JPH10201755A - Method for measuring three-dimensional size in pseudo-three-dimensional image and its system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate an ease of calculating the distances, areas and volumes for an optional region on an image by using the image depth information for points, lines or regions optionally specified on a pseudo-three-dimensional image reformed to determine the surface positions on the pseudo-three-dimensional image and to measure the three-dimensional coordinates values. SOLUTION: The CPU 14 reforms a pseudo-three-dimensional image, saves the depth information both into a magnetic disc 12 and the main memory 13. Using the depth information, the CPU 14 then calculates the surface positions on the pseudo-three-dimensional image. Further, the main memory 13, the CPU 14 and the display memory 15 use the surface positions to measure all the three-dimensional coordinates values to display then both the pseudo-three- dimensional image and the measurement results onto the CRT 16 that displays the changes in the images depth information for points, lines or regions optionally specified on the pseudo-three-dimensional image then displayed on the screen, in terms of an intensity of depth-directional reflection light or concentration value at each pixel dot of the tomogram as depth information, as well as in terms of a graph.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of stacking a plurality of tomographic images of a target part of a subject by a medical image diagnostic apparatus such as an X-ray CT apparatus, an MRI apparatus, and an ultrasonic diagnostic apparatus to form a three-dimensional image. Then, a viewpoint is set for the stacked 3D image, and the stacked 3D image is shaded and projected on the projection surface from the viewpoint position using a volume rendering method to reconstruct a pseudo 3D image. The present invention relates to a method and apparatus for measuring a three-dimensional amount in a pseudo three-dimensional image that can determine a surface position of the image using depth information of the image and measure a three-dimensional coordinate amount.

[0002]

2. Description of the Related Art A pseudo three-dimensional image is obtained by, for example, stacking a plurality of tomographic images of a target portion of a subject with an X-ray CT apparatus to obtain a three-dimensional image, and shading the stacked three-dimensional image on a projection plane. It is projected and reconstructed, and is used to support surgery and treatment planning. The projection method for shading and projecting on the projection plane includes a parallel projection method and a central projection method. Further, as a shading algorithm for projecting a distant object to be small and a close object to be large during projection, there are a surface method, a depth method, a volume rendering method, and the like.

In the surface method, a pixel value of a projection point is given by the magnitude of a pixel value around a pixel of a stacked three-dimensional image (that is, the magnitude of an inclination). In the depth method, a distance R between a pixel position on a stacked three-dimensional image and a projection point on the projection plane from the pixel position (in the central projection method, the distance R is defined as a viewpoint and a projection target point on the tomographic plane). The distance R is larger, the larger the distance R, the smaller the pixel value at the projection point, and the smaller the distance R, the larger the pixel value at the projection point. Furthermore, the volume rendering method considers the opacity of each tomographic image viewed in the depth direction, and calculates the pixel value of the projection point that can be assumed to have been reflected using reflection and transmission based on the opacity. As given.

[0004] In the above, the parallel projection method is suitable for observing an external cut shape, but the center projection method is suitable for obtaining a projection image simulating endoscopic movement. In order to clearly depict the surface shape, a surface method or a depth method is suitable as a shading algorithm, and a volume rendering method is suitable for performing translucent display.

[0005]

However, in a pseudo three-dimensional image obtained by such a conventional method, a reconstructed image using a surface method or a depth method as a shading algorithm has a clear surface. It has position information and can calculate the distance, area, and volume for any specified area on the image, but about the image reconstructed using the volume rendering method as a shading algorithm Has no clear surface position information and cannot determine the surface position, making it difficult to arbitrarily designate a point, line, or area on an image. Therefore,
It has been difficult to calculate the distance, area, and volume for an arbitrary region on an image.

Accordingly, the present invention addresses such a problem and determines the surface position of an image on a pseudo three-dimensional image projected by shading using a volume rendering method, using depth information of the image. It is another object of the present invention to provide a method and an apparatus for measuring a three-dimensional amount in a pseudo three-dimensional image which can measure a three-dimensional coordinate amount.

