JP5595207B2 - Medical image display device - Google Patents

Description

  The present invention relates to a medical image display device that displays three-dimensional volume data captured by a medical image diagnostic apparatus such as an MRI apparatus or an X-ray CT apparatus, and a projection image creation method using the same, and more particularly, the three-dimensional volume data It is related with the technique which produces the projection image of (2) suitably.

  A medical image diagnostic apparatus such as an MRI apparatus or an X-ray CT apparatus can take a tomographic image of a subject. Furthermore, it is possible to obtain three-dimensional volume data by stacking a plurality of tomographic images in a direction perpendicular to the slice plane. Such three-dimensional volume data is displayed on the screen after being converted into a normal projection image.

  The ray trajectory method is generally well known as a method for projecting three-dimensional volume data. In this method, 3D volume data and a 2D plane (projection plane) are arranged in a 3D space, and a virtual ray is projected from the 2D plane to the 3D image data. A pixel having a predetermined value from the volume data is used as the value of the corresponding pixel on the two-dimensional plane. At that time, the method of selecting and projecting the maximum luminance value among the pixels on the light ray is the maximum value projection method (MIP: Maximum Intensity Projection), and the method of selecting and projecting the minimum luminance value is the minimum value projection method. It is appropriately selected according to the tissue to be drawn. There is also a technique such as a volume rendering method in which opacity is given to each pixel of three-dimensional volume data and a projection image is formed based on the amount of light passing therethrough.

  Here, when generating a projection image, if all of the three-dimensional volume data is to be projected, it will be projected including areas that are not necessary, such as fat areas, and it is particularly difficult to diagnose a medical image. There is a risk of becoming a projected image or causing misdiagnosis. Therefore, in order to target only the necessary area, the projection area is limited and only a desired area is selected (referred to as clipping), and projection processing is performed on the limited area (clipping area). Thus, a projection image is obtained (for example, step 705 of Patent Document 1).

JP 2006-340939

  However, more specifically, in Patent Document 1, the range of the clipping region is designated by ROI on the AX (Axial), COR (Coronal), and SAG (Sagittal) images, and the direction of projection in the clipping region is further indicated by an icon. It was specified by the indicated direction vector (301a to 301c in FIG. 3 of Patent Document 1). In this case, when the image in the designated direction is displayed as a projected image in the lower right area of the screen in FIG. There was a problem that it was difficult to see because it was not displayed in the center of the area.

  Accordingly, the present invention has been made to solve the above-described problems, and an object thereof is to provide a medical image display apparatus capable of easily setting a projection area and a projection center and a projection image generation method using the medical image display apparatus. .

  In order to solve the above problems, according to the present invention, first projection image generation means for generating a first projection image by projecting from a first direction onto three-dimensional volume data, and the first projection image An input means for inputting, as an index, a second direction when generating a second projection image for the three-dimensional volume data, and a second projection for generating the second projection image based on the index In the medical image display device including an image generation unit and a display unit that displays the first projection image and the second projection image, the index includes position information in the three-dimensional volume data, and A two-projection image generation unit is provided with a medical image display device that generates the second projection image with the position information as a projection center.

  Further, the display means displays the second projection image such that the position serving as the projection center is the center of the area where the second projection image is displayed on the screen. A medical image display device is provided.

  In addition, a medical image display device is provided in which the display means displays the index with an arrow.

  The medical image display apparatus is characterized in that the index includes area information for generating the second projection image.

  Further, a medical image display device is provided in which the display means displays the depth of the area information with the length of an arrow.

  Further, there is provided a medical image display device characterized in that the display means displays the depth and width of the region information by ROI.

  Further, there is provided a medical image display device characterized in that the input means moves the projection center by moving an arrow on the screen.

  Further, the display means moves the position of the second projection image on the screen by moving an arrow within the ROI on the screen of the first projection image. A medical image display device characterized by the above is provided.

  In addition, there is provided a medical image display device, wherein the first projection image is at least one projection image projected in an arbitrary direction of the subject.

  In addition, the medical image display device is characterized in that the first projected image is three projected images projected in three orthogonal directions of the subject.

