JP4430142B2 - Medical image processing apparatus and medical image processing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a medical image processing apparatus and a medical image processing method for processing medical image data obtained by a medical image capturing apparatus such as an X-ray CT apparatus.
[0002]
[Prior art]
If an image of a large number of adjacent slice planes is captured with an X-ray CT apparatus or the like, the image data is collected three-dimensionally. However, if images of a large number of slice planes are simply displayed in parallel, It is usually difficult to intuitively grasp the three-dimensional structure of a site having an anatomically complex shape. Therefore, conventionally, image processing is performed so that three-dimensional display can be performed.
[0003]
As a three-dimensional display method, an MIP method, a 3D (three-dimensional) method, or the like is employed. In the MIP method, an optical path passing through the imaging volume is set, and the maximum data on the optical path is displayed on a projection plane perpendicular to the optical path. In the 3D method, voxels are binarized into “display” and “non-display” based on a set threshold value, only the boundary surface is extracted, surface rendering is performed, and a three-dimensional image is displayed.
[0004]
[Problems to be solved by the invention]
However, the MIP image does not know the context in the viewing direction, and the 3D image has a problem that it is difficult to set a threshold value. That is, since only the maximum value on the optical path is displayed in the MIP image, the position information on the optical path is inherently lost. In a 3D image, the tissue boundary is determined by a threshold value, so that the image changes if the threshold value is changed, and there is a risk of misjudging the tissue shape.
[0005]
For example, when an image of a blood vessel is obtained using an X-ray CT apparatus, a contrast medium is injected into the blood vessel, and the pixel value (CT value) of the blood vessel portion is increased to make a difference from other tissues. The 3D image of the blood vessel can be created by distinguishing the part from other tissues. However, the CT value in the blood vessel varies due to the partial volume effect or the like, and the CT value tends to be high in the central part of the blood vessel and low in the peripheral part. Therefore, if the threshold value is lowered, the outer edge of the blood vessel is extracted, so that the blood vessel is displayed thicker than it actually is. If the threshold value is increased, the inner edge of the blood vessel is extracted, so the blood vessel is displayed narrowly. Or in extreme cases, the display is interrupted.
[0006]
In view of the above, the present invention provides a medical image processing apparatus and a medical image processing method that are improved so that it is possible to easily confirm whether or not a threshold value of a 3D image is appropriate, so that a diagnosis error does not occur. The purpose is to provide.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, in the medical image processing apparatus according to the present invention, the means for arbitrarily inputting the viewing direction and the above viewing direction from the three-dimensional image data according to the input viewing direction. Means for creating a viewed 3D image, and means for creating a MIP image in the same viewing direction as described above from the same image data as the input viewing direction , and the 3D image and the on the screen and MIP image is displayed, the Rukoto have threshold input box is displayed for entering a threshold value defining a tissue boundary in the 3D image is a feature.
[0008]
When the viewing direction is changed, the 3D image is recreated accordingly, while this change in viewing direction is also reflected in the MIP image, and the MIP image is recreated as having the changed viewing direction. On the screen of the image monitor device, in addition to the 3D image and the MIP image, a threshold value input box for inputting a threshold value for defining a tissue boundary in the 3D image is displayed. Therefore, it is possible to easily confirm whether or not the threshold value of the 3D image is appropriate by comparing the two images with the threshold value input box.
[0009]
The present invention is further characterized in that the 3D image is displayed so as to rotate in accordance with the inputted viewing direction, and the MIP image is also displayed so as to be rotated in synchronization therewith.
[0010]
When the viewing direction is changed, a 3D image is re-created accordingly, and the 3D image is displayed on the screen of the image monitor device so as to rotate according to the change of the viewing direction. On the other hand, this change in viewing direction is also reflected in the MIP image, and the MIP image is re-created as having the changed viewing direction. Therefore, on the screen of the picture display apparatus, a 3D image and MIP image, viewing in accordance with the direction of the change, will be both displayed as continue to rotate in conjunction, various of these two images The threshold value input box for inputting the threshold value for defining the tissue boundary in the 3D image can be viewed and compared while viewing from the direction of the 3D image, and it can be easily confirmed whether or not the threshold value of the 3D image is appropriate.
