calling up and executing a program corresponding to the calculation function 155c from the memory circuitry 152.

Here, if the calculation function 155c determines to continue (step S206, yes), the medical image processing device 150 proceeds to step S204. On the other hand, if the calculation function 155c determines not to continue (step S206, no), the medical image processing device 150 returns to step S201 and performs the determination process.

When the process proceeds to step S204, the calculation function 155c calculates an index value related to blood flow based on the coronary artery CT image of the subject acquired by the acquisition function 155a (step S204). For example, the calculation function 155c calculates WSS. This process is realized, for example, by the processing circuitry 155 calling up and executing a program corresponding to the calculation function 155c from the memory circuitry 152.

Next, the determination function 155b determines whether the calculation result is appropriate (step S207). Specifically, the determination function 155b determines whether the calculation result of WSS calculated by the calculation function 155c is valid. This process is realized, for example, by the processing circuitry 155 calling up and executing a program corresponding to the determination function 155b from the memory circuitry 152.

Here, if the judgment function 155b judges that it is appropriate (step S207, yes), the medical image processing device 150 proceeds to step S208. On the other hand, if the judgment function 155b judges that it is not appropriate (step S207, no), the medical image processing device 150 proceeds to step S209.

When the process proceeds to step S2059, the display control function 155e outputs a warning (step S209). For example, the display control function 155e displays a warning on the display 154 indicating that the calculated WSS value is invalid. This process is realized, for example, by the processing circuitry 155 calling up and executing a program corresponding to the display control function 155e from the memory circuitry 152.

Next, the display control function 155e determines whether to continue processing (step S210). For example, the display control function 155e determines whether an instruction to continue or to stop has been received via the input interface 153. This processing is realized, for example, by the processing circuitry 155 calling up and executing a program corresponding to the display control function 155e from the memory circuitry 152.

Here, if the display control function 155e determines to continue (step S210, yes), the medical image processing device 150 proceeds to step S208. On the other hand, if the display control function 155e determines not to continue (step S210, no), the medical image processing device 150 returns to step S201 and performs the determination process.

When the process proceeds to step S208, the display information generation function 155d generates display information related to the results, and the display control function 155e displays the generated display information on the display 154 (step S208). This process is realized, for example, by the processing circuitry 155 calling up and executing a program corresponding to the display information generation function 155d and a program corresponding to the display control function 155e from the memory circuitry 152.

Next, the display control function 155e switches between displaying 1D-WSS and 3D-WSS depending on the display method (step S211). For example, the display control function 155e changes the display format so that 1D-WSS is displayed when rotating and 3D-WSS is displayed when not rotating. This process is realized, for example, by the processing circuitry 155 calling up and executing a program corresponding to the display control function 155e from the memory circuitry 152.

Next, the display control function 155e determines whether the display conditions have been changed (step S212). For example, the display control function 155e determines whether the rotation conditions or display conditions have been changed. For example, the display control function 155e determines whether the rotation conditions, including at least one of the number of rotations and the rotation speed, or the display conditions, including zooming in or out, have been changed. If the display conditions have been changed (step S212, yes), the display control function 155e further changes the display form (step S213). On the other hand, if the display conditions have not been changed (step S212, no), the display control function 155e proceeds to step S214.

Next, the display control function 155e determines whether an end operation has been received via the input interface 153 (step S212). If an end operation has been received (step S212, yes), the medical image processing device 150 ends processing. On the other hand, if an end operation has not been received (step S212, no), the medical image processing device 150 returns to step S211 and continues switching the display.

(warning display)
As described above, the display control function 155e according to the second embodiment outputs a warning in accordance with the result of the determination process by the determination function 155b. For example, the display control function 155e can display a warning in accordance with each determination result and can also display information on the display 154 notifying whether different image data is to be acquired.

Furthermore, for example, the display control function 155e can also display a warning if an event that is difficult to predict in advance, such as a power outage or a computer malfunction, occurs and the calculation does not complete normally.

