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

Abstract

To provide a medical image processing device capable of visualizing an incompetence region by partial excision of an organ.SOLUTION: A medical image processing device for visualizing an organ includes a processing unit. The processing unit acquires volume data including an organ, designates a tubular tissue included in the organ, designates a first excision region which is a region to be excised in the organ including the tubular tissue, derives a first cutting position where the tubular tissue is cut on the basis of the designated first excision region, derives a first incompetence region included in the organ where a tissue is predicted to become incompetent due to stagnation of circulation in the tubular tissue to be cut on the basis of the tubular tissue and the first cutting position, and displays the organ, the first excision region, and the first incompetent region on a display part.SELECTED DRAWING: Figure 13

Description

[Technical Field]

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

[0002] Conventionally, when resecting an organ, it is known to ligate and cut tubular tissue including blood vessels. Conventionally, medical image processing apparatuses that highlight a ligation and cutting site are known (see Patent Document 1). [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2020-120827 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] The technique of Patent Document 1 can visualize the cut surface of a blood vessel. However, it does not take into account partial resection of an organ including blood vessels. Further, it does not sufficiently consider that tissue becomes non-functional due to blood flow stagnation caused by blood vessel cutting. If the non-functional region is large, the burden on the patient increases. Therefore, it is preferable that the defective region, which is expected to become non-functional due to blood vessel cutting, be visualized to facilitate the formulation of a suitable surgical plan.

[0005] The present disclosure has been made in view of the above circumstances, and provides a medical image processing apparatus, a medical image processing method, and a medical image processing program capable of visualizing a defective region caused by partial resection of an organ. [Means for Solving the Problem]

[0006] One aspect of this disclosure involves acquiring volume data including an organ, specifying tubular tissue included in the organ, specifying a first resection region including the tubular tissue and being a region to be resected within the organ, deriving a first cutting position where the tubular tissue is cut based on the specified first resection region, deriving a first insufficient region included in the organ and being predicted to become non-functional due to impaired circulation within the tubular tissue to be cut based on the tubular tissue and the first cutting position, and displaying the organ, the first resection region, and the first insufficient region on a display unit. By changing the first excision area, a second excision area including the tubular tissue is derived; based on the second excision area, a second cutting position where the tubular tissue is cut is derived; based on the tubular tissue and the second cutting position, a second incomplete area contained within the organ is derived; the organ, the second excision area, and the second incomplete area are displayed on the display unit; the second incomplete area is derived without enlarging the first incomplete area; the second incomplete area is less than or equal to the size of the first incomplete area; and the size of the second excision area is greater than or equal to the size of the first excision area. The second resection region is derived by enlarging the opening on the surface side of the organ in the first resection region, without expanding the first incomplete region. It is a medical image processing device.

[0007] One aspect of the present disclosure is a medical image processing method for visualizing an organ, comprising the steps of: acquiring volume data including the organ; specifying tubular tissue included in the organ; specifying a first resection region including the tubular tissue and which is a region to be resected in the organ; deriving a first cutting position in which the tubular tissue is cut based on the specified first resection region; deriving a first insufficient region included in the organ and which is expected to become non-functional due to impaired circulation within the tubular tissue to be cut, based on the tubular tissue and the first cutting position; and displaying the organ, the first resection region and the first insufficient region. The method includes the steps of displaying on the display unit, deriving a second excision region including the tubular tissue by changing the first excision region, deriving a second cutting position where the tubular tissue is cut based on the second excision region, deriving a second incomplete region included in the organ based on the tubular tissue and the second cutting position, and displaying the organ, the second excision region and the second incomplete region on the display unit, wherein the second incomplete region is derived without enlarging the first incomplete region, the second incomplete region is less than or equal to the size of the first incomplete region, and the size of the second excision region is greater than or equal to the size of the first excision region. The second resection region is derived by enlarging the opening on the surface side of the organ in the first resection region, without expanding the first incomplete region. This is a medical image processing method.

[0008] One aspect of this disclosure is a medical image processing program for causing a computer to perform the above-described medical image processing method. [Effects of the Invention]

[0009] According to this disclosure, it is possible to visualize the incomplete area caused by partial resection of an organ. [Brief explanation of the drawing]

[0010] [Figure 1] Block diagram showing an example of the hardware configuration of a medical image processing device in the first embodiment. [Figure 2] Block diagram showing an example of the functional configuration of a medical image processing device. [Figure 3] Diagram illustrating an example of the interior of a subject's body [Figure 4] Diagram illustrating an example of a resection region in the liver [Figure 5] Diagram illustrating an example of cutting positions of the portal vein and hepatic vein based on a resection region in the liver [Figure 6] Diagram illustrating an example of a necrotic region based on cutting positions of the portal vein and hepatic vein in the liver [Figure 7] Diagram illustrating an example of a modified resection region in the liver [Figure 8] Diagram illustrating an example of modified cutting positions of the portal vein and hepatic vein based on a modified resection region in the liver [Figure 9] Diagram illustrating an example of a modified necrotic region based on modified cutting positions in the liver [Figure 10] Diagram illustrating an example of a re-modified resection region in the liver [Figure 11] Diagram for explaining cutting positions of the portal vein and the vein [Figure 12] Diagram showing a display example of a liver resection region, necrotic region, tumor, portal vein and vein [Figure 13] Flowchart illustrating an operation example of a medical image processing apparatus [Figure 14] Flowchart illustrating an operation example of a medical image processing apparatus (continuation of FIG. 13) DETAILED DESCRIPTION OF EMBODIMENTS

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0012] (First Embodiment) FIG. 1 is a block diagram showing a configuration example 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.

[0013] A CT apparatus 200 is connected to a medical image processing apparatus 100. The medical image processing apparatus 100 acquires volume data from the CT apparatus 200 and performs processing on the acquired volume data. The medical image processing apparatus 100 may be configured by a PC and software installed in the PC.

