JPS6351697B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radiation, in particular an X-ray, diaphragm device.

For example, in an X-ray diagnostic device, an X-ray diaphragm device is used to make the X-rays from the focal point of the X-ray tube into a conical shape and apply them to the object to be imaged (a patient, etc.), and the resulting X-ray transmitted image is, for example, Images are displayed using a television device (hereinafter referred to as X-ray television) for observation and diagnosis. in this case,
If the X-ray transmittance of the surrounding tissue of the object to be observed is too large than that of the object, there is a problem in that a difference in image brightness occurs on the image plane, causing halation. The details of this problem and conventional countermeasures will be explained below.

For example, when performing coronary angiography of the heart, when contrasting the left coronary artery 1a of the heart 1 as shown in FIG. 1, the center of the field of view 2 is positioned there; Since there is a portion 3 of high X-ray transmittance around the heart in a part (right side in the figure), the above-mentioned halation occurs. In order to prevent such problems,
Conventionally, as shown in FIG.
By attaching a The generation of halation was eliminated by eliminating the difference in brightness.

However, this method has the problem that the mounting position of the filter plate 7 must be manually changed each time the imaging position is changed, and this position setting takes time, making it unnecessary for the operator or the patient. There was also the problem of high exposure to X-rays.

The present invention has been made in order to solve the above-mentioned problems, and provides a radiation aperture device in which the position of a filter plate can be easily set and the radiation exposure dose of workers etc. can be extremely reduced. The purpose is to

The present invention will be specifically explained below using Examples.

FIG. 4 is a diagram illustrating the principle of the apparatus of the present invention. The two pairs of aperture blades 6 arranged at a predetermined distance vertically within the box-shaped X-ray aperture device main body 4 have a structure in which the horizontal distance can be varied for each pair, which is different from conventional ones. There is no place. These two pairs of aperture blades constrict the X-rays from the X-ray tube focal point 5 to form an X-ray cone 9. Two filter plates 7 are disposed opposite to each other below the aperture blade 6 so as to penetrate into the inside of the X-ray cone 9. The filter plate 7 is movably supported within the X-ray diaphragm 4 via an appropriate support mechanism, and is movable by an appropriate drive mechanism. Therefore,
By moving the filter plate 7 according to the region to be imaged, it is possible to easily attenuate the X-rays in the target range.

Next, a specific example of the support mechanism and drive mechanism will be described with reference to FIGS. 5 to 7. Here, Fig. 5 is a plan view, Fig. 6 is a sectional view taken along line A-A',
FIG. 7 is a sectional view taken along the line BB'. Note that in these figures, the filter plates are designated by reference numerals 22 and 23 for explanation. In the same figure, 11 is the center hole 1
1a and is a disc-shaped pedestal that is attached to the wall of the X-ray diaphragm (not shown), and the bottom of a ring-shaped pulley 12 is placed in the center hole 11a of this pedestal 11 to direct the X-ray tube focal point 5. It is rotatably supported and mounted at the center. The central hole 12a of this pulley 12 is formed in a size that does not obstruct X-rays passing through it. Further, on this pulley 12, two long flat mounting plates 13 and 14 having L-shaped portions 13a and 14a at their tips are disposed point-symmetrically and facing each other. The pulley 12 is connected to a rotating shaft of a motor 17 provided in the vicinity of the pulley 12 via a transmission wire 16.
It is connected with 5. Mounting plates 18a, 18b and 19a, 19b are fixed to the two mounting plates 13, 14 at predetermined intervals in the longitudinal direction.
Guide rods 20 and 21 are supported along the longitudinal direction of 14 so that both are parallel to each other. Two guide rods 20, 21 arranged in parallel in this way
Two rectangular filter plates 22 and 23 arranged at a predetermined interval are bridged between them, and these filter plates 22 and 23 have sliding fittings arranged at their respective four corners. 24a-24d and 25a-25d
It is slidably attached to two guide rods 20 and 21 via. Also, there are two holes on both end surfaces of the mounting plate 13.
Two pulleys 32 and 33 are rotatably attached to both end faces of the mounting plate 14, and a transmission wire 28 is stretched between the pulleys 26 and 27. , pulley 3
A transmission wire 34 is stretched between 2 and 33. In addition, pulleys 26a and 33a having the same shape are attached to the lower ends of the pulleys 26 and 33. Here, the tip of the sliding fitting 24a between one of the filter plates 22 and the guide rod 21 is connected to the transmission wire 3 near the tip of the sliding fitting 24a.
4, the other filter plate 23 and the guide rod 20
The tip of the sliding fitting 25a between the two is fixed to the transmission wire 28 nearby. Also, mounting plate 1
Motors 31 and 37 are mounted on the L-shaped parts 13a and 14a of the motors 31 and 14, respectively, and pulleys 29 and 3 are attached to the lower ends of the rotation shafts of the motors 31 and 37, respectively.
The pulleys 29 and 35 are connected to the lower end pulleys 26a and 33a of the pulleys 26 and 33 via transmission wires 30 and 36, respectively. The filter plates 22 and 23 are made of a material that attenuates transmitted X-rays, such as aluminum or copper.

With such a mechanism, the pulley 12 is rotated by rotationally driving the motor 17, and the mounting plates 13 and 14 and the two filter plates 22 and 23 arranged thereon are moved to the X-ray tube focal point 5. It can be rotated around the center. In addition, by driving the motors 31 and 37 individually or relative to each other, the pulley 2
The transmission wire 28 stretched between the pulleys 6 and 27 and the transmission wire 34 stretched between the pulleys 32 and 33 are moved, and along with this, the two filter plates 22 and 23 are moved closer or farther apart, and further parallel to each other. It can be moved.

According to the apparatus of the present invention described in detail above, the two filter plates can be easily rotated or moved in parallel by the motor drive, and the combination of these movements allows the filter plate to be moved in the cross-section of the X-ray cone. Can be set at any position. Therefore, for example, while observing an X-ray fluoroscopic image, the filter plate can be easily and quickly positioned at any position within the field of view by remote contact, which prevents halation and minimizes X-ray exposure for workers, etc. It is possible to provide an X-ray diaphragm device that can reduce the amount of radiation to a minimum.

It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made without changing the gist thereof. For example, in the embodiment described above, the filter plates 22 and 23 are rectangular, but as shown in FIG. 8, the filter plates 22 and 23 are shaped to have inner surfaces 22a and 23a that follow the outline of the object so that they can easily cover the periphery of the object to be observed. It's okay.

Alternatively, the thickness of the two filter plates may be changed so that one thick plate is used for adults and the other thin plate is used for children, depending on the diagnosis target.

Furthermore, the support mechanism and drive mechanism may be constructed of other members.

Also, in the above embodiment, the case was described in which two filter plates were used, but of course only one filter plate may be used.
It goes without saying that the number of cards may be three or more. In this case, the support mechanism and drive mechanism also need to be changed accordingly.

Furthermore, it goes without saying that the configuration of the X-ray diaphragm itself can be applied in exactly the same way whether the X-ray diaphragm itself is diaphragm in one stage or in the case of so-called multiple diaphragm in which the diaphragm is diaphragm in multiple stages.

According to the present invention described in detail above, the filter plate can be positioned and set in any shape according to the shape of the subject by combining the parallel movement in the direction orthogonal to the radiation cone and the rotational movement. It has the unique effect of being able to reliably prevent radiation exposure to workers and the like.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of coronary angiography of the heart without using a filter plate, Figure 2 is a diagram showing how a conventional filter plate is used, and Figure 3 is an explanatory diagram of coronary angiography with a filter plate used. , FIG. 4 is a diagram explaining the principle of the device of the present invention,
Fig. 5 is a plan view of a specific example of the device of the present invention, Fig. 6 is a sectional view taken along the line A-A', Fig. 7 is a sectional view taken along the line B-B' in Fig. 5, and Fig. 8 is a sectional view of the filter plate. FIG. 7 is a plan view showing another shape. 4... X-ray aperture device, 5... X-ray tube focus, 6... Aperture blades, 7, 22, 23... Filter plate, 11... cradle,
12... Pulley, 13, 14... Mounting plate, 15, 2
6, 27, 29, 32, 33, 35...Pulley, 1
6, 28, 30, 34, 36... transmission wire, 1
7, 31, 37...Motor, 18a, 18b, 19
a, 19b...support metal fittings, 20, 21...guide rods,
24a-24d, 25a-25d...Sliding metal fittings.

Claims (1)

[Claims] 1. A radiation aperture device in which at least one pair of movable aperture blades is installed inside a box-shaped device main body, and the shape of a cone of radiation passing through the movable aperture blades can be changed by operating the movable aperture blades. At least a pair of filter plates are provided inside the main body and are movable individually or relatively between a position where the radiation beam cone is crossed and a position where it is not crossed by a drive mechanism, and which are rotatable around the focal point of the radiation beam. The driving mechanism includes a ring-shaped rotating member that rotates around a radiation focal point, a guide member that is arranged parallel to the rotating member and to which the filter plate is slidably attached, and A radiation aperture device comprising a rotational drive source for a rotating member and a drive source for moving the filter plate.