  In addition, the first projection image is generated by projecting the three-dimensional volume data from the first direction, and the second projection image is generated for the three-dimensional volume data on the first projection image. A step of inputting the second direction as an index, a step of generating the second projection image based on the index, and a step of displaying the first projection image and the second projection image In the projection image creation method provided, the index includes position information in the three-dimensional volume data, and the second projection image is generated with the position information as a projection center. A creation method is provided.

  In the display step, the second projection image is displayed such that a position serving as the projection center is a center of a region where the second projection image is displayed on the screen. A projection image creation method is provided.

  In the display step, the projected image is generated by displaying the index with an arrow.

  Further, there is provided a projection image creating method, wherein the index includes area information for generating the second projection image.

  In the display step, the depth of the area information is displayed by the length of an arrow.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the medical image display apparatus which can set a projection area | region and a projection center simply, and a projection image production | generation method using the same.

The figure which shows the whole structure of an example of the medical image display apparatus which concerns on this invention The figure which shows one Embodiment of the structure in connection with the control system of an image display apparatus The figure which shows the example of a display of a projection direction and a projection image at the time of generating a projection image of three-dimensional volume data 5 is a flowchart showing a processing flow of the projection image generation method according to the first embodiment of the present invention. The figure which shows the example of a display of a projection direction, a projection center, and a projection image at the time of producing | generating the projection image of three-dimensional volume data in Example 1 of this invention The figure which shows the relationship between the vector which is displayed on the projection image of three orthogonal directions and the three-dimensional vector which is the actual projection direction 7 is a flowchart showing a processing flow of a projection image generation method according to the second embodiment of the present invention. The figure which shows the example of a display of a projection direction, a projection range, and a projection image at the time of producing | generating the projection image of three-dimensional volume data in Example 2 of this invention. The figure which shows the example of a display of the projection range at the time of producing | generating the projection image of the three-dimensional volume data of this invention The figure which shows the example which makes only AX direction projection picture 1st projection picture (left side)

Embodiments of a medical image display apparatus and a projection image generation method using the same according to the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing an overall configuration of an example of a medical image display apparatus according to the present invention, and this medical image display apparatus (hereinafter also simply referred to as an image display apparatus) 100 includes an MRI apparatus, an X-ray CT apparatus, and the like. A control system that inputs image data sent from the imaging apparatus 200, processes the image, displays it as an image on the display 104, which will be described later, and displays a GUI for providing operation means for the operator on the display 104, which will be described later An image processing unit (CPU) 101, a memory 102 for temporarily storing images and other data, images sent from the imaging device 200, projection images created by the image processing unit 101, templates for GUI, etc. A storage device 103 such as a magnetic disk for storing the image, a display 104 for displaying the GUI and the image, and an input device 105 such as a pointing device for operating the GUI displayed on the display.

  In this embodiment, the case where the imaging apparatus 200 is an MRI apparatus will be described. However, the present invention is not limited to the MRI apparatus, and the present invention can also be applied to other medical image diagnostic apparatuses such as an X-ray CT apparatus and a positron imaging apparatus (PET). Although not shown, as a general configuration, a static magnetic field magnet that generates a uniform magnetic field in the vertical or horizontal direction, and three sets of gradient magnetic fields that apply gradient magnetic fields in the X, Y, and Z directions to the static magnetic field Generating coil, RF irradiation coil for irradiating a subject with a high-frequency magnetic field, RF receiving coil for detecting an NMR signal generated from the subject, a signal processing system for processing the NMR signal, a gradient magnetic field generating coil and RF irradiation A sequencer for controlling the operation of the coil according to a predetermined imaging sequence, and a control system for controlling the operation by sending commands to the signal processing system and the sequencer and performing various calculations necessary for imaging. The image display apparatus 100 may be a part of an image diagnostic apparatus integrated with the imaging apparatus (MRI apparatus) 200, or may be an independent display apparatus connected to the imaging apparatus 200 via a cable or wirelessly. In the case of being a part of an image diagnostic apparatus, the image processing unit 101 may include a control system (a part for controlling the apparatus and performing various calculations) included in the image diagnostic apparatus as its function.

