JPH05264788A - Radiaton shielding material, radiological apparatus and radiation diagnostic apparatus - Google Patents

Abstract

PURPOSE:To provide a radiation shielding material which can be formed in a desired shape easily by scissors, a knife or the like, by preparing it from barium sulfate and a material for fixing this barium sulfate, and to use the material thus prepared for a radiation compensation filter. CONSTITUTION:Clay-like silicone rubber and the powder of barium sulfate are so kneaded as to be distributed uniformly. When the weight ratio in kneading of the barium sulfate is made about 40wt.% of the total weight, for instance, a radiation compensation filter 5 using it has an equal X-ray absorbing power to the one made of load-containing acrylic resin in the same thickness as the latter. The quantity of the kneaded barium sulfate is regulated according to the thickness of a material thus obtained, at the time when it is used for the radiation compensation filter 5, and to the degree of the X-ray absorbing power desired. It sometimes happens that the radiation compensation filter 5 prepared beforehand can not be adapted, as it is, to a part of compensation of an X-ray absorption difference. At that time, the material can be processed easily in the course of diagnosis by scissors, a knife or the like. Therefore the time for diagnosis can be shortened, and further it is possible to prevent halation and also to improve the precision of the diagnosis since a diagnostic image becomes easy to see.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation shielding material, a radiation apparatus using a radiation compensation filter made of the radiation shielding material, and a radiation diagnostic apparatus.

[0002]

2. Description of the Related Art Conventionally, a radiation diagnostic apparatus has been used for medical diagnosis for the purpose of obtaining a projected image of a patient. On a TV monitor that displays a perspective image, a portion with little X-ray absorption causes halation, which makes the image difficult to see. For example, in the case of fluoroscopy of the heart, the heart has a high X-ray absorptivity, and the surrounding tissue, that is, the lung part, has a low X-ray absorptivity with respect to the heart, so that in the part around the heart, Halation occurs,
The image of the circular artery on the surface of the heart, which is a clinical subject, becomes difficult to see. Therefore, in such a case, in order to prevent halation, a portion having less radiation absorption, that is, a halation portion (X-ray absorption difference correction portion), is provided by a radiation compensation filter made of a radiation shielding material installed inside the X-ray movable diaphragm body of the radiation diagnostic apparatus. ), The X-ray absorption difference is corrected.

This radiation compensation filter is made of metal, lead-containing acrylic or the like, and it is possible to prevent halation depending on the shape of the site to be diagnosed by preparing a predetermined shape. The halation part is covered by exchanging it with an optimal shape or shifting it to an optimal position. Next, how the radiation compensation filter is installed in the X-ray movable diaphragm body will be described with reference to FIG.

The X-ray movable diaphragm main body 101 is attached to an irradiation port of an X-ray tube (not shown) in order to narrow the range of irradiation of the subject with X-rays. In this X-ray movable diaphragm body 101,
An acrylic cover 102 is attached so as to be openable and closable, and by opening the cover 102, the radiation compensation filter 103 can be replaced. An outer frame 104 made of metal is attached to the radiation compensation filter 103, and the outer frame 104 is fixed on a base 105 provided inside the X-ray diaphragm main body 101. This outer frame 10
4 and the base 105 can be easily removed, and by attaching the outer frame 104 to the radiation compensation filters having different shapes in advance, it is possible to easily change the shape according to the shape of the site to be diagnosed. It is possible to replace the radiation compensation filter with the optimum shape. Also,
The base 105 is driven by a motor (not shown) so as to move in the direction of the arrow in FIG. 10, and the radiation compensation filter 103 can be moved to an optimum position.

[0005]

In the radiation compensation filter as described above, it takes time to form a desired shape, and therefore several kinds of shapes having a predetermined shape are prepared. However, since the shape of the site to be diagnosed is various, the prepared shape alone may not be suitable for the X-ray absorption difference correction site. In other words, halation may not be sufficiently prevented, so that the image on the television monitor may be difficult to see. Therefore, there is a demand for a radiation compensation filter that can be easily processed during diagnosis to match the shape of the X-ray absorption difference correction portion.