[0014] The CT apparatus 200 irradiates a subject with X-rays and captures an image (CT image) by utilizing the difference in X-ray absorption by tissues inside the body. The subject may include a living organism, a human body, an animal, or the like. The CT apparatus 200 generates volume data containing information of any site inside the subject. The CT apparatus 200 transmits the volume data as a CT image to the medical image processing apparatus 100 via a wired line or a wireless line. For CT image capturing, imaging conditions related to CT imaging and contrast conditions related to contrast agent administration may be taken into consideration. Contrasting may be performed on arteries, portal veins, veins, or the like of an organ. Contrasting may be performed a plurality of times at different timings depending on the characteristics of the organ.

[0015] A port 110 in the medical image processing apparatus 100 includes a communication port, an external device connection port, a connection port for an embedded device, or the like, and acquires volume data obtained from a CT image. The acquired volume data may be immediately sent to a processor 140 to be subjected to various types of processing, or may be stored in a memory 150 and then sent to the processor 140 to be subjected to various types of processing when needed. Furthermore, the volume data may be acquired via a recording medium or a storage media. Furthermore, the volume data may be acquired in the form of intermediate data, compressed data, a sinogram, or the like. Furthermore, the volume data may be acquired from information from a sensor device attached to the medical image processing apparatus 100. The port 110 functions as an acquisition unit that acquires various types of data such as volume data.

[0016] The UI120 may include a touch panel, a pointing device, a keyboard, or a microphone. The UI120 accepts arbitrary input operations from the user of the medical image processing device 100. The user may include a physician, a radiologist, a student, or other medical professional (paramedic staff).

[0017] UI120 accepts various operations. For example, it accepts operations such as specifying a region of interest (ROI) and setting brightness conditions in volume data and images based on volume data (e.g., 3D images and 2D images described later). The region of interest may include regions of various tissues (e.g., blood vessels, bronchi, organs, tissues, bones, brain). Tissues may include diseased tissue, normal tissue, or tumor tissue.

[0018] The display 130 may include, for example, an LCD, and displays various information. The various 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, or CPR images, etc. The volume rendering images may include RaySum images, MIP images, MinIP images, average value images, or raycast images, etc. The two-dimensional images may include axial images, sagittal images, coronal images, or MPR images, etc.

[0019] Memory 150 includes primary storage devices such as various ROMs and RAMs. Memory 150 may also include secondary storage devices such as HDDs and SSDs. Memory 150 may also include tertiary storage devices such as USB memory or SD cards. Memory 150 stores various information and programs. The various information may include volume data acquired by port 110, images generated by processor 140, configuration information set by processor 140, and various programs. Memory 150 is an example of a non-transient recording medium on which programs are recorded.

[0020] The processor 140 may include a CPU, DSP, or GPU. The processor 140 functions as a processing unit 160 that performs various processing and control by executing a medical image processing program stored in memory 150.

[0021] Figure 2 is a block diagram showing an example of the functional configuration of the processing unit 160.

[0022] The processing unit 160 comprises a region processing unit 161, an image generation unit 162, a cutting position processing unit 163, and a display control unit 165. The processing unit 160 coordinates all parts of the medical image processing device 100. The processing unit 160 performs processing related to the visualization of organs and tissues. Note that each part included in the processing unit 160 may be implemented as a different function by a single piece of hardware, or as different functions by multiple pieces of hardware. Furthermore, each part included in the processing unit 160 may be implemented by dedicated hardware components.

[0023] The region processing unit 161 acquires volume data of the subject, for example, via port 110. The region processing unit 161 extracts any region included in the volume data. The region processing unit 161 may automatically specify a region of interest and extract it, for example, based on the voxel values ​​of the volume data. The region processing unit 161 may manually specify a region of interest and extract it, for example, via UI 120. The region of interest may include regions such as the liver, lungs, bronchi, pulmonary artery, pulmonary vein, portal vein, hepatic vein, etc. The region of interest may be at least a part of the organs to be excised from the subject. The region of interest may also be at least a part of tubular tissue (e.g., blood vessels (e.g., portal vein, artery, vein), bronchi, bile duct). The region processing unit 161 may generate a tree structure showing the course of tubular tissue based on the regions of tubular tissue.

[0024] The region processing unit 161 may divide the subject's organs into regions. The regions may at least roughly correspond to anatomical regions. The organs may include the liver, kidneys, lungs, and other organs. A region may be at least a part of a combination of multiple regions. A region may be a unit of range finer than a region. Voronoi tessellation may be performed in the region division, for example, by performing Voronoi tessellation using the portal vein or artery as a seed to derive each region of the organ.

[0025] The region processing unit 161 may determine the domain supplied by a portal vein or artery (also referred to as a portal vein, etc.) based on its course (portal vein tree, etc.). The domain supplied by a portal vein, etc. refers to the area nourished by the portal vein or artery that nourishes (transports nutrients to) the tumor. The portal vein, etc. that nourishes the tumor is also called the responsible vessel. The region processing unit 161 may calculate the domain supplied by a portal vein, etc., for example, by using the portal vein or artery as a seed and performing a Voronoi tessellation.

[0026] The region processing unit 161 may determine the supply area of ​​a vein based on the course of the vein (vein tree), which is a type of tubular tissue. The supply area of ​​a vein is the perfusion area through which the vein perfuses. The region processing unit 161 may calculate the perfusion area of ​​a vein, for example, by using the vein as a seed and performing a Voronoi tessellation. The perfusion area of ​​a vein may or may not overlap with the supply area of ​​a portal vein, etc.

[0027] The region processing unit 161 may calculate the necrotic region based on the supply area of ​​the portal vein, etc., and the supply area (perfusion area) of the vein. The necrotic region is the region in which tissue necrosis is predicted to occur due to the permanent ischemia of the artery or portal vein, as well as the severance of the vein and the resulting stagnation of blood flow. The necrotic region is one of the affected regions that are impacted by the severance of tubular tissue. For example, the necrotic region is the region that integrates the supply area of ​​the portal vein, etc., where blood flow is stagnate due to the severance of the portal vein, etc., and the perfusion area of ​​the vein, where blood flow is stagnate due to the vein's severance. Therefore, the necrotic region will include the supply area located downstream in the blood flow from the severance site of the portal vein, etc., or vein. Stagnation of blood flow is an example of stagnation of circulation within the tubular tissue that is severed.