In addition to displaying a warning, the display control function 155e can automatically search for images that meet the conditions from the medical image storage device 120 or X-ray CT device 110 on the network 160 and present them as candidates. In such cases, the determination function 155b performs a determination process on image data of the same subject stored in the medical image storage device 120 or X-ray CT device 110 to extract image data that meets the conditions. The display control function 155e then displays information about the extracted image data (candidates for calculation) on the display 154. Here, the determination conditions used by the determination function 155b may be newly set conditions for presenting candidates. For example, the conditions for presenting candidates may be set based on the strength of the impact on the calculation accuracy in the WSS calculation.

In addition, the display control function 155e can display warnings not only about WSS, but also about other index values. For example, the display control function 155e displays a warning about calculations similar to WSS (such as FFR), as these calculations are likely to cause problems.

Note that the determination function 155b according to the second embodiment performs the same determination processing as in the first embodiment.

As described above, according to the second embodiment, the display control function 155e displays a warning depending on the determination of the validity of the calculation target and the validity of the WSS calculation result. Therefore, the medical image processing apparatus 150 according to the second embodiment enables efficient WSS calculation.

(Third embodiment)
In the third embodiment, various modes for displaying a cross-sectional image showing a cross section of a blood vessel will be described. For example, the display control function 155e according to the third embodiment displays, as a display image, an image to which a WSS value at a pixel position corresponding to the pixel value of each pixel in the cross-sectional image showing a cross section of a blood vessel is assigned. The input interface 153 accepts an input operation for moving the position of the cross section to be displayed as a display image. The display control function 155e changes the speed of movement of the position of the cross section based on the input operation, based on the calculation result of the WSS.

Figure 11 is a diagram illustrating an example of display control by the display control function according to the third embodiment. Figure 11 illustrates the display of short-axis cross-sectional images (cross-cut images), which are cross-sections perpendicular to the centerline of a blood vessel, as cross-sectional images showing the cross-section of a blood vessel. For example, as shown in Figure 11, the display control function 155e displays a VR image of a coronary artery in display area A1, and displays short-axis cross-sectional images of the coronary artery at various positions in display areas A21 to A26. The display control function 155e can display an image in which each pixel of the short-axis cross-sectional image is expressed according to the WSS value corresponding to each pixel position. For example, a color image expressed in a color according to the WSS value can be displayed. Alternatively, an image expressed using transparency, brightness, grayscale values, textures, symbols, marks, or the like according to the WSS value may be displayed. Of course, these are merely examples, and any image expressed according to the WSS value may be displayed.

The input interface 153 accepts scrolling operations on the scroll bar B1. Here, the scroll bar B1 shown in FIG. 11 is a GUI for switching between the short-axis cross-sectional images displayed in the display areas A21 to A26 from among the multiple short-axis cross-sectional images generated at positions along the centerlines of the coronary arteries. In other words, by operating the scroll bar B1 via the input interface 153, the user can switch between the short-axis cross-sectional images displayed in the display areas A21 to A26 along the centerlines of the coronary arteries. In the following description, it is assumed that the speed at which the short-axis cross-sectional images are switched is specified by an input operation performed by the user using the input interface 153.

