JPH03284248A - Tomographic camera - Google Patents

Abstract

PURPOSE:To enable simplification of a mechanism by a method wherein a photographing system is moved parallel with respect to a subject to store an image at each position together with a position data and pixel positions of numerous images are converted according to a position of gaining and a desired depth of a section to add data per pixel between a plurality of images. CONSTITUTION:An X-ray device 3 and an X-ray image intensifier 4 are moved to the right with respect to a subject 1 to be inspected and a table 2 and the subject is exposed to X-rays at positions of the process to record a video signal into an image recorder 8 together with positional information. Numerous images recorded are read out and processed with an image computing device 9 to display a tomographic image on an image display device 10. Here, on point P on a desired section Q is projected to a position X of an image receiving surface of the X-ray image intensifier 4. When projection images at points P of the pictures are put one upon another at the same position, the part of the point P alone appears clearly to obtain an image of the section Q. In this case, the mere parallel movement of the X-ray tube device 3 and the X-ray image intensifier 4 is enough for the subject 1. Thus, an X-ray tomographic photography is possible with a very simplified construction or utilizing an ordinary X-ray perspective photographing base.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a tomography apparatus that obtains only an image of a tomographic plane at a certain depth by superimposing a large number of transmitted images obtained while moving a radiation generating means and an imaging means with respect to a subject. 1

[Conventional technology]

Conventionally, an X-ray tube and an X-ray film are connected by a swinging rod,
The fulcrum of this swinging rod is aligned with the tomographic plane of the subject, and X-rays are irradiated while swinging the swinging rod, and the chi-ray transmitted images from each are multiple-exposed onto a single piece of X-ray film. An X-ray tomography apparatus is known that obtains an image of a tomographic plane by blurring images other than those near the tomographic plane. Also known is a tomography device that uses a combination of an X-ray image intensifier and a TV camera instead of an X-ray film to obtain an X-ray image signal, and electronically performs multiple exposure of a large number of images. There is.

[Problem to be solved by the invention]

However, in conventional tomography equipment, Xli tube and
It is connected to an imaging system such as a line film using a swinging rod so as to move in opposite directions with the subject as the center, which poses a problem in that the mechanical structure is complex and requires a special mechanism. That is, mechanical components such as a swinging rod and a mechanism for changing its fulcrum according to the height of the fault plane are required, and rigidity is required for mechanical precision, resulting in a large-sized device as a whole. An object of the present invention is to provide an improved tomography apparatus that does not require a complicated mechanism and can even use a normal X-ray fluoroscopy table.

[Means to solve the problem]

In order to achieve the above object, the tomography apparatus according to the present invention includes: a radiation generating means; an imaging means for obtaining two-dimensional image data corresponding to the radiation transmitted through the subject;
A moving means for integrally moving the radiation generating means and the imaging means parallel to the subject, a means for detecting the position of this movement, a means for storing image data together with data of the position at which it was acquired; Image calculation means is provided for converting the moving direction position of the image data read from the storage means based on the desired tomographic depth and the above-mentioned position data, and then adding the converted data.

[For production]

- An imaging system consisting of a radiation generating means and an imaging means is integrally moved parallel to the subject, and images obtained at each position are stored together with data for that position. The pixel positions of these many images are converted according to the position where the images were acquired and the desired tomographic depth, and then the data for each pixel is added between the many images. Then, only the image near the cross section at the above-mentioned tomographic depth appears clearly, and a tomographic image is obtained.