[0028] In Voronoi tessellation, the region processing unit 161 may divide an organ into multiple regions or calculate the innervation and perfusion regions based on a reference line or the distance to a point on this line. The reference line may be a line representing the course of tubular tissues such as blood vessels and bronchi. For example, the region processing unit 161 may divide the organ into regions or determine the innervation and perfusion regions based on an extracted tree structure T1 (e.g., a tree of portal veins, arteries, or bronchi) that easily runs through the center of the organ regions. The region processing unit 161 may correct the regions and innervation regions resulting from this region division based on a tree structure T2 (e.g., a tree of veins or lymphatic vessels) that easily runs along the ends or boundaries of the regions and innervation regions. Furthermore, the region processing unit 161 may divide the organ into regions and determine the innervation regions based on the extracted tree structures T1 and T2. An example of region division is disclosed in Reference Patent Document 1. (Reference Patent Document 1: Japanese Unexamined Patent Publication No. 2020-120828)

[0029] The region processing unit 161 may derive the resection region, which is the region of the organ to be resected. The resection region is, for example, the region containing the tumor to be removed from the organ. The resection region may be the same as or different from the determined area of ​​control. The resection region may be the same as or different from the divided area containing the tumor. The region processing unit 161 may manually specify the resection region via the UI 120, or it may automatically specify the resection region according to a predetermined algorithm. The resection region may be the region of the organ to be resected by partial resection surgery or the like.

[0030] For example, the region processing unit 161 may generate a simple shape (e.g., a frustocone shape) encompassing the tumor by specifying the center point on the organ surface where the resection will begin and the diameter of the resection area via the UI 120. Alternatively, if one or more points (control points) on the organ surface are specified, the region processing unit 161 may derive the resection area by using the lines connecting the specified control points as the outer perimeter of the resection area. In other words, the resection area can be derived simply by the user giving a simple instruction (an instruction to specify control points) via the UI 120, indicating where to approach the organ.

[0031] The region processing unit 161 may generate a curved surface using any point within the organ, for example, a point on tubular tissue running within the organ, as the resection plane. The resection region does not have to depend on any of the aforementioned organ regions, supply regions such as portal veins, or venous perfusion regions.

[0032] The region processing unit 161 may modify (re-derive) the derived excision region. For example, the region processing unit 161 may manually modify the excision region via the UI 120. The region processing unit 161 may also automatically modify the excision region based on the derived necrotic region. For example, the excision region may be modified so that a predetermined (e.g., important) portal vein or vein is outside the excision region. For example, the excision region may be modified so that it expands without expanding the necrotic region.

[0033] The image generation unit 162 generates various images. The image generation unit 162 generates three-dimensional images and two-dimensional images based on at least a portion of the acquired volume data (for example, volume data of extracted regions or areas). The image generation unit 162 may generate images in which a portion of the organ included in the resection region is excluded. In this case, the resection region within the organ is excluded, but the image may be generated in which at least a portion of the tubular tissue within the resection region remains, or the image may be generated in which at least a portion of the tubular tissue within the resection region is also excluded.

[0034] The image generation unit 162 may generate an image by performing various rendering methods (e.g., volume rendering or surface rendering). The image generation unit 162 may generate an image using a mask. When a mask is used, only voxels in the masked area are drawn in the image, and voxels in the non-masked area are not drawn in the image. Multiple masks can be used for each area. Image generation using masks is disclosed, for example, in Reference Patent Document 2. The image generation unit 162 may also generate an image without using a mask. (Reference Patent Document 2: Patent No. 4188900)

[0035] The cutting position processing unit 163 determines the location (cutting position, cutting point) where tubular tissue (e.g., portal vein, artery, or vein) is cut. The cutting position processing unit 163 may manually determine the cutting position of the tubular tissue via the UI 120. The cutting position processing unit 163 may calculate the cutting position of tubular tissue running around or within an organ based on the organ resection area. The cutting position of tubular tissue is synonymous with the cutting position on the tubular tissue tree.

[0036] The tubular tissue to be cut may be tubular tissue to be ligated and cut. Ligation and cutting may be performed in conjunction with tumor removal of an organ, segmental resection of an organ, wedge resection of an organ, etc.

[0037] The display control unit 165 displays various data, information, or images on the display 130. The images include images generated by the image generation unit 162. The display control unit 165 may display the excised area, the controlled area, the perfusion area, or the necrotic area, etc. In this case, at least one of the excised area, the controlled area, the perfusion area, or the necrotic area, etc., may be displayed in different display modes. The display control unit 165 may also superimpose information that emphasizes the cutting position (cutting position) (emphasis information) onto the rendered image. The emphasis information may include contour emphasis information that emphasizes the contour of the cutting position, or surface emphasis information that emphasizes the cut surface.

[0038] Figure 3 shows an example of the inside of a subject's body. In Figure 3, the inside of the subject's body is shown as the liver 10, tumor 20, portal vein 12, and vein 14. The portal vein 12 and vein 14 are located inside the surface 11 of the liver 10. A portion of the portal vein 12 is the responsible vessel 12a, which nourishes the tumor 20. For explanatory purposes, in Figure 3, the portal vein 12 is shown as a solid line and the vein 14 is shown as a dotted (dashed) line. The same applies to subsequent figures.

[0039] Figure 4 shows an example of a resection region 17 in the liver 10. The region processing unit 161 determines the supply region of the portal vein, etc., which is the region nourished by the responsible vessel 12a, based on the portal vein 12 including the responsible vessel 12a, by Voronoi tessellation or the like. The region processing unit 161 may also determine the supply region of the portal vein, etc., based on the portal vein 12 including the responsible vessel 12a and the vein 14, by Voronoi tessellation or the like. In Figure 4, the outer periphery of the supply region of the portal vein, etc., may be formed by making the distances from multiple portal veins 12 located close to each other approximately equidistant. Alternatively, the outer periphery of the supply region may be formed along the course of the vein 14. The region processing unit 161 manually or automatically specifies the resection region 17 including the tumor 20. In Figure 4, a vein is included near the periphery of the resection region 17. The region processing unit 161 may specify a frustoconical resection region 17, for example, via UI 120.