First, we will explain how to switch short-axis cross-sectional images by operating the scroll bar B1. The user uses the input interface 153 to operate the mouse pointer displayed on the screen. The scroll bar B1 displays icons (rectangular areas within the scroll bar B1), which conceptually indicate which positions of the short-axis cross-sectional images of the blood vessels to be displayed are displayed in the display areas A21 to A26. That is, when the icon is located at the top of the scroll bar B1, multiple short-axis cross-sectional images near the origin of the blood vessels are displayed; when the icon is located at the bottom of the scroll bar B1, multiple short-axis cross-sectional images near the distal end of the blood vessels are displayed. The user operates the mouse pointer and drags the icon to specify the destination of the icon. The display control function 155e sequentially switches from the short-axis images already displayed in the display areas A21 to A26 to short-axis images that are not currently displayed, according to the destination of the specified icon. Specifically, the image displayed at position A22 is moved to position A21, and the image displayed at position A23 is moved to position A22, and this switching is repeated, with the short-axis cross-sectional image that was not displayed when the input operation began being displayed in A26. By sequentially repeating this display position switching, the display of short-axis images that were not displayed progresses, and the switching ends when the short-axis cross-sectional image corresponding to the position of the specified icon is displayed in display areas A21 to A26.

Instead of dragging the icon, this operation can also be performed by using the mouse pointer to specify a position on the scroll bar B1 and clicking the mouse to confirm the position, which will scroll the icon to the specified position and switch the display of short-axis images in conjunction with the scrolling of the icon.

Next, we will explain the switching speed of short-axis cross-sectional images. As described above, the user operates the scroll bar B1 to switch to and display short-axis cross-sectional images that were not displayed when the input operation began. The speed of this switching display increases the greater the distance between the icon position when the input operation began and the destination position of the icon specified by the user via a drag operation, etc., and conversely, the speed decreases the closer the distance.

The display control function 155e according to the third embodiment changes the speed at which cross-section positions are switched based on input operations, based on the WSS calculation results, when switching between short-axis cross-sectional images in response to operation of the scroll bar B1. For example, when a short-axis cross-sectional image of a blood vessel position for which the maximum and minimum WSS values have been calculated is displayed, the display control function 155e reduces the switching speed in the display areas A21 to A26 of the short-axis cross-sectional image. Note that, similar to the conditions for controlling the rotation speed in the rotational display described in the above embodiment, the display control function 155e according to the third embodiment can change the switching speed in the display areas A21 to A26 of the short-axis cross-sectional image based on the position where an error exists in the WSS calculation results, the characteristics of the blood vessel, the location of the lesion, etc.

Furthermore, the display control function 155e according to the third embodiment can change the display format of short-axis tomographic images in accordance with the switching speed of the tomographic images based on an input operation. For example, when a user operates the scroll bar B1 via the input interface 153 to switch between short-axis tomographic images displayed in the display areas A21 to A26 along the centerlines of the coronary arteries, if the user scrolls the scroll bar B1 at a speed equal to or greater than a predetermined threshold, the display control function 155e displays the short-axis tomographic images as images expressed in colors corresponding to the 1D-WSS values. On the other hand, if the user scrolls the scroll bar B1 at a speed less than the predetermined threshold, the display control function 155e displays the short-axis tomographic images as images expressed in colors corresponding to the 3D-WSS values.

In the above example, a case has been described in which a short-axis tomographic image is displayed as a cross-sectional image showing a cross section of a blood vessel, but the display control function 155e can also display a CPR image as a cross-sectional image showing a cross section of a blood vessel. FIG. 12 is a diagram illustrating an example of display control by the display control function according to the third embodiment. For example, as shown in FIG. 12, the display control function 155e displays a VR image of a coronary artery in display area A1 and a CPR image of the coronary artery in display area A3. Note that, as in the case of a short-axis tomographic image, the display control function 155e can display an image in which each pixel of the CPR image is represented according to the WSS value corresponding to each pixel position.

Here, the display control function 155e changes the speed at which the position of the cross section is switched based on the input operation for the CPR image, similar to the display of the short-axis cross-sectional image, based on the WSS calculation results. In such a case, for example, the scroll bar B1 is a GUI that switches the position of the CPR image displayed in the display area A3 along the direction of the blood vessels.

