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

Abstract

To provide a medical image processing device capable of improving determination accuracy for a surface that serves as an index in a site having three or more tuft-like structures in a subject.SOLUTION: Volume data including three tuft-like structures of a subject is acquired; three end points on the most upstream side of the tuft-like structures are set; a reference plane including the three end points is set; a first plane including one or two end points and perpendicular to the reference plane is set; a second plane including one or two end points and perpendicular to the reference plane is set, which includes all the three end points when the end points of the first plane are added, different from a combination of the end points of the first plane; a reference image visualizing the reference plane is displayed with three end points on the reference plane; a first image visualizing the first plane is displayed with an end point on the first plane simultaneously with the reference image; a second image visualizing the second plane is displayed with an end point on the second plane simultaneously with the reference image; and the reference plane is updated on the basis of an input operation for moving at least one of the three end points.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to a medical image processing device, a medical image processing method, and a medical image processing program. [Background technology]

[0002] TAVI is known as one of the surgical procedures for patients. TAVI stands for Transcatheter Aortic Valve Implantation. TAVI refers to transcatheter aortic valve replacement. TAVI is also called TAVR. TAVR stands for Transcatheter Aortic Valve Replacement. When planning a TAVI surgery, measurements of the aortic valve are made. Specifically, the annular surface of the aortic valve is obtained, and the circumference and diameter of the annular surface are measured.

[0003] A method for determining the valve annulus plane is known (Non-Patent Document 1). In the method of Non-Patent Document 1, as shown in Section 3.1 and Figure 1, the lowest points of the three coronary cusps included in the valve annulus plane are determined by manipulating points within a cross section of the aortic valve displayed on the axial, sagittal, and coronal planes of the aortic valve. In this process, the axial, sagittal, and coronal planes are rotated or translated within each plane, without changing their mutual perpendicular relationship. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] "Computed tomography imaging in the context of transcatheter aortic valve implantation (TAVI) / transcatheter aortic valve replacement (TAVR): An expert consensus document of the Society of Cardiovascular Computed Tomography", Philipp Blankea, Jonathan R. Weir-McCallb, Stephan Achenbachc, Victoria Delgadod, Jorg Hausleitere, Hasan Jilaihawif, Mohamed Marwanc, Bjarne L. Norgaardg, Niccolo Piazzah,Paul Schoenhageni, Jonathon A. Leipsica, Journal of Cardiovascular Computed Tomography 13 (2019) 1-20 Summary of the Invention [Problem to be solved by the invention]

[0005] The method of Non-Patent Document 1 has room for improvement, as it is difficult to accurately determine the annular plane. Similarly, it is expected to be difficult to determine a plane that serves as an index in a region of the subject that has three or more chamber-like structures, such as the annular plane of the aortic valve.

[0006] The present disclosure provides a medical image processing device, a medical image processing method, and a medical image processing program that can improve the accuracy of determining a plane that serves as an index in a region having three or more tuft-like structures within a subject. [Means for solving the problem]

[0007] One aspect of the present disclosure is a medical image processing device including a processor, wherein the processor acquires volume data including three tuft-like structures of a subject, sets three end points of the three tuft-like structures in the volume data that are the most upstream of each of the three tuft-like structures, sets a reference plane including the three end points, sets a first plane that is a plane that includes one or two of the three end points and is perpendicular to the reference plane, and sets a second plane that is a plane that includes one or two of the three end points that is different from the combination of the one or two end points of the first plane and that includes all of the three end points when combined with the end points of the first plane, and is perpendicular to the reference plane. a reference image that visualizes the reference plane together with the three endpoints included in the reference plane on a display; simultaneously with the reference image, a first image that visualizes the first plane together with the one or two endpoints included in the first plane on the display; simultaneously with the reference image, a second image that visualizes the second plane together with the one or two endpoints included in the second plane on the display; receiving an input operation via a user interface to move at least one of the three endpoints, and moving at least one of the three endpoints based on the input operation to update the reference plane.

[0008] One aspect of the present disclosure includes the steps of: acquiring volume data including three tuft-like structures of a subject; setting three end points of the three tuft-like structures in the volume data that are the most upstream of each of the three tuft-like structures; setting a reference plane including the three end points; setting a first plane that is a plane that includes one or two of the three end points and is perpendicular to the reference plane; setting a second plane that is a plane that includes one or two of the three end points that is different from the combination of the one or two end points of the first plane and that includes all of the three end points when combined with the end points of the first plane, and is perpendicular to the reference plane; A medical image processing method comprising the steps of: displaying a quasi-image on a display together with the three endpoints included in the reference plane; displaying a first image that visualizes the first plane on the display together with the reference image, together with the one or two endpoints included in the first plane; displaying a second image that visualizes the second plane on the display together with the reference image, together with the one or two endpoints included in the second plane; receiving an input operation via a user interface to move at least one of the three endpoints; and moving at least one of the three endpoints based on the input operation and updating the reference plane. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to improve the accuracy of determining a plane that serves as an index in a region having three or more tuft-like structures within a subject. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a block diagram showing an example of the hardware configuration of a medical image processing apparatus according to a first embodiment; [Figure 2] Block diagram showing an example of the functional configuration of a medical image processing device [Figure 3] An example of the annular plane SA, including the lowest points of the three coronary cusps of the aortic valve. [Figure 4]Figure showing an example of annular plane SA based on mask settings [Figure 5] Diagram showing an example of the annular plane and three longitudinal planes [Figure 6] Diagram showing an example of the annular plane and nine longitudinal planes [Figure 7] FIG. 1 shows an example of a reference line drawn on the annulus surface. [Figure 8A] Flowchart showing an example of operation of a medical image processing device (part 1) [Figure 8B] Flowchart showing an example of operation of a medical image processing device (part 2) [Figure 9] A diagram showing a first example of highlighting reference lines [Figure 10] A diagram showing a second example of reference line highlighting. [Figure 11] 10 is a flowchart showing an example of the operation of the medical image processing apparatus according to the second embodiment. [Figure 12] FIG. 10 is a diagram showing an example of a reference line displayed on an auxiliary MPR plane, which indicates the position of a reference MPR plane and the position of another auxiliary MPR plane; DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters or descriptions of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0012] (How the first embodiment of the present disclosure was achieved) For example, calcification of the aortic valve or aging can cause the aortic valve to no longer close properly, resulting in the backflow of blood. In such cases, TAVI, which can reduce the burden on the patient, is sometimes performed. In TAVI, an artificial valve is inserted to replace the aortic valve. This artificial valve is expensive.

[0013] With TAVI, it is necessary to properly estimate the appropriate TAVI valve size for the patient before surgery. It is also necessary to determine whether TAVI is suitable for the patient. It is important to confirm the size of the patient's valve, the size of the aorta, and whether there is sufficient space in the upstream part of the aorta (upstream of the blood circulation, i.e., the coronary arteries, closer to the heart). Therefore, before TAVI surgery, the aortic valve must be measured to determine what type of prosthetic valve can be used. Measuring the aortic valve requires information about the annulus surface, but it is difficult to obtain accurate information about the annulus surface.

[0014] The aortic valve has three chambers (atrium-like structures). These chambers are the NCC, RCC, and LCC. NCC stands for Non-Coronary Cusp and refers to the non-coronary cusp of the aortic valve. RCC stands for Right Coronary Cusp and refers to the right coronary cusp of the aortic valve. LCC stands for Left Coronary Cusp and refers to the left coronary cusp of the aortic valve. The most upstream end point of the NCC is also called the nadir of the NCC. The most upstream end point of the RCC is also called the nadir of the RCC. The most upstream end point of the LCC is also called the nadir of the LCC. The nadir of the NCC, RCC, and LCC are collectively called the nadir of the three coronary cusps. The plane including the nadir of the three coronary cusps is the annulus plane. The circle passing through the nadir of the three coronary cusps is the annulus. The diameter of the annulus is used as an index to estimate the size of a TAVI valve.

[0015] The coronary arteries emerge upstream of the LCC and RCC. Therefore, the artificial valve replaced with an aortic valve by TAVI must not block the entrance of the coronary arteries. Therefore, to determine the size of the artificial valve, it is desirable to accurately grasp the circumference and diameter of the annular surface, and therefore the annular surface. Furthermore, if the distance from the annular surface to the coronary arteries is insufficient, it may be determined that TAVI is not suitable for the patient.

[0016] In the method of Non-Patent Document 1, the center point of an MPR plane is positioned at a characteristic site in the aortic valve and its surroundings. Then, while referring to three mutually perpendicular orthogonal planes (axial, coronal, and sagittal planes are used as initial planes), the plane (MPR plane) is rotated to approach the target plane. In Non-Patent Document 1, due to the limitations that the three orthogonal planes, i.e., the three MPR planes, are mutually perpendicular and the orthogonal point of the three planes is a single point, the final MPR image may not display the three nadir points of the coronary cusps. Furthermore, it is difficult to confirm whether the nadir points of the coronary cusps have been correctly specified. For example, if the nadir point of the first coronary cusp is set at the center of the three orthogonal planes, the nadir points of the other coronary cusps often do not appear on any of the three orthogonal planes. Furthermore, for example, if the center of the three orthogonal planes is set at a point believed to be the first nadir point, and then the nadir points of the second and third coronary cusps are set as the most upstream positions (lowest points), it may be discovered that the first or second nadir point was not the most upstream position (lowest point). In this case, skill is required to perform the work, such as adjusting the lowest point of the second coronal cusp and the lowest point of the third coronal cusp to become the new centers of the three planes of the three orthogonal cross sections.

