JP6744127B2 - Medical image processor - Google Patents

Description

Embodiments of the present invention relate to a medical image processing apparatus.

Conventionally, an X-ray diagnostic apparatus may be used for coil embolization for a cerebral aneurysm. For example, in coil embolization, an operator such as a doctor inserts a microcatheter into a cerebral aneurysm under fluoroscopy and occludes the blood flow by packing a platinum coil into the cerebral aneurysm. Here, the operator clearly observes the neck surface, which is the boundary between the cerebral aneurysm and the parent blood vessel, by continuously performing fluoroscopic imaging on the cerebral aneurysm to be treated before performing the procedure. Search for possible shooting directions.

JP, 2002-119502, A

The problem to be solved by the present invention is to provide a medical image processing apparatus capable of reducing exposure to a subject when determining an imaging direction.

The medical image processing apparatus according to the embodiment includes an extracting unit and a specifying unit. The extraction unit extracts the parent blood vessel and the aneurysm from the three-dimensional image data. The specifying unit is an inner product of a normal vector of the neck surface, which is a boundary between the parent blood vessel and the aneurysm, and a projection direction vector set in the three-dimensional image data, a core line vector of the parent blood vessel, and the projection. The imaging direction of the X-ray diagnostic apparatus is specified based on the dot product with the direction vector.

FIG. 1 is a diagram showing a configuration example of a medical information processing system according to the first embodiment. FIG. 2A is a diagram for explaining a conventional technique. FIG. 2B is a diagram for explaining the conventional technique. FIG. 2C is a diagram for explaining the conventional technique. FIG. 2D is a diagram for explaining the conventional technique. FIG. 2E is a diagram for explaining the conventional technique. FIG. 3 is a block diagram showing a configuration example of the medical image processing apparatus according to the first embodiment. FIG. 4 is a flowchart showing a processing procedure by the processing circuit according to the first embodiment. FIG. 5A is a diagram for explaining the extraction function according to the first embodiment. FIG. 5B is a diagram for explaining the extraction function according to the first embodiment. FIG. 6A is a diagram for explaining a specific function according to the first embodiment. FIG. 6B is a diagram for explaining the specific function according to the first embodiment. FIG. 6C is a diagram for explaining the specific function according to the first embodiment. FIG. 7 is a flowchart showing a processing procedure of the shooting direction specifying processing by the specifying function according to the first embodiment. FIG. 8 is a diagram for explaining the specific function according to the first embodiment. FIG. 9 is a diagram for explaining the specific function according to the first embodiment. FIG. 10 is a diagram for explaining the specific function according to the first embodiment.

Hereinafter, a medical image processing apparatus according to an embodiment will be described with reference to the drawings. In the following embodiments, a medical information processing system having a medical image processing apparatus will be described as an example. The embodiments are not limited to the following embodiments. Moreover, the content described in one embodiment is similarly applied to other embodiments in principle.

(First embodiment)
FIG. 1 is a diagram showing a configuration example of a medical information processing system 1 according to the first embodiment. The medical information processing system 1 according to the present embodiment is installed in, for example, a facility where intervention treatment of a cerebral aneurysm is performed, and a CT examination using an X-ray CT (Computed Tomography) apparatus and a treatment using the X-ray diagnostic apparatus are provided. Are used together. For example, as shown in FIG. 1, the medical information processing system 1 according to the first embodiment includes a medical image storage device 2, a medical information management device 3, an X-ray CT device 4, and an X-ray diagnostic device 5. , And the medical image processing apparatus 100. The respective devices are mutually connected via a network 6 and mutually transmit and receive medical image data and the like imaged by the X-ray CT apparatus 4 and the X-ray diagnostic apparatus 5. Here, for example, when a PACS (Picture Archiving and Communication System) is installed in the medical information processing system 1, each device has a DICOM (Digital Imaging and Communications in Medicine) format in which incidental information is added to medical image data. Medical image data etc. are mutually transmitted and received. Here, the supplementary information includes, for example, a patient ID (Identifier) for identifying a patient, an examination ID for identifying an examination, an apparatus ID for identifying each apparatus, and a series ID for identifying one imaging by each apparatus. Be done.

The medical image storage device 2 stores medical image data captured by the medical information processing system 1. For example, the medical image storage device 2 stores medical image data imaged by the X-ray CT device 4 and the X-ray diagnostic device 5.

The medical information management device 3 manages the medical information system 1. The medical information system 1 is an information system used in a hospital, and includes, for example, HIS (Hospital Information System), RIS (Radiology Information System), electronic medical record system, receipt computer processing system, ordering system, receptionist (personal, qualification authentication). ) System, medical support system, etc. As an example, the medical information management apparatus 3 accepts a reservation for an examination by the X-ray CT apparatus 4 and an operation using the X-ray diagnostic apparatus 5. Then, the medical information management device 3 registers the reservation in each device used in each examination or surgery. As a result, the reserved examination or surgery is executed using the X-ray CT apparatus 4 and the X-ray diagnostic apparatus 5.

