JPH0429384B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a diagnostic X-ray imaging apparatus that performs simultaneous multilayer tomographic X-ray imaging.

[Technical Background of the Invention and Problems Therewith] Simultaneous multilayer tomographic X-ray photography is a method of simultaneously photographing cross-sectional images of each multilayer cross section of a subject within an X-ray irradiation field of view.

An example of a conventional diagnostic X-ray imaging apparatus using this simultaneous multilayer tomography method will be described with reference to FIGS. 1 and 2.

FIG. 1 is a schematic explanatory diagram of a parallel type simultaneous multilayer tomography diagnostic X-ray imaging apparatus. In FIG. 1, an X-ray film cassette 1 is housed in an imaging stand 4 and moves in the direction A in the figure. A subject 6 is placed on the imaging table 4, and the X-ray tube 2 is placed opposite the X-ray cassette 1 with the subject 6 in between. The collimator 3 narrows down the X-ray beam emitted from the X-ray tube 2. Then, the X-ray tube 2 and collimator 3 move in the direction B in the figure, and the X-ray cassette 1 moves in the direction A in the figure, emitting oblique X-rays to the subject 6. Each cross section 5
X-ray photography is now being performed.

As shown in FIG. 2, the X-ray film cassette 1 includes an X-ray film 1-1 and an X-ray screen (hereinafter also referred to as screen) 1-2 disposed on both sides of the X-ray film 1-1. and a low X-ray absorption sponge spacer 1-3 for arranging the X-ray film 1-1 and the screen 1-2 at regular intervals while maintaining adhesion. An X-ray transmission image of each section 5 is taken on the X-ray film 1-1 arranged at equal intervals in this manner.

The mutual spacing between the X-ray films 1-1 corresponds to the cross-sectional spacing of the subject 6 with geometric expansion. If is set to 1.2, the X-ray film spacing will be 6 mm. Therefore, for example, if the thickness of the screen 1-2 is 0.5 mm, the thickness of the low X-ray absorption sponge 1-3 must be 5 mm.

On the other hand, the action of the low X-ray absorption sponge 1-3 is
In addition to setting the distance between the X-ray film surfaces, the adhesion between the X-ray film 1-1 and the screen 1-2 may be maintained. Therefore, X-ray low absorption sponge 1-
If the thickness of 3 is made too thin, the adhesion effect cannot be achieved. If the X-ray film/screen adhesion is not achieved, the photographic effect on the X-ray film, especially the image quality and the amount of X-ray sensitization, will be reduced.

As explained above, depending on the conventional method,
There was a physical limit to setting the tomographic interval of the subject as long as the low X-ray absorption sponge 1-3 was used.

On the other hand, clinically, the diseases for which simultaneous multilayer tomography is used are, in the chest, the internal structure of lesions such as lung cancer and pulmonary tuberculosis, the relationship between the periphery of the lesion and the inside of the lung, or the relationship between tumors and lymph nodes in the mediastinal sinus. In the head, there are bone diseases that occur in the base of the skull and facial bones, which have complex structures, and bone diseases that overlap the trabeculae and are difficult to diagnose.In the laryngopharynx, there are bone diseases that occur in soft parts such as the vocal cords and airways. Lesions occurring in the walls, gallstones and bile duct lesions in the biliary system, and conditions inside and outside the kidneys are confirmed. In recent years, highly accurate diagnosis has been required in these disease fields, and in particular, the detection of early cancer requires cross-sectional plane spacing down to the order of several millimeters. In this sense, it is extremely important to accurately capture cross-sectional lesions in mm units.

However, there are drawbacks that conventional methods cannot adequately meet these demands for clinical diagnosis.
Furthermore, since the distance between the X-ray film planes cannot be freely and automatically changed, there is a drawback that simultaneous multilayer tomographic diagnosis according to the disease site cannot be performed quickly.

[Object of the Invention] The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a diagnostic X-ray imaging apparatus that can freely and quickly set the tomographic interval in simultaneous multilayer tomography. The purpose is to

[Summary of the invention] The outline of this invention for achieving the above object is as follows:
In a diagnostic X-ray imaging apparatus that performs simultaneous multilayer tomographic X-ray imaging, a plurality of stimulable phosphor holding members each holding a plurality of stimulable phosphors in a removable manner;
The plurality of X-ray recording medium holding members are moved parallel to each other and maintained at equal intervals along the X-ray beam direction, and have interval adjusting means for varying the distance between them in the X-ray beam direction. It is characterized by:

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings. FIG. 3 is a schematic perspective view of a cassette for simultaneous multilayer tomography according to the present invention, and FIG. 4 is a partial front view.

In FIG. 3, the cassette for simultaneous multilayer tomography according to the present invention includes a plurality of stimulable phosphor holding members 8 that removably hold stimulable phosphor 7, and a plurality of stimulable phosphor holding members 8. The distance adjusting means 10 moves parallel to each other along the X-ray beam direction (direction C in the figure) and changes the distance between them in the X-ray beam direction at equal intervals.

Unlike the conventional X-ray film 1, the stimulable phosphor 7 does not require a screen, and the adhesion required by the film/screen combination is not a problem.