[0011]
The present invention further includes a 3D image viewed from the viewing direction created from the three-dimensional image data according to the input viewing direction, and the same viewing direction as the above from the same image data. A step of displaying the MIP image on the same screen; and a step of setting a threshold value for defining a tissue boundary in the 3D image while observing the 3D image and the MIP image. .
[0012]
On the screen of the image monitor device, the 3D image recreated according to the input viewing direction and the MIP image recreated according to the same viewing direction as the input are on the same screen. Is displayed. By observing the 3D image and the MIP image and setting a threshold value for defining a tissue boundary in the 3D image, a diagnostically appropriate 3D image can be easily obtained.
[0013]
The invention method described above further includes a step of displaying the 3D image so as to rotate according to the input viewing direction, and displaying the MIP image so as to rotate in synchronization with the 3D image. .
[0014]
Thus, by observing the 3D image and the MIP image that rotate in conjunction with changes in the viewing direction from various directions, a threshold value that determines the tissue boundary in the 3D image is input, thereby providing a 3D image suitable for diagnosis. Images can be easily obtained.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in detail with reference to the drawings. In FIG. 1, the image memory 11 of the image processing apparatus 10 stores image data from a medical image capturing apparatus 20 such as an X-ray CT apparatus. This image data is, for example, CT image data for a large number of adjacent slice planes, and each image is only two-dimensional image data, but is obtained for a large number of adjacent slice planes. Then, it can be called three-dimensional image data. Therefore, a MIP image can be created from the image data by the MIP image creation unit, and a 3D image can be created by the 3D image creation unit 13.
[0016]
The created MIP image and 3D image are stored in the image memory 14 and then transferred to the image monitor device 21 for display. The threshold value for creating the 3D image is set by the threshold value setting unit 16 based on the value input by the input device 22 such as a keyboard or a mouse. The viewing direction setting necessary for creating the MIP image and the 3D image is set by the viewing direction setting unit 15 based on values input by the input device 22 such as a keyboard, a mouse, and a trackball.
[0017]
FIG. 2 shows a display screen 31 of the image monitor device 21. In this display example, two image windows 32 and 33 are displayed on one screen 31, and a 3D image 34 and an MIP image 35 are displayed, respectively. In addition to these windows 32 and 33, a threshold value input box 38 is displayed so that a desired threshold value can be input.
[0018]
In each image window 32, 33, a rotation arrow 36 is displayed at the four corners, and a triangular rotation mark 37 is displayed at the center of the four sides, and these are clicked with a mouse or the like. And the rotation arrow 36 causes the image to rotate in the display plane (that is, in a plane parallel to the display screen 31). When the rotation mark 37 is clicked, it is displayed as if the solid is rotated. When the left and right rotation marks 37 are clicked, the displayed 3D image 34 and the like rotate around the vertical axis, and when the upper and lower rotation marks 37 are clicked, the 3D image 34 and the like rotate around the horizontal axis.
[0019]
That is, when the rotation mark 37 is clicked, this input is given to the viewing direction setting unit 15 and a viewing direction setting command corresponding to the input is sent to the 3D image creation unit 13. The 3D image creation unit 13 creates a 3D image viewed from the viewing direction based on the viewing direction setting command. At the same time, the viewing direction setting command is also given to the MIP image creating unit 12, and the MIP image creating unit 12 creates an MIP image viewed from the viewing direction based on the viewing direction setting command. Thus, when the rotation mark 37 is clicked, the 3D image 34 is displayed so as to rotate three-dimensionally, and the viewing direction of the MIP image 35 is also rotated in synchronization with this (to be precise, the viewing direction is always the screen). The direction on the front side of the displayed image changes).
[0020]
Accordingly, since the 3D image 34 and the MIP image 35 viewed from various directions can be observed, an appropriate threshold value can be set by comparing these. In the example of FIG. 2, it can be clearly seen from a comparison with the MIP image 35 that the narrowed portion (thinned portion) of the blood vessel is interrupted in the 3D image 34 from this viewing direction. That is, since the CT value of the blood vessel is low in the stenosis, it can be seen that it is not displayed with the set threshold value. Thus, by comparing the thickness of the blood vessel between the 3D image and the MIP image, it is possible to determine whether or not the blood vessel is correctly extracted in the 3D image 34. Therefore, in this case, a 3D image (not shown) displayed as if the blood vessels are narrowly connected can be obtained by lowering the threshold value, and it becomes possible to accurately diagnose a narrowed blood vessel without error. .
