JPH01151442A - Radiation diagnostic apparatus - Google Patents

Abstract

PURPOSE:To obtain the subject diagnostic apparatus especially excellent in the recognition capacity of positional relation with respect to the diagnosis of an image, by respectively synthesizing digital images such as a usual X-ray transmission image, a soft tissue image due to an energy differential method, a bone image, a blood vessel contrast image or the like in an arbitrary ratio before displaying the same. CONSTITUTION:In the synthesis of two images obtained by an energy differential method, (a) is the image only of soft tissue and (b) is the image only of a bone. When the image (a) is set to S(a) and the image (b) is set to S(b), a synthetic image S(A) is represented by formula S(A)=KXS(a)+(1-K)XS(b) (0<=K<=1). By changing K between 0 and 1, the continuity and positional relation of (a) and (b) on a picture and correlation relating to which is sick, soft tissue or a bone in the case of the presence of lesion can be cleared. By this method, the synthesis of an image is performed at a high speed by a computer and, when the image is displayed on a CRT display, various images can be observed by one CRT display while the mutual positional relation between the are grasped.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an image processing and display method in a medical X-ray diagnostic apparatus.

(Prior Art) In recent years, with the advancement of image processing technology, many medical images have become digital images, and many new images have become available. First, a blood vessel image is contrasted using a method called a digital subtraction method, and an image of only bones and an image of only soft tissues are obtained using a method called an energy subtraction method. These images are displayed alone or in parallel on a plurality of CRT displays or films together with conventional X-ray transmission images for observation by a physician.

(Problems to be Solved by the Invention) As mentioned above, when images are displayed in parallel as in the conventional method, a specific part of the image obtained by the difference method as described above,
Especially when it is a small part, there is a drawback that it requires a great deal of effort to determine which part of the original normal X-ray transmission image it is. In other words, doctors made decisions based on their own experience in reading images.

It is an object of the present invention to overcome the drawbacks of the prior art and use computer-aided image synthesis technology to create digital images such as ordinary X-ray transmission images, soft tissue images by energy subtraction, bone images, and even angiography images. It is an object of the present invention to provide a radiological diagnostic apparatus that has superior ability to recognize positional relationships and the like for diagnosis of images conventionally displayed in parallel by combining and displaying images at an arbitrary ratio.

(Means for Solving the Problems) The radiological diagnostic apparatus of the present invention has an image processing section and a display section, and includes normal transmission X-ray images, images of only bones obtained by the energy difference method, and images of only soft tissues. Images selected from contrast images obtained by angiography are combined by multiplying each by a coefficient and changing the display density to display one composite image, and the average density of the composite image is displayed. It adjusts the coefficients applied to the original image so that it has an intermediate density for the medium.

(for production) Because it is conventionally separated by the above method.

Problems such as the positional relationship between different images being unclear and comparisons being insufficient are improved. Furthermore, by continuously changing the compositing conditions, it is possible to obtain a composite image that is optimal for the observer's judgment.

(Example) An example of the present invention will be described based on FIGS. 1 to 3.6 As a first example, synthesis of two images obtained by the energy difference method will be described. (a) shown in FIG. 1 is an image of only soft tissues, and (b) is an image of only bones.

The image in (a) is 5(a), and the image in (b) is 5(b).
Then, the composite image S (A) is expressed by the following equation.

5(A)=KXS(a)+(1-K)xS(b) −
(1) 0≦to≦1 Changes in composite image 5(A) due to K are shown in FIG.

FIG. 2 (a) is when = 1, (b) is = 0.5.
(c) is the case where = O, and by changing K between 1 and O, the continuity and positional relationship between (a) and (b) on the screen, and the case where there is a lesion. It is possible to clarify the correlation between (a) and (C), that is, whether the disease is in the soft tissue or the bone.

A second embodiment is shown in FIG. FIG. 3(a) is a soft tissue image, FIG. 3(b) is a pulmonary artery contrast image, and FIG. 3(c) is an intermediate image obtained by combining both images. In this case as well, the positional relationship between the soft tissue and the pulmonary artery becomes clear.

Further, according to the present invention, the number of images to be combined can be two or more, and each image can be combined, for example, 5(a).
, 5(b), 5(c), and 5(d), the composite image 5
(A) can be expressed by the following formula.

5(A)”kXS(a)+QXS(b)+mX5(c)
+nX5(d) ・・・・・・(2)
k+[+m+n=1 0≦, Q, m, n≦1 As shown in equation (2), when images are synthesized within the conditions of k, Q, m, and n, the characteristics of each image are It becomes possible to display the image while checking its positional relationship with the image. Diagnosis becomes easier if one of the images is combined with a normal X-ray transmission image.

As described above, if images are synthesized at high speed by a computer and displayed on a CRT display, it is possible to observe various images while grasping their mutual positional relationships using one CRT display.

(Effects of the Invention) According to the present invention, digital images such as normal X-ray transmission images, soft tissue images obtained by energy difference method, bone images, and even angiography images can be converted into arbitrary images using computer-based image synthesis technology. By combining and displaying images in proportions, the ability to recognize positional relationships, etc. is significantly superior to diagnosis of images that are conventionally displayed in parallel, and in future medical image diagnosis, for example, the number of CRT displays can be reduced. Its practical effects, such as being able to do it, are extremely personal.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of an image, and FIGS. 2 and 3 are diagrams showing an example of combining images, and FIG. 1 (a). Figures 2(a) and 3(a) are images of soft m weave only;
Figure (b), Figure 2 (b) is an image of only bones, Figure 3 (b)
is a contrast-enhanced image, and FIG. 2(C) and FIG. 3(c) are composite images. Figure 1 Figure 2 (a)

Claims (2)

[Claims] (1) It has an image processing unit and a display unit, and you can select from ordinary transmission X-ray images, images of only bones and images of only soft tissue obtained by energy difference method, and contrast images obtained by angiography. A radiation diagnostic apparatus characterized by displaying a composite image by multiplying each image by a coefficient, changing the display density, and synthesizing the images. (2) The radiological diagnostic apparatus according to claim 1, wherein a coefficient applied to the original image is adjusted so that the average density of the composite image becomes an intermediate density of the display medium.