[0017] In the following embodiments, a medical image processing device, a medical image processing method, and a medical image processing program that can improve the accuracy of determining a surface that serves as an index in a region having three or more tuft-like structures within a subject will be described.

[0018] (First embodiment) 1 is a block diagram showing an example of the configuration of a medical image processing apparatus 100 according to the first embodiment. The medical image processing apparatus 100 includes a port 110, a UI 120, a display 130, a processor 140, and a memory 150.

[0019] A CT device 200 is connected to the medical image processing device 100. The medical image processing device 100 acquires volume data from the CT device 200 and processes the acquired volume data. The medical image processing device 100 may be configured by a PC and software installed on the PC.

[0020] The CT device 200 irradiates an object with X-rays and captures an image (CT image) by utilizing differences in X-ray absorption by tissues within the body. The object may include a living organism, a human body, an animal, or the like. The CT device 200 acquires a sinogram from an X-ray detector and generates a tomographic image of the object (also referred to as a slice image or slice data) by image reconstruction based on the sinogram. The CT device 200 generates volume data based on the slice data, for example, by stacking the slice data. The slice data and volume data include information on any location inside the object. The CT device 200 transmits the volume data as a CT image to the medical image processing device 100 via a wired or wireless connection. The CT image may be captured taking into consideration imaging conditions related to CT imaging and contrast conditions related to the administration of a contrast agent. Contrast imaging may be performed on blood vessels, digestive organs, bile ducts, etc. Contrast imaging may be performed multiple times at different timings depending on the characteristics of the organs.

[0021] The port 110 in the medical image processing apparatus 100 includes a communication port, an external device connection port, a connection port to an embedded device, or the like, and acquires volume data obtained from CT images. The acquired volume data may be immediately sent to the processor 140 for various processing, or may be stored in the memory 150 and then sent to the processor 140 for various processing when necessary. The volume data may also be acquired via a recording medium or storage media. The volume data may also be acquired in the form of intermediate data, compressed data, sinogram, slice data, or the like. The volume data may also be acquired from information from a sensor device attached to the medical image processing apparatus 100.

[0022] The UI 120 may include a touch panel, a pointing device, a keyboard, or a microphone. The UI 120 accepts any input operation from a user of the medical image processing apparatus 100. The user may include a doctor, a radiologist, a student, or other paramedic staff.

[0023] The UI 120 accepts various operations. For example, it accepts operations such as specifying a region of interest (ROI) and setting brightness conditions (e.g., window information) in volume data or an image based on the volume data (e.g., a 3D image or a 2D image, which will be described later). The region of interest may include regions of various tissues (e.g., blood vessels, bronchi, organs, bones, and the brain). The tissues may include diseased tissue, normal tissue, tumor tissue, etc. The window information includes at least one of a window width (WW) and a window level (WL), and is information for adjusting the brightness of the displayed image.

[0024] The display 130 may include, for example, an LCD or an organic EL display, and displays various types of information. The various types of information may include three-dimensional images and two-dimensional images obtained from volume data. The three-dimensional images may include volume rendering images, surface rendering images, virtual endoscopic images, virtual ultrasound images, etc. The volume rendering images may include RaySum images, MIP images, MinIP images, average images, raycast images, etc. The two-dimensional images may include MPR images or CPR images, etc. The MPR images may include axial images, sagittal images, coronal images, and other MPR images.

[0025] The memory 150 includes various primary storage devices such as ROMs and RAMs. The memory 150 may include secondary storage devices such as HDDs and SSDs. The memory 150 may include tertiary storage devices such as USB memory and SD cards. The memory 150 stores various types of information and programs. The various types of information may include volume data acquired by the port 110, images generated by the processor 140, setting information set by the processor 140, and various programs. The memory 150 is an example of a non-transitory recording medium on which programs are recorded.

[0026] The processor 140 may include a CPU, a DSP, a GPU, or the like. The processor 140 may be configured with various integrated circuits (e.g., an LSI or an FPGA). The processor 140 executes a medical image processing program stored in the memory 150 to function as a processing unit 160 that performs various processes and controls.

[0027] FIG. 2 is a block diagram showing an example of the functional configuration of the processing unit 160.

[0028] The processing unit 160 includes a region processing unit 161, a mask setting unit 162, a surface generation unit 163, an image generation unit 164, a display control unit 165, and a movement control unit 166. The processing unit 160 supervises the processing and control of each unit of the medical image processing apparatus 100. Note that each unit included in the processing unit 160 may be realized as different functions by a single piece of hardware, or may be realized as different functions by multiple pieces of hardware. Furthermore, each unit included in the processing unit 160 may be realized by a dedicated hardware component.

[0029] The region processing unit 161 acquires volume data of the subject via, for example, the port 110. The region processing unit 161 extracts any region included in the volume data. The region processing unit 161 may automatically designate and extract a region of interest based on, for example, voxel values ​​of the volume data. The region processing unit 161 may manually designate and extract a region of interest via, for example, the UI 120. In this embodiment, the region of interest includes, for example, the heart and tubular tissues (e.g., the aorta and coronary arteries).

[0030] The mask setting unit 162 sets a mask to be used to render an image in volume rendering. The mask setting unit 162 sets an arbitrary region in the volume data as a mask region. When a mask is used, voxels in the mask region are rendered in the image, and voxels in the non-mask region outside the mask region are not rendered in the image. The mask region may be a region obtained by subdividing a region extracted by the region processing unit 161, or may be a region not extracted by the region processing unit 161. Furthermore, multiple mask regions may be set for each region extracted by the region processing unit 161. The mask setting unit 162 may automatically extract a mask region using a known method, or may manually extract a mask region in response to a user input operation via the UI 120.

[0031] The surface generator 163 generates (sets) any surface in the volume data. The surface generator 163 generates an annulus surface SA. For example, the surface generator 163 specifies the lowest points of three coronary cusps and generates an annulus surface SA including the specified three lowest points of the coronary cusps. In other words, the annulus surface SA is a surface including the lowest point N1 of the NCC, the lowest point R1 of the RCC, and the lowest point L1 of the LCC. The annulus surface SA may include a provisional annulus surface that is used before the annulus surface SA is finally determined (confirmed). The provisional annulus surface may include an annulus surface generated by the method of Non-Patent Document 1, an annulus surface generated using a mask, etc.

[0032] The plane generating unit 163 generates a longitudinal plane SF, which is a plane that passes through one or two of the three coronary cusp nadir points and is perpendicular to the annulus plane SA. The longitudinal plane SF includes, for example, longitudinal planes SN1, SL1, SR1, SN2, SL2, SR2, SN3, SL3, and SR3, which will be described later. For example, the plane generating unit 163 may generate a longitudinal plane SN1 that includes (passes through) the RCC nadir R1 and the LCC nadir L1. The plane generating unit 163 may generate a longitudinal plane SR1 that includes the LCC nadir L1 and the NCC nadir N1. The plane generating unit 163 may generate a longitudinal plane SL1 that includes the NCC nadir N1 and the RCC nadir R1. The plane generating unit 163 may generate a longitudinal plane SN2 that includes the NCC nadir N1 and the incenter O of the triangle TR. Note that triangle TR is a triangle connecting the nadir R1 of the RCC, the nadir L1 of the LCC, and the nadir N1 of the NCC as vertices (see FIG. 7 ). Triangle TR is on the annulus plane SA. The plane generating unit 163 may generate a longitudinal plane SR2 that includes the nadir R1 of the RCC and the incenter O of triangle TR. The plane generating unit 163 may generate a longitudinal plane SL2 that includes the nadir L1 of the LCC and the incenter O of triangle TR. The plane generating unit 163 may generate a longitudinal plane SN3 that includes the nadir N1 of the NCC and is perpendicular to the longitudinal plane SN2. The plane generating unit 163 may generate a longitudinal plane SR3 that includes the nadir R1 of the RCC and is perpendicular to the longitudinal plane SR2. The plane generating unit 163 may generate a longitudinal plane SN3 that includes the nadir L1 of the LCC and is perpendicular to the longitudinal plane SN2. The longitudinal surface may be a flat MPR surface or a curved CPR surface.

[0033] The image generating unit 164 generates various images. The image generating unit 164 generates a three-dimensional image, a two-dimensional image, or a tomographic image based on at least a part of the acquired volume data (for example, volume data of an extracted region). The image generating unit 164 may generate an image by performing various rendering (for example, volume rendering or surface rendering).

[0034] The image generating unit 164 generates an MPR image that visualizes the MPR plane, for example, based on volume data (voxels) located on the MPR plane. The MPR image is an image that visualizes, for example, the annulus plane SA and the longitudinal plane SF. The image generating unit 164 generates a CPR image that visualizes the CPR plane, for example, based on volume data (voxels) located on the CPR plane. The CPR image is an image that visualizes, for example, the annulus plane SA and the longitudinal plane SF.

