JP5809926B2 - Medical image processing apparatus and medical image processing method - Google Patents

Description

  The present invention relates to a medical image processing apparatus and a medical image processing method for supporting an operation for setting a point at a desired three-dimensional position for a three-dimensional medical image.

Conventionally, for example, a series of tomographic images taken by a medical image diagnostic apparatus and other image generating apparatuses including an X-ray CT (computed tomography) apparatus, an MRI (magnetic resonance imaging) apparatus, an ultrasonic diagnostic apparatus, a nuclear medicine diagnostic apparatus, etc. A medical image processing apparatus that generates and displays a three-dimensional image using an image group is known. In addition, this type of medical image processing apparatus has a function of extracting an organ to be observed from a medical image being displayed, and a function of generating and analyzing an image of a plane or curved surface by setting a target plane or curved surface. Some have
For example, Patent Document 1 discloses a contour tracking method for tracking the contour of a region of interest with reference to a local density difference in an image, a certain adjacent point in a region of interest, and a density value range or between adjacent points. A region expansion method for extracting a region by capturing a point satisfying an expansion condition such as a density difference and expanding the region is described. Thus, when extracting a specific area | region from a medical image, an operator may perform operation which sets a point to the center and boundary of an organ. However, since the result (extracted region) may be different just by shifting the position of the set point by several pixels, the result is likely to vary depending on the operator, resulting in poor reproducibility.

  Further, as a conventional method for setting a point at a three-dimensional position of a three-dimensional image, for example, as described in Patent Document 2, a plurality of images viewed from different directions are created and displayed, and an operator can display A method for determining a point position three-dimensionally while alternately referring to a plurality of images has been proposed.

Japanese Patent No. 2087517 JP 2006-246941 A

  However, as described above, when a user sets points while alternately manipulating a plurality of images, the amount of operation is large and it takes a lot of time to set the points. In addition, in a noisy image, the boundary becomes unclear, and it is difficult to accurately set a point on the boundary of an organ. Therefore, it is desired to improve operability and reproducibility in point setting.

  The present invention has been made in view of the above problems, and provides a medical image processing apparatus and a medical image processing method that support an operation of setting a point at an arbitrary three-dimensional position for a three-dimensional medical image. For the purpose.

  In order to achieve the above-described object, the first invention provides a display means for displaying a three-dimensional medical image, a point setting means for setting a point at an arbitrary three-dimensional position of the three-dimensional medical image, An operation input means for operating the position, a density gradient calculating means for calculating a density gradient of the three-dimensional medical image, and a moving speed of the point based on the density gradient. When the moving operation of the position of the point is performed by the moving speed setting means to be set and the operation input means, the moving speed of the point set by the moving speed setting means according to the density gradient at the position of the point And a point position moving means for moving the position of the point by means of the medical image processing apparatus.

  A second invention is a medical image processing method in a medical image processing apparatus including an operation input means for inputting an operation for setting a point at an arbitrary three-dimensional position of a three-dimensional medical image. When the density gradient calculating step for calculating the density gradient of the image, the moving speed setting step for setting the moving speed of the point based on the density gradient, and the operation for moving the position of the point by the operation input means are performed. And a point position moving step of moving the position of the point by the moving speed of the point set by the moving speed setting step according to the concentration gradient at the position of the point. Is the method.

  According to the medical image processing apparatus and the medical image processing method of the present invention, it is possible to effectively support an operation for setting a point at an arbitrary three-dimensional position for a three-dimensional medical image.

The figure which shows the whole structure of the medical image processing apparatus 100 The flowchart explaining the flow of the point setting process of 1st Embodiment The figure which shows an example of the operation screen 300 An example of a concentration curve 23 showing the relationship between the concentration gradient and the moving speed of a point in the organ center setting mode An example of a concentration curve 23 showing the relationship between the concentration gradient and the moving speed of a point in the organ boundary setting mode Example of density curved surface showing the relationship between density gradient, density value, and point movement speed The flowchart explaining the flow of the point setting process of 2nd Embodiment The figure which shows an example of the operation screen 310 of 3rd Embodiment. The flowchart explaining the flow of the point setting process of 3rd Embodiment An example of a curved surface showing the relationship between the moving speed of points in the horizontal direction (or in the plane) and the vertical direction The flowchart explaining the flow of the point setting process of 4th Embodiment (A) Density curve before noise removal, (b) Example of density curve after noise removal

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[First Embodiment]
First, the configuration of an image processing system 1 to which the medical image processing apparatus 100 of the present invention is applied will be described with reference to FIG.

  As shown in FIG. 1, the image processing system 1 includes a medical image processing apparatus 100 having a display device 107, a mouse 108, and an input device 109, and an image database 111 connected to the medical image processing apparatus 100 via a network 110. And a medical image photographing device 112.

The medical image processing apparatus 100 is a computer that performs processing such as image generation and image analysis. For example, a medical image display device installed in a hospital or the like is included.
As shown in FIG. 1, the medical image processing apparatus 100 includes a CPU (Central Processing Unit) 101, a main memory 102, a storage device 103, a communication interface (communication I / F) 104, a display memory 105, and an interface with an external device. (I / F) 106 is provided, and each unit is connected via a bus 113.

  The CPU 101 calls a program stored in the main memory 102 or the storage device 103 to the work memory area on the RAM of the main memory 102 and executes the program, drives and controls each unit connected via the bus 113, and performs medical image processing. Various processes performed by the apparatus 100 are realized.

  Further, the CPU 101 performs point setting for an arbitrary three-dimensional position of the three-dimensional medical image in accordance with the mouse operation of the operator in a point setting process (see FIG. 2) described later. Details of the point setting process will be described later.

  The main memory 102 includes a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The ROM permanently holds a computer boot program, a program such as BIOS, data, and the like. The RAM temporarily stores programs, data, and the like loaded from the ROM, the storage device 103, and the like, and includes a work area used by the CPU 101 for performing various processes.