The X-ray CT apparatus 4 is an apparatus that images a subject and generates medical image data. For example, the X-ray CT apparatus 4 has a rotating frame that supports and rotates an X-ray tube that irradiates X-rays and an X-ray detector that detects X-rays that have passed through a subject, at opposite positions. The X-ray CT apparatus 4 collects X-ray data that has been transmitted, absorbed, and attenuated by rotating the rotating frame while irradiating the X-ray from the X-ray tube. Then, the X-ray CT apparatus 4 performs A/D (Analog to Digital) conversion on the collected data, and further performs correction processing such as logarithmic conversion, offset correction, sensitivity correction, beam hardening correction, and scattered radiation correction. Raw data (raw data) is generated. Then, the X-ray CT apparatus 4 reconstructs the generated raw data to generate three-dimensional volume data. The volume data is an example of medical image data. The medical image data generated by the X-ray CT apparatus 4 is stored in the medical image storage apparatus 2.

The X-ray diagnostic apparatus 5 is an apparatus that images a subject and generates medical image data. For example, the X-ray diagnostic apparatus 5 has a C-arm that supports an X-ray tube that irradiates X-rays and an X-ray detector that detects X-rays that have passed through a subject at opposing positions and is rotatable. The X-ray diagnostic apparatus 5 converts the analog signal input from the X-ray detector into a digital signal, and uses the converted digital signal as an X-ray acquired image. The X-ray acquired image is an example of medical image data. The medical image data generated by the X-ray diagnostic apparatus 5 is stored in the medical image storage apparatus 2.

The medical image processing apparatus 100 processes medical image data and the like generated by the X-ray CT apparatus 4 and the X-ray diagnostic apparatus 5. The configuration of the medical image processing apparatus 100 will be described later.

General processing in the medical information processing system 1 configured as above will be described with reference to FIGS. 2A to 2E. 2A to 2E are diagrams for explaining the conventional technique. In the medical information processing system 1, for example, the head of the subject is inspected using the X-ray CT apparatus 4.

FIG. 2A shows an example of volume data of the head of the subject generated by the X-ray CT apparatus. For example, the volume data shown in FIG. 2A is three-dimensional image data in which blood vessels are drawn. For example, the X-ray CT apparatus 4 subtracts raw data obtained by imaging the same part of the head in the presence and absence of a contrast agent to generate a difference image, and reconstruct this difference image. By doing so, three-dimensional image data in which the blood vessel is depicted is generated. The example of FIG. 2A shows a case where a cerebral aneurysm exists near the center of the volume data. Note that, hereinafter, the three-dimensional image data in which the blood vessel is drawn is referred to as a three-dimensional blood vessel image. In the following, a cerebral aneurysm is also called an aneurysm or simply an aneurysm.

In FIG. 2B, a cerebral aneurysm will be described. In a cerebral aneurysm, a part of the blood vessel wall in the brain bulges like a balloon and the inside thereof is filled with blood. Here, the blood vessel that is the source of the cerebral aneurysm is called the parent blood vessel. Further, the boundary surface between the cerebral aneurysm and the parent blood vessel is called a neck surface. Small cerebral aneurysms have a lower risk of rupture, while large cerebral aneurysms have a higher risk of rupture. When a blood vessel called a perforator branch extends from the vicinity of a cerebral aneurysm, caution should be exercised when considering the application of surgery. Here, the perforator branch refers to a blood vessel that directly enters the brain parenchyma from a relatively large artery and feeds the brain parenchyma. If there is no other circulation to the parenchyma to which the perforator is nourished, the brain parenchyma becomes necrotic when the perforator is occluded.

As shown in FIGS. 2A and 2B, when a cerebral aneurysm is detected by the examination by the X-ray CT apparatus 4, the doctor uses the volume data generated by the X-ray CT apparatus 4 to treat the aneurysm. Consider measures such as. For example, a clipping method and a coil embolization method are known as treatment methods for preventing rupture of an aneurysm. The clipping method involves craniotomy under general anesthesia and clipping of the aneurysm as shown in Figure 2C. On the other hand, in the coil embolization, a catheter is inserted through the artery at the base of the foot to reach the blood vessel in the brain, and then a platinum coil is embedded in the cerebral aneurysm without any gap as shown in FIG. 2D. Such clipping method and coil embolization are performed under fluoroscopy using the X-ray diagnostic apparatus 5.

Further, during the treatment using the X-ray diagnostic apparatus 5, the projection angle suitable for the treatment is identified. For example, at the time of treatment such as coil embolization, a projection angle at which the neck surface, which is the boundary between the parent blood vessel and the aneurysm, is clearly visible is desirable. However, for example, as shown in FIG. 2E, at the projection angle where the cerebral aneurysm appears to overlap the parent blood vessel, the neck surface that is the boundary between the parent blood vessel and the aneurysm cannot be clearly seen. Therefore, a surgeon such as a doctor will continuously take images from various projection angles and search for the optimum projection angle. In such a case, the exposure of the subject increases.