[0035] The display control unit 165 displays various data, information, or images on the display 130. The images are images that represent a part of tissue in the subject, and may include, for example, an image generated by the image generation unit 164, a cross-sectional image (e.g., an MPR image or a CPR image) of a predetermined cross section (e.g., an MPR plane or a CPR plane), or a tomographic image of a predetermined cross section.

[0036] The movement control unit 166 moves any point or plane in the volume data. The movement control unit 166 may move any point or plane in response to a user's input operation via the UI 120, or may move any point or plane in conjunction with the movement of another point or plane different from the arbitrary point or plane. The arbitrary point may include the lowest point of the three coronary cusps. The arbitrary plane may include the annulus plane SA or the longitudinal plane SF.

[0037] In this embodiment, the annulus surface SA and the longitudinal surface SF are mainly exemplified as MPR surfaces, but they can also be applied to CPR surfaces. Also, the images visualizing the annulus surface SA and the longitudinal surface SF are mainly exemplified as MPR images, but they can also be applied to CPR images.

[0038] Next, an example of generating the annulus surface SA will be described.

[0039] The medical image processing device 100 provides a UI for manually adjusting and confirming the provisionally set annulus AR and annulus plane SA (provisional annulus plane), and finally sets the annulus AR and annulus plane SA. The processing unit 160 displays multiple longitudinal planes SF that pass through the provisionally set nadir of the coronary cusp and are perpendicular to the annulus plane SA. In this case, the orientation of each longitudinal plane SF is determined based on the three nadirs of the coronary cusp, so the longitudinal planes SF are not bound by a perpendicular relationship, such as the relationship between the axial, coronal, and sagittal planes. Therefore, the processing unit 160 can easily adjust the position of the nadir of the coronary cusp without worrying about the relative positions of the longitudinal planes SF, thereby easily adjusting the annulus plane SA and the longitudinal plane SF. For example, the processing unit 160 can adjust the position and orientation of the nadir of the coronary cusp, the annulus plane SA, and the longitudinal plane SF by specifying and moving the nadir of the coronary cusp within the MPR plane of each annulus plane SA and longitudinal plane SF by clicking, dragging, or the like. For example, the processing unit 160 may recalculate the annulus plane SA and the longitudinal plane SF and redisplay the MPR images of the annulus plane SA and the longitudinal plane SF each time the nadir of the coronary cusp moves. The processing unit 160 may move the nadir of the coronary cusp, the annulus plane SA, or the longitudinal plane SF via the UI 120.

[0040] FIG. 3 is a diagram showing an example of an annular plane SA including the lowest points of the three coronary cusps of the aortic valve 55.

[0041] In Fig. 3, an MPR image of the annulus plane SA is displayed. Also shown in Fig. 3 is the annulus AR, which connects the lowest points of the three coronary cusps. The lowest points of the three coronary cusps and the annulus plane SA in Fig. 3 are set using, for example, the method described in Patent Document 1, but the accuracy of this method is insufficient.

[0042] FIG. 4 is a diagram showing an example of an annulus plane SA based on the mask setting.

[0043] In FIG. 4, the mask setting unit 162 extracts the ascending aorta 50A from the region of the aorta 50 using a mask setting. FIG. 4 shows a volume rendering image including the ascending aorta 50A, the aortic valve 55, and the lowest points of the three coronary cusps. The mask setting unit 162 can set the annulus plane SA by searching for a plane tangent to the mask of the ascending aorta 50A. FIG. 4 also shows the annulus AR connecting the lowest points of the three coronary cusps. Extracting the ascending aorta 50A using a mask does not provide sufficient extraction accuracy for the annulus plane SA. This is because the mask of the ascending aorta 50A is affected by, for example, a set CT value threshold, and the NCC, RCC, and LCC are not always clearly depicted.

[0044] FIG. 5 is a diagram showing an example in which the annulus plane SA and three longitudinal planes SF are simultaneously displayed on the display 130. In FIG.

[0045] Each of the three longitudinal planes SF in Fig. 5 is perpendicular to the annular plane SA and includes two different nadir points of the three coronary cusps. Specifically, as shown in Fig. 5, the longitudinal plane SN1 includes the nadir point L1 of the LCC and the nadir point R1 of the RCC. The longitudinal plane SL1 includes the nadir point R1 of the RCC and the nadir point N1 of the NCC. The longitudinal plane SR1 includes the nadir point N1 of the NCC and the nadir point L1 of the LCC.

[0046] The user performs a movement operation via the UI 120, for example, to the lowest point of the coronary cusp included in one of the longitudinal planes SF. The processing unit 160 acquires the movement operation input via the UI 120 and updates the position of the lowest point of the coronary cusp in response to the movement operation, thereby updating the annulus plane SA. In this way, the medical image-processing device 100 gradually updates the annulus plane SA to optimize it. Furthermore, the updated results can be displayed in a list as MPR images of the annulus plane SA and three longitudinal planes SF, as shown in FIG. 5, allowing the user to compare and confirm the results of the four MPR images.

[0047] 5, the longitudinal surface SR1 is in focus, but it does not have to be in focus. Also, the thicknesses of the reference lines RLN1, RLL1, and RLR1 may be the same.

[0048] FIG. 6 is a diagram showing an example of an annular plane SA and nine longitudinal planes SF.

[0049] The longitudinal planes SF are perpendicular to the annular plane SA and include at least one of the three nadir points of the coronary cusps, so there are an infinite number of them. Of these, there are three longitudinal planes that include two different nadir points of the three cusps (see Figure 5). For example, the intersection of the longitudinal plane SF and the annular plane SA appears as a straight line on the annular plane SA.

[0050] 6, the nine longitudinal planes SF are grouped into a first group G1, a second group G2, and a third group G3. The first group G1 is a group to which three longitudinal planes SF that include two different nadir points of the three cusps belong. The first group G1 includes longitudinal planes SN1, SL1, and SR1.

[0051] The second group G2 is a group to which three longitudinal planes SF belong, each of which includes one of the three nadir points of the coronary cusp and the medial center O of the triangle TR whose vertices are the three nadir points. That is, each of the three longitudinal planes SF belonging to the second group G2 includes one of the three nadir points of the coronary cusp and the medial center O of the triangle TR made up of the three nadir points. The second group G2 includes the longitudinal planes SN2, SL2, and SR2.

[0052] The third group G3 is a group that includes one of the three cusp nadir points and includes three longitudinal planes SF that are perpendicular to a longitudinal plane that includes this one cusp nadir point and the medial center O (i.e., the longitudinal plane SF of the second group G2). In other words, each of the three longitudinal planes SF belonging to the third group G3 is perpendicular to a line that passes through each of the three cusp nadir points and the medial center O of the triangle TR. The third group G3 includes longitudinal planes SN3, SL3, and SR3.

[0053] The second group G2 has a longitudinal plane SF including the nadir of the coronary cusp and the medial center O. That is, the longitudinal plane SF included in the second group G2 is located at a position that bisects the angle formed by the two longitudinal planes included in the first group G1 (see FIG. 7). Similarly, the longitudinal plane SF included in the third group G3 is located at a position that bisects the angle formed by the two longitudinal planes included in the first group G1 (see FIG. 7). Therefore, even if the nadir of the coronary cusp does not exist at the position of the longitudinal plane SF of the first group G1, the nadir of the coronary cusp is likely to be located at the position of the longitudinal plane SF of the second group G2 and the third group G3. This is because the longitudinal planes SF included in the second group G2 and the third group G3 are evenly arranged at a position that bisects the angle formed by the two longitudinal planes included in the first group G1. Therefore, the medical image processing device 100 can easily find the lowest point of the coronary cusp within any of the longitudinal planes SF, and can also easily confirm that the lowest point of the coronary cusp displayed within the longitudinal plane SF is the true lowest point of the coronary cusp, thereby improving the accuracy of determining the annulus plane SA.

[0054] The user performs a movement operation via the UI 120, for example, to the lowest point of the coronary cusp included in one of the longitudinal planes SF. The processing unit 160 acquires the movement operation input via the UI 120 and updates the position of the lowest point of the coronary cusp in response to the movement operation, thereby updating the annulus plane SA. In this way, the medical image-processing device 100 gradually updates the annulus plane SA to optimize it. Furthermore, the updated results can be displayed in a list as MPR images of the annulus plane SA and nine longitudinal planes SF, as shown in FIG. 6, allowing the user to compare a total of 10 MPR images.

[0055] Although nine longitudinal surfaces are illustrated here, this is not a limitation. For example, if ten or more longitudinal surfaces are provided, it becomes easier to find the lowest point of the coronal cusp. Furthermore, although the nine longitudinal surfaces are illustrated as being angularly evenly arranged to facilitate searching for areas that cannot be reached by the longitudinal surfaces of the first group G1, this is not a limitation. The angles formed by the longitudinal surfaces do not have to be equal.