  The storage device 103 is a storage device that reads and writes data to and from an HDD (hard disk drive) and other recording media, and stores a program executed by the CPU 101, data necessary for program execution, an OS (operating system), and the like. . As for the program, a control program corresponding to the OS and an application program are stored. Each of these program codes is read by the CPU 101 as necessary, transferred to the RAM of the main memory 102, and executed as various means.

The communication I / F 104 includes a communication control device, a communication port, and the like, and mediates communication between the medical image processing apparatus 100 and the network 110. The communication I / F 104 controls communication with the image database 111, another computer, or a medical image photographing apparatus 112 such as an X-ray CT apparatus or an MRI apparatus via the network 110.
The I / F 106 is a port for connecting a peripheral device, and transmits / receives data to / from the peripheral device. For example, a pointing device such as a mouse 108 or a touch pen may be connected via the I / F 106.

  The mouse 108 has a button switch and a sensor for detecting the displacement, and outputs position displacement data, button switch input data, and the like to the CPU 101 via the I / F 106. Note that the mouse 108 preferably has two button switches such as a left button and a right button. When a touch pen is used instead of the mouse 108, it is desirable to use a touch pen having a side switch.

  The display memory 105 is a buffer that temporarily accumulates display data input from the CPU 101. The accumulated display data is output to the display device 107 at a predetermined timing.

  The display device 107 includes a display device such as a liquid crystal panel and a CRT monitor, and a logic circuit for executing display processing in cooperation with the display device, and is connected to the CPU 101 via the display memory 105. The display device 107 displays display data stored in the display memory 105 under the control of the CPU 101.

  The input device 109 is an input device such as a keyboard, for example, and outputs various instructions and information input by the operator to the CPU 101. The operator interactively operates the medical image processing apparatus 100 using external devices such as the display device 107, the input device 109, and the mouse 108.

Next, a mouse operation method used in each embodiment of the present invention will be described.
The present invention performs processing for setting a point at an arbitrary three-dimensional position of a three-dimensional medical image displayed on a medical image processing apparatus. In the operation of determining the point position, the operator performs the following operation using the mouse 108.
Drag ... To move the mouse cursor while keeping the button switch of the mouse 108 pressed. In each embodiment of the present invention, the position of the point in the horizontal and vertical directions is moved by a drag operation.
Mouse down: To keep the mouse 108 button switch pressed. Letting the left button switch remain pressed is called the left mouse down, and keeping the right button switch pressed is called the right mouse down. In each embodiment of the present invention, the position of the point is moved in the depth direction (the depth direction with respect to the display screen) by a mouse down operation.
Mouse Up ... Release the button switch when the mouse is down. In each embodiment of the present invention, the movement in the depth direction is stopped by a mouse up operation.

In the case of the mouse 108 having a mouse wheel, the operation of the mouse wheel and the point movement in the depth direction may be linked. For example, the point may be moved backward when the mouse wheel is rotated forward, and the point may be moved forward when the mouse wheel is rotated backward.
In addition, an input device other than the mouse 108 may be used as long as it can input an operation corresponding to the above-described drag operation, mouse down operation, and mouse up operation. For example, a touch pen with a side switch is also suitable.

  The network 110 includes various communication networks such as a LAN (Local Area Network), a WAN (Wide Area Network), an intranet, and the Internet, and communication connection between the image database 111, a server, other information devices, and the medical image processing apparatus 100. Mediate.

  The image database 111 accumulates and stores image data photographed by the medical image photographing device 112. In the image processing system 1 shown in FIG. 1, the image database 111 is configured to be connected to the medical image processing apparatus 100 via the network 110, but the image database 111 is provided in, for example, the storage device 103 in the medical image processing apparatus 100. You may do it.

  Next, the operation of the medical image processing apparatus 100 will be described with reference to FIGS.

  The CPU 101 of the medical image processing apparatus 100 reads the program and data related to the point setting process of FIG. 2 from the main memory 102, and executes processing based on the program and data. In addition, when the execution of the following processing is started, image data to be calculated is acquired from the image database 111 or the like via the network 110 and the communication I / F 104 and stored in the storage device 103 of the medical image processing apparatus 100. And

  In the point setting process shown in FIG. 2, first, when the operator operates the mouse 108, the keyboard (input device 109) or the like and selects image data to be observed, the CPU 101 of the medical image processing apparatus 100 is selected. The read image data is read as input image data (step S101). Suitable examples of the input image data include a CT image, an MR image, or an ultrasonic image.

Next, the CPU 101 creates a three-dimensional medical image of the organ region from the image data acquired in step S101 (step S102) and displays it on the display device 107 (step S103). In the following description, the three-dimensional medical image is referred to as a 3D image 20.
For example, an operation screen 300 as shown in FIG. 3 is displayed on the display device 107, and the above-described 3D image 20 is displayed in the 3D image display area 301 in the operation screen 300.

Here, the operation screen 300 will be described.
The operation screen 300 includes a 3D image display area 301, a mode selection area 302, a horizontal orthogonal cross-sectional image display area 303, a vertical orthogonal cross-sectional image display area 304, a density gradient display area 305, and the like.
In the 3D image display area 301, the 3D image 20 generated in step S102 is displayed. In the following description, the projection plane of the 3D image 20 is an xy plane. A point object 306 for setting a point at an arbitrary three-dimensional position is displayed on the 3D image 20. When the user drags the point object 306 using the mouse 108 and moves to a desired position, the position of the point object 306 in the horizontal direction (x direction) and the vertical direction (y direction) is determined. The position of the point object 306 in the depth direction (z direction) is set by “mouse down operation”. That is, while the first button (for example, the left button) provided on the mouse is pressed (left mouse down), the CPU 101 moves the position of the point object 306 to the back side in the depth direction. Further, while a second button (for example, right button) provided on the mouse 108 is pressed (right mouse down), the CPU 101 moves the position of the point object 306 toward the front side in the depth direction.