Therefore, in the medical information processing system 1 according to the first embodiment, the medical image processing apparatus 100 identifies a projection angle suitable for treatment. FIG. 3 is a block diagram showing a configuration example of the medical image processing apparatus 100 according to the first embodiment.

As shown in FIG. 3, the medical image processing apparatus 100 includes an input device 101, a display 102, a storage circuit 110, and a processing circuit 120. The input device 101, the display 102, the storage circuit 110, and the processing circuit 120 are communicably connected to each other.

The input device 101 has a mouse, a keyboard, buttons, a panel switch, a touch command screen, a foot switch, a trackball, a joystick, etc., and receives various setting requests from the operator of the medical image processing apparatus 100. The input device 101 outputs the received various setting requests to the processing circuit 120.

The display 102 displays medical image data generated by the X-ray CT apparatus 4 and the X-ray diagnostic apparatus 5, and a GUI (Graphical User Interface) for a user to input various setting requests using the input circuit 101. Or to display.

The storage circuit 110 stores various programs for displaying a GUI and information used by the programs. The storage circuit 110 also stores medical image data generated by the X-ray CT apparatus 4 and the X-ray diagnostic apparatus 5.

The processing circuit 120 controls the entire processing of the medical image processing apparatus 100. For example, as shown in FIG. 3, the processing circuit 120 executes the extraction function 121 and the specific function 122. Here, for example, each processing function executed by the extraction function 121 and the specific function 122, which are components of the processing circuit 120 illustrated in FIG. 3, is recorded in the storage circuit 110 in the form of a program executable by a computer. There is. The processing circuit 120 is a processor that realizes a function corresponding to each program by reading each program from the storage circuit 110 and executing the program. In other words, the processing circuit 120 in the state where each program is read out has the functions shown in the processing circuit 120 of FIG. Hereinafter, each processing function executed by the processing circuit 120 will be described.

FIG. 4 is a flowchart showing a processing procedure by the processing circuit 120 according to the first embodiment. FIG. 4 shows a flowchart for explaining the operation of the processing circuit 120, and it will be explained which step of the flowchart each component corresponds to. In the example shown in FIG. 4, a case where an operator such as a doctor identifies a projection angle suitable for the treatment prior to the treatment of the cerebral aneurysm will be described.

Steps S101 to S104 are steps corresponding to the extraction function 121. This is a step in which the extraction function 121 is realized by the processing circuit 120 calling and executing a predetermined program corresponding to the extraction function 121 from the storage circuit 110. In step S101, the extraction function 121 acquires three-dimensional image data. For example, the acquisition function 121 acquires the medical image data generated by the X-ray CT apparatus 4 from the storage circuit 110. More specifically, the acquisition function 121 acquires the three-dimensional blood vessel image in which the blood vessel is drawn from the storage circuit 110, as described in FIG. 2A.

In step S102, the extraction function 121 extracts a bump and a parent blood vessel from the three-dimensional image data. FIG. 5A is a diagram for explaining the extraction function 121 according to the first embodiment. FIG. 5A schematically shows three-dimensional image data of the inside of the head of the subject. For example, the extraction function 121 extracts a parent blood vessel and a cerebral aneurysm as shown in FIG. 5A.

More specifically, the extraction function 121 extracts, as blood vessel information, a three-dimensional area having a voxel value equal to or larger than a threshold value from the three-dimensional blood vessel image. Then, for example, the extraction function 121 performs a thinning process on the extracted three-dimensional area to extract the core line of the blood vessel. Although the extraction function 121 has been described as extracting the blood vessel information using the three-dimensional blood vessel image, the embodiment is not limited to this. For example, the extraction function 121 may extract the blood vessel information based on the CT value of the three-dimensional volume data. Alternatively, the extraction function 121 may accept designation of a range of values in which blood vessels exist. Further, the extraction function 121 may further extract the blood vessel information by tracking in consideration of the continuity of the blood vessel and the like.

Subsequently, the extraction function 121 separates the aneurysm and the parent blood vessel from which the aneurysm is derived from the blood vessel information. For example, the extraction function 121 generates a continuous slice image based on the extracted blood vessel core line by a virtual cross section perpendicular to the blood vessel core line. Here, in a portion corresponding to the aneurysm in the continuous slice images, the expansion of the blood vessel cross section or a cross section other than the blood vessel cross section appears. Further, there are various types of aneurysms, and their shapes are also indefinite. The extracting function 121 separates the blood vessel and the aneurysm by recognizing the expansion of the blood vessel cross section or the cross section other than the blood vessel cross section as a feature and grasping as a feature value of the cross section. The extraction function 121 may separate the aneurysm and the parent blood vessel for the aneurysm designated by the operator.

Returning to FIG. In step S103, the extraction function 121 extracts a penetrating branch from the three-dimensional image data. For example, the extraction function 121 extracts a penetrating branch as shown in FIG. 5A. As described above, the perforator branch is a blood vessel that directly enters the brain parenchyma from a relatively large artery and feeds the brain parenchyma. Here, if there is no blood vessel that affects the brain parenchymal region other than the perforating branch, the blood flow by the perforating branch should not be stopped. FIG. 5B is a diagram for explaining the extraction function 121 according to the first embodiment.