Regarding the stimulable phosphor 7, as described in, for example, JP-A-53-84741 and JP-A-53-84744, radiation (X-rays) is applied to a sheet-like stimulable phosphor plate. , α rays, β rays, γ rays, ultraviolet rays, etc.)
When the radiation is incident, part of the energy of this radiation is stored in the phosphor, and when this stimulable phosphor is then irradiated with excitation light, the phosphor emits light according to the stored energy. That is what it is.
Generally, this stimulable phosphor plate is made by injecting radiation in X-ray photography, scanning with a laser beam, reading the emitted light with a detector, modulating the light beam with the read image information, and producing a film. Since the X-ray image is recorded on a computer, etc., post-processing to make it easier to see as a photograph, such as sensitivity correction and image correction, is possible by electrical correction during the modulation stage with the light beam.

The stimulable phosphor holding member 8 has a substantially U-shape, and a groove 11 for holding the stimulable phosphor 7 in a removable manner is formed on its inner surface. Furthermore, guide members 9, which will be described later, are pivoted at right angles to the uppermost stimulable phosphor holding member 8 at its four corners. The stimulable phosphor holding member 8 other than the top part has
A guide groove 12 is provided on the outer surface of the surface having the groove 11. As shown in FIG. 4, the guide groove 12 has a cross-sectional shape in which the width of the opening 12a is narrower than the width of the bottom surface 12b of the groove relative to the opening. Furthermore, the stimulable phosphor holding member 8 other than the top part has a hole 13 through which the guide member 9 is inserted.
It is guided by four guide members 9 and can slide in parallel.

The interval adjustment means 10 includes a guide member 9 that restricts the movement of the X-ray recording medium holding member 8 in parallel;
It consists of a swing link 14 whose one end is rotatably supported by the uppermost stimulable phosphor holding member 8, and guide pins 15 arranged at equal intervals on the swing link 14. The guide pin 15
is adapted to be inserted into a guide groove 12 in the stimulable phosphor holding member 8. Further, the guide groove 12 in the lowest stimulable phosphor holding member 8
The guide pin 15 inserted into the guide groove 12 is provided with a flange 15a to prevent it from coming off from the guide groove 12, as shown in FIG. Furthermore, a knob 16 is provided with a brake mechanism that rubs and presses the lowermost stimulable phosphor holding member 8 and the swing link 14.
is provided on the swing link 14.

The operation of the diagnostic X-ray imaging apparatus equipped with the simultaneous multilayer tomography cassette constructed as described above will be described with reference to FIGS. 5 and 6.

Since the stimulable phosphor 7 does not need to be held closely as described above, the stimulable phosphor holding member 8
Sufficient image quality can be obtained by simply inserting the lens into the groove 11 in the image forming apparatus. In addition, the stimulable phosphor 7
is held by the stimulable phosphor holding member 8 and can freely move in parallel along the guide member 9, and the distance between the stimulable phosphors 7 can be adjusted at equal intervals by operating the swing lever 14. can be varied (fifth
(See Figure 6). Therefore, it becomes possible to freely and quickly set the interval between tomographic planes in simultaneous multilayer tomography.

For example, if the thickness of the stimulable phosphor 7 is 0.6 mm,
If the thickness of the stimulable phosphor holding member 8 is 3 mm, then
When the magnification of the X-ray image is 1.2, the minimum distance between the tomographic planes of the subject is approximately 2.5 mm. Therefore, tomographic lesions can be captured more accurately than in the past.

It goes without saying that the present invention is not limited to the embodiments described above, and includes various modifications within the scope of the gist of the invention. For example, the spacing adjustment means 10 is not limited to the one listed in the above embodiment, but if two swinging links with the uppermost stimulable phosphor holding member 8 as the same pivot point are provided, the guide member The same effect can be achieved without requiring 9. Further, as a member for achieving parallel movement at equal intervals, a pantograph type member can also be applied.

Furthermore, by driving the swing link 14 in the above embodiment electrically rather than manually, the distance between the stimulable phosphors 7 can be automatically set.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide a diagnostic X-ray imaging apparatus that can freely and quickly set the tomographic interval in simultaneous multilayer tomography. Moreover, since the minimum set interval between tomographic planes can be made smaller than in conventional methods, tomographic lesions in units of several millimeters can be accurately captured, making it possible to provide clinically useful X-ray photography.

[Brief explanation of drawings]

Figure 1 shows a diagnostic X using parallel simultaneous multilayer tomography.
2 is a cross-sectional view of a conventional X-ray film cassette, FIG. 3 is a schematic perspective view of a cassette for simultaneous multilayer tomography according to the present invention, and FIG. 4 is a cassette for simultaneous multilayer tomography. Partial front view of 5th
6 are diagrams showing how the cassette for simultaneous multilayer tomography is used. 7...Stormable phosphor, 8...Stormable phosphor holding member, 9...Guide member, 10...Spacing adjustment means.

Claims (1)

[Claims] 1. In a diagnostic X-ray imaging device that performs simultaneous multilayer tomographic X-ray imaging, a plurality of stimulable phosphor holding members each of which holds a plurality of stimulable phosphors in a removable manner, and a plurality of stimulable phosphor holding members are provided. Diagnostic X-rays, characterized by having interval adjusting means for moving the members parallel to each other and at equal intervals along the X-ray beam direction, and for varying the distance between the members in the X-ray beam direction. Photography equipment.