JPH0250596B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an X-ray aperture device that is attached to an X-ray tube for stereo imaging used in an X-ray apparatus.

[Technical background of the invention]

Circulatory system X such as angiography of the brain, heart, and abdominal region
In radiographic diagnosis, an X-ray diagnostic apparatus is used that can perform direct radiography and indirect radiography separately and quickly. For example, in the X-ray imaging device shown in Fig. 1,
Opposed to the ray tube 1 and the X-ray aperture device 2, an X-ray image detection device such as an image intensifier (hereinafter referred to as II) 3, a cine camera 4, a TV camera 5, and a film changer 6 are mounted. , fluoroscopy, cine photography, and monoscopic direct continuous photography using a film changer. In addition, 7 in the figure is a bed,
P is the subject.

In addition, in cardiovascular angiography and coronary angiography, in order to further improve diagnostic ability, we perform cine imaging from various directions, or cine imaging from two directions using two X-ray tubes. Efforts are being made to spatially separate and recognize blood vessels that are dimensionally complexly distributed.

In recent years, stereocine photography and stereocine projectors have been developed as a means to more intuitively obtain a large amount of diagnostic information, and it has become possible to perform static and dynamic stereoscopic viewing, as well as multi-person stereoscopic viewing in an interpretation room.

The X-ray diagnostic equipment that can perform stereo imaging as described above uses an X-ray tube that has a pair of X-focus points for stereo imaging placed on one target at a predetermined interval. As a limiting device,
Conventionally, an X-ray diaphragm device 8 as shown in FIGS. 2a and 2b
It has been known. That is, in FIG. 2a, the X-ray cone XR1 emitted from the focal points A and A' of the X-ray tube 9,
The aperture operation for each XR2 is performed by a fixed blade 10 and a movable blade 11 provided on the X-ray radiation port side for the X-ray cone XR1, and by a fixed blade 10 and a movable blade 11 provided on the X-ray radiation port side for the X-ray cone XR2. Fixed blade 12, movable blade 1
This is done by 3.

[Problems with background technology]

In the conventional X-ray diaphragm device 8 as described above, when stereo imaging a necessary part of the subject P as shown in FIG. 2b, the inside of the X-ray cones XR1 and XR2 cannot be diaphragm. There was a problem in that unnecessary X-rays (the perspective part in FIG. 2b) were given to the subject P. In addition, since the fixed blades 10 and 12 are fixed, if the focal point-image receiving surface distance (hereinafter referred to as SID) H changes, the X-ray irradiation fields of the X-ray cones XR1 and XR2 will no longer match, resulting in a sharp X-ray image. There was a drawback that the line irradiation end could not be obtained, and therefore only a fixed SID image could be taken.

[Purpose of the invention]

The present invention was made based on the above circumstances, and
During stereo imaging in an X-ray device using an X-ray tube with one target and two focal points, the amount of X-ray exposure to the subject is reduced by narrowing down the emitted X-rays to the necessary minimum, and the distance between the focal point and the image receiving surface is reduced. An object of the present invention is to provide an X-ray diaphragm device that enables good imaging even when the change occurs.

[Summary of the invention]

The present invention uses an X-ray tube provided with two focal points on one target, and performs a stereoscopic operation in which X-rays are alternately emitted from both focal points, and X-rays are emitted from only one of the two focal points. In an X-ray diaphragm device for restricting the X-ray irradiation field to a rectangular shape in an X-ray apparatus that performs a monoscopic operation for emitting radiation, the first and second movable vanes that are movable along one direction within a plane orthogonal to the irradiation direction of the X-ray weights and that limit first side edges of the two X-ray weights that are close to each other; The first movable blade is provided outside the X-ray weights at a distance from the X-ray emission port of the X-ray tube than the first and second movable blades, and is located outside the X-ray weight in a plane perpendicular to the X-ray emission direction. third and fourth movable vanes that are movable along the direction and limit respective second side edges parallel to the respective first side edges of both the X-ray weights; is provided between the movable blade and the third and fourth movable blades, and is movable along a direction perpendicular to the one direction within a plane perpendicular to the irradiation direction of the X-rays; The configuration includes fifth and sixth movable blades that respectively limit third and fourth side edges perpendicular to the first and second side edges of the X-ray weight, and a desired X-ray irradiation field is Even if the distance between the focal point and the image receiving surface changes, the X-rays emitted from both focal points can be adjusted by adjusting the first and second movable blades. It is characterized by matching the irradiation fields.