In FIG. 5B, three cases will be described for each origin of the perforator. In FIG. 5B, a cerebral aneurysm An1, a parent blood vessel V1, a penetrating branch 5a, a penetrating branch 5b, and a penetrating branch 5c are schematically illustrated. In the example shown in FIG. 5B, it is assumed that the brain parenchyma fed by the penetrating branch 5a, the penetrating branch 5b, and the penetrating branch 5c are not fed from other blood vessels. In such a case, if the perforating branch 5a, the perforating branch 5b, and the perforating branch 5c are stopped, there is a possibility that the brain parenchyma nourished by each penetrating branch will be adversely affected. In the example shown in FIG. 5B, the perforation branch 5a and the perforation branch 5b cannot avoid the influence on the brain parenchyma which they nourish by treatment. On the other hand, the perforating branch 5c can avoid complications of treatment by taking care so that the embolization range of the coil does not reach the origin of the perforating branch 5c and the blood flow is not stopped. Therefore, the extraction function 121 extracts the penetrating branch 5c connected to the vicinity of the neck surface outside the aneurysm from the three-dimensional image data. Note that this step S103 can be omitted depending on the situation.

Returning to FIG. In step S104, the extraction function 121 extracts the X-ray high absorption region from the three-dimensional image data. As shown in FIG. 5A, the extraction function 121 extracts an X-ray high absorption region such as a dental implant.

Steps S105 to S110 are steps corresponding to the specific function 122. This is a step in which the specific function 122 is realized by the processing circuit 120 calling and executing a predetermined program corresponding to the specific function 122 from the storage circuit 110. In step S105, the specifying function 122 specifies the range of the three-dimensional image data corresponding to the range of the space that can be imaged by the X-ray diagnostic apparatus 5. FIG. 6A is a diagram for explaining the specific function 122 according to the first embodiment.

Here, the imaging direction of the X-ray diagnostic apparatus 5 is, as shown in FIG. 6A, “CRA (head direction: CRAnial)/CAU (tail direction: CAUdal), RAO (first oblique position, right front oblique position: Right). Antelier Oblique)/LAO (second oblique position, left front oblique position: Left Anterior Oblique)". In other words, the imaging direction of the X-ray diagnostic apparatus 5 is represented by a combination of C arm angles (LAO/RAO, CAU/CRA). The specific function 122 acquires, for example, information about the movable range of the C arm of the X-ray diagnostic apparatus 5. In the example shown in FIG. 6A, the movable range 6a of the C arm of the X-ray diagnostic apparatus 5 is indicated by a broken line. Then, the specifying function 122 specifies the range of the three-dimensional image data corresponding to the movable range 6a of the C arm.

In step S106, the specifying function 122 excludes the range other than the imaging target from the range of the three-dimensional image data specified in step S105. For example, the specifying function 122 excludes the direction in which the bump extracted in step S102 and the X-ray high absorption region extracted in step S104 overlap from the imaging direction specified in step S105. 6B and 6C are diagrams for explaining the specific function 122 according to the first embodiment.

FIG. 6B schematically shows three-dimensional image data of the inside of the head of the subject. In the example shown in FIG. 6B, a cerebral aneurysm, a parent blood vessel, a perforator branch, and an X-ray high absorption region such as a dental implant are illustrated. The specifying function 122 specifies the imaging direction in which the aneurysm and the X-ray high absorption region overlap, as shown in FIG. 6B, from the combination of C arm angles within the range of the three-dimensional image data specified in step S105. Here, in the imaging direction in which the high X-ray absorption region and the cerebral aneurysm overlap, X-rays are absorbed in the high X-ray absorption region, so the cerebral aneurysm is not seen through. Therefore, the specifying function 122 excludes the imaging direction in which the aneurysm and the X-ray high absorption region overlap from the range of the three-dimensional image data specified in step S105. In other words, the specific function 122 excludes an imaging direction in which the X-ray high absorption region and the parent blood vessel and the perforator branch that are the treatment target and the peripheral region of the treatment target overlap. For example, the specific function 122 excludes the imaging direction 6b in which the aneurysm and the X-ray high absorption region overlap from the movable range 6a of the C arm of the X-ray diagnostic apparatus 5, as shown in FIG. 6C. Then, the specific function 122 excludes the imaging direction 6b in which the aneurysm and the X-ray high absorption region overlap from the movable range 6a of the C-arm of the X-ray diagnostic apparatus 5 as a target range of imaging direction identification processing described later. Specify as.

In step S107, the specifying function 122 executes a shooting direction specifying process. In the imaging direction identification processing in step S107, the imaging direction of the X-ray diagnostic apparatus 5 suitable for the treatment such as coil embolization is identified from the target range of the imaging direction identification processing. The shooting direction specifying process by the specifying function 122 will be described with reference to FIG. 7. FIG. 7 is a flowchart showing the processing procedure of the shooting direction specifying processing by the specifying function 122 according to the first embodiment.