  Moving the position of the point object 306 in the 3D image display area 301 in the depth direction means switching to the 3D image 20 of a different viewpoint according to the position (z position) in the depth direction after the movement. For example, moving the position of the point in the depth direction means that the distance between the virtual viewpoint position of the 3D image 20 and the projection plane is reduced. Since the projection plane does not move, the virtual viewpoint position is moved to reduce the distance. Moving the virtual viewpoint position means generating a 3D image 20 with a different viewpoint and switching to the 3D image 20 for display. That is, when the position of the point object 306 is continuously moved, the 3D image 20 is switched like a slide show. Hereinafter, in order to make the description easy to understand, the description of the switching process of the 3D image 20 in the movement process of the point object 306 is omitted.

  In the horizontal cross-sectional image display area 303 in the horizontal direction, the horizontal cross-sectional image 21 including the three-dimensional position of the point set by the point object 306 on the 3D image 20 is displayed. When the projection plane of the 3D image 20 is the xy plane, the orthogonal cross section in the horizontal direction is the zx plane. In addition, a point object 306 is displayed at a position corresponding to the point object 306 in the 3D image 20 on the horizontal orthogonal cross-sectional image 21. When moving the position of the point object 306 in the depth direction, the CPU 101 moves the point object 306 on the horizontal orthogonal cross-sectional image 21 of the same section according to the position in the depth direction after the movement.

  In the orthogonal cross-sectional image display area 304 in the vertical direction, the vertical orthogonal cross-sectional image 22 including the three-dimensional position of the point set by the point object 306 on the 3D image 20 is displayed. When the projection plane of the 3D image 20 is the xy plane and the horizontal cross section is the zx plane, the vertical cross section is the yz plane. A point object 306 is displayed at a position corresponding to the point object 306 in the 3D image 20 on the vertical orthogonal cross-sectional image 22. When moving the position of the point object 306 in the depth direction, the CPU 101 moves the point object 306 on the vertical orthogonal cross-sectional image 22 of the same section according to the position in the depth direction after the movement.

The mode selection area 302 displays a list of selectable modes. For example, there are an organ boundary setting mode for setting a point at the boundary of the organ, an organ center setting mode for setting a point at the center of the organ, and the like.
In the density gradient display area 305, a graph showing the density gradient of the 3D image 20 is displayed. For example, in the first embodiment, the density curve 23 in the depth direction of the 3D image 20 at the position of the point object 306 is displayed. The horizontal axis of the density gradient display area 305 of the first embodiment corresponds to the depth direction of the 3D image 20, and the vertical axis of the density gradient display area 305 represents the density value.

  In general, a medical image is characterized in that the concentration gradient is close to 0 at the center of the organ and the concentration gradient is steep near the organ boundary. The operator can determine whether the point object 306 is at the organ center or the organ boundary by referring to the density curve 23.

Returning to the flowchart of FIG.
When the 3D image 20 is displayed on the operation screen 300 and a desired mode is selected and set from the modes displayed in a list in the mode selection area 302 (step S104), the CPU 101 applies a moving speed to be applied according to the set mode. Determine the function. The moving speed function is a function indicating the relationship between the density gradient of the 3D image 20 and the moving speed. For example, the linear function and the nonlinear function shown in FIGS. 4 and 5 are suitable. In any mode, the moving speed of the point object 306 is determined based on the magnitude (absolute value) of the density gradient of the image in the direction in which the point is moved (the depth direction in the first embodiment) (step). S105).
It is assumed that the moving speed function is prepared in advance for each mode and stored in the storage device 103 or the like.

As described above, the concentration gradient is close to 0 at the organ center, and the concentration gradient is steep near the organ boundary. For this reason, in the organ center setting mode, for example, as shown in the linear function graph 400 of FIG. 4A, the moving speed of the point object 306 is decreased as the absolute value of the concentration gradient decreases. Further, the moving speed of the point object 306 is increased as the absolute value of the density gradient increases. Further, when the absolute value of the density gradient becomes larger than a threshold 401, the moving speed of the point object 306 may be the same as the moving speed at the threshold 401. Further, as shown in a nonlinear function graph 402 shown in FIG. 4B, the moving speed may be changed according to a nonlinear function such as a quadratic curve.
In this way, in the organ center setting mode, if the moving speed of the point object 306 is decreased as the absolute value of the concentration gradient decreases, the point object 306 moves slowly in the vicinity of the organ center where the change in the density value is small. For this reason, the operator can determine the point position without missing the timing of mouse up. Further, since the moving speed of the point object 306 is high except at the center of the organ, it can be quickly moved to a desired position.

In the organ boundary setting mode, for example, as shown in the linear function graph 403 shown in FIG. 5A, the moving speed of the point object 306 is increased as the absolute value of the concentration gradient is decreased. Further, the moving speed of the point object 306 is decreased as the absolute value of the density gradient increases. Furthermore, when the absolute value of the density gradient becomes larger than a threshold value 404, the moving speed of the point object 306 may be the same as the moving speed at the threshold value 404. Further, as shown in a nonlinear function graph 405 shown in FIG. 5B, the moving speed may be changed according to a nonlinear function such as a quadratic curve.
In this way, in the organ boundary setting mode, if the moving speed of the point object 306 is decreased as the absolute value of the concentration gradient increases, the point object 306 moves slowly in the vicinity of the organ boundary where the concentration value changes greatly. For this reason, the operator can determine the point position without missing the timing of mouse up. Further, since the moving speed of the point object 306 is high except at the organ boundary, it can be quickly moved to a desired position.

  Next, the point object 306 is moved to a desired position (horizontal and vertical position) by the operator's mouse operation on the 3D image 20 displayed in the 3D image display area 301, and the mouse down operation is performed at that position. If so (step S106), the CPU 101 creates an orthogonal cross-sectional image including the position where the mouse is down (step S107). An orthogonal cross-sectional image is created for each of the horizontal direction and the vertical direction based on the image data acquired in step S101. The CPU 101 displays the created horizontal cross-sectional image 21 and vertical cross-sectional image 22 in the horizontal cross-sectional image display area 303 and the vertical cross-sectional image display area 304, respectively (step S108). At this time, the CPU 101 draws a point object 306 on each orthogonal cross-sectional image 21, 22 at a position (a position in the depth direction of the point) corresponding to the position where the operator has moved the mouse down.