[0040] Figure 5 shows an example of the cutting positions 12p and 14p of the portal vein 12 and vein 14 based on the resection region 17 in the liver 10. Cutting position 12p is the position where the portal vein 12 (responsible vessel 12a) is cut. Cutting position 14p is the position where the vein 14 is cut. Cutting positions 12p and 14p are shown, for example, in a two-dimensional cross-section. Cutting position 12p may be the intersection of the portal vein 12 (responsible vessel 12a) and the outer surface of the resection region 17. Cutting position 14p may be the intersection of the vein 14 and the outer surface of the resection region 17.

[0041] Figure 6 shows an example of a necrotic region 19 based on the cleavage points 12p and 14p of the portal vein 12 and vein 14 in the liver 10. The necrotic region 19 includes the supply area of ​​the portal vein 12 downstream of the cleavage point 12p and the perfusion area of ​​vein 14 downstream of the cleavage point 14p. The region processing unit 161 determines the necrotic region 19 that will become necrotic due to the interruption of perfusion by the resected region 17, based on the portal vein 12 including the responsible vessel 12a and the cleavage point 12p of the portal vein 12, by Voronoi division or the like. The region processing unit 161 may also determine the necrotic region 19 that will become necrotic due to the interruption of perfusion by the resected region 17, based on the portal vein 12 including the responsible vessel 12a and the cleavage point 12p of the portal vein 12 and the vein 14 and the cleavage point 14p of the vein 14, by Voronoi division or the like. In addition, the outer periphery of the necrotic region 19 may be formed along the course of vein 14 and cleavage point 14p. Figure 6 shows the portal vein removal portion 12c, which is removed by cutting at the cutting position 12p of the portal vein 12, and the vein removal portion 14c, which is removed by cutting at the cutting position 14p of the vein 14. The portal vein removal portion 12c and the vein removal portion 14c are included in the necrotic area 19. The excised area 17 is included in the necrotic area 19.

[0042] Figure 7 shows an example of a modified resection area in the liver 10. The region processing unit 161 modifies the resection area 17 to generate a modified resection area 17m. In the modified resection area 17m, the veins 14 that run along the peripheral edge of the resection area 17 are modified to be outside the modified resection area 17m.

[0043] Figure 8 shows an example of corrected cutting positions 12mp and 14mp of the portal vein 12 and vein 14 based on the corrected resection area 17m in the liver 10. Corrected cutting position 12mp is the position where the cutting position 12p of the portal vein 12 (responsible vessel 12a) is corrected as the resection area 17 was corrected to form the corrected resection area 17m. Corrected cutting position 14mp is the position where the cutting position 14p of the vein 14 is corrected as the resection area 17 was corrected to derive the corrected resection area 17m. Corrected cutting positions 12mp and 14mp are shown, for example, in a two-dimensional cross-section. Corrected cutting position 12mp may be the intersection of the portal vein 12 (responsible vessel 12a) and the outer surface of the corrected resection area 17m. Corrected cutting position 14mp may be the intersection of the vein 14 and the outer surface of the corrected resection area 17m.

[0044] Figure 9 shows an example of a modified necrotic area 19m based on modified resection positions 12mp and 14mp of the portal vein 12 and vein 14 in the liver 10. The modified necrotic area 19m is the area in which the necrotic area 19 has been modified by correcting the resection positions 12p and 14p to derive modified resection positions 12mp and 14mp. The modified necrotic area 19m includes the supply area of ​​the portal vein 12 downstream of the modified resection position 12mp and the perfusion area of ​​the vein 14 downstream of the modified resection position 14mp. In Figure 9, the modified portal vein removal portion 12mc, which is removed by resection at the modified resection position 12mp of the portal vein 12, and the modified vein removal portion 14mc, which is removed by resection at the modified resection position 14mp of the vein 14, are shown. The modified portal vein removal portion 12mc and the modified vein removal portion 14mc are included in the modified necrotic area 19m. The modified resection area 17m is included in the modified necrotic area 19m.

[0045] The region processing unit 161 may generate a modified resection area 17m manually or automatically, similar to the specification of the resection area 17 shown in Figure 4. The modified resection area 17m may be smaller than the resection area 17. This reduces the volume of the necrotic area 19, thereby reducing the burden on the patient. The size of the volume of the necrotic area 19 in the liver 10 is inversely proportional to, for example, the quality of liver function. Alternatively, the region processing unit 161 may generate the modified resection area 17m based on the volume of the necrotic area 19, for example, so that the volume of the necrotic area 19 or the ratio of the necrotic area to the remaining area (volume ratio) is less than or equal to a predetermined value. In this case, the processing unit 160 may repeatedly perform the generation of the modified resection area 17m, the generation of the modified necrotic area 19m, and the volume determination of the modified necrotic area 19m. The remaining area is the area from which the resection area 17 has been removed from the liver 10, and is the area that remains as part of the liver 10 after partial resection surgery, etc.

[0046] Figure 10 shows an example of a revised resection area 17m2 in the liver 10. The region processing unit 161 modifies the revised resection area 17m to generate the revised resection area 17m2. In Figure 10, the revised resection area 17m is enlarged to prevent the necrotic area 19 from expanding, thereby generating the revised resection area 17m2. The region processing unit 161 may generate the revised resection area 17m2 manually or automatically, similar to the specification of the resection area 17 shown in Figure 4. The revised resection area 17m2 may be smaller than the resection area 17 and larger than the revised resection area 17m. For example, the region processing unit 161 may generate the revised resection area 17m2 by enlarging the opening of the surface 11 of the liver 10 in the revised resection area 17m. This reduces the burden on the patient and makes it easier for the physician to perform the procedure (e.g., resection of the area including the tumor 20).

[0047] Figure 11 is a diagram illustrating the cutting positions 12p and 14p of the portal vein 12 and vein 14. The portal vein 12 flows towards the center of a predetermined region in the liver (region Z1 in Figure 11) and nourishes the tumor 20. Therefore, the cutting position processing unit 163 may determine the cutting position 12p to cut from the base of the portal vein 12. On the other hand, vein 14 runs around the ends (near the boundaries) of predetermined regions Z1 and Z2 in the liver. Also, it is unlikely that a low-stage tumor 20 crosses the region boundary. Therefore, the cutting position processing unit 163 may determine the cutting position 14p to preserve the main vessel of vein 14 and cut the branch vessels that enter the region. The same applies to determining the modified cutting positions 12mp and 14mp. Thus, the portal vein and veins are cut according to different criteria.

