JPS6323054Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to an X-ray diaphragm device for a CT scanner.

[Conventional technology]

An X-ray tube device that emits Fan beam X-rays and an X-ray detector having a plurality of detection elements arranged along the spread of the X-rays rotate in accordance with the spread angle of the Fan beam X-rays. In the CT scanner, which performs lateral scan every time,
Scannagraphy has already been used to obtain images similar to X-ray fluoroscopic images obtained with ordinary X-ray equipment. This is done by stopping the rotation of the X-ray tube device and X-ray detector, allowing them to perform only lateral scans, and each time a lateral scan is performed, the top plate supporting the subject is moved. Therefore, this is done by constructing a fluoroscopic image from data obtained by an X-ray detector.

[Means for solving problems]

However, in scannagraphy, all of the detection elements that make up the X-ray detector are required to capture data, so it takes a considerable amount of time to compose an image, and moreover, it does not expose the subject to unnecessary X-rays. There is the problem of exposure.

The purpose of the present invention is to be able to construct an image in a shorter time when performing scanagraphy.
Moreover, the purpose is to reduce the radiation exposure to the subject, and for this purpose, X
An object of the present invention is to provide an X-ray constriction device for a CT scanner that can constrict X-rays to an arbitrary thickness and can constrict X-rays so as to cover only a single detector.

[Means for solving problems]

The X-ray diaphragm device for a CT scanner of the present invention is located close to an X-ray tube constituting an X-ray tube device, and includes a first diaphragm means for diaphragming an irradiation tube and X-rays to an arbitrary thickness, and an X-ray diaphragm means for diaphragming a single X-ray detector so as to cover the single X-ray detector.
and a second aperture means for narrowing the beam, the first aperture means having two first members made of X-ray shielding material and arranged in parallel, and a drive mechanism for moving these members in parallel in the arrangement direction, the second aperture means having a mask plate made of X-ray shielding material and provided with an opening that passes only X-rays that cover a single X-ray detector, arranged perpendicular to the first members, and a drive mechanism for moving the mask plate in a direction perpendicular to the movement direction of the first members.

An embodiment of the X-ray diaphragm device for a CT scanner according to the present invention will be described below with reference to the accompanying drawings.

〔Example〕

Figure 1 shows a CT equipped with an X-ray aperture device according to the present invention.
It shows Sukiyana. The X-ray tube 1 and the plurality of detectors 2 are supported by a scanning frame 3. The scanning frame is attached to a guide rail 5 on a rotating plate 4.
The rotary plate is placed on rollers 7 on a base 6 and can rotate on the rollers. The scanning frame and the rotating plate are arranged so that the scanning frame 3 is moved along the guide rail 5 each time the rotating plate 4 is rotated by an angle corresponding to the spread of the X-ray a by a drive mechanism (not shown). being forced to move.

The X-ray diaphragm device 10 according to the present invention
It is installed in the scanning frame 3 located in the radiation hole,
The X-rays emitted from the X-ray tube can be narrowed down to fan beam X-rays a that cover all of the detector 2 and have different thicknesses, and the X-rays can cover only a single detector. Now you can narrow down your search to b.

Figures 2 to 4 show details of this diaphragm device. An irradiation tube 12 is fixed to the substrate 11. The entire irradiation tube is made of an X-ray shielding material, and an X-ray passage 13 is provided therethrough. A guide plate 14 is fixed to the opposite surface of the board. Two members 15 made of X-ray shielding material are arranged on the lower surface of this guide plate. These members have straight edges and are arranged so that each edge is parallel. Discs 16 are positioned near both ends of the member 15, and shafts extending from the discs 16 are held in bearings on the base plate. The member is fastened to the disk by a pin 17 so that the width W between opposing edges can be changed as the disk rotates. The rotation of the disc is performed by a pulse motor 18 installed on the board. The pulse motor has its rotating shaft connected to the shaft of one disc. Further, a torsion coil spring 19 is engaged with the boss of the other disc, and both ends are fixed to the base plate and the disc. This torsion coil spring constantly rotates the disk in one direction, maximizes or minimizes the width W between the members 15, eliminates bumps in the gear head of the pulse motor, and allows smooth movement of the members. ing.

On the other hand, an opening 21 connected to the X-ray passage 13 is provided in the guide plate 14 fixed to the substrate. A pair of opposing walls perpendicular to the member 15 in this opening are provided with a straight groove, into which the mask plate 22 is slidably inserted. An opening 23 is provided at the edge of the mask plate on the member 15 side,
A long hole 24 is provided near the opposite edge. The crank plate 25 is fixed to a rotating shaft of a motor 26 installed on a board, and a bottle 7 extending from the crank plate 25
is fitted into the long hole 24 of the mask plate 22. The mask plate is rotated by the rotation of the motor in one direction.
5 into a position intersecting the space formed by the member 15, and by rotation of the motor in the opposite direction, the member 15 is moved to a position outside the maximum space formed by the member 15, respectively.

As shown in FIG. 1, the diaphragm device according to the present invention fixes the substrate to the scanning frame 3 and connects the upper part of the irradiation tube 12 to the X-ray tube 1 via the dark current shutter 26. It is installed in Sukiyana. The size of the X-ray passage 13 in the irradiation tube 12 and the width W of the opening formed when the member 15 is fully opened allow the X-rays emitted from the X-ray tube device 1 to enter the entire X-ray detection device. opening 2 in the mask plate.
The size No. 3 allows X-rays to be incident only on one detector in this detection device, for example, the central detector.

With this CT scanner, during normal imaging,
By moving the two members 15 outward and forming the largest opening between the members 15, the
Let the X-rays from the
Fan beam X-rays with a large thickness can be obtained, and by moving the two members 15 toward each other, fan beam X-rays with a smaller thickness can be obtained. , it is possible to set a slice surface with a thickness depending on the diagnostic purpose.

Furthermore, scanning scanner photography can also be performed simply by moving the mask plate 22. As mentioned above, this is done by stopping the rotation of the X-ray tube device 1 and the X-ray detector 2, moving the scanning frame 3, and performing only a lateral scan on the X-ray tube device and the X-ray detector. Each time a lateral scan is performed, the top plate supporting the subject is slightly moved, and the image reconstruction device uses the data obtained by the X-ray detector by moving the top plate supporting the subject over the entire diagnostic target area. This is done by constructing a perspective image. According to the present invention, the diaphragm device at this time makes the opening formed by the member 15 as large as possible, and by moving the mask plate 22 between the members 15, the X The X-rays are blocked by the mask plate 22, and the X-rays emitted from the X-ray tube device can be incident on only one detector, so compared to the conventional one,
The amount of X-rays that the subject is exposed to can be reduced, the storage capacity of the image reconstruction device can be reduced, and calculations for constructing a fluoroscopic image can be performed easily and in a short time.

In the embodiments described above, the movement of the mask plate 22 is performed by the crank plate 25 and the rotary solenoid. It is also possible to connect the spring back to the side.

[Effect of idea]

As mentioned above, the X-ray diaphragm of the present invention has the following features:
It is located close to the X-ray tube that constitutes the X-ray tube device, and includes a first aperture means that constricts the irradiation tube and X-rays to an arbitrary thickness, and an X-ray tube that covers the single X-ray detector. It is equipped with a second aperture means that constricts the beam, the first aperture means is made of an X-ray shielding material, and includes two first members arranged in parallel, and a drive mechanism that moves these members in parallel in the arrangement direction. and the second aperture means is made of an X-ray shielding material, is provided with an opening that covers a single X-ray detector and allows only X-rays to pass through, and is disposed orthogonally to the first member. the mask plate; and a drive mechanism that causes the mask plate to move in a direction perpendicular to the moving direction of the first member. Since the X-ray flux can be detected by only one detector, the X-ray exposure to the subject can be reduced during scanagraphy imaging, and the fluoroscopic image can be constructed in a short time. By retracting the mask plate and moving the first member, it is possible to obtain fan beam X-rays with different thicknesses, so the thickness of the slice plane can be selected depending on the diagnostic purpose, and moreover, Since images can be taken using one device, diagnosis can be made efficiently.

[Brief explanation of the drawing]

The drawings show one embodiment of the X-ray diaphragm device of the present invention, and FIG. 1 is an explanatory diagram showing an example of the state installed in a CT scanner, FIG. 2 is a front view of the X-ray diaphragm device itself, and FIG. 3 is a side view thereof, and FIG. 4 is a bottom view thereof. DESCRIPTION OF SYMBOLS 1... X-ray tube, 2... Detector, 11... X-ray diaphragm device, 12... Irradiation tube, 15... Member, 16-
19... Drive mechanism, 22... Mask plate, 23...
Opening, 24-27... Drive mechanism.

Claims (1)

[Scope of utility model registration request] An X-ray tube device that emits Fan beam X-rays and a plurality of X-ray detectors arranged along the spread of the X-rays rotate in accordance with the spread angle of the Fan beam, and perform a lateral scan with each rotation. an X-ray constriction device for a CT scanner, the first constriction means being located close to an X-ray tube constituting the X-ray tube device and constricting the irradiation tube and the X-rays to an arbitrary thickness; X to cover a single X-ray detector
a second aperture means for constricting the wire, the first aperture means is made of an X-ray shielding material, two first members arranged in parallel, and a drive for moving these members in parallel in the arrangement direction. the second aperture means is made of an X-ray shielding material, is provided with an opening that covers a single X-ray detector and allows only X-rays to pass through, and is arranged orthogonally to the first member. and a drive mechanism that causes the mask plate to move in a direction perpendicular to the direction of movement of the first member;
An X-ray diaphragm device for CT scanners featuring the following.