  FIG. 2 is a diagram showing an embodiment of a configuration related to the control system of the image display apparatus described above. In this embodiment, the control system displays the display control unit 111 that controls the gradation, scale, color, and the like of the display on the display 104, the GUI necessary for the operation of the operator, and the operation on the GUI. GUI unit 112 that accepts an operator's command via image processing, and performs image processing such as projection processing and composition processing on image data, and also receives commands input via GUI unit 112, and performs calculations such as coordinate conversion of image data A calculation unit 113 that performs the operation and a main control unit 110 that comprehensively controls operations of these units are provided.

  When the image display apparatus is a part of the MRI apparatus, the control system further includes an imaging control unit that controls the RF transmission system, the gradient magnetic field generation system, and the like of the MRI apparatus 200 according to a predetermined imaging sequence.

  Next, Embodiment 1 of the image display device 100 configured as described above and a projection image generation method using the image display device 100

This will be described with reference to the flowcharts of FIGS. 3 and 4 and FIGS. 5 and 6. FIG. FIG. 3 shows that the image display area on the display 104 is divided into four areas, and three-dimensional volume data is obtained from three orthogonal axes (AX (axial) direction, COR (coronal) direction, and SAG (sagittal) direction). Three two-dimensional images obtained by projection are displayed in three divided areas, respectively, and the remaining one area is the result of projection processing from the desired projection direction to the three-dimensional volume data. An example of display is shown.

  These projection processes are performed by the CPU 101 executing a predetermined program recorded on the magnetic disk 103. At that time, the CPU 101 reads out the 3D volume data obtained by the acquisition means for acquiring the 3D volume data of the subject from the magnetic disk 103 to the memory 102, and performs a projection process or the like on the data according to a predetermined program. The result is displayed on the display 104.

  More specifically, FIG. 3 (a) shows three projection directions orthogonal to each other, each of the AX direction, the COR direction, and the SAG direction, and a desired projection direction that is the same as or different from these three directions. Yes. The desired projection direction is set by the operator as will be described later.

  Figure 3 (b) shows the AX direction projection image at the lower left of the four divided areas, the COR direction projection image at the upper left, the SAG direction projection image at the upper right, and the desired projection at the lower right. An example is shown in which a projected image in a direction (more specifically, a direction from the position where the direction is the same as the COR direction and the projection center is the left eye of the subject) is displayed.

  In this embodiment, designation of the direction of the projected image from the desired projection direction displayed on the lower right is displayed as a vector on the orthogonal three-direction projected image, and the direction of each vector is input via the input device 105. And the combined vector of these three vectors is set as a desired projection direction. Then, an image obtained by projecting in the direction designated by such an operation is displayed in the lower right. At this time, the display update at the lower right may be performed every time the vector on the orthogonal three-direction projection image is changed, and is obtained by projecting in that direction after the projection direction is finally determined. The projected image may be displayed.

  Next, the procedure of the projection image generation method according to the first embodiment of the present invention will be described with reference to the flowchart of FIG. Hereinafter, this flowchart will be described step by step. However, the processing flow shown in this flowchart is executed by the CPU 101 in FIG. 1 reading and starting a program stored in the magnetic disk 103 in FIG.

(Step 401)
In step 401, the CPU 101 reads the three-dimensional volume data obtained by the obtaining unit that obtains the three-dimensional volume data of the subject stored in advance on the magnetic disk 103 based on a command input by the user. Alternatively, when the data stored in the magnetic disk 103 is a plurality of slice images, the plurality of slice image data stored in advance is read onto the memory 102 to construct three-dimensional volume data.

(Step 402)
In step 402, based on an input command from the user, the CPU 101 uses a first projection image generation unit that generates a first projection image from a first direction with respect to the three-dimensional volume data as a projection image in a reference direction. Project and create and display on UI. More specifically, as shown in FIG. 5, with three orthogonal directions (AX direction, COR direction, and SAG direction) as reference directions, a projection image of 3D volume data is generated and displayed for each of those directions. . As shown in FIG. 5, each reference direction projection image is divided into four divided areas on the display 104 (more specifically, the AX direction projection image is the lower left, the COR direction projection image is the upper left, and the SAG direction. The projected images are displayed in the upper right).