[0056] In Fig. 6, the longitudinal surface SR2 is in focus, but it does not have to be in focus. Furthermore, the reference lines RLN2, RLL2, and RLR2 may have the same thickness. Furthermore, although the illustration of the reference lines RL other than these three reference lines is omitted in Fig. 6, they may be displayed.

[0057] FIG. 7 is a diagram showing an example of a reference line RL indicated on the annulus plane SA.

[0058] On the annular plane SA, the positions of various longitudinal planes SF perpendicular to the annular plane SA are represented by reference lines RL, e.g., straight lines. The reference lines RL include reference lines RLN1, RLR1, RLL1, RLN2, RLR2, RLL2, RLN3, RLR3, and RLL3. The reference line RLN1 indicates the intersection line between the annular plane SA and the longitudinal plane SN1. The reference line RLR1 indicates the intersection line between the annular plane SA and the longitudinal plane SR1. The reference line RLL1 indicates the intersection line between the annular plane SA and the longitudinal plane SL1. The reference line RLN2 indicates the intersection line between the annular plane SA and the longitudinal plane SN2. The reference line RLR2 indicates the intersection line between the annular plane SA and the longitudinal plane SR2. The reference line RLL2 indicates the intersection line between the annular plane SA and the longitudinal plane SL2. The reference line RLN3 indicates the intersection line between the annular plane SA and the longitudinal plane SN3. Reference line RLR3 indicates the intersection line between the annulus plane SA and the longitudinal plane SR3. Reference line RLL3 indicates the intersection line between the annulus plane SA and the longitudinal plane SL3.

[0059] The display controller 165 may display all of the reference lines RL on the annulus plane SA, or may display only some of the reference lines RL and omit displaying some of the reference lines RL. For example, when the focus is on one of the longitudinal planes SF of the first group G1, only the reference lines for the first group G1 may be displayed on the annulus plane SA, and the others may be hidden. For example, when the focus is on one of the longitudinal planes SF of the second group G2, only the reference lines for the second group G2 may be displayed on the annulus plane SA, and the others may be hidden.

[0060] 8A and 8B are flowcharts showing an example of the operation of the medical image processing apparatus 100. FIG.

[0061] First, the region processing unit 161 acquires volume data of the subject and extracts from the volume data the region of the aorta 50. The mask setting unit 162 sets the region between the aortic valve and the ascending aorta, including the region between them, as a mask region in the region of the aorta 50, and extracts the mask region (S11).

[0062] The surface generation unit 163 extracts the nadir N1 of the NCC, the nadir R1 of the RCC, and the nadir L1 of the LCC in the mask region, and generates (sets) an annulus surface SA including the nadir N1 of the NCC, the nadir R1 of the RCC, and the nadir L1 of the LCC (S12). This annulus surface SA is an initial annulus surface and a provisional annulus surface. Therefore, its accuracy may be low. Note that instead of generating a provisional annulus surface using a mask, the nadir N1 of the NCC, the nadir R1 of the RCC, and the nadir L1 of the LCC may be manually determined using the method described in Patent Document 1 to generate the provisional annulus surface.

[0063] The surface generation unit 163 generates (sets) three longitudinal surfaces SN1, SR1, and SL1 of the first group G1 (S13). The surface generation unit 163 obtains the incenter O of the triangle TR, and generates (sets) three longitudinal surfaces SN2, SR2, and SL2 of the second group G2 (S14). The surface generation unit 163 generates (sets) three longitudinal surfaces SN3, SR3, and SL3 of the third group G3 (S15).

[0064] The image generator 164 generates MPR images of the MPR planes using the generated annulus plane SA and nine longitudinal planes SF as MPR planes. Specifically, it generates MPR images of the annulus plane SA and nine longitudinal planes SN1, SR1, SL1, SN2, SR2, SL2, SN3, SR3, and SL3. The display controller 165 displays the MPR images of the annulus plane SA and nine longitudinal planes SN1, SR1, SL1, SN2, SR2, SL2, SN3, SR3, and SL3 on the display 130 (S16).

[0065] The display controller 165 displays the MPR image of the annulus plane SA including the three coronary cusp nadir points located on the annulus plane SA: the NCC nadir N1, the RCC nadir R1, and the LCC nadir L1. The display controller 165 also displays the MPR images of the nine longitudinal planes SF including the coronary cusp nadir points (i.e., one or two coronary cusp nadir points) among the NCC nadir N1, the RCC nadir R1, and the LCC nadir L1 that are located on the respective longitudinal planes SF (S17).

[0066] The display controller 165 displays reference lines RL on the MPR image of the annulus plane SA as the intersection lines between the annulus plane SA and each of the nine longitudinal planes SF (S18). Specifically, a reference line RLN1 is displayed as the intersection line between the annulus plane SA and the longitudinal plane SN1. A reference line RLR1 is displayed as the intersection line between the annulus plane SA and the longitudinal plane SR1. A reference line RLL1 is displayed as the intersection line between the annulus plane SA and the longitudinal plane SL1. A reference line RLN2 is displayed as the intersection line between the annulus plane SA and the longitudinal plane SN2. A reference line RLR2 is displayed as the intersection line between the annulus plane SA and the longitudinal plane SR2. A reference line RLL2 is displayed as the intersection line between the annulus plane SA and the longitudinal plane SL2. A reference line RLN3 is displayed as the intersection line between the annulus plane SA and the longitudinal plane SN3. A reference line RLR3 is displayed as the intersection line between the annulus plane SA and the longitudinal plane SR3. A reference line RLL3 is displayed as the intersection line between the annulus plane SA and the longitudinal plane SL3.

[0067] The user looks at the display 130 and checks the MPR images of the annulus plane SA and each longitudinal plane SF, as well as the display of the nadir of the coronary cusp on the MPR images. At the annulus plane SA stage, the position of the nadir of the coronary cusp may not actually be the nadir. The nadir of the coronary cusp indicates the boundary between one of the cusps (NCC, RCC, or RCC) of the aortic valve and the heart (particularly the left ventricle), i.e., the most upstream end point of the coronary cusp. When the position is not the nadir of the coronary cusp, the position designated as the nadir of the coronary cusp is often shifted toward the inside of the coronary cusp, that is, away from the heart (e.g., the left ventricle). Whether or not the position is the nadir of the coronary cusp can be determined, for example, by the fact that the nadir of the coronary cusp is slightly above the nadir in the MPR images of the longitudinal plane SF in Figures 5 and 6 , or by the fact that the tuft of the coronary cusp is visible in the MPR image of the annulus plane SA. When the lowest point of the coronary cusp coincides with the actual position of the lowest point, the MPR image of the annulus plane SA is displayed with the coronary cusp tufts invisible, making them visible to the user.

[0068] If the user determines that the position of the lowest point of the coronary cusp is not the lowest point of the coronary cusp (NCC, RCC, or LCC), the user can manually move the position determined to be the lowest point of the coronary cusp using the UI 120.

[0069] For example, the user may move at least one of the nadir point N1 of the NCC, the nadir point R1 of the RCC, and the nadir point L1 of the LCC on at least one of the annulus plane SA and each longitudinal plane SF using the UI 120. In this case, the movement control unit 166 may receive an input operation from the user via the UI 120 to move at least one of the nadir point N1 of the NCC, the nadir point R1 of the RCC, and the nadir point L1 of the LCC on at least one of the annulus plane SA and each longitudinal plane SF. In response to this input operation, the movement control unit 166 moves at least one of the nadir point N1 of the NCC, the nadir point R1 of the RCC, and the nadir point L1 of the LCC on at least one of the annulus plane SA and each longitudinal plane SF (S19).

[0070] Furthermore, the user may use the UI 120 to rotate a plane including the center point of any one of the nadir N1 of the NCC, the nadir R1 of the RCC, and the nadir L1 of the LCC on the annulus surface SA and at least one of the longitudinal planes SF. The plane movement in this case involves tilting the plane around the center point. In this case, the movement control unit 166 may receive an input operation from the user via the UI 120 to move a plane including the nadir N1 of the NCC, the nadir R1 of the RCC, and the nadir L1 of the LCC on the annulus surface SA and at least one of the longitudinal planes SF. In response to this input operation, the movement control unit 166 moves a plane including the nadir N1 of the NCC, the nadir R1 of the RCC, and the nadir L1 of the LCC on the annulus surface SA and at least one of the longitudinal planes SF around the center point of any one of the nadir N1 of the NCC, the nadir R1 of the RCC, and the nadir L1 of the LCC (S20). Then, the movement control unit 166 moves at least one of the lowest point N1 of the NCC, the lowest point R1 of the RCC, and the lowest point L1 of the LCC on this surface in conjunction with the movement of this surface.

[0071] The user may also use the UI 120 to translate at least one of the annulus plane SA and each longitudinal plane SF in a direction (i.e., toward the depth or toward the front) perpendicular to the MPR plane (i.e., the annulus plane SA and at least one of the longitudinal planes SF). In this case, the movement control unit 166 may receive an input operation from the user via the UI 120 to translate at least one of the annulus plane SA and each longitudinal plane SF in a direction perpendicular to the MPR plane. In response to this input operation, the movement control unit 166 translates at least one of the annulus plane SA and each longitudinal plane SF in a direction perpendicular to the MPR plane (S21). Then, in conjunction with the movement of this plane, the movement control unit 166 moves at least one of the NCC nadir N1, the RCC nadir R1, and the LCC nadir L1 on this plane. The movement control unit 166 may, in conjunction with the movement of this surface, select at least one of the lowest point N1 of the NCC, the lowest point R1 of the RCC, and the lowest point L1 of the LCC on this surface as a candidate for movement, and may move it upon a confirmation operation from the user.