[Embodiments of the invention]

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

First, the schematic structure of this embodiment will be explained with reference to FIGS. 3a and 3b. That is, the X-ray diaphragm device of this embodiment is composed of a device main body indicated by the reference numeral 14, a control device (not shown), and various switches installed in the X-ray diagnostic device. It is attached and fixed to the X-ray emission port side of the X-ray tube 15 having a focal point. And the device main body 14 is
The first and second rectangular blades 16, 1 limit one side edge of each of the X-ray cones XR1 and XR2 to the X-ray emission port side.
7 is provided. A circular aperture blade 18 is provided below the first and second rectangular blades 16 and 17 to cut out X-rays that exceed the circumference of the X-ray image receiving device (not shown). . Below the circular aperture blade 18 is a compensation filter 19 for compensating for the difference in X-ray absorption between the myocardium and the lung field.
is provided. Below this compensation filter 19, a square X is provided along with third and fourth square blades, which will be described later.
fifth and sixth rectangular blades 20 for setting the radiation field;
21 is provided, and the fifth and sixth rectangular blades 2
Below the X-ray cones XR1 and XR2, there are third and fourth rectangular blades 22,
23 are provided. Note that the first to sixth rectangular blades 16, 17, 20, 21, 22, 23,
The circular aperture blades 18 and the compensation filter 19 are each made of a radiation shielding material such as a lead plate, and are movable by a control device and a drive mechanism, which will be described later. Further, the fourth rectangular blade 23 has a double sliding mechanism consisting of two blades. and the third
Fig. 3a shows the state during stereoscopic imaging using two focal points (during stereoscopic imaging), and Fig. 3b shows the state during fluoroscopy and general imaging using one focal point (during monoscopic imaging).

Next, details of the apparatus main body 14 of this embodiment will be explained with reference to FIGS. 4a and 4b. FIG. 4a is a front view, and FIG. 4b is a side view, and the same parts as in FIGS. 3a and 3b are given the same reference numerals. That is, the device main body 14 includes a base 2 attached to an X-ray tube 15.
4, and a base 26 is attached by a support fitting 25 attached to this base 24.
A base 28 is attached by a support fitting 27 attached to the base 28. And base 24, 26, 2
8 and the support fittings 25, 27 are provided with a square blade mechanism including first to sixth square blades 16, 17, 22, 23, 20, 21, and the base 26 is provided with a circular blade mechanism including a circular aperture blade 18 . A compensating filter mechanism including a compensating filter 19 is provided.

The first and second rectangular blades 16 and 17 are connected to the base 2
Bearing 29 and lead screw shafts 30A, 30 fitted to support fitting 25 attached to 4
B, the nut 31A, the guide 31B, and the metal fittings 32 connected to these are respectively attached. Also, lead screw shaft 30A, 30
Stepping motors 34 are fixed to the ends of B by support fittings 35 via coupling rings 33, respectively.

The third and fourth rectangular blades 22 and 23 and the fifth and sixth rectangular blades 20 and 21 are attached to the aforementioned first and second rectangular blades 16 and 17 on support fittings 36 and 37 provided on the base 28. Similarly, bearings 38, 39, lead screw shafts 40A, 40B and 41
A, 41B, nuts 42A, 43A, guides 42B, 43B, metal fittings 44, 45, coupling rings 46, 47, coupling rings 48, 49, stepping motors 50, 51, and metal fittings 52, 53. Further, a blade position detection switch 55 is provided on the support fitting 54 of the bases 26 and 28, respectively. The circular aperture blade 18 is attached to a support fitting 56 attached to the base 20, a bearing 57, a lead screw shaft 58, a guide 59, a nut 60 thereof, and a metal fitting 61 connected thereto.
A stepping motor 63 is fixed to the end of the blade 8 by a holding fitting 64 using a coupling 62 similar to the square blade described above.

Further, in the compensation filter mechanism including the compensation filter 19 , a base 66 of the compensation filter mechanism is attached to a support fitting 65 provided on the base 26. This base 66 includes a compensation filter 19.
A, 19B ( 19 ) is provided with a bearing 68 for rotationally holding the base 67 and its support fitting 69, and a spacer 7 is provided on the compensation filter base 47.
A motor 72 with a gear head is attached to the motor 72 for rotation in mesh with a gear 71 connected to the motor 71 through a gear 71.