[0007]

In order to achieve the above object, a method for measuring a three-dimensional amount in a pseudo three-dimensional image according to the first aspect of the present invention provides a method for reconstructing a pseudo three-dimensional image for a target portion of a subject. In advance, depth information that is a condition for determining a surface position in the reconstructed pseudo three-dimensional image is set in advance, and a plurality of tomographic images captured of the target part of the subject are stacked to obtain a three-dimensional image. A certain viewpoint is set for the stacked 3D image, and from the viewpoint position, the stacked 3D image is shaded and projected on a projection surface using a volume rendering method, and a pseudo 3D image is reconstructed. An arbitrary point, line, or area is specified on the pseudo three-dimensional image, and the surface position on the pseudo three-dimensional image is determined using the depth information of the image with respect to the specified point, line, or area. And measures the three-dimensional coordinates quantities using the surface position.

In the method for measuring a three-dimensional amount in a pseudo three-dimensional image according to the second invention, a plurality of tomographic images taken of a target part of a subject are stacked to obtain a three-dimensional image. A viewpoint is set, and from the viewpoint position, the stacked 3D image is shaded and projected on a projection surface using a volume rendering method to reconstruct a pseudo 3D image, and an arbitrary image is formed on the reconstructed pseudo 3D image. A point, a line or a region is designated, depth information of an image for the designated point, line or region is calculated and displayed, and depth information serving as a condition for determining a surface position is calculated using the displayed depth information. Set, determine the surface position on the pseudo three-dimensional image using the depth information of the image with respect to the specified point, line or area, and measure the three-dimensional coordinate amount using this surface position Than it is.

In the first and second inventions, as the depth information of the image, the reflected light intensity or density value or opacity in the depth direction at each pixel point of the tomographic image is used, or the reflected light intensity or density is used. A differential value, an integral value, or an average value of the value and the opacity in the depth direction may be used.

In the first and second inventions, the surface position on the pseudo three-dimensional image is determined using the depth information of the image, when a plurality of arbitrarily designated points are present, Determined using depth information between points,
In the case of an area surrounded by a plurality of points, the area may be determined using depth information between a plurality of points surrounding the area.

Further, in the first and second inventions, the three-dimensional coordinate amount is measured using the determined surface position, and the distance between two points on the determined surface is determined. In this case, the distance may be obtained by a three-dimensional coordinate linear distance between the two points, or the three-dimensional coordinate shortest distance along the surface between the two points.

Further, in the first and second inventions, the three-dimensional coordinate amount is measured using the determined surface position in the area surrounded by a plurality of points on the determined surface. When the area or the volume of is determined, the area or the volume in three-dimensional coordinates may be obtained along the surface surrounded by the plurality of points.

A three-dimensional image measuring apparatus for a pseudo three-dimensional image according to a related invention accumulates a plurality of tomographic images taken of a target portion of a subject to obtain a three-dimensional image. Means for setting a viewpoint, shading and projecting the stacked 3D image on the projection surface from the viewpoint position using a volume rendering method to reconstruct a pseudo 3D image, and a surface in the reconstructed pseudo 3D image. Storage means for storing depth information serving as a position determination condition; and arbitrarily specifying a point, line or area on the reconstructed pseudo three-dimensional image, and depth information of the image with respect to the specified point, line or area. Means for calculating the surface position on the pseudo three-dimensional image using the method, means for measuring a three-dimensional coordinate amount using the obtained surface position, Those comprising a display means for displaying the measurement result.

The display means displays the change of the depth information of the image with respect to an arbitrarily designated point, line or area in a graph, and uses the displayed depth information to display a pseudo three-dimensional image. The calculation of the surface position may be possible.

Further, the display means displays the change of the depth information of the image with respect to an arbitrarily designated point, line or area in a graph, and, as the depth information, the reflected light in the depth direction at each pixel point of the tomographic image. The intensity, density value, opacity, or the differential value, integral value, average value, or the like of the reflected light intensity, density value, or opacity in the depth direction may be switched and displayed.

[0016]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a flowchart showing a procedure of a method for measuring a three-dimensional amount in a pseudo three-dimensional image according to the first invention. In the three-dimensional quantity measuring method according to the first invention, depth information serving as a condition for determining a surface position on the pseudo three-dimensional image is set in advance before reconstructing the pseudo three-dimensional image. First, as a prerequisite, for example, a plurality of tomographic images (X-ray CT images) are taken of a target site of a subject, for example, a certain luminal organ by an X-ray CT apparatus, and these tomographic images are stacked and stacked to form a three-dimensional image. Is obtained. In this state, a viewpoint position for reconstructing a pseudo three-dimensional image with respect to the stacked three-dimensional image is set (step in FIG. 1). This viewpoint position is, for example, the viewpoint at infinity in the parallel projection method or the viewpoint in the central projection method.