  Next, the CPU 101 creates a density curve 23 in the depth direction at the position where the current point is set (step S109). The density curve 23 can be created based on the image data input in step S101. The CPU 101 displays the density curve 23 created in step S109 in the density gradient display area 305 of the operation screen 300 (step S110). The CPU 101 draws a point object 306 on the density curve 23 at a position corresponding to the position where the operator has mouse-downed.

While the mouse down operation is being performed, the CPU 101 sets whether to move the point object 306 forward or backward according to the operation of the mouse 108. For example, when the currently performed operation is the left mouse down state, the moving direction of the point object 306 is set to the back direction, and when the operation being performed is the right mouse button state, the moving direction of the point object 306 is set to the front side (step S111). .
Then, the CPU 101 calculates the density gradient at the position where the point object 306 currently exists from the density curve 23 created in step S109, and corresponds to the current density gradient with reference to the moving speed function set in step S105. Get travel speed. Then, the point object 306 is moved at the acquired moving speed. The moving direction is the direction set in step S111. When the point is moved, the CPU 101 also moves the drawing position of the point object 306 displayed on the orthogonal cross-sectional images 21 and 22 and the density curve 23.

If the operator confirms the orthogonal cross-sectional images 21, 22 and the density curve 23, etc., the position of the point is determined to be appropriate (step S113; OK), and the mouse is moved up (step S114), the CPU 101 moves the point. To stop. On the other hand, when it is determined that the position of the point is not valid (step S113; NG), the mouse down operation is continued, and therefore, step S111 to step S112 are repeated to move the point object 306.
When the position of the point object 306 has passed the desired position, the operator may set the button switch opposite to the button switch that has been pressed so far to the down state. For example, if the left mouse is down for moving in the back direction, the position of the point object 306 can be returned to the near side if the right mouse is down.
With the mouse up operation by the operator, the CPU 101 stops the movement of the point object 306 in the depth direction (steps S114 and S115).

Through the above processing, the operator can set a point at a desired three-dimensional position only by operating the mouse on the 3D image 20. In particular, not only the horizontal and vertical directions but also the position in the depth direction of a point can be moved by performing a simple mouse operation (for example, a mouse down operation), so that the point setting operation is facilitated.
Further, during the setting operation of the depth direction position (during the mouse down operation), the moving speed of the point object 306 is increased or decreased based on the magnitude of the density gradient at the point position. That is, based on the density gradient of the image, the movement speed is reduced near the center of the organ in the organ center setting mode, and the movement speed is reduced near the boundary of the organ in the organ boundary setting mode. Therefore, the operator can accurately set a point at a desired position without missing the mouse up timing. In addition, at points other than the position where the point should be set, the point moving speed is increased, so that the point can be quickly moved to a desired position.

  Further, on the operation screen 300, along with the target 3D image 20, a density curve 23 in the depth direction at a pointed position and horizontal and vertical orthogonal cross-sectional images 21 and 22 including the point position are displayed. The point object 306 is also displayed at a position corresponding to the position of the point object 306 on the 3D image 20 on the curve 23 and the orthogonal cross-sectional images 21 and 22. For this reason, the operator can confirm the position of the point from various viewpoints, and the point position can be set more accurately. Therefore, it is possible to set points with high reproducibility.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS.
The hardware configuration of the medical image processing apparatus 100 of the second embodiment is the same as that of the first embodiment. Further, the mouse operation and the operation screen at the time of point setting may be the same as those in the first embodiment. Hereinafter, the description which overlaps with 1st Embodiment is abbreviate | omitted, and the same each part shall be demonstrated using the same code | symbol.

The medical image processing apparatus 100 according to the second embodiment sets the moving speed based on both the density gradient and the density value in the depth-direction point setting process.
That is, in the first embodiment, the moving speed function is set based on the concentration gradient (concentration curve) in the depth direction as shown in FIGS. 4 and 5, but in the second embodiment, the depth direction is set. In addition to the density gradient, the moving speed of the point object 306 is set in consideration of the magnitude of the density value.

  FIG. 6 is an example of a curved surface function 600 showing the relationship between the density gradient and density value in the boundary center setting mode and the moving speed of the points. When such a curved surface function 600 is applied, the moving speed can be set to be low at a portion where the concentration gradient is small, and the moving speed can be set to be low at a portion where the concentration gradient is large. In addition to this, the moving speed can be set to be smaller at a location where the density value is small than at a location where the density value is large. Thus, if the moving speed of the point is set in consideration of the density value in addition to the density gradient, the moving speed is changed according to the type of organ or the presence or absence of a contrast agent. It becomes possible. This makes it possible to set points more quickly.

  Hereinafter, the flow of the point setting process in the second embodiment will be described with reference to the flowchart of FIG.

  Steps S201 to S204 are the same as those in the first embodiment. That is, the CPU 101 of the medical image processing apparatus 100 reads the input image data in accordance with the operation by the operator, creates a 3D image (3D image 20) of the organ area, and displays it in the 3D image display area 301 of the operation screen 300 ( Step S201 to Step S203).

  Next, the CPU 101 receives a mode selection (step S204). In the mode selection, a desired mode is selected and set from the modes displayed in a list in the mode selection area 302 as in the first embodiment. As modes, in addition to the organ center setting mode and the organ boundary setting mode, the modes may be switched depending on the type of organ to be extracted or the presence or absence of a contrast agent. For example, in an examination using a contrast agent, the target organ is a contrasted portion, that is, a high concentration value, and therefore, a high concentration value organ extraction mode may be selected. Further, in an examination without using a contrast agent, when it is desired to quickly pass a bone region (high concentration value) around the target organ, the low concentration value organ extraction mode may be selected.