Steps S201 to S207 are steps corresponding to the specific function 122. This is a step in which the specific function 122 is realized by the processing circuit 120 calling and executing a predetermined program corresponding to the specific function 122 from the storage circuit 110.

In step S201, the specific function 122 determines the normal vector N of the neck surface of the aneurysm, for example, as shown in FIG. Further, in step S202, the specific function 122 determines the core line vectors P ₁ and P ₂ of the parent blood vessel, as shown in FIG. 8, for example. Further, in step S203, the specific function 122 determines the core line vector B ₁ of the penetrating branch, as shown in FIG. 8, for example. Note that FIG. 8 is a diagram for explaining the specific function 122 according to the first embodiment.

In step S204, the specific function 122 sets a projection direction vector. For example, the specifying function 122 sets a projection direction vector from the target range of the shooting direction specifying process specified in step S106, as illustrated in FIG. 6C. Here, the specific function 122 expresses the projection direction vector to be set by a combination of the angles of the C arm (LAO/RAO, CAU/CRA). FIG. 9 is a diagram for explaining the specific function 122 according to the first embodiment.

In FIG. 9, the range in which the imaging direction 9b in which the aneurysm and the X-ray high absorption region overlap is excluded from the movable range 9a of the C-arm of the X-ray diagnostic apparatus 5 is the target range of the imaging direction identification processing. The specific function 122 sets the projection direction vector at a predetermined interval from the target range of the shooting direction specifying process. More specifically, the specific function 122 sets the projection direction vector at intervals indicated by black circles in FIG. This projection direction vector is expressed by a combination of C arm angles (LAO/RAO, CAU/CRA). Then, the specific function 122 selects any one projection direction vector that has not been selected from the set projection direction vectors, and proceeds to step S205.

Returning to FIG. In step S205, the specific function 122 calculates an evaluation value. Here, the imaging direction of the X-ray diagnostic apparatus 5 suitable for the treatment such as coil embolization is, for example, the imaging direction in which the neck surface that is the boundary between the parent blood vessel and the aneurysm can be clearly seen. In such an imaging direction in which the neck surface can be clearly seen, the normal vector of the neck surface of the aneurysm is orthogonal to the imaging direction, and the parent blood vessel vector is orthogonal to the imaging direction. Further, when considering the penetrating branch, the vector of the penetrating branch and the imaging direction are further orthogonal to each other in the imaging direction in which the neck surface is clearly visible. That is, in the optimum imaging direction, the inner product of the imaging direction and the normal vector of the neck surface of the aneurysm is close to 0, the inner product of the imaging direction and the parent blood vessel vector is close to 0, and the imaging direction and the penetration branch vector The inner product of and is close to zero. Therefore, the specific function 122 calculates the inner product of the normal vector of the neck surface, which is the boundary between the parent blood vessel and the aneurysm, and the projection direction vector set in the three-dimensional image data, the core line vector of the parent blood vessel, and the projection direction vector. The evaluation value is calculated based on the inner product and the inner product of the core line vector of the penetrating branch and the projection direction vector.

More specifically, the specific function 122 calculates the evaluation value I using the following formula “I=kN·R+l(P1·R+P2·R)+m(B1·R)”. In the formula, R is the projection direction vector selected in step S204, and k, l, and m represent coefficients. That is, as shown in FIG. 8, the specific function 122 extracts the normal vector N of the neck surface of the aneurysm, the parent blood vessel vectors P1 and P2, and the penetrating branch vector B1, and extracts each extracted vector and the X-ray irradiation direction. The sum of inner products with the assumed projection direction vector R is calculated as an evaluation value. The coefficients k, l and m in the formula for calculating the evaluation value I can be set arbitrarily. For example, the weight of each coefficient can be appropriately set according to the size of the aneurysm and the diameter of the neck surface. More specifically, when the size of the aneurysm or the size of the neck surface is small, the error of the normal vector N extracted may be large. Therefore, for example, when the size of the aneurysm or the size of the neck surface is small, the coefficient k of the normal vector N may be increased. Further, each coefficient is, for example, a first coefficient for specifying a shooting direction in which the neck surface can be clearly observed and a second coefficient for specifying a shooting direction in which the penetrating branch can be clearly observed. Each may be set, and the first coefficient and the second coefficient may be switched by a user operation and used properly. More specifically, the operator uses the first coefficient to specify an imaging direction in which the neck surface can be clearly observed when performing treatment while switching the C-arm angle, and the operator carefully looks at the neck surface and coils. Put in. Then, after inserting the coil, the operator uses the second coefficient to specify the imaging direction in which the perforator branch can be clearly observed, and confirms the perforator branch in detail.

In step S206, the specific function 122 determines whether or not evaluation values have been calculated for all projection direction vectors. For example, the specific function 122 determines whether or not evaluation values have been calculated for all projection directions indicated by black circles in FIG. For example, the specific function 122 determines whether or not there is an unselected projection direction vector among the projection direction vectors set in step S204. Here, when the specific function 122 does not determine that the evaluation values have been calculated for all the projection direction vectors (step S206, No), that is, when it determines that there is an unselected projection direction vector, the process proceeds to step S204. Then, one of the unselected projection direction vectors is selected, and the evaluation value is calculated.