(Step 403)
In step 403, a second projection image is generated for the three-dimensional volume data on the first projection image with a desired projection direction for the projection image to be displayed in the lower right divided region by the user. The second direction is set by an input means for inputting as an index. More specifically, a direction (one of indices) for generating a projection image in a desired direction is set by inputting a vector (arrow) on a projection image in three orthogonal directions. For example, as shown in FIG. 5, a desired projection direction is set by changing the angle of a vector 501 displayed on a projection image in three orthogonal directions via the input device 105, respectively. Then, the CPU 101 generates the second projection image based on the index, using the desired fourth image as the projection direction of the projection image to be displayed at the lower right of the divided region, with the direction in which the three vectors are combined. It is generated by the second projection image generation means. In addition, the display 104 displays the first projection image and the second projection image, and the display unit displays the first projection image and the desired projection direction that is the second projection image in the three orthogonal directions as the first projection image. The projected image from is displayed.

(Step 404)
In step 404, the projection center desired by the user is set. The projection center is a coordinate serving as a center when a partial region of the subject is projected by clipping. For example, as shown in FIG. 5, the desired projection center 502 is set by moving the vectors 501 displayed on the projection image in the reference direction via the input device 105, respectively. Specifically, the CPU 101 sets the coordinates of the centers of the three vectors (shown by x) as a desired projection center. That is, the index includes position information in the three-dimensional volume data, and the second projection image is generated with the position information as a projection center.

(Step 405)
In step 405, the CPU 101 projects three-dimensional volume data with the desired projection direction and projection center input in steps 403 and 404 to generate a projection image. For example, as shown in FIG. 5, the generated projection image is displayed in the remaining one area at the lower right of the four-divided area on the display 104, and the position on the subject indicated by the center of the vector is the remaining area. It is the center in one area. That is, the display means displays the second projection image such that the position serving as the projection center is the center of the area where the second projection image is displayed on the screen.

  The relationship between the vector displayed on the projection image in the three orthogonal directions and the three-dimensional vector as the actual projection direction will be described with reference to FIGS. 6 (a) and 6 (b). However, FIG. 6 (a) is an example of vector arrangement in FIG. 5, and FIG. 6 (b) is an example of vector arrangement different from FIG. 6 (a). According to FIG. 6 (a) and FIG. 6 (b), the vector 601 displayed on the projection image in the three orthogonal directions is a three-dimensional vector 602 indicating the actual projection direction on the projection image in the three orthogonal directions. It is what you represent. When the user operates the vector 601 displayed on the projection image in the three orthogonal directions, the three-dimensional vector 602 indicating the actual projection direction is linked to determine the projection direction.

  However, in the present embodiment, in FIG. 5, the vector in the three-dimensional space is displayed as an arrow or a point on the projection image. However, in the case indicated by the point, the direction of the vector is perpendicular to one of the projection images. Shows the case. However, for simplification, it is not necessary to display the points. Further, the order of step 403 and step 404 may be either.

  According to the above embodiment, when the projection direction is input in order to generate and display a projection image projected in the desired direction on the lower right, the projection center can be input. When a projected image in a desired direction is displayed, the desired position can be displayed in the middle, and the place to be interpreted by the operator can be preferably observed. That is, according to the above embodiment, the input means moves the projection center by moving an arrow on the screen. However, it goes without saying that what is indicated by an arrow does not have a length and may be indicated by only a point as indicating the projection center.

  Next, an embodiment 2 of the image display apparatus and the projection image generation method using the image display apparatus 100 that can be performed by the image display apparatus 100 having the configuration shown in FIGS. 1 and 2 will be described with reference to the flowchart of FIG. 7 and FIG. explain. However, the present embodiment is an embodiment in which the index includes region information (hereinafter referred to as a projection range) for generating the second projection image.

  Hereinafter, the flowchart of FIG. 7 will be described step by step.

  Steps 701 to 703 are the same as steps 401 to 403, and thus description thereof is omitted.