[0021]
Note that the above description relates to one embodiment, and therefore, the present invention is not limited to the above description. Various changes such as the specific configuration of FIG. 1 and the display of the screen of FIG. 2 can be made.
[0022]
【The invention's effect】
As described above, according to the medical image processing apparatus of the present invention, when the viewing direction of the 3D image is changed , the viewing direction of the MIP image can be changed at the same time , so that the tissue boundary in these 3D image, MIP image, and 3D image The threshold value input box for inputting the threshold value for determining the threshold value can be compared with each other, so that it can be easily confirmed whether or not the threshold value of the 3D image is appropriate. As a result, it is possible to prevent a diagnosis mistake and improve the diagnostic efficiency.
[0023]
Further, according to the medical image processing apparatus of the present invention, when the 3D image viewing direction is changed and displayed so as to rotate, the MIP image viewing direction can also be changed and displayed simultaneously. While viewing the 3D image and the MIP image from various directions, a threshold value input box for inputting a threshold value for defining a tissue boundary in the 3D image can be viewed and compared. It becomes easy to confirm whether it was appropriate. As a result, it is possible to prevent a diagnosis mistake and improve the diagnostic efficiency.
[0024]
Further, according to the medical image processing method of the present invention, the 3D image recreated according to the input viewing direction and the same viewing direction as the input one are displayed on the screen of the image monitor device. The re-created MIP image is displayed on the same screen. While observing the 3D image and the MIP image, it is possible to input a threshold value that defines a tissue boundary in the 3D image, and thus a diagnostically appropriate 3D image can be easily obtained. As a result, it is possible to prevent a diagnosis mistake and improve the diagnostic efficiency.
[0025]
Further, according to the medical image processing method of the present invention, the 3D image is displayed so as to rotate in accordance with the inputted viewing direction, and the MIP image is also displayed so as to be rotated in synchronization with this. By observing 3D images and MIP images that rotate in conjunction with changes in the viewing direction from various directions and inputting a threshold value that defines a tissue boundary in the 3D image, a diagnostically appropriate 3D image can be easily obtained Can get to. As a result, it is possible to prevent a diagnosis mistake and improve the diagnostic efficiency.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of the present invention.
FIG. 2 is a view showing an example of a display screen according to the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Image processing apparatus 11, 14 Image memory 12 MIP image creation part 13 3D image creation part 15 View direction setting part 16 Threshold value setting part 20 Medical image pick-up device 21 Image monitor apparatus 22 Input device 31 Display screen 32, 33 Image window 34 3D image 35 MIP image 36 Rotation arrow 37 Rotation mark 38 Threshold input box

Claims (2)

  Means for arbitrarily inputting a viewing direction; means for creating a 3D image of a blood vessel viewed from the viewing direction from three-dimensional image data according to the inputted viewing direction; and the input viewing direction And a means for creating a MIP image in the same viewing direction as the above from the same image data as described above, and on the image on which the 3D image of the blood vessel and the MIP image are displayed. A threshold value input box for inputting a threshold value for defining a tissue boundary in the 3D image is displayed, and further, the 3D image of the blood vessel is displayed so as to rotate according to the input viewing direction. A medical image processing apparatus, wherein the MIP image is also displayed so as to rotate synchronously. A 3D image of a blood vessel viewed from the viewing direction created from the three-dimensional image data according to the input viewing direction, and a MIP viewed from the same viewing direction created from the same image data as described above step accept and displaying an image on the same screen, a threshold setting to correctly extract the blood vessel defines a tissue border in a 3D image of the blood vessel while observing the said MIP image and a 3D image of the blood vessel And a step of displaying the 3D image of the blood vessel so as to rotate according to the input viewing direction, and displaying the MIP image so as to rotate in synchronization therewith. Processing method.

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