On the other hand, when the specifying function 122 determines that the evaluation values have been calculated for all the projection direction vectors (step S206, Yes), in step S207, the shooting direction is specified using the calculated evaluation values. For example, in the imaging direction suitable for treatment, the inner product of each term in the above equation approximates to zero. Therefore, in the imaging direction suitable for the treatment, the entire evaluation value also approaches 0. Therefore, the specifying function 122 specifies, for example, the projection direction when the calculated evaluation value is the minimum value as the shooting direction. In addition to the projection direction when the calculated evaluation value is the minimum value, the specific function 122 also includes the projection direction when the evaluation value is the second minimum value and the projection direction when the evaluation value is the third minimum value. The direction may be specified. In this way, the specific function 122 evaluates the visibility of the boundary between the aneurysm to be treated and the parent blood vessel and the penetrating branch, which is the peripheral region of the aneurysm, in each projection direction set from the target range of the imaging direction identification processing. The value is calculated, and the imaging direction by the X-ray diagnostic apparatus 5 suitable for the treatment is specified using the calculated evaluation value. In step S207, the number of shooting directions specified by the specifying function 122 can be set arbitrarily.

Returning to FIG. In step S108, the specifying function 122 generates and displays a virtual image obtained by virtually projecting the three-dimensional image data from the specified shooting direction and a schematic diagram showing the specified shooting direction. FIG. 10 is a diagram for explaining the specific function 122 according to the first embodiment.

FIG. 10 illustrates the virtual image 10a and the schematic diagram 10b showing the shooting direction, which are displayed on the display 102. In addition, the example of FIG. 10 illustrates a case where three shooting directions are specified in step S207. In such a case, the specifying function 122 generates and displays the schematic diagram 10b in which the projection direction vector indicating the specified shooting direction is indicated by a black circle. Then, the specific function 122, for example, when the cursor 10c is moved to accept the designation of any of the projection direction vectors in the schematic diagram 10b, the three-dimensional image data is obtained from the shooting direction corresponding to the designated projection direction vector. A virtual image 10a that is virtually projected is displayed. When a different projection direction vector is designated by moving the cursor 10c, the specific function 122 causes the display 102 to display the virtual image generated in the shooting direction corresponding to the newly designated projection direction vector.

Succeedingly, in a step S109, the specific function 122 receives the selection of the imaging direction to be used as the imaging direction during the treatment. For example, the operator of the medical image processing apparatus 100 designates a projection direction vector indicated by a black circle in the schematic diagram 10b shown in FIG. 10, displays a virtual image, and determines whether or not to use it as an imaging direction during treatment. to decide. Here, when the operator determines not to use it as the imaging direction during the treatment, the operator performs an operation of deleting the projection direction vector corresponding to the imaging direction from the schematic diagram 10b via the input device 101. In such a case, the specific function 122 newly generates a schematic diagram in which the designated projection direction vector is deleted from the schematic diagram 10b. In addition, in step S109, all the projection direction vectors may be used as the imaging direction during the treatment. In such a case, the specific function 122 maintains the schematic diagram generated in step S108.

In step S110, the specific function 122 transmits information indicating the imaging direction to the medical information management device 3. For example, the specific function 122 transmits the virtual image and the specified schematic diagram indicating the shooting direction to the medical information management device 3 as information indicating the shooting direction. Alternatively, the specific function 122 transmits, to the medical information management device 3, a combination of C-arm angles indicating the specified shooting direction as information indicating the shooting direction. As a result, the X-ray diagnostic apparatus 5 can perform imaging in the imaging direction suitable for the treatment at the start of imaging by acquiring the information indicating the specified imaging direction from the medical information management apparatus 3. The specific function 122 may send information indicating the imaging direction to the X-ray diagnostic apparatus 5. In this way, the specifying function 122 transmits information indicating the specified shooting direction to another device.

As described above, in the first embodiment, the inner product of the normal vector of the neck surface, which is the boundary between the parent blood vessel and the aneurysm, and the projection direction vector set in the three-dimensional image data, and the core line vector of the parent blood vessel And the projection direction vector, the imaging direction of the X-ray diagnostic apparatus 5 is specified based on the dot product. For example, in the first embodiment, the inner product of the imaging direction and the normal vector of the neck surface of the aneurysm is close to 0, the inner product of the imaging direction and the parent blood vessel vector is close to 0, and the imaging direction and the penetrating branch The shooting direction is specified such that the dot product with the vector is close to zero. In such an imaging direction, the parent blood vessel and the aneurysm do not overlap, and the imaging direction and the running direction of the parent blood vessel do not overlap, so that the neck surface that is the boundary between the parent blood vessel and the aneurysm can be clearly seen. By setting this imaging direction prior to the start of treatment, the X-ray diagnostic apparatus 5 can perform imaging in the imaging direction suitable for treatment at the start of imaging. As a result, according to the first embodiment, it is possible to reduce extra exposure to the subject when determining the imaging direction.