As shown in FIG. 5, the base 67 of the compensation filter mechanism has two compensation filters 19 on its left and right sides.
A and 19B indicate a motor 74 attached to a support fitting 73, a gear 75, a gear 76 meshing with this gear 75, a lead screw shaft 77 attached to this gear 76, its screw nut 78, and this. Holding metal fittings 79 provided in
installed on. Further, on the opposite side, a guide 80 for preventing rotation and a shaft 81 are held by a metal fitting 82.

Next, the control system of the apparatus main body 14 described above will be explained with reference to FIG. 6.

That is, as shown in FIG.
3 is equipped with switches such as an SID detector 84, an image size changeover switch, an II/film changer changeover switch 85, an imaging method selection switch 86, and a collimator open/close switch 87, and information from these switches is provided. is an analog/digital converter (A/D) 89 of the aperture device control section 88 and an interface (I/F)
Microcomputer (CPU) through 90
91. It is assumed that the storage section of this microcomputer (CPU) 91 stores in advance data indicating the size of the image receiving surface in the X-ray imaging device section in which this X-ray diaphragm device is incorporated, and this data and the above-mentioned switches are stored in advance. With information,
Stepping motors 34, 50, 5 mounted on square blades to obtain the desired image receiving surface size.
A drive command is outputted via a stepping motor drive circuit 92 having a pulse counting mechanism at 1 and 63 to rotate the lead screw, and
The opening and closing operations of the first to sixth rectangular blades 16, 17, 22, 23, 20, and 21 shown in FIGS. 4a and 4b are also performed. Note that the limit position information from the blade position switch 55 is given to a microcomputer (CPU) 91 via a stepping motor drive circuit 92. Furthermore, Figure 3a,
b and the compensation filter 19 shown in FIGS. 4a and 4b.
A, 19B ( 19 ) are opened and closed by applying information from the above-mentioned switches to the motor 74 shown in FIG. 5 via an interface (I/F) 90 and a compensation filter drive circuit 93. .

Next, the operation of this embodiment configured as described above will be described. That is, Fig. 3 a, b, Fig. 4 a, b
and a square blade mechanism and a circular blade mechanism shown in FIG.
A desired driving operation of the compensating filter mechanism is performed by the operator providing driving amount information to the control system shown in FIG. 6 through the operating section.

Here, the setting of a desired rectangular irradiation field (image receiving surface size) will be specifically described. That is, as shown in Fig. 7, the image receiving surface size W, the distance to the rectangular aperture blade position are h1, h2 is the focal point A, the distance between A' is T, the focal point A,
Letting the distance between A' and the image receiving surface be H, the square blade opening degrees W1 and W2 at any SID can be given by W1=W/H・h1 W2=(W-T)・h2/H+T, Feathers 16, 17, 2
0, 21, 22, and 23 are moved to the positions W ₁ and W ₂ by the control drive system shown in FIG. When further narrowing down is desired by the operator's intention using the X-ray photographing device collimator opening/closing switch 87, the X-ray photographing device collimator opening/closing switch 87 can be fully closed from the image receiving surface size and can be freely opened and closed. Therefore, even if the SID changes, it is possible to obtain a sharp X-ray irradiation edge. Therefore, the X-rays emitted from the focal point can be narrowed down to the necessary minimum, reducing the amount of X-ray exposure to the patient. The distant third and fourth rectangular blades 22 and 23 can restrict the outward spread of X-rays, making it possible to obtain a sharp image. Further, the circular diaphragm blades 18 are linked to the II-film changer switch 85 of the X-ray imaging device section 83, and when II is selected, they can be moved to cut off X-rays that exceed the exterior size of II. .

Next, an example of the operation during monoscopic fluoroscopy or photographing will be described with reference to FIG. That is, since X-rays are emitted only from one focal point A, the X-ray irradiation field is divided into the first, second, fifth, and sixth square blades 16, 1
It is limited not only by the blades 7, 20 and 21 but also by the second and third rectangular blades 22 and 23. At this time, since the second and third rectangular blades 22 and 23 are of a double sliding type as shown in the figure, the range for restricting the X-ray irradiation area can be reduced without increasing the outer diameter of the entire aperture. It can be made wider, and a sharper X-ray irradiation end that cannot be obtained by using only the first and second rectangular blades 16 and 17 can be obtained.