The CPU 101 determines a moving speed function to be applied according to the set mode (step S205).
The moving speed function applied in the second embodiment is a function indicating the relationship between the concentration gradient and the concentration value and the moving speed as shown in FIG. 6, for example. As described above, the curved surface function shown in FIG. 6 is an example of a moving speed function to be applied when a point is set near the center of an organ having a low concentration value. In addition, when setting a point near the boundary of an organ with a low concentration value, when setting a point near the center of an organ with a high concentration value, or when setting a point near the boundary of an organ with a high concentration value, etc. It is assumed that the moving speed functions to be applied are prepared in advance and stored in the storage device 103 or the like.

  Next, the point object 306 is moved to a desired position (horizontal and vertical position) by the operator's mouse operation on the 3D image 20 displayed in the 3D image display area 301, and the mouse down operation is performed at that position. When this occurs (step S206), as in the first embodiment, the CPU 101 creates orthogonal cross-sectional images (horizontal orthogonal cross-sectional image 21 and vertical orthogonal cross-sectional image 22) including the mouse-down position, respectively. They are displayed in the horizontal cross-sectional image display area 303 and the vertical cross-sectional image display area 304 (steps S207 and S208). At this time, the CPU 101 draws a point object 306 on each orthogonal cross-sectional image 21, 22 at a position corresponding to the position where the operator mouses down.

  Similarly to the first embodiment, the CPU 101 creates the density curve 23 in the depth direction of the position where the current point object 306 is present, and displays it in the density gradient display area 305 (steps S209 and S210). . At this time, the CPU 101 draws a point object 306 on each orthogonal cross-sectional image 21, 22 at a position (a position in the depth direction of the point) corresponding to the position where the operator has moved the mouse down.

  Similarly to the first embodiment, the CPU 101 sets whether to move the point object 306 forward or backward (step S211), and the CPU 101 sets the density curve 23 created in step S209. Then, the concentration gradient at the position where the point object 306 currently exists is calculated, and the moving velocity corresponding to the current concentration gradient and the concentration value is acquired with reference to the moving velocity function (curved surface function) set in step S205. Then, the point object 306 is moved at the acquired moving speed. The moving direction is the direction set in step S211. When the movement of the point is executed, the CPU 101 moves the drawing position of the point object 306 displayed on the orthogonal cross-sectional images 21 and 22 and the density curve 23. When the operator raises the mouse (step S214), the movement of the point object 306 is stopped (step S215).

When the operator confirms the orthogonal cross-sectional images 21 and 22 and the density curve 23 and the like, the position of the point is determined to be appropriate (step S213; OK), and the mouse is moved up (step S214), the CPU 101 moves the point. To stop. On the other hand, if it is determined that the position of the point is not valid (step S213; NG), the mouse down operation is continued, so that steps S211 to S212 are repeated to move the point object 306.
When the position of the point object 306 has passed the desired position, the operator may set the button switch opposite to the button switch that has been pressed so far to the down state. For example, if the left mouse is down for moving in the back direction, the position of the point object 306 can be returned to the near side if the right mouse is down.
With the mouse up operation by the operator, the CPU 101 stops the movement of the point object 306 in the depth direction (steps S214 and S215).

  As described above, according to the processing of the second embodiment, it is possible to set the moving speed of the point based on not only the density gradient but also the density value. Therefore, the point moves according to the presence or absence of the organ or contrast agent, such as moving the point at a high speed except for the organ for which the point is to be set, or moving the point at a low speed at a point (organ) where the contrast agent is present. The speed can be set to an appropriate value. Therefore, in addition to the effects of the first embodiment, it is possible to set points more easily and quickly.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIGS.
The hardware configuration of the medical image processing apparatus 100 of the third embodiment is the same as that of the first embodiment. Hereinafter, the description which overlaps with 1st Embodiment is abbreviate | omitted, and the same each part shall be demonstrated using the same code | symbol.

In the first embodiment, the point is moved in the depth direction only by the mouse down operation. However, in the first embodiment, when the point position is to be moved in the horizontal direction, the vertical direction, or the like, it is necessary to move the mouse to the desired horizontal and vertical position after dragging the point object once.
Thus, in the third embodiment, the point can be moved in directions other than the depth direction by further performing an operation of moving the mouse in a predetermined direction during the mouse down operation. The direction other than the depth direction is an arbitrary direction in a plane orthogonal to the depth direction (that is, a plane (xy plane) parallel to the projection plane of the 3D image 20). For example, the horizontal direction (x direction), the vertical direction (y direction), or any other direction (any direction in the xy plane) may be used. The moving direction may be a predetermined direction (for example, a horizontal direction or a vertical direction), or a user may set an arbitrary angle. If the user can arbitrarily set the point, it is effective when, for example, it is desired to move a point along a blood vessel or the like.
In addition, the reason why the movement direction of the points is a total of two directions including another direction in addition to the depth direction is that if the number of directions is three or more, the operation becomes rather complicated.

Here, the mouse operation and operation screen in the third embodiment will be described.
In the third embodiment, an operation that combines mouse down and mouse movement is performed. When the mouse is moved while the mouse is down, the CPU 101 moves the point object 306 in a predetermined direction within a plane (xy plane) orthogonal to the depth direction.
For example, consider a setting in which the point object 306 is moved in the horizontal direction when the mouse is moved during the mouse down operation. In this case, the following four movements can be considered.
(A) In the left mouse down state, when the mouse is moved to the left side (strictly not to the left), the CPU 101 moves the point to the back and to the left.
(B) In the left mouse down state, when the mouse is moved to the right (not necessarily rightward), the CPU 101 moves the point in the back direction and in the right direction.
(C) In the right mouse down state, when the mouse is moved to the left side (strictly not to the left), the CPU 101 moves the point forward and to the left.
(D) When the mouse is moved to the right (not necessarily rightward) in the right mouse down state, the CPU 101 moves the point forward and to the right.
Similarly, in the case of setting that the point object 306 is moved in the vertical direction in addition to the movement in the depth direction, the left mouse down or the right mouse down is combined, and the mouse movement upward or downward is combined. There are four possible movements.