Further, in such an imaging direction, since the imaging direction and the traveling direction of the parent blood vessel do not overlap with each other, the perforator branch can be clearly confirmed. Therefore, an operator such as a doctor does not stop the blood flow in the perforator branch. Can be kept in mind.

In the above-described embodiment, the extraction function 121 extracts the X-ray high absorption region of the dental implant or the like in step S106, and the specific function 122 determines the direction in which the aneurysm and the X-ray high absorption region overlap from the imaging direction. Although the case of exclusion is described, the embodiment is not limited to this. For example, the extraction function 121 may further extract the X-ray sensitive region from the three-dimensional image data. For example, the extraction function 121 extracts the eyeball from the three-dimensional image data in advance. In such a case, the specifying function 122 specifies a shooting direction such that the aneurysm portion and the eyeball do not overlap. As a result, the X-ray diagnostic apparatus 5 can reduce the exposure to the X-ray highly sensitive region such as the eyeball. Further, the specific function 122 may receive the setting of the range excluded from the shooting direction from the operator.

Further, in the above-described embodiment, the specifying function 122 has been described as specifying the projection direction when the calculated evaluation value is the minimum value as the shooting direction in step S207, but the embodiment is not limited to this. Not a thing. For example, the specific function 122 may set a detailed combination of C-arm angles in the vicinity of the projection direction where the evaluation value is the minimum value, and further calculate the evaluation value. Further, the specifying function 122 may specify the shooting direction using an algorithm such as the steepest descent method from the vicinity of the projection direction in which the evaluation value is the minimum value. That is, the specific function 122 calculates the gradient of the evaluation value distribution from the vicinity of the projection direction in which the evaluation value is the minimum value, and searches for a combination of C arm angles in the direction in which the evaluation value decreases.

Further, in the above-described embodiment, when the specification function 122 accepts the designation of any of the projection direction vectors in the schematic diagram 10b in step S108, the three-dimensional image is obtained from the shooting direction corresponding to the designated projection direction vector. Although it has been described that the virtual image 10a in which data is virtually projected is displayed, the embodiment is not limited to this. For example, the specific function 122 may cause the display 102 to display virtual images in which three-dimensional image data is virtually projected from all the specified shooting directions in parallel. Alternatively, the specifying function 122 may cause the display 102 to display virtual images obtained by virtually projecting three-dimensional image data from all the specified shooting directions in a predetermined order.

Further, in the above-described embodiment, the case where the specifying function 122 specifies the shooting direction by using one formula for calculating the evaluation value I has been described, but the embodiment is not limited to this. For example, the specifying function 122 is used to specify an evaluation value calculated by using an equation in which a coefficient is set for specifying a shooting direction in which the neck surface can be clearly observed, and a shooting direction in which the perforator can be clearly observed. The shooting direction may be specified using each of the evaluation values calculated using the equation in which the coefficient is set.

Further, in the above-described embodiment, the extraction function 121 has been described as extracting the penetrating branch in step S103 shown in FIG. 4, but the embodiment is not limited to this. For example, when the influence of the perforation branch can be ignored or when the imaging direction is specified without considering the perforation branch, the extraction function 121 may omit step S103 shown in FIG. In such a case, the specific function 122 determines the inner product of the normal vector of the neck surface, which is the boundary between the parent blood vessel and the aneurysm, and the projection direction vector set in the three-dimensional image data, the core line vector of the parent blood vessel, and the projection direction. The imaging direction of the X-ray diagnostic apparatus is specified based on the dot product with the vector.

Further, in the above-described embodiment, the medical image processing apparatus 100 has been described as extracting the parent blood vessel, the aneurysm, and the perforating branch using the three-dimensional image data generated by the X-ray CT apparatus 4. The embodiment is not limited to this. For example, when the medical information processing system 1 has an MRI (Magnetic Resonance Imaging) device, the medical image processing device 100 uses the volume data generated by the MRI device to identify the parent blood vessel, the aneurysm, and the perforation branch. You may extract.

(Other embodiments)
The embodiment is not limited to the above-mentioned embodiment.

Further, although the above-described embodiment has been described as being implemented in the medical image processing apparatus 100, the embodiment is not limited to this. For example, the X-ray diagnostic apparatus 5 may execute the same processing as the extraction function 121 and the specific function 122. More specifically, the X-ray diagnostic apparatus 5 acquires the three-dimensional image data by rotating the C arm once during the operation. Then, the X-ray diagnostic apparatus 5 extracts the parent blood vessel and the aneurysm from the acquired three-dimensional image data. Then, the X-ray diagnostic apparatus 5 calculates the inner product of the normal vector of the neck surface, which is the boundary between the parent blood vessel and the aneurysm, and the projection direction vector set in the three-dimensional image data, the core line vector of the parent blood vessel, and the projection. The imaging direction of the X-ray diagnostic apparatus 5 is specified based on the dot product with the direction vector. The X-ray diagnostic apparatus 5 may further extract the penetrating branch from the three-dimensional image data, and further specify the imaging direction by further using the inner product of the core line vector of the penetrating branch and the projection direction vector.