[0048] Figure 12 shows an example of displaying the resected area 17, necrotic area 19, tumor 20, portal vein 12, and vein 14 of the liver 10. The image generation unit 162 may render at least a portion of the areas included in the liver 10, such as the resected area 17, necrotic area 19, remaining area, artery, portal vein 12, or vein 14, to generate a rendered image. The display control unit 165 may display the rendered image. Additional information regarding the rendering target may also be displayed.

[0049] In Figure 12, in the liver 10, the area other than the necrotic region 19 is covered by the surface 11 of the liver 10. The display control unit 165 may display the resected region 17 and the necrotic region 19 in different display modes so that the user can distinguish between them. Furthermore, the display control unit 165 may display the resected region 17, the necrotic region 19, the tumor 20, the portal vein 12, and the vein 14 in different display modes so that the user can distinguish between them.

[0050] In Figure 12, the necrotic area 19 is shown semi-transparently, and necrotic areas 19A and 19B are shown as necrotic area 19. Necrotic area 19A indicates that there is no remaining non-necrotic portion of the liver 10 on the far side of the page beyond necrotic area 19A, meaning that necrotic area 19A penetrates the liver 10. Necrotic area 19B indicates that there is remaining non-necrotic portion of the liver 10 on the far side of necrotic area 19B.

[0051] Furthermore, the display control unit 165 may display volume information relating to the volume of the entire liver, the resected area 17, the necrotic area 19, or the remaining area. The volume information may include the volume values ​​of the entire liver, the resected area 17, the necrotic area 19, or the remaining area. The volume information may include the ratio of the resected area 17 to the entire liver (volume ratio of the resected area 17), the ratio of the necrotic area 19 to the entire liver (volume ratio of the necrotic area 19), or the ratio of the remaining area to the entire liver (volume ratio of the remaining area). The volume information may also include the volume ratio of any two of the volumes contained in the resected area 17, the necrotic area 19, and the remaining area.

[0052] Furthermore, the processing unit 160 can apply the technology described in Reference Patent Document 3 to the visualization (display) of multiple regions (for example, the excised region 17, the necrotic region 19, the portal vein 12, and the veins 14). In other words, even if multiple regions overlap in the image shown on the two-dimensional display surface, the user can distinguish between the multiple regions by coloring each region. (Reference Patent Document 3: Japanese Unexamined Patent Publication No. 2016-202319)

[0053] In the rendering performed by the image generation unit 162, the tumor 20, excised area 17, necrotic area 19, remaining area, portal vein 12, or vein 14 may be volume-rendered, surface-rendered, or a combination of both. The image generation unit 162 may generate images of various areas by generating masks from volume data, or it may generate images of various areas using solids or surfaces. The image generation unit 162 may also generate a rendering image by blending surface rendering and volume rendering (see Reference Patent Document 4). Furthermore, the image generation unit 162 may make the boundary of the excised area 17, necrotic area 19, or remaining area semi-transparent so that the course of blood vessels inside the excised area 17, necrotic area 19, or remaining area can be confirmed through the boundary. Furthermore, the image generation unit 162 may draw only the shading at the boundary of the excised area 17, the necrotic area 19, or the remaining area so that the course of blood vessels inside the excised area 17, the necrotic area 19, or the remaining area can be confirmed (see Reference Patent Document 5). (Reference Patent Document 4: Japanese Unexamined Patent Publication No. 2018-121857) (Reference Patent Document 5: Japanese Unexamined Patent Publication No. 2017-189460)

[0054] Next, an example of the operation of the medical image processing device 100 will be described. Figures 13 and 14 are flowcharts illustrating examples of the operation of the medical image processing device 100. The processing shown in Figure 13 is performed, for example, by various parts within the processing unit 160.

[0055] First, port 110 acquires volume data (portal venous phase, venous phase) of the subject (S11). The region processing unit 161 extracts the liver region (liver 10) and the tumor region (tumor 20) from the volume data (S12). The region processing unit 161 extracts the portal venous region (portal vein 12) and the venous region (vein 14) from the volume data (S13). The region processing unit 161 generates a portal vein tree based on the portal vein region and a venous tree based on the venous region (S14). The region processing unit 161 specifies the resection region via UI 120 (S15). The resection position processing unit 163 calculates the resection position on the portal vein tree based on the resection region and the portal vein tree, and calculates the resection position on the venous tree based on the resection region and the venous tree (S16).

[0056] The region processing unit 161 calculates the necrotic area based on the portal vein tree, the venous tree, the cutting positions on the portal vein tree, and the cutting positions on the venous tree (S17). In this case, the portal vein supply area may be calculated based on the portal vein tree and its cutting positions, the venous perfusion area may be calculated based on the venous tree and its cutting positions, and the necrotic area may be calculated based on the portal vein supply area and the venous perfusion area.

[0057] The display control unit 165 displays a rendering image including the liver region, tumor region, resected region, and necrotic region on the display 130 (S18). The display control unit 165 may display the volumes of the liver region, the necrotic region, and the remaining region (S19). The display control unit 165 may also display the volume ratio of the necrotic region to the liver region, the volume ratio of the remaining region to the liver region, etc. (S19).

[0058] After processing in step S19, the process proceeds to Figure 14. The cutting position processing unit 163 determines whether there is an instruction to modify the cutting position of the portal vein or the vein (S21). For example, the instruction to modify the cutting position may be given based on user operation via the UI 120. If there is an instruction to modify either cutting position (Yes in step S21), the cutting position processing unit 163 derives a modified cutting position 12mp2 for the portal vein or a modified cutting position 14mp2 for the vein based on the above modification instruction (S22). The region processing unit 161 calculates a modified resection region 17m3 based on the derived modified cutting positions 12mp2 and 14mp2 (S23). After processing in step S23, the process proceeds to step S17 in Figure 13, and the processing from step S17 onward is performed. For example, the region processing unit 161 calculates a modified necrotic region (modified necrotic region 19m2) based on the portal vein tree, the venous tree, the modified portal vein cutting position (modified portal vein cutting position 112mp2), and the modified venous cutting position (modified venous cutting position 14mp2) (S17).