Next, depth information serving as a condition for determining a surface position is set in a pseudo three-dimensional image reconstructed in a later step (step). Here, as the depth information of the image, for example, the reflected light intensity in the depth direction at each pixel point of the tomographic image may be used. Specifically, the reflected light intensity calculated from the CT value of the X-ray CT image may be used. The depth information is not limited to the above-described reflected light intensity, but may be a density value or opacity in the depth direction at each pixel point of the tomographic image, or may be a depth direction of the reflected light intensity or density value or opacity. May be used as a differential value, an integral value, or an average value with respect to the change in.

Thereafter, a pseudo three-dimensional image is reconstructed (step). That is, a plurality of tomographic images taken of a target part of the subject are stacked to obtain a three-dimensional image, a viewpoint is set for the stacked three-dimensional image, and the stacked three-dimensional image is projected on the projection plane from the viewpoint position. A pseudo three-dimensional image is reconstructed by shading and projecting using a volume rendering method. At this time, as shown in FIG. 2, the reconstructed pseudo three-dimensional image 3 is displayed on the image display unit 2 set on the screen of the display device 1. Note that, in addition to the image display unit 2, a display panel unit 4 that displays depth information in a graph or the like is set on the screen, and a measurement method for measuring a three-dimensional amount described below and a start of measurement are specified. An operation panel unit 5 in which a switch for switching the displayed depth information is arranged is set.

Next, the reconstructed pseudo three-dimensional image 3
An arbitrary point, line, or area is designated on the screen (step).
That is, the pseudo three-dimensional image 3 displayed on the image display unit 2 of the display device 1 shown in FIG. 2 is input to the pseudo three-dimensional image 3 by using an input device such as a mouse, a trackball, and an electronic pen (not shown) as shown in FIG. , A point 6, a line 7, 8 or an area 9 is designated. The line 7 is a line connecting the two designated points with a straight line, and the line 8 is a line connecting the two designated points with a curve. An area 9 shows the inside of a range in which a plurality of designated points are connected by a straight line or a curve. FIG. 4 shows a pseudo three-dimensional image 3 in the depth direction of a certain blood vessel at a certain target site, which is viewed from an arbitrary tomographic plane.

Next, the surface position on the pseudo three-dimensional image 3 is determined using the depth information of the image with respect to the specified point 6, line 7, 8 or region 9 (step). At this time, as shown in FIG. 3, the display panel unit 4 of the display device 1 includes depth information set in advance in the above-described steps and depth information related to the point 6, the line 7, 8 or the area 9 specified in the steps. Graph 10 shows the horizontal axis as depth (Depth)
The vertical axis is displayed as depth information such as reflected light intensity (Intensity) calculated from the CT value of the image. The depth information at point 6 shown in FIG. 4 and the depth information about all points or a plurality of points on the lines 7 and 8 are further added to the area 9.
For, depth information on all points or a plurality of points surrounding the boundary line or area is displayed.
Therefore, a plurality of depth information graphs 10 are displayed on the display panel unit 4 by the number of designated points 6, lines 7, 8 or regions 9. In this state, the operator uses the input device such as a mouse to operate the display panel unit 4.
By processing the depth information graph 10 and the line 11 set in parallel to the horizontal axis of the depth information, or inputting a numerical value using a keyboard (not shown) to define the depth as a surface position. The information is determined, and the surface position on the pseudo three-dimensional image 3 is determined.

Thereafter, a three-dimensional coordinate amount is measured using the determined surface position (step). The three-dimensional coordinate amount is a distance, an area, a volume, or the like at a surface position on the pseudo three-dimensional image 3 shown in FIG. For example, when calculating the distance between two points on the surface determined as described above, the distance is calculated based on the linear distance in three-dimensional coordinates between the two points (for example, the length of the straight line 7 shown in FIG. 4). Or the shortest distance in three-dimensional coordinates along the surface between the two points (for example, the length of the curve 8 shown in FIG. 4). When the area or volume of a region surrounded by a plurality of points on the surface determined as described above is determined, the area or volume in three-dimensional coordinates along the surface surrounded by the plurality of points (for example, The area or volume of a portion surrounded by the region 9 shown in FIG.