【Example】

Next, an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a subject (patient) 1 is placed on a table 2, and an X-ray tube device 3 is placed above it.
However, an X-ray image intensifier 4 is arranged below. A TV right camera is connected to this X-ray image intensifier 4. These X-ray tube device 3, X-ray image intensifier 4, and TV right camera are attached to one frame (not shown) and are movable. Furthermore, the table 2 can also be moved relative to this frame. Further, a high voltage is supplied to the X-ray tube device 3 from a high voltage device 6. These configurations are similar to conventional X-ray TV fluoroscopy systems. The positional relationship between the table 2, the X-ray tube device 3, and the X-ray image intensifier 4 is read by a position detector 7, and the position information is obtained from the X-ray transmission obtained from the TV right camera. The image is recorded in the image recording device 8 together with the video signal of the image. For example, as shown by the arrow in FIG.
It is assumed that the line image intensifier 4 moves parallel to the right side with respect to the subject 1 and the table 2, and as a result of the movement, the state shown in FIG. 2 and the state shown in FIG. 3 are achieved. X-ray exposure is performed at each position during this movement, and the video signal at that time is recorded in the image recording bag W8 along with the position information. In this way, a large number of images are recorded. A large number of these recorded images are later read out and processed in the image processing unit W9, and the obtained tomographic images are displayed on an image display device (for example, a CRT monitor device) 10.
is displayed. The control device 11 controls the high voltage generator 6 to generate X! ! In addition to controlling the exposure, the TV right camera,
It controls the image recording device 8 and the image calculation device 9. Here, a description will be given assuming that a tomographic image of a cross section Q at a certain height is obtained. One point P on the cross section Q is projected at a position X on the coordinates of the image receiving surface of the X-ray image intensifier 4. If the projected images of this point P in each image are superimposed at the same position, parts at other heights will be blurred and only the part at point P will appear clearly, thereby making it possible to obtain an image of the cross section Q. The X-ray focal point is F, and the height of this focal point F from the image receiving surface of the X-ray image intensifier 4 is H1 The distance from the focal point F to the cross section Q is C1 The distance from the image receiving surface to the cross section Q is D
If (D=H-C), the relationship between the position of point P (distance L from the central axis) and X is: X=H・ (L/C) = (C+D)・(L/C) L・ +1+ (D/C))6, and this relationship does not change even if the relative positional relationship between the subject 1 and table 2 and the X-ray tube device 3 and X-ray image intensifier 4 changes. Therefore, by using this relationship and converting the X coordinates of each image and superimposing them (adding data between images for each pixel), a tomographic image at the cross section Q at the desired depth (C, D) is obtained. can be obtained. In this case, since it is sufficient to simply move the X-ray tube M3 and the X-ray image intensifier 4 in parallel to the subject 1, there is an advantage that the mechanism is extremely simple. Furthermore, since a normal X-ray fluoroscopic imaging table is also equipped with such a mechanism, X-ray tomography can be performed using a normal X-ray fluoroscopic imaging table. Furthermore, in the above description, the X-ray tube device 3 and the X-ray image intensifier 4 are arranged vertically and moved horizontally; however,
By tilting only the X-ray tube device 3 in the vertical direction and tilting the X-ray irradiation direction in or around the body axis of the subject 1, the image receiving surface of the X-ray image intensifier 4 is parallel to the surface of the table 2. The X-ray tube device 3 and the X-ray image intensifier 4 may be moved together while the X-ray tube device 3 and the X-ray image intensifier 4 remain in this state. In this way, data that avoids obstacles can be obtained, so that a tomographic image of the region of interest can be obtained more clearly. A normal Xt fluoroscopy table is equipped with a mechanism for moving the X-ray tube device 3 and the X-ray image intensifier 4 in parallel in this tilted state, so this can be used. In particular, if the X-ray irradiation direction is tilted toward the moving direction of the subject 1 or the X-ray tube device 3, the angle 0 in FIG.
Transmission image data at the above angles can be obtained. The irradiation angle 2θ shown in Fig. 1 corresponds to the tomographic angle in a conventional tomography apparatus, and the larger this angle is, the thinner the tomographic depth becomes, and the more accurately an image near the desired cut plane can be obtained. be able to. Therefore, by tilting the X-ray irradiation direction while keeping the image receiving surface of the X-ray image intensifier 4 parallel to the surface of the table 2, the tomographic angle is increased. The angle data of this tilted state is stored together with the image data and used when composing the image. Furthermore, since a large number of images shifted in the moving direction of the X-ray tube device 3 and the X-ray image intensifier 4 can be recorded in the image recording device 8, the imaging area is the same size as the image receiving surface of the X-ray image intensifier 4. not limited to. Therefore, for example, by moving in the longitudinal direction of the human body and recording a large number of images, it is possible to obtain a tomographic image of a desired region or to seamlessly obtain a tomographic image of the entire longitudinal direction of the human body. Although the case where the X-ray imaging system is simply moved linearly parallel to the subject 1 has been described above, it can also be moved on any trajectory within a plane (so-called multi-orbit). In this way, a tomographic image similar to that of conventional multi-orbit tomography can be obtained. Furthermore, it is possible to keep the imaging system still and move the subject 1, or conversely, to keep the subject 1 still and move the imaging system, or to move both at the same time. Bye. Furthermore, X
The ray tube M3 and the X-ray image intensifier 4,
It is also applicable to three-dimensional motion methods such as circular motion and spherical motion in which the subject 1 is moved along a surface other than a plane, such as a spherical surface. From the data obtained using this method,
Due to the image composition method, a plane parallel to table 2 (subject 1
In addition to tomographic images of planes parallel to the body axis direction, tomographic images of planes perpendicular to or inclined to the body axis can also be obtained, and three-dimensional display is also possible.

【Effect of the invention】

According to the tomography apparatus of the present invention, a tomographic image of any cross section can be obtained with a simple mechanism. Furthermore, it is also possible to display a three-dimensional image using a three-dimensional image configuration. Further, the photographing area is not limited by the size of the film or the detector, and can be made into a large area.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one state of an embodiment of the present invention, and FIGS. 2 and 3 are block diagrams showing other states, respectively. 1... Subject, 2... Table, 3... X-ray tube device, 40 - X-ray image intensifier, 5... TV right camera 6... High voltage generator, 7...・Position detector, 8
...image recording device, 9...image calculation device, ]0...
Picture 1 anger display device.

Claims (1)

[Claims] (1) a radiation generating means, an imaging means for obtaining two-dimensional image data corresponding to the radiation transmitted through the subject, and a moving means for integrally moving the radiation generating means and the imaging means parallel to the subject; means for detecting the position of this movement;
means for storing the image data together with data on the position at which the image data was acquired, and converting the position in the movement direction of the image data read from the storage means based on the desired tomographic depth and the above position data; 1. A tomography apparatus comprising: image calculation means for performing addition.