JPS642724Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to an X-ray fluoroscopic imaging table, and more specifically, an X-ray fluoroscopic imaging table that is equipped with a so-called divided imaging means that can set a plurality of imaging areas on a film. Regarding.

[Conventional technology]

In recent years, in so-called under-table tube X-ray fluoroscopic imaging tables, in which the X-ray source is housed in the table and the image section is placed opposite the X-ray source across the table, The purpose of the X
The X-ray irradiation area is set by a variable aperture provided in the radiation source and a divided imaging mask provided between the X-ray source and the top plate, and a means for moving the film provided in the image section is used. Accordingly, the film is moved so that the X-ray irradiation area and the imaging area on the film coincide with each other, so that a plurality of X-ray images can be taken on one film.

[The problem that the idea aims to solve]

However, such conventional devices do not have a mask for segmented imaging just in front of the film, which causes scattered rays generated from the subject to reach the non-imaging area of the film through the X-ray entrance window in the image section. However, there was a problem in that the obtained X-ray image lost its clarity.

An object of the present invention is to prevent a decrease in image clarity due to scattered radiation in such an undertable tube-shaped X-ray fluoroscopic imaging table.

[Means to solve the problem]

In order to achieve the above object, the X-ray fluoroscopic imaging table of the present invention includes an X-ray source having a variable aperture installed below a top plate, and an X-ray source installed between the variable aperture in the X-ray source and the top plate. division mask means for setting an X-ray irradiation area for divided imaging; In an under-table tube-type X-ray fluoroscopic imaging table, which is equipped with an X-ray entrance window of approximately the same area as the area for full-scale imaging, and an image section with a film movement mechanism, the area outside the imaging area is Scattered ray removal means is provided which is composed of a plurality of movable plates and an opening/closing mechanism for the movable plates for removing scattered rays from the subject that are incident on the film surface of the film, and the scattered ray removal means is flattened using a thin plate. It has a shape similar to that of the film, and is disposed within the image section and immediately in front of the subject-side surface of the film.

[Effect]

Since the under-table tube type X-ray fluoroscopic imaging table is configured as described above, the distance between the film and the subject is approximately 1/1 that of a conventional X-ray fluoroscopic imaging table.
By shortening to 2 or less, scattered rays generated from the subject during divided imaging are prevented from reaching outside the imaging area from the X-ray entrance window of the image section,
Alternatively, by attenuating it, it is possible to reduce the scattering caused by scattered radiation to a level that does not pose a practical problem, and at the same time, it is possible to reduce the magnification ratio. For this reason, it becomes possible to take an X-ray image in divided imaging into a photograph with high clarity and less blur.

〔Example〕

An embodiment of the present invention will be described below with reference to the accompanying drawings.

1 and 2 show an X-ray fluoroscopic imaging table according to the present invention. The table 11 is installed on a base 12 so that it can be raised and lowered. A top plate 13 is incorporated into the table 11 so as to be linearly movable in the longitudinal direction and the direction perpendicular to the longitudinal direction. The X-ray source 14 is on the top plate 1
3, and is installed inside the table 11. The image portion 15 is cantilevered and slidably supported by a support 16 erected on the side surface of the table 11 along the support 16, and can move towards or away from the top plate 13. The X-ray fluorescence intensifier tube 17 directs its fluorescent screen toward the top plate 13,
It is attached on the image section 15. Furthermore, a film changer is provided in the image section 15. The film exchanger is known per se and comprises a supply magazine for storing unexposed film, a storage magazine for storing exposed film, a film holder with an intensifying screen, and a transport mechanism for the film, as well as an imager. The front side of section 15, i.e.
On the surface facing the radiation source 14, an X-ray entrance window is provided that coincides with the center of the X-ray flux and has an area equivalent to the full size of the film used. The X-ray entrance window is equipped with a light-shielding member or a lithoform to prevent light from entering therethrough. The film holder is indicated at 18 in the drawing and is in the photographing position. After shooting, the film holder 18 is moved to the image area 15.
At this time, the photographed film is sent to the transport mechanism so as to be stored in a storage magazine located at the rear of the image section 15. Next, at the time of photography, an unphotographed film is pulled out from the supply magazine at the rear of the image section 15, and this film is loaded into the film holder 18 by the transport mechanism. will be moved up to

On the other hand, below the top plate 13 is a split mask means 19.
is provided on the table 11 between the X-ray source 14 and the top plate 13, and is provided on the table 11 between the X-ray source 14 and the top plate 13. Thus, the X-ray irradiation area is made to coincide with the imaging area on the film in the image section 15. The film holder 18 divides the film photographing area between the variable aperture and the dividing mask means 19.
The image section 15 is moved within the image section 15 so as to match the X-ray irradiation area that has been narrowed down.

FIG. 5 shows a divided photographing state. First, quadrant photography will be explained. Division mask means 19
When the X-ray flux x is narrowed down to only the region a ₁ in the entire region, the X-rays are irradiated only to the region f ₁ of the photographing region of the film f, and this region is photographed. In this state, when only the film f is moved in the direction of the arrow A, the X-rays are irradiated only to the region _f2 in the photographing region of the film f, and the region _f2 is photographed. Next, by moving the film in the direction of arrow B in the state shown in _FIG . Area _f4 can be photographed in the photographing area of . Next, for two-part imaging, that is, imaging in which the imaging areas of the film f are f ₁ , f ₃ and f ₂ , f ₄ , the X-ray flux x is transferred to the combined area of a ₁ , a ₂ , and a ₃ . Aperture the film f to a position symmetrical to the direction of arrow A
By photographing one of the photographing areas f ₁ and f ₃ while moving _the film in the direction shown in _FIG . It can be accomplished. Incidentally, the entire surface of the film f can be photographed by setting the X-ray flux x to a region in which it is not focused at all.

The dividing mask means 19 for narrowing down the X-ray flux is a conventionally known device, for example, as shown in FIG.
This is achieved by stacking four X-ray beams 3 and 24 orthogonally and moving each aperture plate to narrow down the X-ray flux x to an arbitrary size.

FIG. 4 shows an example of a mechanism for moving the film holder 18 as described above. Two guide rails 31 and 32 are laid in parallel and facing each other inside a box-shaped base 33 of the image section 15.
Slides 34 and 35 are provided on the film holder 18. The film holder 18 is mounted on a slide 34,
35 is engaged with the guide rails 31, 32, so that it is supported by the guide rails 31, 32 so that it can move linearly along the guide rails 31, 32. A chain 36 is installed on one side of the base body 33 in parallel with the guide rail 31. The film holder 18 is fixed to this chain 36. The servo motor, which is not shown, is chain 3.
6, the film holder 1
Reference numeral 8 moves between the film loading position and the above-mentioned divisional photographing or full-size photographing position. In this example, film holder 1
8 moves only in one direction, but it goes without saying that it is necessary to provide another set of guide mechanism and moving mechanism to move in two directions in order to photograph the film in four parts.

In the X-ray fluoroscopic imaging table according to the present invention, in order to prevent the scattered rays generated from the subject from reaching the imaging area other than the predetermined imaging area of the film during such divisional imaging, it absorbs or absorbs the scattered rays. The apparatus is equipped with means for attenuating scattered radiation to the extent that it does not affect the clarity of the X-ray photograph. This scattered radiation removing means includes a plurality of thin and flat movable plates, and when these movable plates are used for dividing the film into an X-ray entrance window of the image section 15, that is, a window that enables the entire film to be photographed. The device is characterized by comprising an opening/closing mechanism configured in a flat shape similar to the movable plate, which moves to a position that prevents scattered rays incident on the object from entering outside the imaging area. These movable plates are located in front of the film f (on the X-ray source 14 side) inside the image section 15, as indicated by numerals 41 and 42 in FIG. They are opened and closed so as to form a gap corresponding to the width of the imaging areas f ₁ and f ₃ and a gap corresponding to the entire width of the film f. Therefore, in the case of two-part imaging, when imaging areas f ₁ and f ₃ are imaged, scattered rays reach the remaining imaging areas f ₂ and f ₄ (more specifically, a part of f ₂ and f ₄ ). Also, when regions f ₂ and f ₄ are in the imaging state, it prevents the scattered radiation from reaching regions f ₁ and f ₃ (more specifically, parts of f ₁ and f ₃ ). be able to. Although this embodiment has been described as an example of two-division imaging, even if four-division imaging is performed with this embodiment as it is, a considerable scattered radiation removal effect can be obtained. In this embodiment, a set of movable plates is used to shorten the distance from the front surface of the image section 15 to the film surface. Two sets of movable plates may be provided within the interval to enhance the scattered radiation removal effect.

In the present invention, the movable plate is made of a thin plate made of non-lead material, which not only prevents scattered radiation from the subject from reaching the film outside the shooting area during divided shooting, but also reduces the distance between the film and the subject from the conventional method. It has been shortened to about 1/2 or less (as an example, the conventional 15-20 mm has been shortened to 7-8 mm). As a result of numerous experiments conducted by the inventors, it has been shown that by using a thin plate made of lead-free highly elastic material for the movable plate, fog caused by scattered radiation can be reduced to a level that does not pose a practical problem. Based on confirmation that In the present invention, based on this knowledge, by constructing the movable plate from a thin plate such as stainless steel and a highly elastic material with extremely little deflection, the scattered radiation is attenuated and the film and subject are This makes it possible to shorten the distance by more than half compared to conventional methods. Therefore,
In the present invention, the term "removal of scattered radiation" includes attenuation of scattered radiation so that fog caused by scattered radiation does not become a practical problem.

The movable plate can be opened and closed by various mechanisms, but in the scattered radiation removal means of this embodiment, a parallelogram link is used for the opening and closing mechanism, and the opening and closing mechanism is connected to the base of the image section 15 together with the movable plate. Like the movable plate, the main movable part is made of a thin plate made of a non-lead material with high elasticity so that it can be assembled between the lower wall of the film holder 33 and the film holder 18. In FIGS. 3 and 4, a parallelogram link made from a thin plate has one pair of parallel link arms 43,
44 is arranged along the direction perpendicular to the longitudinal direction of the top plate 13, and is formed on the same plane as the movable plates 41 and 42 extending perpendicularly from the intermediate position of the arms 43 and 44. Arms 45, 46
is an arm in which each end of the arms 43, 44 is connected with a pin, and the center thereof, more specifically, the arms 43, 44,
44 is rotatably attached to shafts 47 and 48 fixed to the base body 33.
When the arm 45 is rotated around the shaft 47, the arms 43 and 44 connected to the arm 45 are moved in parallel, thereby causing the movable plates 41 and 42 that are integrated with the arms 43 and 44 to move toward each other. The X-ray entrance window that has been moved closer or further away can be opened or closed. The arm 45 is rotated by solenoids 51 and 52 attached to the base 33. These solenoids 51 and 52 are so-called rotary solenoids having shafts that rotate back and forth. Each solenoid 51, 52 has a shaft 47 whose rotation axis is the center of rotation of the arm 45.
Arm 5 is placed equidistant from
3 and 54 connect the rotating shafts of the solenoids 51 and 52 to the arm 45 so as to rotate in opposite directions. When the rotary shaft of one of the solenoids 51 and 52 rotates, the arm 45 rotates around the shaft 47, and the arms 43 and 44 move to move the movable plates 41 and 42 toward and away from each other. The film is moved to form an X-ray entrance window in a gap corresponding to the width of the film divided into two parts. Also,
When the rotation shaft of the other solenoid rotates, the arms 43 and 44 move in the opposite direction, and the movable plates 41 and 42 form a gap corresponding to the width of the film. Note that the solenoids 51 and 52 are connected to the base 33.
The solenoid 51,
52 can be converted together with arms 53 and 54.

[Effect of idea]

As shown in the embodiments described above, the X-ray fluoroscopic imaging table of the present invention has an X-ray entrance window with an area approximately equal to that for full-scale imaging of the film size used for imaging, and The front side of the film is By providing a mask mechanism with a flat shape that prevents scattered rays from the subject from entering the film outside the divided imaging area, X-ray photographs taken in divided imaging can be prevented from being covered by scattered rays. This will result in a clear image.

[Brief explanation of the drawing]

The drawings show an embodiment of the X-ray apparatus of the present invention, in which Fig. 1 is a front view, Fig. 2 is a side view, and Fig. 3 is a cross-sectional view of a part of the image part taken along the line of Fig. 1. Figure 4 is a sectional view along the line of Figure 3, and Figure 5
The figure is an explanatory diagram showing the operating state. 11...Table, 13...Top plate, 14...X-ray source,
15... Image section, 19, 31-36... Divided photographing means, 41, 42... Movable plate, 43-48... Opening/closing mechanism of the movable plate, 51-54... Operating means of the opening/closing mechanism.

Claims (1)

[Scope of claims for utility model registration] 1.
a radiation source, a dividing mask means for setting an X-ray irradiation area for divided imaging provided between a variable aperture in the X-ray source and the top plate, and a division mask means for setting the X-ray irradiation area for divided imaging, and the X-ray source and the top plate are provided above the top plate. An under-table tube type, which is arranged so as to be movable toward or away from the top plate and has an X-ray entrance window with approximately the same area as the entire surface of the film being used, and an image section with a film movement mechanism. The X-ray fluoroscopic imaging table includes a plurality of movable plates for removing scattered rays from the subject that are incident on the film surface outside the imaging area from the X-ray entrance window of the image section, and an opening/closing mechanism for the movable plates. A scattered ray removing means is provided, and the scattered ray removing means is configured in a flat shape using a thin plate, and is disposed within the image area and immediately in front of the surface of the film on the subject side. X-ray fluoroscopy table. 2. The X-ray fluoroscopy imaging stand according to claim 1, wherein the movable plate constituting the scattered radiation removing means and the movable part of the opening/closing mechanism are made of a non-lead material and made of a highly elastic thin plate.