FIG. 8 is an example of the operation screen 310 according to the third embodiment.
8 includes a mode selection area 302, a 3D image display area 301, a horizontal direction orthogonal cross-section image display area 303, a vertical direction orthogonal cross-section image display area 304, a density gradient display area 305, and a direction setting area 311. Have.

  In the orthogonal cross-sectional image display area 303 in the horizontal direction, the horizontal orthogonal cross-sectional image 21 including the three-dimensional position of the point set by the point object 306 on the 3D image 20 is displayed. In addition, a point object 306 is displayed at a position corresponding to the point object 306 in the 3D image 20 on the horizontal orthogonal cross-sectional image 21. When moving the position of the point object 306 in a certain direction, the CPU 101 switches to the horizontal orthogonal cross-sectional image 21 of a different cross section or changes the point object on the horizontal cross-sectional image 21 of the same cross section according to the moved position. 306 is moved. For example, when the position of the point is moved in the depth direction and upward, it means that the position of the cross section is also moved upward. Moving the position of the cross-section means that a horizontal cross-sectional image 21 of a different cross-section is generated and switched to the horizontal cross-sectional image 21 for display. That is, when the position of the point object 306 is continuously moved, the horizontal direction orthogonal sectional image 21 is switched like a slide show. Hereinafter, in order to make the description easy to understand, the description of the switching process of the horizontal orthogonal cross-sectional image 21 in the movement process of the point object 306 is omitted.

  In the orthogonal cross-sectional image display area 304 in the vertical direction, the vertical orthogonal cross-sectional image 22 including the three-dimensional position of the point set by the point object 306 on the 3D image 20 is displayed. A point object 306 is displayed at a position corresponding to the point object 306 in the 3D image 20 on the vertical orthogonal cross-sectional image 22. When moving the position of the point object 306 in a certain direction, the CPU 101 switches to the vertical orthogonal cross-sectional image 22 of a different cross section or changes the point object on the vertical cross-sectional image 22 of the same cross section according to the moved position. 306 is moved. For example, when moving the position of the point in the depth direction and in the right direction, this means that the position of the cross section also moves in the right direction. Moving the position of the cross section means that a vertical cross-sectional image 22 of a different cross-section is generated and switched to the vertical cross-sectional image 22 for display. That is, when the position of the point object 306 is continuously moved, the vertical orthogonal cross-sectional image 22 is switched like a slide show. In the following, in order to make the description easy to understand, the description of the switching process of the vertical cross-sectional image 22 in the movement process of the point object 306 is omitted.

The direction setting area 311 is an area for setting whether or not to move a point in an arbitrary angular direction within a plane orthogonal to the depth direction, and setting the moving direction of the point.
When a check is input to the check field 312 in the direction setting area 311, the CPU 101 moves the point in an arbitrary angular direction in a plane orthogonal to the depth direction in accordance with the mouse moving operation in the mouse down state. I do. If there is no check, the same processing as in the first or second embodiment is performed.
The angle setting field 313 is an area for inputting the moving direction of the point. When “0” degrees is input in the angle setting field 313, the point object 306 can move not only in the depth direction but also in the horizontal direction. Further, when “90” degrees is input, it is possible to move in the depth direction and the vertical direction.

  Next, a flow of point setting processing in the third embodiment will be described with reference to the flowchart of FIG.

  Steps S301 to S303 are the same as those in the first embodiment. That is, the CPU 101 of the medical image processing apparatus 100 reads input image data in accordance with an operation by the operator, creates a 3D image (3D image 20) of the organ area, and displays it in the 3D image display area 301 of the operation screen 310 ( Step S301 to Step S303).

  Next, the CPU 101 receives a mode selection (step S304). In the mode selection, a desired mode is selected and set from the modes displayed in a list in the mode selection area 302 as in the first embodiment.

The CPU 101 determines a moving speed function to be applied according to the set mode (step S305). As in the first embodiment, for example, the moving speed function shown in FIG. 4 is applied in the organ center setting mode, and the moving speed function shown in FIG. 5 is applied in the organ boundary setting mode. .
Alternatively, as in the second embodiment, the moving speed may be set based on the concentration gradient and the concentration value.

  Next, the point object 306 is moved to a desired position (horizontal and vertical position) on the 3D image 20 displayed in the 3D image display area 301 according to the mouse operation of the operator, and the mouse is moved down at that position. When an operation is performed (step S306), as in the first embodiment, the CPU 101 creates orthogonal cross-sectional images (horizontal orthogonal cross-sectional image 21 and vertical orthogonal cross-sectional image 22) including the mouse-down position. They are displayed in the horizontal cross-sectional image display area 303 and the vertical cross-sectional image display area 304, respectively (steps S307 and 3208). At this time, the CPU 101 draws a point object 306 on each orthogonal cross-sectional image 21, 22 at a position corresponding to the position where the operator mouses down.

  Next, the CPU 101 creates a density curved surface 800 including information about the depth direction and the direction set in the direction setting area 317 of the operation screen 310 including the current position of the point object 306, and the density gradient display area 305. (Step S309, Step S310). At this time, the CPU 101 draws the point object 306 on the density curved surface 800 at a position corresponding to the position where the operator mouses down.

FIG. 10 is an example of the density curved surface 800.
As shown in FIG. 10, the density curved surface 800 is a curved surface showing the relationship between the density gradient in the depth direction and the horizontal direction and the moving speed. In FIG. 10, the density gradients in the depth direction and the horizontal direction are shown, but instead of the horizontal direction, any direction in a plane orthogonal to the depth direction set on the operation screen 310 may be used. In addition, the point object 306 is drawn at a position on the density curved surface 800 corresponding to the position of the point object 306 on the 3D image 20. By referring to the position of the point object 306 on the density curved surface 800, the operator can easily confirm the position where the current point is.

