JPH01135339A - Three-dimensional image diagnostic apparatus - Google Patents

Abstract

PURPOSE:To perform fluoroscopic display and to enhance diagnostic capacity, by forming shadow value image data from three-dimensional image data and constituting a three-dimensional fluoroscopic image on the basis of said shadow value image data and the positional relation between an outside region and an inside region. CONSTITUTION:A three-dimensional image forming means 2 loads the multistylus image data of an object to be examined and forms each three-dimensional image data of the outside region and inside region of the objective region of the subject. A shadow value image forming means 3 loads each three- dimensional image data to form shadow value image data. A position discrimination means 4 discriminates the positional relation between the outside region and the inside region and a fluoroscopic image constituting means 5 constitutes a three-dimensional fluoroscopic image from said discrimination result and the shadow value image data to display the same on a display means.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to a three-dimensional image diagnostic apparatus, and more particularly, to a three-dimensional image capable of three-dimensional transparent display of a target part of a subject. This invention relates to diagnostic equipment.

(Prior art) Generally, CT (Computed Tomograph)
In a two-dimensional image of a target part of a subject obtained by a hy) apparatus, a magnetic resonance diagnostic apparatus (MRI), or the like, it is difficult to understand, for example, the three-dimensional relationship of organs as the target part.

For this reason, techniques for three-dimensional display of diagnostic images using computer graphics have been attempted in the past.

There are a patch method and a voxel method as methods for such three-dimensional display, and a comparison of these two methods is shown in FIG.

Among the various characteristics of these two methods, focusing on the perspective display of the target area or the semi-fluoroscopic surface water point, in the patch method, organs located inside the target area, such as the ventricles of the brain, are displayed using the surf ace method, and the outside By displaying the brain surface located in the frame using the frame method, it is possible to easily observe the inner ventricle through the outer brain surface.

On the other hand, although the voxel method has other characteristics such as higher display accuracy and suitability for high-speed processing than the patch method, it requires a special algorithm to perform perspective display like the patch method, and as a result, the voxel method For example, when applied to surgical planning for extracranial nerves, it is extremely inconvenient because it is not possible to see through the ventricles from the outer brain surface.

The reason why perspective display of three-dimensional images using the voxel method is not possible is because the voxel method uses threshold processing for multi-slice (continuous tomography) images of the target area to extract and display only the outer boundary surface. This is because each pixel component inside the boundary surface is not targeted for display (only the boundary surface visible from the outside is targeted for processing).

(Problems to be Solved by the Invention) As mentioned above, in the conventional three-dimensional image diagnostic apparatus using the voxel method, it is difficult to transparently display the target part of the subject, and as a result, the diagnostic performance is reduced. There was a problem.

Therefore, an object of the present invention is to provide a three-dimensional image diagnosis vIrT apparatus that employs the voxel method and is capable of transparently displaying a target region, thereby contributing to improving diagnostic performance.

[Structure of the Invention] (Means for Solving the Problems) The three-dimensional image diagnostic apparatus of the present invention takes in multi-slice image information of a subject and generates three-dimensional images of an outer region and an inner region of the target region. A three-dimensional image creating means for creating information using a voxel method, and a shading value image creating means for creating each shading value image information reflecting the direction of light for each of the three-dimensional image information of the outer region and the inner region. means, a position determining means for determining the positional relationship between the two parts, and a light capable of capturing the respective shade value image information and allowing the outer part to be seen through and the inner part to be visually recognized based on the determination result of the position determining means. and a perspective image forming means for forming a three-dimensional perspective image having a transmittance of .

(for production) Next, the operation of the device having the above configuration will be explained.

The three-dimensional image creation means of this apparatus takes in multi-slice image information of the subject and creates three-dimensional image information of an outer region and an inner region of the target region of the subject.

The shade value image creation means takes in each three-dimensional image information of the two parts, and creates shade value image information each of which reflects the direction of light.

On the other hand, the position determining means determines the positional relationship between the two parts and sends the determination result to the fluoroscopic image composing means.

The fluoroscopic image composition means takes in the shading value image information of both the parts, and based on the determination result of the position determination means, creates a three-dimensional image having a light transmittance that allows the outer part to be seen through and the inner part to be visually recognized. A perspective image is constructed and displayed.