Among conventional radiation shielding materials, materials that can be easily processed into desired shapes using scissors, knives and the like include heavy metal silicon rubber and aluminum containing plastic. Since it contains heavy metals, it is harmful to the human body and is not suitable for medical diagnosis. On the other hand, the aluminum-containing plastic has a drawback that it has a small radiation absorbing ability and the plate thickness becomes large to be used for preventing halation.

Therefore, the present invention has been made in view of the above circumstances, and an object thereof is to provide a radiation shielding material which can be easily processed into an optimum shape by using scissors, a knife or the like. An object of the present invention is to provide a radiation apparatus and a radiation diagnostic apparatus that use a radiation compensation filter made of a shielding material.

[0008]

To achieve the above object, the radiation shielding material of the present invention comprises barium sulfate and a material for immobilizing this barium sulfate.

The radiation device of the present invention further comprises a radiation source for generating radiation, and a radiation compensation filter provided near the radiation outlet of the radiation source for partially attenuating the dose of radiation generated by the radiation source. And the radiation compensation filter is made of barium sulfate and a material for fixing the barium sulfate.

Further, the radiation apparatus of the present invention is arranged so that a radiation source for generating radiation, a radiation diaphragm for limiting a radiation irradiation range from the radiation source to a cone shape, and a cone line of the cone radiation are opposed to each other. And a pair of radiation compensating filters for partially attenuating the radiation dose generated from the radiation source, the radiation compensating filter being composed of barium sulfate and a material for immobilizing the barium sulfate. is there.

Further, the radiation diagnostic apparatus of the present invention for irradiating a subject with radiation to obtain a radiation image of the subject is provided with a radiation source for generating radiation and a radiation source provided near this radiation source. A radiation device having a radiation compensation filter for partially attenuating the generated radiation dose, wherein the radiation compensation filter is barium sulfate,
It is made of a material for immobilizing this barium sulfate.

[0012]

According to the present invention, a radiation-shielding material is obtained from barium sulfate and a material for fixing the barium sulfate, so that a radiation-compensating filter made of this radiation-shielding material is a scissors or knife. It is possible to process by using so as to easily obtain a desired shape. Therefore, in a radiation apparatus and a radiation diagnostic apparatus using this radiation compensation filter, no matter what shape the X-ray absorption difference correction portion has, the radiation compensation filter is processed according to the shape to cause halation. It can be suppressed sufficiently.

[0013]

EXAMPLES A method of manufacturing a radiation shielding material according to the present invention will be described below. In this description, the case where silicon rubber is used as a material for fixing barium sulfate will be described.

First, clay-like silicon rubber and powdered barium sulfate are kneaded using a roller or a kneader so that barium sulfate is evenly distributed.
If the weight ratio of the kneading at this time is, for example, about 40% by weight of barium sulfate with respect to the total weight, the X-ray absorbing power is the same as that of the conventional radiation compensating filter made of lead-containing acrylic. The kneading amount of barium sulfate may be appropriately adjusted depending on the thickness when finally used as a radiation compensation filter and how much X-ray absorption capacity is required. Further, if the particle size of barium sulfate to be kneaded is too small, it will be difficult to mix with the silicon rubber at the time of kneading, and if too large, the shadow of barium sulfate will appear in the X-ray fluoroscopic image. Therefore, it suffices to use barium sulfate having a particle size that does not cause the above-mentioned inconvenience, and in this embodiment, barium sulfate having a particle size of about 1.2 μm was used.

Next, a vulcanizing material is added to the kneaded mixture, and the mixture is further kneaded, pressed with a mold having a desired shape to perform primary vulcanization, and then taken out from the mold to undergo secondary vulcanization to obtain the desired vulcanization. A radiation shielding material in the form of is obtained. The radiation shielding material obtained as described above can be easily processed with scissors or a knife.

The method of manufacturing the radiation shielding material according to the present invention is not limited to the above-mentioned manufacturing method, and it is sufficient that a mixture of silicon rubber and barium sulfate is finally obtained.

Further, in the above embodiment, since silicon rubber is excellent in radiation resistance, silicon rubber was used as the material for fixing barium sulfate, but the material is not particularly limited to silicon rubber. Further, for radiation shielding, other material having a radiation shielding effect, such as lead, may be added together with barium sulfate, but the amount of lead to be added can be very small because barium sulfate has a high radiation absorbing property. .. The radiation shielding material described above is shown in FIG.
The material of the radiation compensation filter 103 shown therein is the radiation apparatus and the radiation diagnostic apparatus of the present invention. Next, an embodiment of a radiation diagnostic apparatus which is one of the radiation apparatuses according to the present invention will be described with reference to FIG.

FIG. 1 shows an overall view of the radiation diagnostic apparatus. The X-ray tube 2 emits X-rays from an irradiation port toward a subject (not shown). An X-ray movable diaphragm body 1 is attached to the irradiation opening of the X-ray tube 2 in order to limit the irradiation range of the exposed X-rays. The X-ray transmitted through the subject is converted into an optical image by the image intensifier 8 and finally displayed as a diagnostic image on a television monitor (not shown). Next, the X-ray movable diaphragm body 1 will be described with reference to the model diagram of FIG.

The rectangular blade 3 provided inside the X-ray movable diaphragm main body 1 and having the central portion cut out in a square shape, and the circular blade 4 also cut out in a circular shape reduce the X-ray dose received by the subject and reduce the image intensity. It has a role of narrowing the X-ray irradiation range to a necessary range so as to match the shape of the input phosphor screen of the fire 8. Further, in order to prevent halation on the diagnostic image that occurs when there is a portion with a large X-ray absorption difference in the fluoroscopic region, two radiation compensation filters 5 are used to cover the portion with a small X-ray absorption. ing. The radiation compensating filter 5 is made of the radiation shielding material made of a mixture of, for example, silicon rubber and barium sulfate described above. The radiation compensation filter 5 is attached to a lead screw 7 provided on a base 6 rotatable with respect to the X-ray irradiation axis, and its top view is shown in FIG. The two radiation compensation filters 5 are movable in the direction of arrow A along the lead screw 7, respectively.
Is rotatable with respect to the X-ray irradiation axis, so that the two can be simultaneously rotated in the direction of arrow B and are driven by a drive mechanism (not shown). Next, diagnosis using the embodiment apparatus configured as described above will be described.

A radiation compensation filter 5 having a shape capable of preventing halation in a general diagnosis of a subject is prepared in advance in accordance with a diagnosis region, and the radiation compensation filter 5 is properly used according to a region to be diagnosed. In this description, the case of diagnosing the heart will be described with reference to FIG. The radiation compensation filter used for heart diagnosis has a shape matching the contour of the heart.

FIG. 4A shows an example in which the radiation compensation filter 5 is inserted in a region (shaded portion) where the X-ray absorption difference is corrected when the X-ray is irradiated from the front of the heart. The heart has a high X-ray absorption rate, and the tissues (hatched portions) around the heart have a low X-ray absorption rate with respect to the heart. The compensating filter 5 is linearly moved in the direction of the arrow, and corrects the X-ray absorption difference by covering a region (shaded portion) having a low X-ray absorption rate.

FIG. 4B shows an example in which the radiation compensation filter 5 is inserted in a region (shaded portion) for correcting the X-ray absorption difference when the X-ray is irradiated from the left side of the heart H. Since the spine 9 having a high X-ray absorption rate exists on the right side of the heart H, it is not necessary to correct the right side of the heart H, and the radiation compensation filter 5 is moved from the left side of the heart H in the direction of the arrow.
The line absorption difference is corrected.

However, since the radiation compensation filter prepared in advance has a shape adapted to the size of an organ of a general subject, an organ enlarged due to a disease or the like,
When diagnosing a pediatric organ or a deformed organ, if the original shape cannot be applied to the X-ray absorption difference correction site, or if the X-ray absorption difference correction site is covered, the movement range of the radiation compensation filter will be exceeded. There are cases. However, in such a case, since the radiation shielding material of the present invention can be easily processed with scissors, a knife or the like, the radiation compensation filter is adapted to the X-ray absorption difference correction portion during the diagnosis so as to be suitable for the X-ray absorption difference correction portion. It is possible to process according to the shape of the absorption difference correction portion. Therefore, no matter what shape the X-ray absorption difference correction part has, it can be easily corrected during the diagnosis, so that the diagnosis time can be shortened and the diagnostic image can be more easily seen. Can be improved. Further, by leaving the processed product as it is, the radiation compensation filter can be applied when a similar case occurs in the subsequent diagnosis. Next, the drive mechanism of the radiation compensation filter will be described in detail with reference to FIG.

On the base 10 fixed in the X-ray movable diaphragm body 1, a base 11 is attached via a lead screw 13 and a guide shaft 14, and the base 1
The motor 1 moves in the direction of arrow C along the guide 14 by rotating the lead screw 13 by the motor 12.

A rail 30 is provided on the base 11, and a shaft 31 movably mounted along the rail 30 supports the base 15 and the base 16 on the base 11. The base 15 and the base 16
A gear is cut on the outer circumference of the base 15, and the bases 15 and 16 independently rotate along the rail 30 in the direction of arrow D by the rotation of the pinion gears attached to the motors 17 and 18 meshing with the gear.

Filter mounting portions 23 and 24 are mounted on the bases 15 and 16 via lead screws 21 and 22, respectively, and the filter mounting portions 23 and 24 are rotated by the motors 19 and 20 rotating the lead screws 21 and 22. 24 moves in the direction of arrow E. The filter mounting portions 23 and 24 are made of a substance with a magnet,
The radiation compensating filters 25 and 26 are attached to the filter attaching portions 23 and 24 by magnets 27 and 28 attached to the back side.
It can be easily attached to and detached from. Note that FIG.
The base intervals are drawn wide for clarity, but the intervals may be narrow.

In the above embodiment of the drive mechanism, since the radiation compensation filters 25 and 26 are movable in the X-ray irradiation direction, the X-ray absorption difference can be corrected in accordance with the size of the organ to be diagnosed. Therefore, the radiation compensation filter can be applied to the same organ, such as cardiac hypertrophy or liver hypertrophy, which is enlarged due to a disease or the like, or a pediatric organ which is too small to apply the compensation filter. Like In addition, the radiation compensation filter 25,
In addition to independently moving 26 in the direction of arrow E on a plane perpendicular to the X-ray irradiation direction, and individually rotating in the direction of arrow D, even if the organ has a peculiar shape due to enlargement. The X-ray absorption difference can be easily corrected. Further, since the magnets 27 and 28 attached to the backs of the radiation compensation filters 25 and 26 are attached to the filter attaching portions 23 and 24, they can be easily attached and detached,
By preparing a radiation compensation filter suitable for the shape of various organs, it becomes possible to easily replace the radiation compensation filter according to the diagnosis site. However, there is a case where the radiation compensation filter cannot be adapted to the X-ray absorption difference correction portion with the shape as it is, or the movement range of the radiation compensation filter is exceeded to cover the X-ray absorption difference correction portion. Even in such a case, since the radiation shielding material of the present invention can be easily processed with scissors, a knife, etc., the radiation compensation filter is corrected in situ so as to be suitable for the X-ray absorption difference correction portion. It can be processed according to the shape of the part. Therefore, it is possible to easily correct whatever shape the X-ray absorption difference correction portion has.

Next, another embodiment of the drive mechanism of the radiation compensation filter will be described with reference to FIG. This embodiment is different from the above-described embodiment in that the base 1 in which the filter mounting portions 23 and 24 are driven independently of each other
One base 4 instead of being attached to 5, 16
It is attached to 0. Therefore, the motor 4
The rotation of the base 40 by 1 causes the filter mounting portions 23 and 24 to simultaneously rotate in the direction of arrow D.

In this embodiment, although the radiation compensating filter is inferior in adaptability to the above-described embodiment, the number of parts is reduced and the mechanism is simplified.
The cost can be reduced and the product can be easily commercialized as compared with the case of the embodiment described above.

In the present invention, the radiation compensating filter may be attached by any method that can be easily attached and detached, and for example, an attaching method by screwing may be used. Further, as a method of moving the base and the filter mounting portion, a method using a wire, a belt or the like may be used instead of the method using the lead screw method.

As an example, FIG. 7 shows a method of rotating the base 40 in FIG. 6 using a belt. this is,
The belt 50 hung on the outer periphery of the base 40 is attached to the motor 51.
It is a method of rotating the base 40 by driving the base 40.

Regarding the movement of the filter mounting portion, FIG.
The belt 52 may be fixed to the filter mounting portion 53 and rotated by the motor 55 via the pulley 54, as shown in FIG.

As a method of moving the base 11 in the X-ray irradiation direction, as shown in FIG.
Alternatively, a method may be used in which the motor is fixed to a part K of the side surface of the motor and moved by rotation of the motor 58 via the pulley 57 fixed to the base 10.

The method given here is only an example, and other various methods using a wire or the like are conceivable. It should be noted that the present invention is not limited to the embodiments, and various modifications and combinations are possible unless the subject matter described in the claims is changed. For example, an X-ray movable diaphragm body that uses moving means of various radiation compensation filters independently, and an X-ray movable diaphragm body that uses various moving means in any combination are also conceivable. Also,
Although the number of radiation compensation filters is two in this embodiment,
It may be three or more.

[0035]

As described in detail above, according to the present invention, it is possible to provide a radiation shielding material which can be easily processed into a desired shape with scissors, a knife or the like.

[Brief description of drawings]

FIG. 1 is an overall view of a radiation diagnostic apparatus according to the present invention.

FIG. 2 is a model diagram of the X-ray movable diaphragm body shown in FIG.

FIG. 3 is a top view of the base 6 shown in FIG.

FIG. 4 is a diagram showing an example of inserting a radiation compensation filter into a region for correcting an X-ray absorption difference when diagnosing a heart.

FIG. 5 is a perspective view of a drive mechanism of a radiation compensation filter.

6 is a perspective view showing a modified example of the drive mechanism shown in FIG.

FIG. 7 is a view showing a modified example of the drive mechanism of the base 40.

FIG. 8 is a view showing a modified example of the drive mechanism of the filter mounting portion.

FIG. 9 is a view showing a modified example of the drive mechanism of the base 11.

FIG. 10 is a diagram showing an X-ray movable diaphragm body on which a radiation compensation filter is installed.

[Explanation of symbols]

 1, 101 X-ray movable diaphragm main body 2 X-ray tube 3 Square blade 4 Circular blade 5, 25, 26, 103 Radiation compensation filter

Claims (4)

[Claims] 1. A radiation shielding material comprising barium sulfate and a material for fixing the barium sulfate. 2. A radiation compensation filter, comprising: a radiation source for generating radiation; and a radiation compensation filter provided in the vicinity of a radiation emission port of the radiation source, for partially attenuating a dose of radiation generated from the radiation source. Is a radiation device comprising barium sulfate and a material that fixes the barium sulfate. 3. A radiation source for generating radiation, a radiation diaphragm for limiting a radiation irradiation range from the radiation source to a cone shape, and a radiation source provided so as to face a cone line of the cone-shaped radiation. And a pair of radiation compensating filters for partially attenuating the dose of radiation generated from the radiation compensating filter, wherein the radiation compensating filter comprises barium sulfate and a material for fixing the barium sulfate. 4. A radiation diagnostic apparatus for irradiating a subject with radiation to obtain a radiation image of the subject, the radiation source generating the radiation, and the radiation generated from the radiation source, the radiation source being provided in the vicinity of the radiation exit port of the radiation source. And a radiation compensating filter for partially attenuating the dose of the radiation compensating filter, wherein the radiation compensating filter comprises barium sulfate and a material for immobilizing the barium sulfate.