JPS637212Y2 - - Google Patents

Description

[Detailed explanation of the invention] (a) Industrial application field This invention is a method for panoramic X-ray imaging (pantomography), in which X-rays can be immediately
Concerning pantomotereoscopy in which line images are observed.

(b) Conventional technology A panoramic X-ray tomography apparatus has an X-ray tube and an imaging unit arranged around a subject facing each other, and rotates them at the same angular velocity to produce a panoramic tomographic image of a predetermined part of the subject. This is what you get. Conventionally, this type of apparatus has used a film in the imaging section, and the tomographic image has been formed on the film. In film photography, a tomographic image with an appropriate film density cannot be obtained unless a large amount of X-rays are irradiated.Therefore, in conventional panoramic X-ray tomography equipment, the irradiated X-ray dose must be sufficiently large. Depending on the subject, X-rays may be wasted,
Particularly when used for medical purposes, it is undesirable in terms of preventing X-ray damage to the human body. Furthermore, since film photography is used, it takes time to develop the film, making it impossible to observe tomographic images immediately on the spot.

(c) Purpose The purpose of this invention is to provide a pantomo telescope that can obtain a panoramic X-ray image of a subject with a small amount of X-rays, and also enables immediate observation of the X-ray image.

(d) Configuration The pantomo telescope according to this invention consists of an X-ray tube, an X-ray fluorescence intensifier tube that converts the X-ray image of the subject into a visible light image, and an X-ray incident surface side of the X-ray fluorescence intensifier tube. A slit attached to the slit, a television imaging device that converts a visible light image of a linear X-ray image produced by the X-rays passing through the slit into an electric video signal, and the X-ray tube and X-ray fluorescence intensifier tube detect the subject. A rotation mechanism that rotates these together at an angular velocity w relative to the subject while facing each other, and electrical video signals of linear images obtained one after another during this rotation are connected from the center of rotation to the above-mentioned The writing position of the linear image is perpendicular to the linear image according to the product 1mw of the distance 1 to the incident surface of the X-ray fluorescence intensifier, the reduction ratio m of the image obtained in the television imaging device, and the rotational angular velocity w. A scan converter memory device is moved in a certain direction, and an image is formed by writing electrical video signals of a large number of linear images to this scan converter memory device. and a television device that displays an image formed in the scan converter memory device by reading out images from the scan converter memory device according to television scanning.

(E) Embodiment FIG. 1 is a system diagram of a pantomo telescope according to an embodiment of the present invention. In this embodiment, a dental arch row is tomographically photographed as an object. X
X-rays irradiated onto a dental arch row (subject) 22 by the ray tube 11 are received by an X-ray fluorescence intensifier (conversion device) 14 and converted into a visible light image. This visible light image is transmitted to the television imaging device 1 through the optical system 15.
6 and converted into an electrical video signal. Then, the electric video signal passes through the television camera controller 17 to a scan converter memory device (storage device).
18 by write scanning. By reading out this stored signal and displaying it on the monitor television device 19, a subject image can be obtained.

A slit 23 and a slit 24 facing each other are provided on the front surface of the X-ray tube 11 and the front surface of the X-ray fluorescence intensifier tube 14, respectively. And X-ray tube 11 and
The linear fluorescence multiplier tube 14 is mounted on an appropriate rotating frame (not shown) so that it rotates around the dental arch row 22 at an angular velocity w around a predetermined point while facing the linear fluorescence multiplier tube 14 with the dental arch row 22 in between. It is held by a rotating mechanism. In the case of a full-scale tomographic image of the dental arch row 22, this rotation is first rotated by a predetermined angle around point _O1 ;
Next, a predetermined angle is made around point O ₃ and then around point O ₂ at predetermined angles. A slit 25 is also provided in front of the television camera 26 of the television imaging device 16. Therefore, while rotating, the X-ray fluorescence intensifier tube 14 receives a line image of the dental arch row 22 at each point on the rotational trajectory, and the television imaging device 16 converts this line image into an electrical video signal. . As _{shown in FIG} .
Two line images are input, and electrical video signals corresponding to these line images are output. Furthermore, dental arch row 2
In order to obtain the second line image, instead of rotating the X-ray tube 11 and the X-ray fluorescence intensifier 14, the dental arch row 22 may be rotated at an angular velocity w about a predetermined point.

Now, the electric video signal of the line image from the television image pickup device 16 passes through the television camera controller 17 and is stored in the scan converter memory device 18 by write scanning according to the line image. The scan converter memory device 18 includes, for example, a storage tube 2 as a storage means.
1. The electric video signal of the line image is stored in the storage tube 2.
The information is written and stored on the storage surface No. 1 while moving at a predetermined speed w' in the horizontal scanning direction. Therefore, on the storage surface of the storage tube 21, as shown in _FIG.
An image P formed by superimposing the line images of each frame _up to Po is written and stored. The horizontal scanning speed w' by the scan converter memory device 18 is determined by the distance 1 from the rotation center O ₁ to the fluorescent screen of the X-ray fluorescence intensifier 14, the reduction ratio m of the image formed on the imaging surface of the television camera 26, The product with the rotational angular velocity w is equal to 1 mw.

A television device 19 for reading and monitoring signals stored in the scan converter memory device 18
When displayed, a panoramic tomographic image of the dental arch row 22 can be observed. Furthermore, if a tomographic image on the cathode ray tube surface of the monitor television set 19 is taken by the photographing camera 20, it can be fixed on a film and stored.

(f) Effects According to this invention, since an X-ray fluorescence intensifier tube is used, panoramic X-ray tomographic images can be obtained with higher sensitivity and lower X-ray exposure dose than film.
In addition, since the electric video signal is stored in the scan converter memory device and the image is formed in the scan converter memory device, it is excellent in immediacy, and the disadvantage of using film that it takes time to develop can be overcome. . Furthermore, since images are formed little by little in the scan converter memory device,
If an image of the target region is obtained, X-ray exposure and imaging can be stopped even in the middle, which can contribute to further reducing the X-ray exposure dose.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a pantomo telescope according to an embodiment of this invention, and FIGS. 2a and 2b are explanatory diagrams showing captured line images and composite images. 11... X-ray tube, 14... X-ray fluorescence multiplier tube (conversion device), 15... Optical system, 16... Television imaging device, 17... Television camera controller, 18
...Scan converter memory device, 19...Monitor television device, 20...Photographing camera, 21...
... Storage tube, 22 ... Dental arch row (subject), 23,2
4, 25...slit, 26...TV camera.

Claims (1)

[Scope of utility model registration request] an X-ray tube, an X-ray fluorescence intensifier tube that converts an X-ray image of a subject into a visible light image, and an
A slit attached to the ray entrance surface side, a television imaging device that converts a visible light image of a linear X-ray image generated by the X-rays passing through the slit into an electric video signal, and the X-ray tube and the X-ray fluorescence intensifier tube. A rotating mechanism rotates these together at an angular velocity w relative to the subject while facing each other with the subject in between, and an electric video signal of linear images obtained one after another during this rotation. the product of the distance 1 from the center of rotation to the incident surface of the X-ray fluorescence multiplier, the reduction ratio m of the image obtained in the television imaging device, and the rotational angular velocity w;
A scan converter memory device in which the writing position of the linear image moves in a direction perpendicular to the linear image in accordance with 1 mw, and electrical images of a large number of linear images to this scan converter memory device. A pantomotor comprising: a television device that forms an image by writing a signal and reads the image from the scan converter memory device according to television scanning to display the image formed in the scan converter memory device. telescope.