[0022] Thus, a three-dimensional image that has been stacked up from the set viewpoint position is shaded and projected on the projection surface by using a volume rendering method, and a pseudo three-dimensional image is reconstructed. In addition to determining the surface position of the image, a three-dimensional coordinate amount can be measured.

FIG. 5 is a flowchart showing a procedure of a method for measuring a three-dimensional amount in a pseudo three-dimensional image according to the second invention. The three-dimensional amount measurement method according to the second aspect of the present invention reconstructs a pseudo three-dimensional image, calculates and obtains depth information that is a condition for determining a surface position on the image, and sets the depth information. is there. First, as a prerequisite, for example, a plurality of tomographic images (X-ray CT images) are taken of a target site of a subject, for example, a certain luminal organ by an X-ray CT apparatus,
It is assumed that these tomographic images are stacked to obtain a stacked three-dimensional image. In this state, a viewpoint position for reconstructing a pseudo three-dimensional image with respect to the stacked three-dimensional image is set (step A in FIG. 5). This viewpoint position is, for example, the viewpoint at infinity in the parallel projection method or the viewpoint in the central projection method.

Thereafter, a pseudo three-dimensional image is reconstructed in the same manner as in the step of FIG. 1 (step B). At this time,
As shown in FIG. 2, the reconstructed pseudo three-dimensional image 3 is displayed on the image display unit 2 set on the screen of the display device 1. Next, a point, a line, or an area is arbitrarily designated on the reconstructed pseudo three-dimensional image 3 in the same manner as in the step of FIG. 1 (step C). That is, the pseudo three-dimensional image 3 displayed on the image display unit 2 of the display device 1 shown in FIG. 2 is input to the pseudo three-dimensional image 3 by using an input device such as a mouse, a trackball, and an electronic pen (not shown) as shown in FIG. , A point 6, a line 7, 8 or an area 9 is designated. Next, the depth information of the image with respect to the designated point 6, line 7, 8 or area 9 is calculated and displayed (step D). The calculated depth information is displayed on the display panel unit 4 of the display device 1 shown in FIG.

Next, in the same manner as in the step of FIG. 1, depth information serving as a condition for determining a surface position in the reconstructed pseudo three-dimensional image is set (step E). Here, as the depth information of the image, for example, the reflected light intensity in the depth direction at each pixel point of the tomographic image may be used. Specifically, the reflected light intensity calculated from the CT value of the X-ray CT image may be used. The depth information is not limited to the above-described reflected light intensity, but may be a density value or opacity in the depth direction at each pixel point of the tomographic image, or may be a depth direction of the reflected light intensity or density value or opacity. May be used as a differential value, an integral value, or an average value with respect to the change in.

Next, in the same manner as in the step of FIG. 1, the surface position on the pseudo three-dimensional image 3 is determined using the depth information of the image with respect to the specified point 6, line 7, 8 or region 9 (FIG. Step F). At this time, as shown in FIG.
The display panel unit 4 of the display device 1 includes the depth information set in the above step E, the point 6 specified in the step C,
Graph 10 of depth information for lines 7, 8 or area 9
Are displayed as depth information such as reflected light intensity (Intensity) calculated from the CT value of the image, with the horizontal axis representing depth (Depth). The display panel unit 4 displays a plurality of depth information graphs 10 corresponding to the number of the designated points 6, lines 7, 8 or regions 9. In this state, the operator uses an input device such as a mouse to apply processing to the depth information graph 10 displayed on the display panel unit 4 and the line 11 set in parallel to the horizontal axis, or By inputting a numerical value using a keyboard (not shown), depth information defined as the surface position is determined, and the surface position on the pseudo three-dimensional image 3 is determined.

Thereafter, in the same manner as in the step of FIG.
A three-dimensional coordinate amount is measured using the determined surface position (step G). The three-dimensional coordinate amount is a distance, an area, a volume, or the like at a surface position on the pseudo three-dimensional image 3 shown in FIG. Thus, in the same manner as the first invention shown in FIG. 1, the pseudo three-dimensional image is reconstructed by shading and projecting the stacked three-dimensional image on the projection surface from the set viewpoint position using the volume rendering method. On the image, it is possible to determine the surface position of the image using the depth information of the image and measure the three-dimensional coordinate amount.