  In FIG. 8, the density curve 23 is displayed in the density gradient display area 305. Thus, a predetermined section of the density curved surface 800 may be displayed as the density curve 23 in the density gradient display area 305. Further, as described above, the density object 800 may be displayed in the density gradient display area 305 and the point object 306 may be drawn.

  Further, the CPU 101 sets whether to move the point object 306 forward or backward according to the operation of the mouse, and moves the point object 306 in any direction according to the movement direction of the mouse. It is set whether to do (step S311). For example, when the mouse is moved to the left while the left mouse is down, the moving direction of the points is set to the back and left directions. Further, for example, when the mouse is moved to the right side with the right mouse down, the moving direction of the point is set to the front direction and the right direction.

  The CPU 101 calculates the density gradient at the position where the point object 306 currently exists from the density curved surface 800 created in step S309, and refers to the moving speed function set in step S305 to determine the current density gradient (or density gradient). And the movement speed corresponding to the density value). Then, the point object 306 is moved at the acquired moving speed. The moving direction is the direction set in step S311. When the movement of the point is executed, the CPU 101 moves the drawing position of the point object 306 displayed on the orthogonal cross-sectional images 21 and 22 and the density curve 23. When the operator raises the mouse (step S314), the movement of the point object 306 is stopped (step S315).

The orthogonal cross-sectional images 21 and 22 and the density curved surface 800 are confirmed by the operator, the position of the point is determined to be appropriate (step S313; OK), and the mouse is moved up (step S314), the CPU 101 moves the point. To stop. On the other hand, when it is determined that the position of the point is not valid (step S313; NG), the mouse down operation is continued, and thus the steps S311 to S312 are repeated to move the point object 306.
When the position of the point object 306 has passed the desired position, the operator may bring down the mouse button opposite to the mouse button that has been pressed so far. For example, if the left mouse is down for moving in the back direction, the position of the point object 306 can be returned to the near side if the right mouse is down. If the moving direction of the mouse is the reverse direction, the point object 306 can be moved in the reverse direction to the previous moving direction.
With the mouse up operation by the operator, the CPU 101 stops the movement of the point object 306 in the depth direction (steps S314 and S315).

  As described above, according to the processing of the third embodiment, when the mouse is further moved in the mouse down state, the point is moved not only in the depth direction but also in a predetermined direction set in advance. It becomes possible. Therefore, in addition to the effects of the first and second embodiments, the setting of the three-dimensional position with respect to the 3D image 20 becomes smoother, and the point can be set quickly.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIGS.
The hardware configuration of the medical image processing apparatus 100 of the fourth embodiment is the same as that of the first embodiment. Further, the mouse operation and operation screen at the time of point setting may be the same as in any of the first to third embodiments. In the following description, the description which overlaps with 1st Embodiment is abbreviate | omitted, and the same code | symbol shall be used for the same each part.

In any of the first to third embodiments, the point moving speed is set based on the concentration gradient or the concentration gradient and the concentration value. By the way, depending on the image, it may be difficult to visually distinguish the organ boundary and the vicinity of the center due to noise or the like. For example, in an X-ray CT apparatus or the like, the X-ray dose may be reduced to reduce the exposure dose, and in this case, noise is likely to occur in the image. When noise occurs, the density becomes uneven. Even if the density gradient is obtained, it may be difficult to link the change in the density gradient and the position of the organ center or organ boundary.
Therefore, in the fourth embodiment, the noise of the above-described density gradient is removed, and the point moving speed is set based on the density gradient after noise removal.

  The flow of point setting processing in the fourth embodiment will be described below with reference to the flowchart in FIG.

  Steps S401 to S403 are the same as steps S101 to S104 in the first embodiment. That is, according to the operation by the operator, the CPU 101 of the medical image processing apparatus 100 reads the input image data, creates a three-dimensional image (3D image 20) of the organ region, and displays it in the 3D image display region 301 of the operation screen 300. (Step S401 to Step S403).

  Next, the CPU 101 accepts mode selection (step S404). In the mode selection, a desired mode is selected and set from the modes displayed in a list in the mode selection area 302 as in the first embodiment.

  The CPU 101 determines a moving speed function to be applied according to the set mode (step S405). The setting of the moving speed is the same as that in the first embodiment.

  Next, the point object 306 is moved to a desired position (horizontal and vertical position) by the operator's mouse operation on the 3D image 20 displayed in the 3D image display area 301, and the mouse down operation is performed at that position. When this occurs (step S406), as in the first embodiment, the CPU 101 creates orthogonal cross-sectional images (horizontal orthogonal cross-sectional image 21 and vertical orthogonal cross-sectional image 22) including the mouse-down position, respectively. They are displayed in the horizontal cross-sectional image display area 303 and the vertical cross-sectional image display area 304 (steps S407 and S408). At this time, the CPU 101 draws a point object 306 on each orthogonal cross-sectional image 21, 22 at a position corresponding to the position where the operator mouses down.

  Similarly to the first embodiment, the CPU 101 creates a density curve 900 for the depth direction at the position where the current point object 306 is located (step S409). Then, the CPU 101 creates a density curve 904 obtained by removing the noise components 901 and 902 from the density curve 900 created in step S409 (step S410; see FIG. 12). For the removal of the noise component, for example, a LowPass filter that converts the density curve 900 into a frequency space and removes a high-frequency component may be used, or another filter may be applied. If a one-dimensional density curve is created in step S409, a one-dimensional noise component may be removed in step S410. Alternatively, the density curve 904 may be created after removing two-dimensional noise or three-dimensional noise in advance using input image data or the like.

  The CPU 101 displays the density curve 904 after noise removal in the density gradient display area 305 (step S411). At this time, the CPU 101 draws the point object 306 on the density curve 904 at a position corresponding to the position where the operator mouses down.

  Next, as in the first embodiment, the CPU 101 sets whether to move the point object 306 forward or backward (step S412). From the density curve 904 after noise removal, The concentration gradient at the position where the point object 306 exists is calculated, and the movement speed corresponding to the current concentration gradient (or concentration gradient and concentration value) is acquired with reference to the movement speed function (curved surface function) set in step S205. . Then, the point object 306 is moved at the acquired moving speed (step S413). The moving direction is the direction set in step S412.