[0059] If no instructions for modifying any cutting positions are given in step S21, the region processing unit 161 determines whether or not there are instructions for modifying the excision region (S24). In this case, instructions for modifying the excision region may be given via the UI 120 based on user operation. If there are instructions for modifying the excision region (Yes in step S24), the region processing unit 161 derives the modified excision region (modified excision region 17m) based on these instructions (S25). After processing in step S25, the process proceeds to step S16 in Figure 13, and the processing from step S16 onward is performed. For example, the cutting position processing unit 163 calculates the modified cutting position of the portal vein (modified cutting position of the portal vein 12mp) and the cutting position of the vein (modified cutting position of the vein 14mp) based on the modified excision region 17m (S16).

[0060] Next, variations of this embodiment will be described.

[0061] The resection region 17 may have a shape other than a frustoconical shape. The region processing unit 161 may derive the resection region 17 by specifying a primitive shape via, for example, the UI 120 and then finely modifying the shape. Alternatively, the region processing unit 161 may specify or modify the resection region 17 by specifying the cutting position on the surface 11 of the liver 10 through a two-dimensional operation via the UI 120. The region processing unit 161 may also specify or modify the resection region 17 by specifying the cutting position 12p or cutting position 14p on a blood vessel (e.g., portal vein 12 or vein 14) through a one-dimensional operation via the UI 120. In this case, the user can easily specify or modify the resection region 17 on a three-dimensional image using a region image processing tool.

[0062] Furthermore, the tumor 20 may be represented as a point without having an extent on a two-dimensional plane or three-dimensional space. The safe distance from the tumor 20 may be adjustable. The resection area 16 may be determined taking into account the safe distance from the tumor 20. The tumor 20 may not be located within an organ, or it may be in the area of ​​another lesion.

[0063] Furthermore, the region processing unit 161 may derive the domain supplied by the portal vein, etc., without using the veins, or it may derive the domain supplied by the portal vein, etc., by taking into account both the portal vein, etc., and the veins. In this case, the region processing unit 161 may calculate the portal vein tree and the vein tree separately, or it may calculate based on a graph structure that combines the portal vein tree and the vein tree. In addition, the display control unit 165 may display (for example, highlight) the outline of the portion obtained by adding the excised region 17 and the domain supplied by the portal vein after the domain has been calculated.

[0064] Furthermore, the region processing unit 161 may specify blood vessels to be preserved (not to be resected) via, for example, the UI 120. The region processing unit 161 may also recalculate the supply area of ​​the portal vein or other vessels, or the perfusion area of ​​the veins, etc., based on the specified cutting positions on the blood vessels (e.g., cutting positions 12p, 14p). Furthermore, the cutting position processing unit 163 may adjust the cutting position of the blood vessels by performing a drag operation on the 3D image including the blood vessels displayed on the display 130, for example, via the UI 120. In this case, the cutting position processing unit 163 may control the cutting position so that it moves along the blood vessel path. This allows the user to easily manipulate the cutting position via the UI 120 on the 3D image including the blood vessels displayed on the display 130. For example, if an excessively large resection area 17 is derived, the user can reduce the necrotic area 19 by moving the cutting position 14p of the vein 14 downstream of the vein 14. Furthermore, for example, if an insufficient resection area 17 is obtained, the user can adjust the resection area 17 to be larger by moving the cutting position 14p of the vein 14 upstream of the vein 14, thereby ensuring that the tumor 20 is included within the resection area 17.

[0065] Furthermore, although the organ is exemplified as the liver 10, other organs or tissues (e.g., lungs or brain) may also be used. In addition, the tubular tissue may include the portal vein of the liver 10, the arteries of the liver 10, lungs, or kidneys, the veins 14 of the liver 10, lungs, or kidneys, the bronchi of the lungs, or cranial nerves. Cranial nerves may be extracted using tractography. The image generation unit 162 may also generate a three-dimensional image of the object of observation by mixing volume rendering and surface rendering. In addition, the tubular tissue, such as blood vessels, may also include tissues that do not have a tree structure (e.g., intestines). In this case, it is sufficient that the direction of flow in the tubular tissue is identifiable. Furthermore, the processing unit 160 may use two or more tubular tissues with different developments as the tubular tissue, such as arteries and veins, bronchi and veins, bronchi, arteries and veins, nerve fibers and arteries, fibers, arteries and veins, etc., to calculate the dominant region. Furthermore, when the processing unit 160 uses two or more tubular tissues with different developments, it may use different methods for setting the cutting points. This is because their respective properties can be utilized.

[0066] Furthermore, although the processing unit 160 was shown as an example of determining the necrotic region 19 of the liver 10, it may also derive insufficient regions other than the necrotic region 19. An insufficient region is a region in the tubular tissue to be cut where it is predicted that the tissue will cease to function due to impaired circulation, that is, a region where dysfunction is predicted. Insufficient regions may include areas such as the bronchial region where the airflow is cut off only results in insufficiency, and does not necessarily lead to necrosis. In addition, insufficient regions may include areas such as blood vessels where ischemia temporarily causes insufficiency, but later blood flow is restored or the blood vessel is reconstructed, and therefore does not necessarily lead to necrosis.

[0067] Furthermore, the region processing unit 161 may use the course of the veins to correct the supply areas of the portal vein, etc. This can improve the accuracy of deriving the supply areas of the portal vein, etc. The resected region 17 is not necessarily required to be included in the necrotic region 19, and may not be included in the necrotic region 19.