[0072] The plane generating unit 163 generates (updates) an annulus plane SA including the NCC nadir N1, the RCC nadir R1, and the LCC nadir L1, taking into account the movements made in steps S19 to S21 (S22). Note that it is sufficient if at least one of steps S19 to S21 is performed.

[0073] Furthermore, the display controller 165 may update the MPR images of the annulus plane SA and at least one MPR plane of each longitudinal plane SF, taking into account the moved nadir of the coronary cusp or plane. For example, in response to the movement of one of the nadirs of the coronary cusp, the display controller 165 may update a total of four displays, namely, the annulus plane SA and three longitudinal planes SN1, SR1, and SL1, or may update a total of ten displays, namely, the annulus plane SA and nine longitudinal planes SN1, SR1, SL1, SN2, SR2, SL2, SN3, SR3, and SL3.

[0074] The display controller 165 may also update the display of at least one reference line RL indicating the position of at least one MPR plane of the longitudinal plane SF on the annular plane SA, taking into account the moved nadir of the coronary cusp or plane. For example, when the longitudinal plane SF is translated in the depth direction, the reference line RL indicating the intersection of the longitudinal plane SF with the annular plane SA is translated.

[0075] This allows the medical image processing device 100 to determine the position of the lowest point of each coronary cusp with higher accuracy than in the initial stage of the annulus plane SA (e.g., the provisional annulus plane acquired in step S11). Therefore, the processing unit 160 can generate the annulus plane SA including the lowest points of the three coronary cusps with high accuracy. Therefore, the processing unit 160 can derive (e.g., calculate) the circumference and diameter of the annulus with high accuracy based on the annulus plane SA. Therefore, the medical image processing device 100 can appropriately determine the size of an expensive artificial valve to replace the aortic valve of a subject (e.g., a patient), appropriately determine whether TAVI is applicable, and improve the safety of the subject undergoing TAVI.

[0076] In the medical image-processing apparatus 100, the processing unit 160 may separately determine the appropriateness of the annulus plane SA generated in step S22. In this case, the processing unit 160 repeatedly executes steps S13 to S18 after step S22.

[0077] The user looks at the display 130 again to confirm the display of the annulus plane SA and the MPR images of each longitudinal plane SF, as well as the display of the nadir of the coronary cusp on the MPR images. The user uses the UI 120 to instruct the execution of at least one of steps S19 to S21, as necessary. The processing unit 160 receives an input operation from the user via the UI 120 to instruct the execution of at least one of steps S19 to S21, as necessary, and executes at least one of steps S19 to S21. The processing unit 160 then generates (re-updates) the annulus plane SA in step S22. In this way, the medical image-processing device 100 may repeatedly execute at least some of the processes shown in FIGS. 8A and 8B until a suitable annulus plane SA is obtained.

[0078] In this way, the medical image processing device 100 of this embodiment can improve the accuracy of the annulus plane SA by adjusting the position of the nadir of the coronary cusp or the plane using the UI 120. Furthermore, the user can instruct the movement of points or planes while checking the MPR images of the annulus plane SA or the longitudinal plane SF, and can confirm the results on the display. Therefore, for example, by moving one of the nadirs of the coronary cusp, it can be confirmed that the display of the annulus plane and each longitudinal plane SF is updated. Therefore, by moving one of the nadirs of the coronary cusp, the user can perform the movement operation while successively checking whether the nadirs of the other coronary cusps are shifted from the nadir.

[0079] In addition, in the past, when adjusting the orientation of a plane under the condition that the three orthogonal cross sections were perpendicular, the user had to perform an input operation on a plane other than the plane he or she was focusing on to rotate it. In contrast, the medical image processing device 100 allows the orientation of the longitudinal plane SF to be easily adjusted because the operation of moving the apex's lowest point is linked to adjusting the angle of the longitudinal plane SF.

[0080] Furthermore, the medical image processing device 100 can appropriately determine the lowest point of each of the three coronary cusps, thereby appropriately determining the annulus plane SA. Therefore, the medical image processing device 100 can also improve the accuracy of measuring the circumference and diameter of the annulus plane SA, allowing for appropriate determination of the size of the artificial valve. Therefore, the medical image processing device 100 can prevent the coronary artery emerging from the vicinity of the aortic valve from being blocked by the artificial valve. Furthermore, the medical image processing device 100 can also prevent the artificial valve from falling off due to its small size.

[0081] (Modification of the first embodiment) In the first embodiment, three or nine longitudinal plane MPR images are generated, but this is not limiting. At least two longitudinal plane MPR images may be generated. In this case, the plane generator 163 generates at least two of the nine longitudinal planes SF to minimize the number of longitudinal planes SF. In this case, each of the two longitudinal planes includes one or two coronary cusp nadir points, and the two longitudinal planes together include all three coronary cusp nadir points. This allows the user to check whether the three coronary cusp nadir points are misaligned by looking at the display 130, and allows the medical image processing device 100 to accurately determine the annulus plane SA.

[0082] In the first embodiment, the movement control unit 166 may translate the annulus plane SA and each longitudinal plane SF in a direction perpendicular to the plane (MPR plane), that is, in the depth direction or the front direction. In this case, the movement control unit 166 may update the position of the nadir of the coronary cusp by moving the nadir of the coronary cusp on the plane in conjunction with the movement of at least one of the annulus plane SA and each longitudinal plane SF. Furthermore, the movement control unit 166 may further update the position of the nadir of the coronary cusp on the plane after the movement by specifying and moving the nadir of the coronary cusp.

[0083] The display controller 165 may also display, together with the MPR image of the annulus plane, an MPR image of an offset annulus plane, which is a plane obtained by translating the annulus plane in the depth direction (see FIG. 10 of the second embodiment, described later). Displaying the MPR image of the offset annulus plane also makes it easier for the user to understand the position of the annulus plane. The user can also confirm what exists near the annulus plane SA, and whether the nadir of the coronary cusp is actually at the position of the annulus plane SA (and not at the position of the offset annulus plane). If the position of the annulus plane does not include the nadir of the coronary cusp, the atrium will appear and be visible.

[0084] In the first embodiment, the aortic valve is used as an example of a tuft-like structure, and the movement of the lowest point of the coronary cusp is illustrated, but this is not limiting. For example, the tuft-like structure may be a tricuspid valve, a pulmonary valve, a venous valve, or other tuft-like structure, and the present invention may be applied to the movement and display of the lowest point of the tuft-like structure, the generation, movement, and display of a plane connecting the lowest points of the tuft-like structures, etc.

[0085] In the first embodiment, the plane that includes the lowest point of the coronary cusp and is perpendicular to the annular surface SA is described as the longitudinal plane, but this is not limited to this. That is, it is not essential that the direction perpendicular to the annular surface SA is longer than the direction along the annular surface SA, and the plane may be the lateral plane, in which the direction perpendicular to the annular surface SA is shorter than the direction along the annular surface SA. In either case, the plane is perpendicular to the annular surface.

[0086] The medical image processing apparatus 100 may execute the above-described modifications in combination.

[0087] (How the second embodiment of the present disclosure was achieved) The method of Patent Document 1 attempts to derive the annular plane using three vertical cross sections: the axial plane, the coronal plane, and the sagittal plane. In this case, reference lines indicating the positions of the other two end faces are displayed on the MPR plane of one cross section.

[0088] Here, suppose that a user performs an operation by inputting data into the MPR images on the screen using a UI while multiple (e.g., three or more) MPR images visualizing MPR planes are simultaneously displayed. Conventionally, as described above, medical image processing devices have displayed reference lines on one MPR image indicating the positions of the MPR planes of other MPR images, but it is difficult to determine from one MPR image which of the other MPR images the user is using to perform the operation.

[0089] In the second embodiment, a medical image processing apparatus, a medical image processing method, and a medical image processing program that can easily determine which cross-sectional image among other cross-sectional images is being used for work in one cross-sectional image will be described.

[0090] (Second embodiment) The configuration of the medical image processing device 100 in the second embodiment is similar to the configuration of the medical image processing device 100 in the first embodiment shown in Figures 1 and 2, so the same symbols are used and their descriptions are omitted or simplified.

[0091] In this embodiment, the surface generator 163 generates any surface included in the volume data. For example, it generates a reference MPR surface and an auxiliary MPR surface. The reference MPR surface is an MPR surface that serves as a reference for other MPR surfaces, such as the annulus surface SA described in the first embodiment. The auxiliary MPR surface is a surface that intersects with the reference MPR surface, such as the longitudinal plane SF described in the first embodiment. At least one of the reference MPR surface and the auxiliary MPR surface receives an input operation from the user via the UI 120 and becomes the target of a predetermined process (operation). The input operation is, for example, an operation to move the nadir of the coronary cusp or a surface, as described in the first embodiment. The predetermined process is, for example, a process to move, regenerate, or redisplay the nadir of the coronary cusp or various surfaces (the annulus surface SA or the longitudinal plane SF), as described in the first embodiment, or a process to generate an annulus surface, as described in the first embodiment.