Further, in the above-described embodiment, the case where an aneurysm is targeted for treatment has been described, but the embodiment is not limited to this. For example, when a dural arteriovenous fistula (d-AVF), cerebral arteriovenous malformation (AVM), or an aneurysm cannot be coiled, the blood vessel itself is plugged with a coil. Treatment may be given. The above-described embodiment is also applicable to the treatment of blocking the blood vessel itself with a coil. In such a case, the extraction function 121 extracts the parent blood vessel and the affected part (the point where the coil is packed) to be treated. Subsequently, the specific function 122 uses the inner product of the normal vector of the boundary between the parent blood vessel and the point where the coil is packed and the projection direction vector, and the sum of the inner products of the core vector of the parent blood vessel and the projection direction vector as evaluation values. calculate. Then, the identification function 122 identifies the imaging direction of the X-ray diagnostic apparatus 5 suitable for the treatment, using the evaluation value.

The word "processor" used in the above description means, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an application specific integrated circuit (ASIC), a programmable logic device (for example, It means a circuit such as a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), and a field programmable gate array (FPGA). The processor realizes the function by reading and executing the program stored in the memory circuit. Instead of storing the program in the memory circuit, the program may be directly incorporated in the circuit of the processor. In this case, the processor realizes the function by reading and executing the program incorporated in the circuit. It should be noted that each processor of the present embodiment is not limited to the case where each processor is configured as a single circuit, and a plurality of independent circuits may be combined and configured as one processor to realize its function. Good. Further, the plurality of constituent elements in FIG. 1 may be integrated into one processor to realize its function.

Further, in the above description of the embodiments, each constituent element of each illustrated device is functionally conceptual, and does not necessarily have to be physically configured as illustrated. That is, the specific form of distribution/integration of each device is not limited to that shown in the figure, and all or part of the device may be functionally or physically distributed/arranged in arbitrary units according to various loads and usage conditions. It can be integrated and configured. Furthermore, each processing function performed by each device may be implemented in whole or in part by a CPU and a program that is analyzed and executed by the CPU, or may be realized as hardware by a wired logic.

The control method described in the above embodiment can be realized by executing a control program prepared in advance on a computer such as a personal computer or a workstation. This control program can be distributed via a network such as the Internet. The control program can also be executed by being recorded in a computer-readable recording medium such as a hard disk, a flexible disk (FD), a CD-ROM, an MO, or a DVD, and being read from the recording medium by the computer.

According to at least one embodiment described above, it is possible to reduce the exposure to the subject when determining the imaging direction.

While some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. The embodiments and their modifications are included in the scope of the invention and the scope thereof, as well as in the invention described in the claims and the scope of equivalents thereof.

1 Medical Information Processing System 100 Medical Image Processing Device 120 Processing Circuit 121 Extraction Function 122 Specific Function

Claims (8)

An extraction unit for extracting parent blood vessels and aneurysm from three-dimensional image data generated by a medical image generation apparatus of a type different from that of the X-ray diagnostic apparatus;
Wherein the normal vector of the neck surface which is the boundary between the parent vessel and the aneurysm, the inner product of the projection direction vector set in the three-dimensional image data, and the core wire vectors before Kioya vessels, inner product with the projection direction vector And a specifying unit that specifies an imaging direction of the X-ray diagnostic apparatus based on a coefficient set according to the size of the bump or the neck surface ,
The medical image processing apparatus, wherein the specifying unit further generates a virtual image obtained by virtually projecting the three-dimensional image data from the specified imaging direction, and displays the generated virtual image on a predetermined display unit. The extraction unit further extracts a penetrating branch from the three-dimensional image data,
The medical image processing apparatus according to claim 1, wherein the specifying unit specifies the imaging direction by further using an inner product of the core line vector of the perforating branch and the projection direction vector. The medical image processing apparatus according to claim 2, wherein the extraction unit extracts a penetrating branch connected to the vicinity of the neck surface outside the aneurysm. The medical image according to claim 1, wherein the specifying unit specifies the imaging direction from a range of the three-dimensional image data corresponding to a range of a space that can be imaged by the X-ray diagnostic apparatus. Processing equipment. The extraction unit further extracts an X-ray high absorption region from the three-dimensional image data,
The medical image processing apparatus according to claim 1, wherein the specifying unit excludes a direction in which the bump and the X-ray high absorption region overlap from the imaging direction. The extraction unit further extracts an X-ray sensitive region from the three-dimensional image data,
The medical image processing apparatus according to claim 1, wherein the specifying unit excludes a direction in which the bump and the X-ray high sensitivity region overlap from the imaging direction. The medical image processing apparatus according to claim 1, wherein the identifying unit further causes a predetermined display unit to display a schematic diagram showing the identified imaging direction. The medical image processing apparatus according to claim 1, wherein the specifying unit further transmits information indicating the specified shooting direction to another device.

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