In the above description of the first and second aspects of the present invention, a case where an X-ray CT image is used as a tomographic image has been described. However, the present invention is not limited to this, and an MRI image or an ultrasonic image may be used. Can be similarly applied.

Next, a description will be given of a three-dimensional amount measuring apparatus used for carrying out the method for measuring a three-dimensional amount in a pseudo three-dimensional image according to the first or second invention. This three-dimensional quantity measuring device determines the surface position of the image on the pseudo three-dimensional image reconstructed by shading and projection using the volume rendering method, using the depth information of the image, and at the same time determines the three-dimensional coordinate. A plurality of tomographic images taken of a target part of a subject are stacked to obtain a three-dimensional image, a certain viewpoint is set for the stacked three-dimensional image, and the stacked three-dimensional image is set from this viewpoint position. Means for shading and projecting the image on a projection surface using a volume rendering method to reconstruct a pseudo three-dimensional image, and storage means for storing depth information serving as a condition for determining a surface position in the reconstructed pseudo three-dimensional image And arbitrarily designate a point, a line or an area on the reconstructed pseudo three-dimensional image, and designate the designated point;
Means for calculating the surface position on the pseudo three-dimensional image using the depth information of the image for the line or region, and means for measuring a three-dimensional coordinate amount using the obtained surface position,
Display means for displaying the pseudo three-dimensional image and the measurement result.

FIG. 6 is a block diagram showing a specific hardware configuration of the three-dimensional quantity measuring apparatus. That is, a magnetic disk 12 storing a plurality of tomographic images and image reconstruction programs and the like, a main memory 13 storing a control program of the apparatus, a central processing unit (CPU) 14 controlling the operation of each component, and A display memory 15 for storing the reconstructed image data for display,
CRT for displaying image data from the display memory 15
16, a keyboard 17 for inputting various operation commands,
It has a mouse 18 as a position input device, a controller 19 for controlling the mouse 18, and a common bus 20 for connecting the above-mentioned components. Then, the CPU 1
4 constitutes means for reconstructing a pseudo three-dimensional image, the magnetic disk 12 and the main memory 13 constitute storage means for storing depth information, and the CPU 14 uses the depth information to generate a surface position on the pseudo three-dimensional image. Constitute means for calculating
The main memory 13, the CPU 14, and the display memory 15
Constitutes means for measuring a three-dimensional coordinate amount using the surface position, and further constitutes display means for displaying the pseudo three-dimensional image and the measurement result on the CRT 16.

The CRT 16 as the display means
Displays a change in depth information of an image with respect to a point, a line, or an area arbitrarily specified on the pseudo three-dimensional image 3 displayed on the screen as a graph 10 as shown in FIGS. The surface position on the pseudo three-dimensional image 3 can be calculated using the displayed depth information.

Also, a CRT 16 as the display means is provided.
As shown in FIGS. 2 and 3, a change in depth information of an image with respect to a point, a line, or a region arbitrarily specified on the pseudo three-dimensional image 3 displayed on the screen is displayed in a graph 10, As the depth information, reflected light intensity or density value in the depth direction at each pixel point of the tomographic image, opacity,
Alternatively, the display can be performed by switching a differential value, an integral value, an average value, or the like with respect to a change in the depth direction of the reflected light intensity, the density value, or the opacity.

Thus, by using the apparatus for measuring a three-dimensional quantity of a pseudo three-dimensional image according to the present invention, a three-dimensional image stacked and projected from a set viewpoint position is projected on a projection plane by shading using a volume rendering method. On the reconstructed pseudo three-dimensional image, the surface position of the image can be determined using the depth information of the image, and the three-dimensional coordinate amount can be measured.

In the above three-dimensional quantity measuring apparatus, the same applies to X-ray CT images, MRI images, and ultrasonic images as tomographic images.