[0092] The image generator 164 generates various images, for example, a reference MPR image by visualizing a reference MPR plane and an auxiliary MPR image by visualizing an auxiliary MPR plane. The reference MPR image is, for example, an MPR image of the annulus plane SA. The auxiliary MPR image is, for example, at least one MPR image of the longitudinal plane SF.

[0093] The display control unit 165 controls the display of images and information, and causes the display 130 to display, for example, the reference MPR image and the auxiliary MPR image.

[0094] The movement control unit 166 moves any point or plane in the volume data. The movement control unit 166 may move any point or plane in response to a user's input operation via the UI 120, or may move any point or plane in conjunction with the movement of another point or plane different from the arbitrary point or plane. The arbitrary point may include the lowest points of the three coronary cusps. The arbitrary plane may include at least one of the reference MPR plane and the auxiliary MPR plane, i.e., at least one of the annular plane SA and the longitudinal plane SF.

[0095] 9 is a diagram showing a first example of highlighting the reference line RL. In FIG. 9, a reference MPR image and three auxiliary MPR images are displayed. The reference MPR image is, for example, an MPR image of the annulus plane SA, and the three auxiliary MPR images are, for example, MPR images of the three longitudinal planes SN1, SR1, and SL1.

[0096] In FIG. 9, the display control unit 165 receives input via the UI 120 and focuses on the longitudinal surface SR1. The focused longitudinal surface SF is also referred to as the focus surface SF1. Focus refers to a state in which the mouse cursor of the UI 120 is within the frame (window) of the MPR image of a specific surface. On the other hand, the longitudinal surfaces SN1 and SL1 are not focused. The unfocused longitudinal surfaces SN1 and SL1 are also referred to as the non-focus surface SF2.

[0097] In the MPR image of the annulus surface SA, the positions of the three longitudinal planes SN1, SR1, and SL1 are displayed as reference lines RLN1, RLR1, and RLL1. In this case, the display controller 165 may display the reference line RLR1 of the focused longitudinal plane SR1 in the MPR image of the annulus surface SA more emphasized than the reference line RLN1 of the unfocused longitudinal plane SN1 and the reference line RLL1 of the unfocused longitudinal plane SL1.

[0098] The highlighting here may include, for example, making the reference line RLR1 thicker than the reference lines RLN1 and RLL1, making it brighter or darker, flashing it frequently, or displaying it in other display modes. For example, the reference line RL on the focus plane SF1 may be displayed in an emphasized manner, and the reference line RL on the non-focus plane SF2 may be displayed as is, thereby highlighting the reference line RL on the focus plane SF1 (reference line RLR1) more than the reference lines RL on the non-focus plane SF2 (reference lines RLN1 and RLL1). Furthermore, the reference line RL on the focus plane SF1 may be displayed as is, and the reference line RL on the non-focus plane SF2 may be displayed in a lighter manner, thereby highlighting the reference line RL on the focus plane SF1 (reference line RLR1) more than the reference lines RL on the non-focus plane SF2 (reference lines RLN1 and RLL1).

[0099] According to this first example of display of the reference line RL, the medical image processing apparatus 100 highlights the reference line RL indicating the position of the auxiliary MPR plane in operation, i.e., the focus plane SF1, in the MPR image of the base MPR plane. Therefore, by checking the reference line RL, the user can easily understand at a glance which auxiliary MPR plane is being used in operation.

[0100] FIG. 10 is a diagram showing a second example of highlighting the reference line RL. In FIG. 10, a reference MPR image, two offset reference MPR images, and nine auxiliary MPR images are displayed. The offset reference MPR image is an MPR image on an MPR plane obtained by translating the reference MPR plane in a direction perpendicular to the reference MPR plane. The offset amount may be 5 mm, 10 mm, or other amounts. The reference MPR image is, for example, an MPR image of the annulus plane SA. The nine auxiliary MPR images are, for example, MPR images of nine longitudinal planes SF, namely, longitudinal planes SN1, SR1, SL1, SN2, SR2, SL2, SN3, SR3, and SL3.

[0101] In FIG. 10 , related MPR planes are grouped together. The 12 MPR planes in FIG. 10 are divided into a reference group GS, a first group G1, a second group G2, and a third group G3. As in the first embodiment, the first group G1 includes longitudinal planes SN1, SR1, and SL1. The second group G2 includes longitudinal planes SN2, SR2, and SL2. The third group G3 includes longitudinal planes SN3, SR3, and SL3. In addition to the annulus plane SA as the reference MPR plane, the reference group GS also includes two offset annulus planes SA1 and SA2, which are obtained by translating the annulus plane SA in a direction perpendicular to the reference MPR plane. The offset annulus planes SA1 and SA2 are examples of offset reference MPR planes. The offset annulus planes SA1 and SA2 and their MPR images may be omitted.

[0102] In FIG. 10 , the display control unit 165 receives input via the UI 120 and focuses on the longitudinal plane SR3. The other eight longitudinal planes SF are not focused. In the MPR images of the annular plane SA and the two offset annular planes SA1 and SA2 of the reference group GS, the positions of the three longitudinal planes SN3, SR3, and SL3 included in the third group G3, to which the longitudinal plane SR3, which is the focus plane SF1, belongs, are displayed as reference lines RLN3, RLR3, and RLL3. On the other hand, the positions of the six longitudinal planes SN1, SR1, SL1, SN2, SR2, and SL2 included in the first group G1 and the second group G2, to which the longitudinal plane SR3, which is the focus plane SF1, does not belong, are not displayed as reference lines RL in the MPR images of the annular plane SA and the two offset annular planes SA1 and SA2 of the reference group GS. That is, the display control unit 165 displays only the reference lines RLN3, RLR3, and RLL3 that indicate the positions of the longitudinal planes SN3, SR3, and SL3 included in the group that includes the focus plane SF1 on the reference MPR image and the offset reference MPR image.

[0103] In this case, the display controller 165 highlights the reference line RLR3 of the longitudinal plane SR3 that is the focused plane in the MPR images of the annulus plane SA and the offset annulus planes SA1 and SA2. The highlighting here, for example, highlights the reference line RLR3 of the longitudinal plane SR3 as the focused plane SF1 more than the reference lines RLN3 and RLL3 of the longitudinal planes SN3 and SL3 as the non-focused planes SF2 of the same third group G3. The highlighting here may include, for example, making the reference line RLR3 thicker, brighter, or darker than the reference lines RLN3 and RLL3, or flashing it more frequently.

[0104] According to this second example of displaying the reference lines RL, the medical image processing apparatus 100 can limit the number of reference lines RL displayed on the base MPR plane and the offset base MPR plane even when there are a large number of auxiliary MPR images, thereby preventing the base MPR plane from becoming difficult to observe. For example, the medical image processing apparatus 100 can display the reference lines RL on the base MPR plane and the offset base MPR plane only for the reference lines RL of multiple auxiliary MPR planes belonging to the same group that are suitable for simultaneous input operations via the UI 120 on the display 130. In this case, the user can easily check the reference lines RL displayed on the base MPR plane and the offset base MPR plane, and can smoothly perform input operations on auxiliary MPR planes, etc., that are included in the same group as the auxiliary MPR plane being used.

[0105] Next, an example of the operation of the medical image processing apparatus 100 of this embodiment will be described.

[0106] FIG. 11 is a flowchart showing an example of the operation of the medical image processing apparatus 100 of this embodiment. Processes similar to those shown in FIGS. 8A and 8B of the first embodiment are given the same step numbers, and their descriptions are omitted or simplified. FIG. 11 assumes the second example of the reference line highlighting shown in FIG. 10. In FIG. 11, the description of the offset annulus planes SA1 and SA2 is omitted. The medical image processing apparatus 100 may execute the process of FIG. 11 in parallel with the process shown in FIGS. 8A and 8B of the first embodiment.

[0107] First, the processing unit 160 groups related MPR planes among the multiple MPR planes, for example, via the UI 120. For example, the processing unit 160 sets three longitudinal planes SN1, SR1, and SL1 to a first group G1, three longitudinal planes SN2, SR2, and SL2 to a second group G2, and three longitudinal planes SN3, SR3, and SL3 to a third group G3 (S31). The processing unit 160 also sets the annulus plane SA to a reference group GS.

[0108] The display control unit 165 causes the display 130 to display the MPR images of the annulus plane SA and the nine longitudinal planes SF (S32).

[0109] The display control unit 165 designates the longitudinal plane SF that is focused on via the UI 120 as the focus plane SF1 (S33). The focus plane SF1 can also be considered to be a plane of interest that the user is paying attention to. In this case, the display control unit 165 may designate the focus plane SF1 by designating any MPR image displayed on the display via the UI 120. The designation of the focus plane SF1 may be performed, for example, by clicking, dragging, hovering the mouse over the MPR image, performing various selections, or other input operations.