[0068] According to the medical image processing device 100 of this embodiment, for example, when a user roughly specifies the location to resect a tumor 20 in the liver 10 of a subject based on its simple shape, the device can determine the extent of the resection area 17. The medical image processing device 100 can also estimate the necrotic area 19 when a vein 14 is resected, and can visualize the range in which liver function may be impaired by considering the severance of not only the portal vein 12 but also the vein 14. Furthermore, the medical image processing device 100 can, for example, specify the severance position 12p of one portal vein 12 via the UI 120, derive the resection area 17 based on the severance position 12p, and can also derive the severance positions 12p, 14p of other portal veins 12 and veins 14 passing through the resection area 17 based on the resection area 17. Therefore, the user can confirm the effects of a single severance from various perspectives. Thus, the user can confirm that surgery can be performed to remove a large portion of the portal vein 12 leading to the tumor 20 while minimizing damage to the vein 14. Furthermore, if vein 14 is included in the resection area 17, the necrotic area 19 will expand. Therefore, by adjusting the vein 14 to be outside the resection area 17 via, for example, UI 120, the necrotic area 19 can be reduced. In this case, the burden on the patient during surgery can be reduced.

[0069] Furthermore, the medical image processing device 100 can formulate a surgical plan that is easy to perform while preserving liver function as much as possible (determining the resection area), and can determine, for example, the resection area 17 and the approach direction for resection. In addition, the specification of the resection area 17 and other elements included in the surgical plan may be specified using simple shapes. Furthermore, the medical image processing device 100 can display and present to the user both the numerical value of liver function (volume) affected by the surgical plan and an image of the liver 10. In addition, the impact on liver function (e.g., necrosis) can be improved by modifying the resection area 17 in the surgical plan. That is, after the user initially specifies an arbitrary resection area 17, it can be modified to a resection area 17 that takes into account the necrotic area 19 (modified resection area 17m). Furthermore, the medical image processing device 100 can also modify the resection area 17 (re-modified resection area 17m2) so that the necrotic area 19 does not change, for example, by widening the area on the organ surface side to make it easier to approach the organ. Therefore, the medical image processing device 100 can suppress the impact on liver function and formulate a more easily implementable surgical plan.

[0070] When veins 14 located at the peripheral edge of the resection area 17 are resected, blood may accumulate in the remaining area outside the resection area 17, potentially causing tissue in a portion of the remaining area (necrotic area 19) to become non-functional. In response to this, the medical image processing device 100 can assist in adjusting the size of the resection area 17 by visualizing the necrotic area 19. Furthermore, the size of the resection area 17 can be optimized by repeatedly extracting the resection area 17, the cutting positions 12p and 14p, and the necrotic area 19. Therefore, the medical image processing device 100 can minimize the size of the resection area 17 while including the entire tumor 20, thereby minimizing the burden on the patient while completely resecting the lesion.

[0071] Although various embodiments have been described above with reference to the drawings, it goes without saying that this disclosure is not limited to such examples. It is clear to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of this disclosure.

[0072] Furthermore, the medical image processing device 100 may include at least a processor 140 and memory 150. The port 110, UI 120, and display 130 may be external to the medical image processing device 100.

[0073] Furthermore, it was illustrated that the volume data, as captured CT images, is transmitted from the CT scanner 200 to the medical image processing device 100. Alternatively, the volume data may be transmitted to a server on the network (e.g., an image data server (PACS) (not shown)) for storage. In this case, the port 110 of the medical image processing device 100 may acquire the volume data from the server via a wired or wireless line when necessary, or via any storage medium (not shown).

[0074] Furthermore, it was illustrated that the volume data of the captured CT image is transmitted from the CT scanner 200 to the medical image processing device 100 via port 110. This includes cases where the CT scanner 200 and the medical image processing device 100 are essentially combined into a single product. It also includes cases where the medical image processing device 100 is treated as the console for the CT scanner 200.

[0075] Furthermore, while the example illustrates the acquisition of images using a CT scanner 200 and the generation of volume data containing information about the inside of the subject, images may be acquired and volume data generated using other devices. Other devices include MRI (Magnetic Resonance Imaging) scanners, PET (Positron Emission Tomography) scanners, angiography scanners, or other modality devices. In addition, PET scanners may be used in combination with other modality devices.

[0076] Furthermore, the operation of the medical image processing device 100 can be expressed as a defined medical image processing method. It can also be expressed as a program that causes a computer to execute each step of the medical image processing method.

[0077] (Summary of the above embodiment) One embodiment of the above-described model is a medical image processing device 100 for visualizing an organ (e.g., a liver 10), comprising a processing unit 160. The processing unit 160 may acquire volume data including the organ, specify tubular tissue included in the organ, and specify an excision region 17 (an example of a first excision region) that includes the tubular tissue and is the area to be excised in the organ. Based on the specified excision region 17, the processing unit 160 may derive cutting positions 12p, 14p (an example of a first cutting position) where the tubular tissue is cut. Based on the tubular tissue and the cutting positions 12p, 14p, the processing unit 160 may derive a necrotic region 19 (an example of a first infertile region where the tissue is expected to cease function) included in the organ, where tissue necrosis is expected due to impaired circulation within the tubular tissue to be cut. The processing unit 160 displays the organ, the excision region 17, and the necrotic region 19 on a display 130 (an example of a display unit).

[0078] This allows the medical image processing device 100 to visualize the necrotic area 19 resulting from partial resection of an organ. Therefore, the user can visually identify the necrotic area 19 along with the resection area 17, which can be used to aid in surgical planning. For example, the user can plan a surgery that maximizes the resection area 17 and minimizes the necrotic area 19.

[0079] Furthermore, the processing unit 160 may derive a modified resection region 17m (an example of a second resection region) including tubular tissue by changing the resection region 17, and derive modified cutting positions 12mp, 14mp (an example of a second cutting position) where the tubular tissue is cut, based on the modified resection region 17m. Based on the tubular tissue and the modified cutting positions 12mp, 14mp, the processing unit 160 may derive a modified necrotic region (an example of a second incomplete region) contained in the organ, and display the organ, the modified resection region 17m, and the modified necrotic region 19m on the display 130.

[0080] This allows the medical image processing device 100 to adjust the extent of the necrotic area 19 by adjusting the resection area 17. Therefore, for example, if the necrotic area 19 is large and is considered to be a burden on the patient, the user can reduce the necrotic area 19 by reducing the resection area 17. The medical image processing device 100 can also be adjusted so that lesions such as tumors 20 are reliably included in the resection area 17. Thus, the medical image processing device 100 can formulate a surgical plan that preserves organ function as much as possible while reducing the burden on the patient.