When switching the display position of a CPR image in response to operation of scroll bar B1 shown in FIG. 12, the display control function 155e changes the speed of position switching based on input operations based on the WSS calculation results. For example, the display control function 155e reduces the speed of CPR image switching within display area A3 when the position where the maximum and minimum WSS values are calculated is displayed in the CPR image. Note that the display control function 155e according to the third embodiment can also change the switching speed when displaying a CPR image based on the position where there is an error in the WSS calculation results, the characteristics of the blood vessels, the location of the lesion, etc., similar to the conditions for controlling the rotation speed in the rotational display described in the above embodiment.

Furthermore, the display control function 155e according to the third embodiment can change the display format of a CPR image in accordance with the speed at which the position is switched based on an input operation, even when the CPR image is displayed. For example, when the user operates the scroll bar B1 via the input interface 153 to switch the position of the CPR image displayed in the display area A3, if the user scrolls the scroll bar B1 at a speed equal to or greater than a predetermined threshold, the display control function 155e displays the CPR image as an image expressed in a color corresponding to the 1D-WSS value. On the other hand, if the user scrolls the scroll bar B1 at a speed less than the predetermined threshold, the display control function 155e displays the CPR image as an image expressed in a color corresponding to the 3D-WSS value.

As described above, according to the third embodiment, the display control function 155e displays a display image in which a wall shear stress value is assigned to a cross-sectional image showing a cross-section of a blood vessel. The input interface 153 accepts an input operation to change the position of the cross-section to be displayed as a display image. The display control function 155e changes the speed of the change in the position of the cross-section based on the input operation, based on the calculation result of the wall shear stress. Therefore, the medical image processing device 150 according to the third embodiment allows the user to easily grasp the position of the cross-section that requires attention.

Furthermore, according to the third embodiment, the display control function 155e displays a display image in which a wall shear stress value is assigned to a cross-sectional image showing a cross-section of a blood vessel. The input interface 153 accepts an input operation to change the position of the cross-section to be displayed as the display image. The display control function 155e changes the display form of the display image depending on the speed at which the position of the cross-section is changed based on the input operation. Therefore, the medical image processing device 150 according to the third embodiment makes it possible to appropriately display the WSS depending on the speed at which the display position of the cross-sectional image is changed.

(Other embodiments)
In the above-described embodiment, a case where 1D-WSS showing the WSS at each cross-sectional position of the blood vessel based on the center line of the blood vessel is used as the display format during rotation has been described, but the embodiment is not limited to this. For example, a display equivalent to 1D-WSS may be performed by using the directional average value of the local WSS obtained from 3D-WSS.

Furthermore, in the above-described embodiment, an example was described in which information about the WSS was displayed on the display 144 of the medical image processing device 150, but the embodiment is not limited to this. For example, information about the WSS may also be displayed on the display of the medical information display device 140.

In addition, in the above-described embodiment, an example was described in which the medical image processing device 150 calculates the WSS and displays the calculation results, but the embodiment is not limited to this. For example, when calculating 1D-WSS and 3D-WSS, some calculations may be performed on the server side by using a server-client computer configuration. For example, 3D-WSS, which requires a large amount of calculation, may be calculated on the server side, and 1D-WSS may be calculated on the client side.

Also, for example, the process up to recognizing (extracting) the shape of blood vessels may be performed on the client side, and only the process of calculating WSS using CFD or the like may be performed on the server side. In such cases, rather than transferring the entire image to the server side, only the shape structure extracted on the client side may be transferred to the server side. For example, the server side may store analysis conditions in advance and calculate WSS using the shape structure received from the client side and the stored analysis conditions.

Also, for example, the client side may transfer to the server side, in addition to the shape information, subject-specific blood parameters (such as hematocrit value), boundary conditions, and vascular wall elasticity values. The server side uses this information transferred from the client side to calculate WSS.

Here, the vascular structure information is set to the same value for each structure, and by transmitting only the data associated with the coordinates, data compression can be used to significantly reduce the data size. For example, if there are two types of structures, vascular wall and non-vascular wall, the structures can be expressed using two values, 0 or 1. Similarly, if there are 10 types of structures, the structures can be expressed using 10 values from 0 to 9.