(Step 704)
In step 704, a projection range desired by the user is set. The projection range is a spatial region to be projected when projecting a partial region of the subject by clipping. For example, as shown in FIG. 8, a desired projection range can be obtained by changing the length of a vector 801 displayed on the projection image in the reference direction or the vertical and horizontal lengths of the ROI 802 representing the projection range via the input device 105. Set 802. The CPU 101 sets a region determined by the direction or length of the vector 801 displayed on the projection images in the three reference directions or the vertical and horizontal directions of the ROI 802 as a desired projection range. That is, the display means displays the depth of the area information by the length of the arrow. Alternatively, the display means displays the depth and width of the area information by ROI.

(Step 705)
In step 705, the system projects the 3D image data in the desired projection direction and projection range input in steps 703 and 704 to generate a projection image. The generated projection image is displayed in the remaining one area at the lower right of the four divided areas on the display 104, for example, as shown in FIG.

  In this embodiment, the vector in the three-dimensional space is displayed as an arrow or a point on the projection image in FIG. 8, but the one indicated by the point is one of the projection images in which the vector direction is three orthogonal directions. The vertical case is shown. However, for simplification, it is not necessary to display the points. Also, the order of step 703 and step 704 may be either.

  According to the above embodiment, when the projection direction is input in order to generate and display the projection image projected in the desired direction on the lower right, the projection range (region information for generating the projection image) Therefore, when displaying the projected image in the desired direction, the range can be displayed in the middle, and the place to be interpreted by the operator can be preferably observed. The display means may be configured to move the position of the second projection image on the screen by moving an arrow within the ROI on the screen.

  Next, a third embodiment of the image display device and the projection image generation method using the image display device that can be performed by the image display device 100 having the configuration shown in FIGS. 1 and 2 will be described with reference to FIG.

  The present embodiment is different from the second embodiment in a method for displaying a projection range on a projected image in the reference direction in step 704. More specifically, for example, as a display example of the projection range, as shown in FIG. 9 (a), the depth of the projection range having a three-dimensional volume is displayed by expressing the thickness on the projection image with shading. . For example, the length of the vector 901 displayed on the COR direction projection image designates the projection area 902, and the thickness of the projection range is expressed by shading on the AX direction projection image as in the projection area 903. Further, as shown in FIG. 9 (b), the projection range is expressed by vertical lines on the four AX direction projection images including the back line and the near line.

According to the present embodiment, there is an advantage that the depth of the projection range can be easily grasped as compared with the second embodiment. The present invention can be variously changed without departing from the gist. For example, in Examples 1 and 2, the reference first projection image has three images in three orthogonal directions (AX direction, COR direction, and SAG direction), but at least one image in one arbitrary direction (one image) Needless to say, it may be a projected image. FIG. 10 is an example of this, and shows an example in which only the AX direction projection image is the first projection image (left side). However, the right side of FIG. 10 shows a second projection image.

  501 vector, 502 projection center

Claims (6)

First projection image generation means for generating three first projection images by projecting three-dimensional volume data from three directions of axial, coronal, and sagittal, respectively;
Display means for dividing an image display area into four areas and displaying the three first projection images in the three divided areas;
Second projection image generation means for generating a second projection image as a result of performing projection processing from a desired projection direction on a desired three-dimensional range of the three-dimensional volume data;
In the medical image display device that displays the second projection image in the remaining one divided area of the image display area,
The direction and the range for generating the second projection image are displayed on at least one of the three first projection images displayed by the display means by an arrow and a rectangle, and the screen display of the stereoscopic range A medical image display apparatus, characterized in that the thickness of a region in a vertical direction is displayed in a shade on the first projection image in the rectangle . The display means represents the position of the projection center of the second projection image by the position of the arrow, and when displaying the second projection image, the position of the projection center is the center of the remaining one divided area. The medical image display apparatus according to claim 1, wherein the second projection image is displayed. The medical image display apparatus according to claim 1, wherein the display unit displays the depth of the three-dimensional range with the length of the arrow. The medical image display apparatus according to claim 1, wherein the display unit displays a depth and a width of the stereoscopic range in a rectangular shape. The medical image display apparatus according to claim 2, further comprising an input unit configured to move the position of the projection center by moving the arrow on the image display area. The medical image display apparatus according to claim 4, wherein the display unit moves the position of the second projection image on the remaining one divided region by moving an arrow within the rectangle. .

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