[0081] Furthermore, the size of the corrected necrotic area 19m may be less than or equal to the size of the necrotic area 19. This reduces the burden on the patient. Also, the size of the corrected excision area 17m may be greater than or equal to the size of the excision area 17. This makes the surgery easier for the user by requiring less precise techniques and allowing for the removal of as much of the lesion as possible.

[0082] Furthermore, the processing unit 160 may generate a re-corrected excision area 17m2 (an example of a third excision area) that is larger than the corrected excision area 17m but smaller than the corrected necrotic area 19m, based on the corrected necrotic area 19m. This allows the medical image processing device 100 to automatically generate a re-corrected excision area 17m2 that is easier to operate on by requiring only a rough technique, or that allows for the removal of as much of the lesion as possible, while keeping the size of the corrected necrotic area 19m unchanged.

[0083] Furthermore, the processing unit 160 may specify corrected cutting positions 12mp2 and 14mp2 (an example of a third cutting position) by changing the cutting positions 12p and 14p, and derive a corrected resection region 17m3 (an example of a fourth resection region) and a corrected necrotic region 19m2 (an example of a third incomplete region) contained in the organ based on the tubular tissue and these corrected cutting positions 12mp2 and 14mp2, and display the organ, the corrected resection region 17m3 and the corrected necrotic region 19m2 on the display 130.

[0084] This allows the medical image processing device 100 to adjust a third excision region and a third incomplete region based on a corrected cutting position, resulting from correcting the cutting position on the tubular tissue. For example, when changing the cutting position to preserve a blood vessel at an arbitrary location, the medical image processing device 100 can show the user how much this will affect the excision region 17 and the necrotic region 19.

[0085] Furthermore, the organ may be the liver 10. The tubular tissue may include at least two of the arteries, portal veins, and veins. This allows the medical image processing device 100 to derive a necrotic region 19 that takes into account the respective territories supplied by the multiple tubular tissues. For example, by deriving and displaying the necrotic region 19 that takes into account the vein 14, it becomes easier for the user to determine where on the vein 14 the cutting position 14p should be modified, and whether or not to exclude the vein 14 from the excision region 17. [Industrial applicability]

[0086] This disclosure is useful for medical image processing equipment, medical image processing methods, and medical image processing programs that can visualize incomplete areas caused by partial resection of organs. [Explanation of Symbols]

[0087] 10 Liver 11 Surface 12 Portal Vein 12a Responsible Blood Vessel 12c Portal vein removal section 12mc Modified portal vein removal section 12mp modified cutting position 12p cutting position 14 Veins 14c Vein removal area 14mc Corrective vein removal portion 14mp modified cutting position 14p cutting position 17 Excision area 17m modified resection area 17m2 revision resection area 19 Necrotic area 19m corrected necrotic area 20 Tumors 100 Medical Image Processing Equipment 110 ports 120 User Interface (UI) 130 displays 140 processors 150 memory 160 Processing Unit 161 Area Processing Unit 162 Image generation unit 163 Cutting position processing unit 165 Display Control Unit 200 CT equipment

Claims

1. A medical image processing device for visualizing organs, Equipped with a processing unit, The aforementioned processing unit, We obtain volume data including organs, Specify the tubular tissue contained in the aforementioned organ, A first resection region is designated, which includes the tubular tissue and is the region of the organ to be resected. Based on the specified first excision region, a first cutting position is determined in which the tubular tissue is cut. Based on the tubular tissue and the first cutting position, a first infertile region is derived within the organ, in which it is predicted that tissue will cease to function due to impaired circulation within the tubular tissue to be cut. The organ, the first resection region, and the first incomplete region are displayed on the display unit. By changing the first excision area, a second excision area including the tubular tissue is derived. Based on the second excision region, a second cutting position is derived where the tubular tissue is cut. Based on the tubular tissue and the second cutting position, a second incomplete region within the organ is derived. The organ, the second resection region, and the second incomplete region are displayed on the display unit. The second incomplete region is derived without expanding the first incomplete region, the second incomplete region is less than or equal to the size of the first incomplete region, and the size of the second excised region is greater than or equal to the size of the first excised region. The second resection region is derived by enlarging the opening on the surface side of the organ in the first resection region, without expanding the first incomplete region. Medical image processing equipment.

2. The aforementioned processing unit, By changing the first cutting position, a third cutting position can be specified. Based on the tubular tissue and the third cutting position, a fourth resection region and a third incomplete region within the organ are derived. The organ, the fourth excision region, and the third incomplete region are displayed on the display unit. The medical image processing apparatus according to claim 1.

3. The tubular tissue consists of two different types of tubular tissue. The medical image processing apparatus according to claim 1 or 2.

4. One of the two different types of tubular tissue is a vein. The medical image processing apparatus according to claim 3.

5. The aforementioned organ is the liver. The tubular tissue includes arteries or portal veins and veins. The medical image processing apparatus according to claim 4.

6. A medical image processing method for visualizing organs, Steps to obtain volume data including organs, The steps include specifying the tubular tissue contained in the aforementioned organ, A step of designating a first resection region which includes the tubular tissue and is a region in the organ to be resected, A step of deriving a first cutting position in which the tubular tissue is cut based on the specified first excision region, A step of deriving a first infertile region, which is contained in the organ and is predicted to become non-functional due to impaired circulation within the tubular tissue to be cut, based on the tubular tissue and the first cutting position, The steps include displaying the organ, the first resection region, and the first incomplete region on the display unit, The steps include: deriving a second excision region including the tubular tissue by changing the first excision region; A step of deriving a second cutting position in which the tubular tissue is cut based on the second excision region, A step of deriving a second incomplete region contained in the organ based on the tubular tissue and the second cutting position, The steps include displaying the organ, the second resection region, and the second incomplete region on the display unit, Yes, The second incomplete region is derived without expanding the first incomplete region, the second incomplete region is less than or equal to the size of the first incomplete region, and the size of the second excised region is greater than or equal to the size of the first excised region. The second resection region is derived by enlarging the opening on the surface side of the organ in the first resection region, without expanding the first incomplete region. Medical image processing methods.

7. A medical image processing program for causing a computer to execute the medical image processing method described in claim 6.

Images