[0035]

The present invention has been configured as described above.
According to the first aspect, prior to reconstructing a pseudo three-dimensional image for a target portion of a subject, depth information serving as a condition for determining a surface position in the reconstructed pseudo three-dimensional image is set in advance. A plurality of tomographic images taken of a target site of the subject are stacked to obtain a three-dimensional image, a viewpoint is set for the stacked three-dimensional image, and the volume of the stacked three-dimensional image is projected onto the projection plane from this viewpoint position. Reshape a pseudo three-dimensional image by shading and projecting using a rendering method, and arbitrarily specify a point, line, or area on the reconstructed pseudo three-dimensional image, and specify the specified point, line, or area. By determining the surface position on the pseudo three-dimensional image using the image depth information with respect to, and measuring the three-dimensional coordinate amount using this surface position, the depth information of the preset image is obtained. There are, on the pseudo-three-dimensional image reconstructed with determining the surface position of the image can be measured three-dimensional coordinates quantities. Therefore, the surface position can be determined with clear surface position information, and a point, line, or area can be easily specified on the image, and the distance or the distance to an arbitrary area on the image can be easily determined. Area and volume can be easily calculated.

According to the second aspect of the present invention, a plurality of tomographic images taken of a target portion of the subject are stacked to obtain a three-dimensional image, a certain viewpoint is set for the stacked three-dimensional image, and a certain viewpoint is set from this viewpoint position. The stacked 3D image is shaded and projected on the projection surface by using a volume rendering method to reconstruct a pseudo 3D image, and arbitrarily designate a point, a line, or an area on the reconstructed pseudo 3D image. Calculates and displays depth information of the image for the specified point, line or region, sets depth information that is a condition for determining the surface position using the displayed depth information, and sets the specified point, The surface position on the pseudo three-dimensional image was determined using the depth information of the image with respect to the line or the area, and the pseudo three-dimensional image was reconstructed by measuring the three-dimensional coordinate amount using this surface position. Then, depth information serving as a condition for determining the surface position on the image is calculated and obtained, and the surface position of the image is determined on the reconstructed pseudo three-dimensional image using the depth information of the set image. In addition, a three-dimensional coordinate amount can be measured. Therefore, similarly to the first invention, it is possible to easily calculate the distance, the area, and the volume for an arbitrary region on the image.

Further, according to the three-dimensional quantity measuring apparatus of the present invention, a plurality of tomographic images taken of a target part of the subject are stacked to obtain a three-dimensional image, and a certain viewpoint is set for the stacked three-dimensional image. Means for reconstructing a pseudo three-dimensional image by shading and projecting the stacked three-dimensional image on the projection surface from the viewpoint position using a volume rendering method,
A storage unit for storing depth information serving as a condition for determining a surface position in the reconstructed pseudo three-dimensional image; and arbitrarily specifying a point, line, or area on the reconstructed pseudo three-dimensional image, and Means for calculating the surface position on the pseudo three-dimensional image using the depth information of the image for the point, line or region, means for measuring the three-dimensional coordinate amount using the obtained surface position, The provision of the display means for displaying the pseudo three-dimensional image and the measurement result makes it possible to easily implement the three-dimensional quantity measurement method according to the first or second invention.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a procedure of a method for measuring a three-dimensional amount in a pseudo three-dimensional image according to the first invention.

FIG. 2 is an explanatory diagram illustrating states of an image display unit, a display panel unit, and an operation panel unit set on a screen of a display device.

FIG. 3 is an explanatory diagram showing a graph of depth information of an image displayed on a display panel set on a screen of the display device.

FIG. 4 points required for determining depth information of an image,
FIG. 9 is an explanatory diagram illustrating a method of specifying a line or an area.

FIG. 5 is a flowchart showing a procedure of a method for measuring a three-dimensional amount in a pseudo three-dimensional image according to the second invention.

FIG. 6 is a block diagram showing a specific hardware configuration of a device for measuring a three-dimensional quantity in a pseudo three-dimensional image according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Display apparatus 2 ... Image display part 3 ... Pseudo three-dimensional image 4 ... Display panel part 5 ... Operation panel part 6 ... Specified point 7, 8 ... Specified line 9 ... Specified area 10 ... Graph of image depth information DESCRIPTION OF SYMBOLS 12 ... Magnetic disk 13 ... Main memory 14 ... CPU 15 ... Display memory 16 ... CRT 17 ... Keyboard 18 ... Mouse 19 ... Controller

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Takagi 1-1-1 Uchikanda, Chiyoda-ku, Tokyo Inside Hitachi Medical Corporation

Claims (9)