By communicating only the data necessary for calculation between the server and client in this way, transfer speeds and calculation costs on the server side can be reduced. It is also possible to specify the vascular branches to be calculated on the server side based on user instructions, and calculate the WSS for only those vascular branches.

In the above-described embodiment, examples have been described in which the determination unit, calculation unit, generation unit, display control unit, and control unit in this specification are realized by the determination function, calculation function, display information generation function, display control function, and control function of a processing circuit, respectively, but the embodiments are not limited to this. For example, in addition to being realized by the determination function, calculation function, display information generation function, display control function, and control function described in the embodiment, the determination unit, calculation unit, generation unit, display control unit, and control unit in this specification may also be realized by hardware only, software only, or a combination of hardware and software.

The term "processor" used in the above-described embodiments refers to circuits such as a CPU (Central Processing Unit), GPU (Graphics Processing Unit), or an Application Specific Integrated Circuit (ASIC), a programmable logic device (e.g., a Simple Programmable Logic Device (SPLD), a Complex Programmable Logic Device (CPLD), and a Field Programmable Gate Array (FPGA)). Instead of storing a program in a memory circuit, the processor may be configured so that the program is directly embedded in the circuit. In this case, the processor performs its function by reading and executing the program embedded in the circuit. Furthermore, each processor in this embodiment is not limited to being configured as a single circuit, but may also be configured as a single processor by combining multiple independent circuits to perform its function.

The program executed by the processor is provided in advance in a ROM (Read Only Memory) or storage circuit. The program may also be provided in a format that can be installed on these devices or in an executable file format recorded on a computer-readable, non-transitory storage medium such as a CD (Compact Disk)-ROM, FD (Flexible Disk), CD-R (Recordable), or DVD (Digital Versatile Disk). The program may also be stored on a computer connected to a network such as the Internet and provided or distributed by downloading it via the network. For example, the program is composed of modules that include each of the processing functions described above. In actual hardware, the CPU reads and executes the program from a storage medium such as ROM, causing each module to be loaded into and generated on the main memory.

Furthermore, in the above-described embodiments and variations, the components of each device shown in the drawings are functional concepts and do not necessarily have to be physically configured as shown. In other words, the specific form of distribution or integration of each device is not limited to that shown, and all or part of it can be functionally or physically distributed or integrated in any unit depending on various loads, usage conditions, etc. Furthermore, all or any part of the processing functions performed by each device can be realized by a CPU and a program analyzed and executed by the CPU, or can be realized as hardware using wired logic.

Furthermore, among the processes described in the above embodiments and variations, all or part of the processes described as being performed automatically can be performed manually, or all or part of the processes described as being performed manually can be performed automatically using known methods. In addition, the information, including the processing procedures, control procedures, specific names, various data, and parameters shown in the above documents and drawings, can be changed as desired unless otherwise specified.

At least one of the embodiments described above can reduce the effort required of users when diagnosing heart disease and formulating treatment plans.

While several embodiments have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments may be embodied in a variety of other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. These embodiments and their variations are within the scope of the invention and its equivalents as defined in the claims, as well as the scope and spirit of the invention.

With regard to the above embodiment, the following notes are disclosed as one aspect and optional feature of the invention.