The orthogonal cross-sectional images 21, 22 and the density curve 904 after noise removal are confirmed by the operator, the position of the point is determined to be appropriate (step S414; OK), and the mouse is moved up (step S415). Stops the movement of the point object 306 (step S416). On the other hand, if it is determined that the position of the point is not valid (step S414; NG), the mouse down operation is continued, and therefore, step S412 to step S413 are repeated to move the point object 306.
When the position of the point object 306 has passed the desired position, the operator may bring down the mouse button opposite to the mouse button that has been pressed so far. For example, if the left mouse is down for moving in the back direction, the position of the point object 306 can be returned to the near side if the right mouse is down.
With the mouse up operation by the operator, the CPU 101 stops the movement of the point object 306 in the depth direction (steps S415 and S416).

  As described above, according to the process of the fourth embodiment, the density curve 904 after noise removal can be obtained even when an image having noise and the boundary of the organ and the vicinity of the center are difficult to visually discern. Since the moving speed is set by using and the point position is changed according to the set moving speed, the point can be set with high accuracy near the boundary or center of the organ. For example, even when noise occurs in an image taken with an X-ray CT apparatus or the like with a reduced X-ray dose, by applying the processing of the fourth embodiment, organ boundaries and organs can be accurately and reproducibly applied. A point can be set at the center. As a result, it also leads to a reduction in exposure dose in imaging with an X-ray CT apparatus or the like.

The preferred embodiments of the medical image processing apparatus according to the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples.
For example, the density value and the density gradient are used as an index for setting the moving speed of the point. However, the index is not limited to this, and for example, a secondary differential amount of a density curve may be used. In this case, since the second derivative of the concentration curve tends to approach 0 near the boundary of the organ, when the second derivative is close to 0, the moving speed of the point is reduced to quickly approach the organ boundary. It is possible to set points with high accuracy and reproducibility. Further, the present invention may appropriately combine the first to fourth embodiments. It will be apparent to those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea disclosed in the present application, and these naturally belong to the technical scope of the present invention. Understood.

1. Image processing system 100 Medical image processing apparatus 101 CPU
102... Main memory 103... Storage device 104 .. Communication I / F
105 ... Display memory 106 ... I / F
107... Display device 108 mouse 109 input device 110 network 111 image database 113 image photographing device 300 ... Operation screen 301 ... 3D image display area 302 ... Mode selection area 303 ... Horizontal direction orthogonal cross-section image display area 304 ... Vertical direction orthogonal cross-section image display area 305... Density gradient display area 20... 3D medical image (3D image)
21 ··· Horizontal cross-sectional image 22 ··· Vertical cross-sectional image 23 ····················· Concentration curves 400 and 403
402, 405 ... Movement speed function (non-linear)
401, 404 ... threshold 600 ... moving speed function (curved surface function)
310... Operation screen (third embodiment)
311... Direction setting area 800... Concentration curved surface (third embodiment)
904: Density curve after noise removal

Claims (9)

Display means for displaying a three-dimensional medical image;
Point setting means for setting a point at an arbitrary three-dimensional position of the three-dimensional medical image;
An operation input means for operating the position of the point, and a medical image processing apparatus comprising:
A density gradient calculating means for calculating a density gradient of the three-dimensional medical image;
A moving speed setting means for setting a moving speed of the point based on the concentration gradient;
When the movement operation of the position of the point is performed by the operation input means, the position of the point is moved by the movement speed of the point set by the movement speed setting means according to the density gradient at the position of the point. Point position moving means;
A medical image processing apparatus comprising: The concentration gradient calculating means calculates a concentration curve indicating the concentration gradient in the depth direction,
The moving speed setting means sets the moving speed of the point based on the density curve,
The medical image processing apparatus according to claim 1, wherein the point position moving unit moves the position of the point in the depth direction according to the moving speed of the point set by the moving speed setting unit.   The medical image processing apparatus according to claim 2, wherein the display unit further displays the density curve together with the three-dimensional medical image. The concentration gradient calculating means calculates a concentration curved surface indicating the concentration gradient in the depth direction and the concentration gradient in an arbitrary direction within a plane orthogonal to the depth direction,
The moving speed setting means sets the moving speed of the point for the component in the depth direction and the component in an arbitrary direction in the plane based on the density curved surface,
The point position moving means moves the position of the point in the depth direction and moves the position of the point in an arbitrary direction in the plane according to the moving speed of the point set by the moving speed setting means. The medical image processing apparatus according to claim 1, wherein the medical image processing apparatus is applied to the medical image processing apparatus.   The medical image processing apparatus according to claim 4, wherein the display unit further displays the density curved surface together with the three-dimensional medical image. A density value calculating means for calculating a density value of the three-dimensional medical image;
6. The medical image processing apparatus according to claim 1, wherein the moving speed setting unit sets the moving speed of the point based on the density value and the density gradient. Noise removing means for removing noise of the density gradient,
The said moving speed setting means sets the moving speed of the said point based on the density | concentration gradient after the noise was removed by the said noise removal means. Medical image processing apparatus.   When the horizontal position and the vertical position are determined by the point setting means, the display means displays the tomographic image at the determined horizontal position and the tomographic image at the vertical position together with the three-dimensional medical image. The medical image processing apparatus according to claim 1, wherein: A medical image processing method in a medical image processing apparatus comprising an operation input means for inputting an operation for setting a point at an arbitrary three-dimensional position of a three-dimensional medical image,
A density gradient calculating step for calculating a density gradient of the three-dimensional medical image;
A moving speed setting step for setting the moving speed of the point based on the concentration gradient;
When the movement operation of the position of the point is performed by the operation input means, the position of the point is moved by the movement speed of the point set by the movement speed setting step according to the density gradient at the position of the point. A point position moving step;
A medical image processing method comprising:

Images