[0110] The display controller 165 displays, in the MPR image of the annulus surface SA, the intersection lines between the annulus surface SA and each of the three longitudinal planes SF included in the group to which the focus plane SF1 belongs, as reference lines RL (S34). For example, in Fig. 10, the display controller 165 displays, in the MPR image of the annulus surface SA, the intersection lines between the annulus surface SA and each of the three longitudinal planes SN3, SR3, and SL3 included in the third group G3 to which the longitudinal plane SR3 serving as the focus plane SF1 belongs, as reference lines RLN3, RLR3, and RLL3. In this case, the display controller 165 displays the reference line RLR3 as the intersection line with the focus plane SF1 more emphatically than the reference lines RLN3 and RLL3 as the intersection line with the non-focus plane SF2 of the same group (S34).

[0111] (Modification of the second embodiment) In the second embodiment, the reference plane is illustrated as an MPR plane (reference MPR plane), that is, a flat plane, but this is not limiting. The plane generating unit 163 may generate a CPR plane (also referred to as a reference CPR plane), that is, a curved plane, as the reference plane. Then, the display control unit 165 may display a reference line RL on the reference CPR plane, indicating the line of intersection with the auxiliary MPR plane, as in the case of the reference MPR plane.

[0112] In the second embodiment, the auxiliary surface is an MPR surface (auxiliary MPR surface), that is, a flat surface, but this is not limiting. The surface generating unit 163 may generate a CPR surface (also referred to as an auxiliary CPR surface), that is, a curved surface, as the auxiliary surface. Then, the display control unit 165 may display a reference line RL on the base surface, which indicates the line of intersection with the auxiliary CPR surface, as in the case of the auxiliary MPR surface.

[0113] In the second embodiment, the display control unit 165 mainly displays an MPR image of the reference MPR plane with an emphasis on the reference line RL indicating the position of the focused auxiliary MPR plane, but this is not limiting. As shown in Fig. 12, the display control unit 165 may display a reference line RLS indicating the position of the reference MPR plane and a reference line RLT indicating the positions of one or more other auxiliary MPR planes in each of the MPR images of the multiple auxiliary MPR planes (e.g., the MPR image of the longitudinal plane SL1). When the MPR image of the reference MPR plane is focused, the display control unit 165 may display an emphasis on the reference line RLS indicating the position of the focused reference MPR plane in at least one of the MPR images of the multiple auxiliary MPR planes (e.g., the MPR image of the longitudinal plane SL1).

[0114] In the second embodiment, three or more auxiliary MPR planes do not have to be perpendicular to each other. That is, the auxiliary MPR planes do not have to be perpendicular to each other, like the axial plane, coronal plane, and sagittal plane, whose orientation with respect to the subject is predetermined. Furthermore, when multiple auxiliary MPR planes are parallel to each other, no reference line indicating the position of the other auxiliary MPR planes is displayed on one auxiliary MPR plane.

[0115] In the second embodiment, being focused on may include clicking or hovering the mouse over a window displayed in the MPR image of the reference MPR plane or the auxiliary MPR plane (within a frame displaying an MPR image corresponding to each plane) via the UI 120. Also, being focused on may include making some selection using a button or pull-down menu on the MPR image of the reference MPR plane or the auxiliary MPR plane via the UI 120.

[0116] In the second embodiment, at least a part of the reference line RL indicating the position of the out-of-focus auxiliary MPR plane does not need to be displayed in the MPR image of the reference MPR plane.

[0117] The medical image processing apparatus 100 may execute the above-described modifications in combination.

[0118] In this way, the medical image processing apparatus 100 of this embodiment can highlight the position of the focus plane SF1 that the user is currently focusing on on the reference plane with a reference line, allowing the user to easily grasp the auxiliary plane that is currently being worked on on the reference plane.

[0119] Furthermore, even when there are many auxiliary planes, the medical image processing apparatus 100 can display only the reference lines RL of the auxiliary planes included in the group to which the focus plane SF1 belongs. This prevents the display of many reference lines from making it difficult to understand the position of the plane. This is particularly useful when there is an unordered relationship among the many auxiliary planes, and even if each auxiliary plane is positioned according to some condition relative to the reference plane, the relationship between the reference plane and the multiple auxiliary planes is easily lost when the auxiliary planes are in a non-constrained relationship with each other.

[0120] The first embodiment, the modified example of the first embodiment, and the second embodiment, and the modified example of the second embodiment may be combined in any combination.

[0121] Although various embodiments have been described above with reference to the drawings, it goes without saying that the present disclosure is not limited to such examples. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that such modifications also fall within the technical scope of the present disclosure.

[0122] The medical image processing apparatus 100 may also include at least a processor 140 and a memory 150. The port 110, the UI 120, and the display 130 may be external to the medical image processing apparatus 100.

[0123] Also, in the example shown, the volume data as the captured CT image is transmitted from the CT device 200 to the medical image processing device 100. Alternatively, the volume data may be transmitted to a server on the network (for example, an image data server (PACS) (not shown)) or the like so that it is temporarily accumulated and stored. In this case, the port 110 of the medical image processing device 100 may acquire the volume data from the server or the like via a wired or wireless line when necessary, or may acquire the volume data via an arbitrary storage medium (not shown).

[0124] Also, an example has been given in which volume data as a captured CT image is transmitted from the CT device 200 to the medical image processing device 100 via the port 110. This includes a case in which the CT device 200 and the medical image processing device 100 are essentially combined into one product. It also includes a case in which the medical image processing device 100 is used as a console for the CT device 200.

[0125] Although the example has been given in which an image is captured by the CT device 200 and volume data including information about the inside of the subject is generated, images may be captured by other devices and volume data may be generated. Examples of other devices include an MRI (Magnetic Resonance Imaging) device, a PET (Positron Emission Tomography) device, an angiography device, or other modality devices. The PET device may also be used in combination with other modality devices.

[0126] It can also be expressed as a medical image processing method that defines the operations of the medical image processing apparatus 100. It can also be expressed as a program that causes a computer to execute each step of the medical image processing method.

[0127] (Summary of the above embodiment) As a result, the present disclosure describes at least the following: Note that, in parentheses, examples of components corresponding to the above-described embodiments are given, but the present disclosure is not limited to these.

[0128] [Item 1] A medical image processing device (medical image processing device 100) including a processor (processor 140), The processor: Acquire volume data including three chamber-like structures of the subject; Three end points (the lowest point of the coronary cusp, the lowest point N1 of the NCC, the lowest point R1 of the RCC, and the lowest point L1 of the LCC) that are located most upstream of each of the three tuft-like structures in the volume data are set; A reference plane (annular plane SA) including the three end points is set, A first plane (longitudinal plane SN1) is set as a plane that includes one or two of the three end points and is perpendicular to the reference plane; A second plane (longitudinal plane SR1) is set as a plane perpendicular to the reference plane, including one or two end points that are different from the combination of the one or two end points of the first plane and that include all of the three end points when combined with the end points of the first plane; a reference image (MPR image of the annulus plane SA) visualizing the reference plane is displayed on a display (display 130) together with the three end points included in the reference plane; simultaneously with the reference image, a first image (MPR image of the longitudinal plane SN1) visualizing the first plane is displayed on the display together with the one or two end points included in the first plane; simultaneously with the reference image, a second image (MPR image of the longitudinal plane SR1) visualizing the second plane is displayed on the display together with the one or two end points included in the second plane; receiving an input operation to move at least one of the three end points via a user interface (UI120); moving at least one of the three end points based on the input operation, and updating the reference plane; Medical imaging equipment.

[0129] As a result, the medical image processing apparatus can adjust the positions of the three endpoints using the UI 120, thereby improving the accuracy of the position and orientation of the reference plane and making the adjustments accordingly. Furthermore, the user can instruct the movement of the three endpoints while checking the reference image, the first image, and the second image, and can confirm the results on the display. Therefore, for example, by moving at least one of the three endpoints, the user can confirm that the display of the reference image, the first image, and the second image is updated. Therefore, by moving at least one of the three endpoints, the user can perform the movement operation while successively checking whether the other endpoints are shifted from the lowest point. Furthermore, the medical image processing apparatus can appropriately determine all three endpoints, thereby appropriately determining the reference plane. Therefore, the accuracy of determining a surface that serves as an index in a region having three or more tuft-like structures within a subject can be improved.

[0130] [Item 2] the reference plane is the annulus plane; The three chamber-like structures are the non-coronary aortic valve cusp (NCC), the right aortic valve cusp (RCC), and the left aortic valve cusp (LFF); The three end points are the lowest points of the respective cusps. Item 1. A medical image processing device according to item 1.

[0131] This allows the medical image processing device to measure the annulus surface with high accuracy, and to measure the circumference and diameter of the annulus surface with high accuracy. Therefore, the medical image processing device can appropriately determine the size of the artificial valve to replace the aortic valve. Therefore, the medical image processing device can prevent the artificial valve from blocking the coronary arteries emerging from the vicinity of the aortic valve. Furthermore, the medical image processing device can prevent the artificial valve from being too small and becoming dislodged.