(Appendix 1)
an acquisition unit that acquires a three-dimensional image of a blood vessel of a subject and a spatial distribution of a value of wall shear stress at each position of the blood vessel;
a display control unit that displays a display image in which the value of the wall shear stress is assigned to the three-dimensional image from an arbitrary angle;
an input operation receiving unit that receives an input operation to change the angle;
and
the display control unit changes the display form of the display image in which the value of the wall shear stress is assigned to the three-dimensional image between a rotational display in which the display image is displayed while changing the angle over time and a non-rotational display in which the angle is not changed.
Medical imaging equipment.
(Appendix 2)
The display control unit may extract the core line of the blood vessel, and generate a first display image in which one-dimensional information assigned to each core line position is assigned to the three-dimensional image of the spatial distribution of wall shear stress values at each position of the blood vessel, and a second display image in which three-dimensional information assigned to each spatial position of the blood vessel is assigned to the three-dimensional image, and when the display image is to be displayed in a rotated manner, the first display image is displayed, and when the display image is to be displayed non-rotated, the second display image is displayed.
(Appendix 3)
The display control unit may further change a display form of the display image in accordance with at least one of a rotation count and a rotation speed of the display image.
(Appendix 4)
The display control unit may further change a display form of the display image in accordance with the enlargement or reduction of the display image.
(Appendix 5)
The display control unit may further change a display form of the display image in accordance with a size of a display area in which the display image is displayed.
(Appendix 6)
In the rotational display, the display control unit may change a rotation speed of the display image based on the calculation result of the wall shear stress.
(Appendix 7)
The display control unit may perform control such that the rotation speed is reduced at the timing when the positions of the blood vessels at which the maximum and minimum values of the wall shear stress are calculated are displayed in the rotation display.
(Appendix 8)
The display control unit may control the rotation display so as to increase the rotation speed at a timing when a position of a blood vessel for which the calculation result of the wall shear stress is erroneous is displayed.
(Appendix 9)
In the rotation display, the display control unit may change a rotation speed of the display image based on a property of the blood vessel.
(Appendix 10)
The display control unit may perform control such that the rotation speed is reduced at a timing when the position of a lesion site in the blood vessel is displayed in the rotation display.
(Appendix 11)
The method further includes a determination unit that determines the validity of a calculation target in calculating the wall shear stress,
The display control unit may display the result of the validity determination.
(Appendix 12)
a determination unit that determines the validity of a calculation result in calculating the wall shear stress,
The display control unit may display a determination result of the validity of the calculation result.
(Appendix 13)
The display control unit may display a list of the calculation results of the wall shear stress for each subject, and may highlight results that deviate from a reference value in the list.
(Appendix 14)
The display control unit may further display analysis results other than the wall shear stress in the list.
(Appendix 15)
The display control unit may display a display image in which the values of wall shear stress at each position of the blood vessel are reflected in a three-dimensional image of the blood vessel, and add information indicating the validity of the calculation results to positions where the validity of the calculation results is low.
(Appendix 16)
a calculation unit that calculates a value of wall shear stress at each position of the blood vessel;
a control unit that transfers the calculation result of the wall shear stress to a predetermined transfer destination;
may further comprise:
(Appendix 17)
The control unit may transfer the calculation result of the wall shear stress to a medical report.
(Appendix 18)
The control unit may transfer information relating to the calculation of the wall shear stress to a three-dimensional printer.
(Appendix 19)
The control unit may transfer the calculation result of the wall shear stress to a medical image diagnostic apparatus.
(Appendix 20)
The control unit may switch a transfer destination of the calculation result of the wall shear stress depending on an index value related to blood flow in the blood vessel.
(Appendix 21)
The system may further include a control unit that reserves an examination device or outputs a notification urging the user to reserve the examination device based on the calculation result of the wall shear stress.
(Appendix 22)
The system may further include a control unit that controls to secure computational resources to be used for calculating the wall shear stress in accordance with a reservation for collection of medical image data to be used for calculating the wall shear stress.
(Appendix 23)
the display control unit displays a display image in which the value of the wall shear stress is assigned to a cross-sectional image showing a cross section of the blood vessel;
the input operation receiving unit receives an input operation for changing a position of the cross section to be displayed as the display image;
The display control unit may change a speed of changing the position of the cross section based on the input operation, based on a calculation result of the wall shear stress.
(Appendix 24)
the display control unit displays a display image in which the value of the wall shear stress is assigned to a cross-sectional image showing a cross section of the blood vessel;
the input operation receiving unit receives an input operation for changing a position of the cross section to be displayed as the display image;
The display control unit may change a display form of the display image in accordance with a speed at which the position of the cross section is changed based on the input operation.
(Appendix 25)
A medical image processing system including a medical image processing device and a medical information display device,
the medical image processing device acquires a three-dimensional image of a blood vessel of a subject and a spatial distribution of a value of wall shear stress at each position of the blood vessel;
The medical information display device,
a display image in which the value of the wall shear stress is assigned to the three-dimensional image is displayed from an arbitrary angle;
Accepting an input operation to change the angle;
In displaying the display image in which the wall shear stress value is assigned to the three-dimensional image, a display form of the display image is changed between a rotational display in which the display image is displayed while changing the angle over time and a non-rotational display in which the angle is not changed.
Medical image processing system.
(Appendix 26)
Obtaining a three-dimensional image of a blood vessel of a subject and a spatial distribution of wall shear stress values at each position of the blood vessel;
a display image in which the value of the wall shear stress is assigned to the three-dimensional image is displayed from an arbitrary angle;
Accepting an input operation to change the angle;
In displaying the display image in which the wall shear stress value is assigned to the three-dimensional image, a display form of the display image is changed between a rotational display in which the display image is displayed while changing the angle over time and a non-rotational display in which the angle is not changed.
A medical image processing method comprising:

100 Medical image processing system 140 Medical information display device 150 Medical image processing device 155 Processing circuit 155b Determination function 155c Calculation function 155d Display information generation function 155e Display control function 155f Control function

Claims (18)

an acquisition unit that acquires a three-dimensional image of a blood vessel of a subject and a spatial distribution of a value of wall shear stress at each position of the blood vessel;
a display control unit that displays a display image in which the value of the wall shear stress is assigned to the three-dimensional image from an arbitrary angle;
an input operation receiving unit that receives an input operation to change the angle;
and
The display control unit
extracting a center line of the blood vessel;
generating a first display image in which one-dimensional information of the spatial distribution of the wall shear stress value at each position of the blood vessel is assigned to each centerline position to the three-dimensional image, and a second display image in which three-dimensional information of the spatial distribution of the blood vessel is assigned to each spatial position to the three-dimensional image;
In displaying the display image in which the value of the wall shear stress is assigned to the three-dimensional image, the first display image is displayed during a rotational display in which the display image is displayed while changing the angle over time, and the second display image is displayed during a non-rotational display in which the input operation is not accepted and the angle is not changed.
Medical imaging equipment. The medical image processing device of claim 1, wherein the display control unit switches the display image from the first display image to the second display image when the rotation speed of the display image is changed to a threshold value or less during the rotation display, and/or continues displaying the second display image when the rotation display is started at a rotation speed less than the threshold value during the non-rotation display, or changes the type of medical image used for the display image when at least one of the number of rotations and the rotation speed of the display image is less than a threshold value during the rotation display. The medical image processing device of claim 1, wherein the display control unit switches the display image from the first display image to the second display image when the display image is enlarged at a magnification rate exceeding a threshold during the rotated display, and/or switches the display image from the second display image to the first display image when the display image is reduced at a reduction rate exceeding a threshold during the non-rotated display, or changes the type of medical image used for the display image when the display image is enlarged at a magnification rate exceeding a threshold and/or reduced at a reduction rate exceeding a threshold. The medical image processing device according to claim 1, wherein the display control unit changes the type of medical image used for the display image depending on the size of the display area in which the display image is displayed. a determining unit for determining the validity of a medical image from which the spatial distribution of the wall shear stress value is obtained as a medical image from which the wall shear stress value is obtained;
The medical image processing apparatus according to claim 1 , wherein the display control unit displays the validity determination result. a determination unit that determines the validity of the spatial distribution of the wall shear stress value,
The medical image processing apparatus according to claim 1 , wherein the display control unit displays the result of the determination of the validity of the value. 7. The medical image processing device according to claim 1 , wherein the display control unit displays a list of the wall shear stress values for each subject, and emphasizes values in the list that deviate from a reference value. The medical image processing apparatus according to claim 7 , wherein the display control unit further displays analysis results other than the wall shear stress in the list. 7. The medical image processing device according to claim 6, wherein the display control unit displays a display image in which the values of wall shear stress at each position of the blood vessel are reflected in a three-dimensional image of the blood vessel, and adds information indicating that the validity of the values is low at positions where the validity of the values is low. a calculation unit that calculates a spatial distribution of values of wall shear stress at each position of the blood vessel using the three-dimensional image of the blood vessel of the subject acquired by the acquisition unit;