[Claims] 1. Prior to reconstructing a pseudo three-dimensional image of a target part of a subject, depth information serving as a condition for determining a surface position in the reconstructed pseudo three-dimensional image is set in advance. A plurality of tomographic images taken of a target part of the subject are stacked to obtain a three-dimensional image, a viewpoint is set for the stacked three-dimensional image, and the stacked three-dimensional image is subjected to a volume rendering method on the projection plane from this viewpoint position. Reconstructing a pseudo three-dimensional image by shading and projecting using it, designating a point, line or region arbitrarily on this reconstructed pseudo three-dimensional image, and reconstructing an image for the designated point, line or region. A method of measuring a three-dimensional amount in a pseudo three-dimensional image, wherein a surface position on a pseudo three-dimensional image is determined using depth information, and a three-dimensional coordinate amount is measured using the surface position. Law. 2. A three-dimensional image is obtained by stacking a plurality of tomographic images photographed for a target portion of a subject, a viewpoint is set for the stacked three-dimensional image, and the stacked three-dimensional image is projected from the viewpoint position. Reconstruct a pseudo 3D image by shading and projecting using a volume rendering method, and arbitrarily designate a point, line or area on the reconstructed pseudo 3D image, and specify the designated point, line Alternatively, the depth information of the image for the region is calculated and displayed, and the depth information serving as the condition for determining the surface position is set using the displayed depth information, and the depth information of the image for the specified point, line, or region is set. A method for measuring a three-dimensional amount in a pseudo three-dimensional image, comprising determining a surface position on a pseudo three-dimensional image by using, and measuring a three-dimensional coordinate amount using the surface position. 3. As the depth information of the image, reflected light intensity, density value, or opacity in the depth direction at each pixel point of the tomographic image is used, or the reflected light intensity, density value, or opacity in the depth direction is used. 3. The method according to claim 1, wherein a differential value, an integrated value, or an average value for the change is used. 4. The method of determining a surface position on a pseudo three-dimensional image using the depth information of the image, when a plurality of arbitrarily designated points are present, is determined by using depth information between the plurality of points. 3. The method according to claim 1, wherein, in the case of a region surrounded by a plurality of points, the determination is performed using depth information between the plurality of points surrounding the region. . 5. The method of measuring a three-dimensional coordinate amount using the determined surface position is performed when a distance between two points on the determined surface is determined. The three-dimensional quantity in the pseudo three-dimensional image according to claim 1 or 2, wherein the three-dimensional quantity is determined by a three-dimensional coordinate linear distance or a three-dimensional minimum distance along the surface between the two points. Measurement method. 6. The method of measuring a three-dimensional coordinate amount using the determined surface position is to calculate the area or volume of a region surrounded by a plurality of points on the determined surface.
3. The method of measuring a three-dimensional quantity in a pseudo three-dimensional image according to claim 1 or 2, wherein the three-dimensional quantity is determined by a three-dimensional coordinate area or volume along a surface surrounded by the plurality of points. 7. A three-dimensional image is obtained by stacking a plurality of tomographic images photographed on a target portion of a subject, a viewpoint is set for the stacked three-dimensional image, and the stacked three-dimensional image is projected from the viewpoint position. Means for shading and projecting using a volume rendering method to reconstruct a pseudo three-dimensional image, storage means for storing depth information serving as a condition for determining a surface position in the reconstructed pseudo three-dimensional image, Means for arbitrarily specifying a point, line, or area on the reconstructed pseudo three-dimensional image, and calculating a surface position on the pseudo three-dimensional image using depth information of the image with respect to the specified point, line, or area; Means for measuring a three-dimensional coordinate amount using the obtained surface position, and display means for displaying the pseudo three-dimensional image and the measurement result. 3D quantity measurement device for 3D images. 8. The method according to claim 1, wherein the display means includes a designated point,
8. The method according to claim 7, wherein a change in the depth information of the image with respect to the line or the area is displayed as a graph, and the surface position on the pseudo three-dimensional image can be calculated using the displayed depth information. Three-dimensional quantity measurement device for pseudo three-dimensional images. 9. The display device according to claim 8, wherein the display means comprises:
Along with displaying the change in the depth information of the image with respect to the line or the area in a graph, the reflected light intensity or density value in the depth direction at each pixel point of the tomographic image as the depth information, the opacity, or the reflected light intensity or density value, 9. The three-dimensional quantity measurement device for pseudo three-dimensional images according to claim 8, wherein a differential value, an integral value, an average value, or the like with respect to a change in the opacity in the depth direction can be switched and displayed.