(Example) The present invention will be explained in detail below.

The three-dimensional image diagnosis apparatus 1 shown in FIG. ) and medial site PI (for example, a ventricle containing a brain tumor).
The three-dimensional image information of P1. A shading value image creating means 3 that creates shading value image information corresponding to P2; A position determining means 4 that determines the positional relationship of P2, that is, whether the outer region P2 is in front of the inner region P1 or vice versa; A fluoroscopic image composing means 5 constitutes a three-dimensional fluoroscopic image of the target region having a light transmittance that allows the inner region P1 to be visually recognized through the outer region P2 based on the discrimination result, and the fluoroscopic image composing means 5 A display means 6 such as a CRT that displays a three-dimensional perspective image, a program memory 7 that stores an operation program for controlling the operation of this device, and a CPU that controls the entire device based on the operation program. The device includes a storage section 9 that stores the results of various information processing executed in each of the above-mentioned elements in this device.

The three-dimensional image creation means 2 includes a first contour extraction unit 10 that extracts the contour of an outer region P2 of the target region using the voxel method based on multi-slice image information, and a first contour extraction unit 10 that extracts the contour of the outer region P2 of the target region based on multi-slice image information; The second contour extracting unit 11 extracts the contour of the image using the voxel method.

Both parts P created by this three-dimensional image creation means 2
A three-dimensional image corresponding to the three-dimensional image information of 1 and P2 is shown in FIG. In other words, when this three-dimensional image is defined in the three-dimensional space with x, y, and z coordinate axes as shown in the figure,
For example, the three-dimensional image of the outer part P2 looks like a shell, and the three-dimensional image of the inner part P1 looks like the yolk of an egg.

The position determining means 4 determines the outer region P2 and the inner region P1 based on the two 3D image data corresponding to the 3D image as shown in FIG. 2 created by the 3D image creation means 2. a depth image creation section 12 that creates depth image information corresponding to a two-dimensional depth image representing the positional relationship between the two; The depth value comparison section 13 compares the degree of depth of parts Pi and P2.

That is, if the depth image is defined as the image projected and displayed on the two-dimensional image display @Q when the three-dimensional image is viewed from a certain direction as shown in FIG.
Each pixel value of the depth image displayed represents the degree of depth from the image display surface Q to the outer region P2 and the inner region P1, that is, the depth value. In this case, the depth value of a portion close to the image display surface Q is small, and the depth value of a portion farther away is large.

Here, each pixel value of the inner region P1 in the depth image is calculated using the following equation (1), and each pixel value of the outer region P2 is calculated using the following equation (1).
2) It shall be given by Eq.

Zl+1 = (zT, zT, ++, Z+:
) , , , , zH)...(1) Z ″= (Zt7J , 212) , ++*,
Z? , *t+, zz')...(2) The depth value comparison unit 13 compares each pixel value shown in the above-mentioned (1) (21), and determines the positional relationship between the two parts P1 and P2. , that is, the inner part P1 with respect to the image display surface Q
is in the front, or whether the outer part P2 is in the front.

The shading value image creating means 3 includes the depth image creating section 12
A predetermined light source direction is defined for the depth image corresponding to the depth image information created by For 21, the following (31, (shading value Cf1 shown in formula 43),
It is designed to give CIM.

C111= (CT, CT, ・,
・, Cl1l , ・,, , C1#
)...(3) C'n = (CT, Q?,...Ql:l,
..., C helmet) ... (4) The fluoroscopic image composition means 5 is configured such that the outer region P2 is the inner region P
1, perform the calculation shown in formula (5) to see through the outer part P2 and see the inner part P1? J2
A transmittance calculating section 14 calculates the perceptible light transmittance t1, the light transmittance ti calculated by the transmittance calculating section 14, and the shading values C111 and C1 given by the above equations (3) and (4).
211 and performs the calculation shown in equation (6) below to construct a three-dimensional perspective image that can see through the inner region P1 from the outer region P2.

t+ =to + (tl-to)(1-cosθ)
P...(5) C;=t+C':'+(1-t+)CT ・(6]
Here, CT: shading value of the medial site.

CT”: Shading value of the outer region.

C1: Pixel value of perspective image.

to: Transmittance when the angle θ=0° shown in FIG.

tl: Transmittance at the angle θ-90'' shown in FIG.

P: Transmission intensity parameter (For example, 1, 2, 3, 4...) It is.

Next, the operation of the apparatus of the embodiment having the above structure will be explained with reference to the flowchart shown in FIG. 4 showing the operation of this apparatus.

The first contour extraction means 10 of the three-dimensional image creation means 2, the second
The contour extracting means 11 each takes in multi-slice image information, extracts the contours of the outer region P2 and the inner region P1, and constructs both three-dimensional image information corresponding to both three-dimensional images as shown in FIG. (ST1).

Next, the depth image creation unit 12 of the position determination means 4 generates a depth image corresponding to the inner region P1 and expressed by the above equation (1) based on the three-dimensional image information of both the inner region P1 and the outer region P2. Information Z′″′ and the above (21
Depth image information Z'' shown by the formula is created respectively (S
T2>.

The shading value image creating means 3 is configured to generate the both depth image information Zl.
ll, Zl'' are taken in, and the shading values C''+1. C'2' is given to each pixel to create shading value image information of the inner part P1 and the outer part P2 (ST3, ST4, 5T5).

Next, the depth value comparison unit 13 of the comparison and determination means 4 takes in the depth image information Z+lI, 7-On, and compares the depth value Z";l, Z121 for each corresponding pixel.
6) Determine the positional relationship between the inner region P1 and the outer region P2.

Then, if it is determined that the depth value Z":'≧depth value Z171, that is, if it is determined that the inner region P1 is closer to the display plane Q than the outer region P2, the perspective image configuration The unit 15 constructs a three-dimensional image using the shading value image information given the shading value C"1' ST7
．． ST8, 5T9), this is sent to the display means 6 for image display.

On the other hand, in the depth value comparison section 13, depth value ZT<depth value Z
? When it is determined that ), the perspective image composition unit 15 calculates the transmittance 1. and the shading value C11l
, based on the shading value image information of both the inner part P1 and the outer part P2 having C'2', the calculation shown in the above equation (6) is executed for each pixel (ST11.ST8,5
T9).

As a result, a three-dimensional fluoroscopic image is constructed in which the inner region P1 can be viewed through the outer region P2, and this three-dimensional fluoroscopic image is displayed on the display means 6 and used for diagnosis.

According to the present embodiment device described in detail above, it is possible to solve the inconvenience of difficulty in displaying images of organs, etc. located inside the surface of a subject, as in the case of conventional examples, and for example, in neurosurgery, etc. Three-dimensional image display facilitates surgical planning.

That is, it becomes easy to see through the brain surface and understand the three-dimensional positional relationship of internal organs such as the ventricles related to a brain tumor, which brings great advantages to surgical planning.

The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the invention.

[Effects of the Invention] According to the present invention as described above, there is provided a three-dimensional image diagnostic apparatus that eliminates the drawbacks of the conventional voxel method, is capable of three-dimensional transparent display of a target region, and is capable of improving diagnostic performance. can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing the positional relationship between a three-dimensional image and a depth image in the same apparatus, and FIG. 3 is an illustration of light during perspective display in the same apparatus. FIG. 4 is a flowchart showing the operation of the apparatus, and FIG. 5 is an explanatory diagram for comparing the patch method and the voxel method. DESCRIPTION OF SYMBOLS 1... Three-dimensional diagnosing device, 2... Three-dimensional image creation means, 3... Shade value image creation means, 4... Position discrimination means, 5... Fluoroscopic image composition means.

Claims (1)

[Claims] a three-dimensional image creation means that captures multi-slice image information of a subject and creates three-dimensional image information of an outer region and an inner region of the target region by a voxel method; and three-dimensional images of the outer region and the inner region. Shade value image creation means for creating each shade value image information reflecting the direction of light with respect to the information; position determining means for determining the positional relationship between the two parts; a three-dimensional perspective image construction means for constructing a three-dimensional perspective image having a light transmittance that allows the outside part to be seen through and the inside part to be visually recognized based on the determination result of the position determination means; Diagnostic imaging equipment.