a control unit that transfers the calculation result of the wall shear stress to at least one of a processing unit within the device itself and an external device;
The medical image processing device according to claim 1 , further comprising: The medical image processing apparatus according to claim 10 , wherein the control unit transfers the calculation result of the wall shear stress to a processing unit that processes a medical report. The medical image processing apparatus according to claim 10 , wherein the control unit transfers the vascular morphology information and the calculation result of the wall shear stress to a three-dimensional printer that generates a model of the blood vessel using the received information. The medical image processing apparatus according to claim 10 , wherein the control unit transfers information including the calculation result of the wall shear stress to a medical image diagnostic apparatus. The medical image processing apparatus according to claim 10 , wherein the control unit switches a transfer destination of the calculation result of the wall shear stress depending on an index value related to the blood flow in the blood vessel. The medical image processing device according to claim 1 , further comprising a control unit that reserves an examination device or outputs a notification urging the user to reserve the examination device based on the value of the wall shear stress. The medical image processing device according to any one of claims 10 to 14, further comprising a control unit that acquires reservation information for collection of medical image data used in calculating the wall shear stress, and controls to secure computational resources to be used in calculating the wall shear stress when a reservation for collection of the medical image data is made. A medical image processing system including a medical image processing device and a medical information display device,
the medical image processing device acquires a three-dimensional image of a blood vessel of a subject and a spatial distribution of a value of wall shear stress at each position of the blood vessel;
The medical information display device,
a display image in which the value of the wall shear stress is assigned to the three-dimensional image is displayed from an arbitrary angle;
Accepting an input operation to change the angle;
extracting a center line of the blood vessel;
generating a first display image in which one-dimensional information of the spatial distribution of the wall shear stress value at each position of the blood vessel is assigned to each centerline position to the three-dimensional image, and a second display image in which three-dimensional information of the spatial distribution of the blood vessel is assigned to each spatial position to the three-dimensional image;
In displaying the display image in which the value of the wall shear stress is assigned to the three-dimensional image, the first display image is displayed during a rotational display in which the display image is displayed while changing the angle over time, and the second display image is displayed during a non-rotational display in which the input operation is not accepted and the angle is not changed.
Medical image processing system. Obtaining a three-dimensional image of a blood vessel of a subject and a spatial distribution of wall shear stress values at each position of the blood vessel;
a display image in which the value of the wall shear stress is assigned to the three-dimensional image is displayed from an arbitrary angle;
Accepting an input operation to change the angle;
extracting a center line of the blood vessel;
generating a first display image in which one-dimensional information of the spatial distribution of the wall shear stress value at each position of the blood vessel is assigned to each centerline position to the three-dimensional image, and a second display image in which three-dimensional information of the spatial distribution of the blood vessel is assigned to each spatial position to the three-dimensional image;
In displaying the display image in which the value of the wall shear stress is assigned to the three-dimensional image, the first display image is displayed during a rotational display in which the display image is displayed while changing the angle over time, and the second display image is displayed during a non-rotational display in which the input operation is not accepted and the angle is not changed.
A medical image processing method comprising: