JPH0351040A - X-ray photographing method - Google Patents

Abstract

PURPOSE:To re-constitute an optional tomogram face with one photographing by rotating an X-ray tube and a photographing device once centering respective rotation centers while the relative position relationship is maintained, moving photographed multiple images by the specific distance in the direction of rotation centers, and overlapping them. CONSTITUTION:The rotation center of an X-ray tube is set to 0, the rotation center of a photographing device is set to 0', an X-ray tube focal point 1 is rotated in the directions 11-14, and a photographing device is interlockingly rotated in the directions 11'-14' for photographing. Photographed images 16 are stored during photographing, stored images are added and processed by image processing after photographing, only the point B is clearly displayed on the image, and an image of the tomogram face (b) of a photographed body is obtained. When stored images 11'-14' are moved by the same distance and added and processed by image processing in the direction of the rotation center 0' so that positions of the point A in stored images 11'-14' are overlapped, only the point A is clearly displayed on the image, and the image of the tomogram (a) of the photographed body is obtained. The shift distance and direction are changed likewise. An optional tomogram image can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for taking X-ray images used in medical X-ray diagnostic equipment or industrial X-ray examination equipment. The shooting method called "method" is
The method is shown in FIG. The X-ray tube focus position and film position can be moved in parallel relative to each other as shown in the figure, centering on the center point O inside the subject. When the film is moved relatively continuously to the position l"2'3' and images are taken, only the tomographic plane containing the transparent image of the subject and the center dot B is shown on the film. In focus (\other AC
The image of the tomographic plane that includes this will be blurred. In this way, even if an image of only the tomographic plane including the center point 0 is obtained, the problem that the invention aims to solve is still solved.The above method can only obtain one tomographic plane in one imaging, and many tomographic planes cannot be obtained. In order to obtain a surface, it is necessary to change the position of the center point each time and take an image.The present invention is intended to solve the problems of the above-mentioned conventional example.
The purpose of this is to reconstruct an arbitrary tomographic plane through image processing in a single imaging session. The subject is photographed by rotating the imaging device around each rotation center while maintaining the relative positional relationship (N, multiple images taken by the imaging device within one rotation are rotated in the direction of the rotation center of the imaging device). The above-mentioned X-ray imaging method also works by moving the image a specific distance and superimposing the images (L). It becomes possible to obtain.

EXAMPLE Hereinafter, an embodiment of the X-ray photographing method of the present invention will be described with reference to the drawings. FIG. 1 shows an X-ray photographing method according to one embodiment of the present invention. Even if the X-ray tube and the imaging device 15 are rotated so that the relative relationship between the focus position of the X-ray tube and the imaging device 15 is maintained around a point within the subject (here B), the center of rotation of the X-ray tube is 0,
Set the rotation center of the imaging device to 0' and the LX-ray tube focal point 1 to 11-1.
Rotate in direction 4 and rotate the imaging device 11-
Photographing is performed by rotating the camera in the direction of ~14'.

In the photographed image in the figure (corresponding to point ABC within the subject, point ABC in photographed image 16 obtained at positions 11' to 14- of the photographing device is shown). When these memory images are added through image processing after the memory record is taken, only point B appears clearly on the image, while points A and C become blurred and disappear.In other words, an image of the tomographic plane of the object is obtained.

Next If we move the points A in the memory images 11' to 14' by an equal distance in the direction of the rotation center 0' and perform addition processing, only point A will appear clearly on the image, and the point B and C become blurry and invisible. The method is shown in Figure 2. Sunawazaka Even if an image of the tomographic plane a of the subject is obtained, by changing the moving distance and direction,
It is possible to obtain any tomographic image.By increasing the number of times the image is taken during one rotation, the degree of blur increases and it becomes possible to obtain a clearer tomographic image.

The radius of rotation of the X-ray tube focal point is rl, and the radius of rotation of the imaging device is r.
2, the distance between the X-ray tube focus rotation center point 0 and the object center point is 11, the distance between the imaging device rotation center point O and the object center point is 12, and the screen movement distance dx and the tomographic plane movement distance ay are The relationship (referring to Figure 3 above, the calculation is as follows: d y=d x* l+/ (r++ ra), or 4
3. By appropriately selecting dx, the tomographic plane can be changed arbitrarily.

Blur correction filter C used in the present invention Since the intensity of blur near the focal point is strongest, it is possible to easily obtain a large effect by using a spatial filter such as edge enhancement.
- As an example, an example of a 3x3 filter is shown below.

The photographing device used in the present invention may be any device as long as it converts a planar image into an electrical signal.For example, an image pickup tube such as an image intensifier or an X-ray vidicon may be used. With one imaging session, it is possible to easily obtain a tomographic image in any thickness direction of the subject through image processing, which can be of great use in non-destructive X-ray diagnostic tests.

[Brief explanation of drawings]

Figure 1 shows the imaging method of the present invention. Figure 2 shows the method of adding images by image processing. Figure 3 shows the moving distance of the screen and the moving distance of the tomographic plane. Figure 4 shows the conventional example. FIG.

Claims (2)

[Claims] (1) An X-ray tomography method that performs imaging by moving the X-ray tube focal point and the imaging device relative to each other around a specific point within the subject, with the X-ray tube and the imaging device being placed at their respective centers of rotation. The object is photographed by rotating the object while maintaining the relative positional relationship around the center, and multiple images taken by the photographing device within one rotation are superimposed by moving a specific distance toward the center of rotation of the photographing device. An X-ray imaging method characterized by obtaining an image of an arbitrary tomographic plane of a subject by combining the images. (2) The X according to claim 1, characterized in that blur correction filter processing is applied to the tomographic images obtained by the superposition to reduce blur components of the images due to the superposition.
Line photography method