In addition, the compensation filter mechanism includes the X-ray imaging device section 8.
When monoscopic fluoroscopy or cine imaging technique of the heart is selected by the radiography method selection switch 86 of No. 3, as shown in FIGS. Linear absorption differences can be compensated for.
Further, the compensation filters 19A and 19B can be moved left and right by motors 74, and rotated by a motor 72 to match the shape of the heart.

Note that the above embodiment is merely an example, and it goes without saying that each member can be replaced with another member having the same function.

It goes without saying that this mechanism can also be applied as an X-ray diaphragm device that is attached to a conventional X-ray tube exclusively used for monoscopic imaging.

〔Effect of the invention〕

As described in detail above, the present invention uses an X-ray tube provided with two focal points on one target, and uses a stereoscopic operation in which X-rays are alternately emitted from both focal points, and one of the two focal points. X from one side only
In an X-ray diaphragm device for restricting an X-ray irradiation field to a rectangular shape in an X-ray apparatus that performs a monoscopic operation for emitting radiation, the first and second movable vanes that are movable along one direction within a plane perpendicular to the X-ray irradiation direction and that limit respective first edges of the X-ray weights that are close to each other; The first movable blade is provided outside the X-ray weights at a distance from the X-ray emission port of the X-ray tube than the first and second movable blades, and is located outside the X-ray weight in a plane perpendicular to the X-ray emission direction. third and fourth movable vanes that are movable along the direction and limit respective second side edges parallel to the respective first edge sides of both the X-ray weights; is provided between the movable blade and the third and fourth movable blades, and is movable along a direction perpendicular to the one direction within a plane perpendicular to the irradiation direction of the X-rays; The fifth and sixth movable blades respectively limit third and fourth side edges perpendicular to the first and second side edges of the X-ray cone, and a desired X-ray irradiation field is formed. X-rays can be set by the first to sixth movable blades, and even if the distance between the focal point and the image receiving surface changes, the X-rays are emitted from both focal points by adjusting the first and second movable blades. Since the respective irradiation fields are made to match, it is possible to reduce the amount of X-rays irradiated to the subject by reducing the amount of X-rays exposed during stereo imaging to the necessary minimum, making it possible to take clear images. An X-ray aperture device can be provided.

[Brief explanation of drawings]

Figure 1 is a diagram showing an example of an X-ray diagnostic device used for circulatory system diagnosis, Figures 2 a and b are schematic diagrams for explaining a conventional X-ray aperture device, and Figures 3 a and b are diagrams of A schematic diagram showing an embodiment of the X-ray diaphragm according to the invention, FIGS. 4a and 4b are diagrams showing the detailed configuration of this embodiment, and FIG. 5 is a diagram showing the configuration of the compensation filter mechanism in this embodiment, Fig. 6 is a block diagram showing the configuration of the control drive system of this embodiment, Fig. 7 is a diagram for explaining the operation in stereoscopic mode in this embodiment, and Fig. 8 is a diagram for explaining the operation in monoscopic mode in this embodiment. FIG. 3 is a schematic diagram for explaining the action. 14... Device main body, 16, 17... First, second
Square blades, 18...Circular aperture blades, 19 (19
A, 19B)... Compensation filter, 20, 21...
...5th and 6th square blades, 22, 23...3rd,
Fourth square blade.

Claims (1)

[Claims] 1 Stereoscopic operation in which an X-ray tube with two focal points is used on one target, and X-rays are alternately emitted from both focal points, and X-rays are emitted from only one of the two focal points. In an X-ray diaphragm device for restricting an X-ray irradiation field to a rectangular shape in an X-ray apparatus that performs monoscopic operation, it is provided between both X-ray weights emitted from both focal points,
first and second movable vanes that are movable along one direction within a plane perpendicular to the X-ray irradiation direction, and that limit respective first side edges of both X-ray weights that are close to each other; and, provided outside of both the X-ray weights at a distance from the first and second movable blades with respect to the X-ray emission opening of the X-ray tube, and within a plane perpendicular to the X-ray emission direction. third and fourth side edges that are movable along said one direction and that limit respective second side edges parallel to respective first side edges of both said X-ray weights;
a movable blade, and is provided between the first and second movable blades and the third and fourth movable blades, and is perpendicular to the one direction within a plane perpendicular to the X-ray irradiation direction. third and fourth side edges that are movable along the direction and perpendicular to the first and second side edges of each of the X-ray weights;
an X-ray diaphragm device comprising fifth and sixth movable blades that respectively limit the side edges of the X-ray diaphragm.