[0132] [Item 3] The processor: updating the reference plane by moving, via the user interface, at least one of the three end points on the first plane or the second plane including at least one of the three end points; Item 1 or 2. The medical image processing device according to item 1 or 2.

[0133] This allows the user to intuitively adjust the reference plane by moving either the end point on the first plane or the end point on the second plane via the user interface.

[0134] [Item 4] At least one of the reference plane, the first plane, and the second plane is a plane to be moved, The processor: updating the reference image, the first image, and the second image by translating the plane of the movement target in a direction perpendicular to the plane of the movement target via the user interface; moving at least one of the three end points so that at least one of the three end points included in the plane of the movement object before the translation is included in the plane of the movement object after the translation; updating the reference plane in response to movement of at least one of the three end points; Item 1 or 2. The medical image processing device according to item 1 or 2.

[0135] This allows the user to indirectly move the end points by moving the plane to be moved via the user interface, thereby intuitively adjusting the reference plane.

[0136] [Item 5] The processor: A third plane (longitudinal plane SL1) is set as a plane that includes one or two of the three end points and is perpendicular to the reference plane; the first plane includes a first end point (the lowest point of the RCC) and a second end point (the lowest point of the LCC) of the three end points; the second plane includes the second end point and the third end point (the lowest point of the NCC) of the three end points, the third plane includes the third end point and the first end point of the three end points; 5. The medical image processing device according to any one of items 1 to 4.

[0137] This allows the medical image processing apparatus to set a first plane and a second plane that include as many end points as possible, and adjust the reference plane using the first plane and the second plane.

[0138] [Item 6] The processor: A third plane is set which is a plane including one or two of the three end points and which is perpendicular to the reference plane; the first plane includes a first end point (the lowest point of the NCC) of the three end points and the incenter (incenter O) of a triangle (triangle TR) having the three end points as vertices; the second plane includes the second end point (the lowest point of the RCC) of the three end points and the incenter; The third plane includes the third end point (the lowest point of the LCC) of the three end points and the incenter. 5. The medical image processing device according to any one of items 1 to 4.

[0139] This allows the medical image processing device to set a first plane and a second plane that include the end points, and adjust the reference plane using the first and second planes. Also, by using the first and second planes supplementarily together with a plane that includes more end points, it becomes easier to adjust the reference plane more accurately.

[0140] [Item 7] The processor: A third plane is set which is a plane including one or two of the three end points and which is perpendicular to the reference plane; the first plane includes a first endpoint (the lowest point of the NCC) of the three endpoints and is perpendicular to a first line connecting the first endpoint and the incenter of a triangle having the three endpoints as vertices; the second plane includes a second end point (the lowest point of the RCC) of the three end points and is perpendicular to a second line connecting the second end point and the incenter; The third plane includes a third end point (the lowest point of the LCC) of the three end points and is perpendicular to a third line connecting the third end point and the incenter. 5. The medical image processing device according to any one of items 1 to 4.

[0141] This allows the medical image processing device to set a first plane and a second plane that include the end points, and adjust the reference plane using the first and second planes. Also, by using the first and second planes supplementarily together with a plane that includes more end points, it becomes easier to adjust the reference plane more accurately. can.

[0142] [Item 8] acquiring volume data including three chamber-like structures of a subject; setting three end points on the most upstream side of each of the three cluster-like structures in the volume data; setting a reference plane including the three end points; A step of setting a first plane that is a plane that includes one or two of the three end points and is perpendicular to the reference plane; setting a second plane that is a plane perpendicular to the reference plane and includes one or two of the three end points, which is different from the combination of the one or two end points of the first plane and includes all of the three end points when combined with the end points of the first plane; a step of displaying a reference image in which the reference plane is visualized on a display together with the three end points included in the reference plane; a step of displaying, on the display, a first image that visualizes the first plane together with the reference image, along with the one or two end points included in the first plane; a step of displaying, on the display, a second image that visualizes the second plane together with the reference image, along with the one or two end points included in the second plane; receiving, via a user interface, an input operation to move at least one of the three endpoints; moving at least one of the three end points based on the input operation and updating the reference plane; A medical image processing method comprising:

[0143] As a result, the medical image processing method can achieve the same effect as in item 1.

[0144] [Item 9] 9. A medical image processing program for causing a computer to execute the medical image processing method according to item 8.

[0145] This allows the medical image processing program to achieve the same effect as item 1. [Industrial Applicability]

[0146] The present disclosure is useful for a medical image processing device, a medical image processing method, a medical image processing program, and the like that can improve the accuracy of determining a plane that serves as an index in a region having three or more tuft-like structures within a subject. [Explanation of symbols]

[0147] 50 aorta 50A ascending aorta 55 Aortic valve 100 Medical image processing device Port 110 120 User Interface (UI) 130 Display 140 processors 150 memory 160 Processing section 161 Area Processing Unit 162 Mask setting section 163 Surface generation part 164 Image Generation Unit 165 Display control unit 166 Movement control unit 200 CT equipment AR annulus L1 LCC lowest point N1 NCC lowest point R1 RCC lowest point SA annulus surface SF,SN1,SR1,SL1,SN2,SR2,SL2,SN3,SR3,SL3 Longitudinal surface SF1 Focal Plane SF2 non-focus plane RL,RLN1,RLR1,RLL1,RLN2,RLR2,RLL2,RLN3,RLR3,RLL3 Reference line

Claims

1. A medical image processing device including a processor, The processor: Acquiring volume data including three chamber-like structures of a subject; three end points located most upstream of each of the three cluster-like structures in the volume data are set; A reference plane including the three end points is set, A first plane is set that includes one or two of the three end points and is perpendicular to the reference plane; a second plane including one or two of the three end points that is different from the combination of the one or two end points of the first plane and includes all of the three end points when combined with the end points of the first plane, the second plane being a plane perpendicular to the reference plane; a reference image visualizing the reference plane is displayed on a display together with the three end points included in the reference plane; simultaneously displaying on the display a first image in which the first plane is visualized together with the one or two end points included in the first plane; simultaneously displaying on the display a second image in which the second plane is visualized together with the one or two end points included in the second plane; receiving an input operation via a user interface to move at least one of the three end points; moving at least one of the three end points based on the input operation and updating the reference plane; Medical imaging equipment.

2. the reference plane is the annulus plane; the three chamber-like structures are the non-coronary aortic valve cusp, the right aortic valve cusp, and the left aortic valve cusp; The three end points are the lowest points of the respective cusps. The medical image processing device according to claim 1 .

3. The processor: updating the reference plane by moving, via the user interface, at least one of the three end points on the first plane or the second plane including at least one of the three end points; The medical image processing device according to claim 1 or 2.

4. At least one of the reference plane, the first plane, and the second plane is a plane to be moved, The processor: updating the reference image, the first image, and the second image by translating the plane of the movement target in a direction perpendicular to the plane of the movement target via the user interface; moving at least one of the three end points so that at least one of the three end points included in the plane of the movement object before the translation is included in the plane of the movement object after the translation; updating the reference plane in response to movement of at least one of the three end points; The medical image processing device according to claim 1 or 2.

5. The processor: a third plane is set that includes one or two of the three end points and is perpendicular to the reference plane; the first plane includes a first end point and a second end point of the three end points; the second plane includes the second and third endpoints of the three endpoints, the third plane includes the third endpoint and the first endpoint of the three endpoints; The medical image processing device according to claim 1 or 2.

6. The processor: a third plane is set that includes one or two of the three end points and is perpendicular to the reference plane; the first plane includes a first end point of the three end points and the incenter of a triangle having the three end points as vertices, the second plane includes a second end point of the three end points and the incenter; the third plane includes a third end point of the three end points and the incenter; The medical image processing device according to claim 1 or 2.

7. The processor: a third plane is set that includes one or two of the three end points and is perpendicular to the reference plane; the first plane includes a first end point of the three end points and is perpendicular to a first line connecting the first end point and the incenter of a triangle having the three end points as vertices; the second plane includes a second end point of the three end points and is perpendicular to a second line connecting the second end point and the incenter; the third plane includes a third end point of the three end points and is perpendicular to a third straight line connecting the third end point and the incenter. The medical image processing device according to claim 1 or 2.

8. acquiring volume data including three chamber-like structures of a subject; setting three end points on the most upstream side of each of the three cluster-like structures in the volume data; setting a reference plane including the three end points; A step of setting a first plane that is a plane that includes one or two of the three end points and is perpendicular to the reference plane; setting a second plane that is a plane perpendicular to the reference plane and includes one or two of the three end points, which is different from the combination of the one or two end points of the first plane and includes all of the three end points when combined with the end points of the first plane; a step of displaying a reference image in which the reference plane is visualized on a display together with the three end points included in the reference plane; a step of displaying, on the display, a first image that visualizes the first plane together with the reference image, along with the one or two end points included in the first plane; a step of displaying, on the display, a second image that visualizes the second plane together with the reference image, along with the one or two end points included in the second plane; receiving, via a user interface, an input operation to move at least one of the three endpoints; moving at least one of the three end points based on the input operation and updating the reference plane; A medical image processing method comprising:

9. A medical image processing program for causing a computer to execute the medical image processing method according to claim 8.

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