JPS6115377B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a scintillation camera that detects the radiation dose from a subject who has been administered a radioactive isotope.

In recent years, radioactive isotopes (hereinafter referred to as RI) are administered to test subjects for the diagnosis of certain diseases, and most of the administered RI concentrates in some form of tissue, and the concentrated RI Scintillation cameras are widely used to quickly measure the distribution of tissue in tissues. In this case, γ-ray energy from RI administered into the body of the subject is radiated outside the body, and the γ-ray energy is detected by the scintillation camera and imaged as an RI body distribution image. However, a collimator is installed on the patient side of the detector of the scintillation camera in order to give directionality to the emitted gamma ray energy and increase the sensitivity and resolution of the scintillation camera. A collimator is a hole made in thick lead about 5 cm to 10 cm, and can achieve the above purpose by allowing only gamma rays from a specific direction to pass through and removing gamma rays from other directions. It is. When using these collimators, an appropriate collimator must be selected depending on the type and amount of radiation isotope, the type of organ tissue, etc. In addition, in order to obtain RI distribution images of the subject from multiple directions, a scintillation camera main body 1, to which an optimal collimator 2 is attached at the time of inspection, is mounted on a scintillation camera support 3, as shown in FIG. It is necessary to rotate around the support axis 5 of the support arm 4, which slides vertically along the support arm 4.

Conventionally, the rotation of the support arm 4 of the scintillation camera body 1 about the rotation support shaft 5 as described above has been performed by a power source such as a motor. In this case, in a scintillation camera,
The balance with respect to the rotation support shaft 5 is unbalanced due to various collimators 2 attached to the scintillation camera, and the collimator 2
After being mounted, the center of gravity of the scintillation camera and the rotational support point are misaligned. Further, the very delicate rotational operation of the scintillation camera desired by a doctor who is a diagnostician cannot be achieved by rotation using a power source such as the motor. Therefore, a method may be considered in which the diagnostician manually rotates the scintillation camera body 1 to a desired angle. However, as mentioned above, the collimator 2
The scintillation camera body 1 is very heavy, for example, about 50Kg to 100Kg, and its center of gravity and the center of rotation are misaligned, so the scintillation camera body 1 is unbalanced with respect to the center of rotation and cannot be operated manually. It's impossible.

SUMMARY OF THE INVENTION An object of the present invention is to provide a scintillation camera equipped with a collimator that allows easy manual rotation of the scintillation camera around its rotation center.

In the scintillation camera of the present invention, when a scintillation camera is equipped with many types of collimators, the scintillation camera body is provided with a mechanism to maintain balance about the rotation center of the scintillation camera with respect to the weight of each collimator. By providing a counterweight, the center of gravity of the scintillation camera with the collimator attached coincides with the center of rotation, and the diagnostician can easily rotate the scintillation camera by any angle manually, thereby achieving the object of the present invention. can be achieved.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

As shown in FIG. 2, a collimator 2 is attached to the entrance side of the radiation emitted from the person to be inspected in the casing 7 of the scintillation camera body 1, and the casing 7
A flat plate-shaped counterweight 6 is provided in the interior of the scintillation camera body 1, sandwiching the collimator 2 and a rotation center 5' corresponding to the rotation support shaft 5 of the support arm 4 of the scintillation camera body 1. A plurality of springs 8 are provided between a side of the housing 7 opposite to the collimator 2 and the counterweight 6, and two rods 9 are provided on a side of the counterweight 6 opposite to the springs 8. Two screws 10 are screwed into the housing 7 in a straight line so as to face each of these rods 9. Therefore, the screw 1 of the housing 7
A thread is cut in the portion corresponding to 0, and a hole into which the screw 10 is inserted is similarly provided in the collimator 2 portion.

Next, the operation of the embodiment of the present invention described above will be explained with reference to the drawings.

In FIG. 2, an arbitrary collimator 2 is attached to the casing 7 of the scintillation camera body 1,
In this case, the center line l passing through the rotation center 5' of the scintillation camera body 1 is parallel to the vertical direction, and in this state, the screw 10 is adjusted so that it is balanced with the arbitrary collimator 2. Then, the linear distance between the counterweight 6 and the rotation center 5' is adjusted. In this case, the amount of movement of the counterweight 6 is calculated at the time of design so that the balance can be maintained with respect to the arbitrary collimator 2, and the movement direction of the balance weight 6 and the center of rotation 5' are adjusted by the amount of movement. Adjust the length of the arm and adjust the rotational moment around the center of rotation 5'. Therefore, the counterweight 6
The rotation moment around the rotation center 5' due to the gravity of the collimator 2 is made equal to the rotation moment around the rotation center 5'. the result,
The center of gravity of the scintillation camera 1 equipped with the collimator 2 can be made to coincide with the center of rotation 5'. Therefore, the diagnostician can easily rotate the scintillation camera body 1 even manually, and can therefore operate the scintillation camera body 1 by minute angular displacements.

A second embodiment of the invention is shown in FIG.

Collimator 2 of scintillation camera body 1
A first counterweight 11 is attached to the side opposite to the mounting side, and a second counterweight is installed inside the scintillation camera body 1 and on the side where the collimator 2 is attached from the rotation center point 5' of the scintillation camera body 1. 12, a plurality of flanges 13 are provided approximately at the center inside the scintillation camera body 1, a plurality of springs 14 are provided between the flanges 13 and the second counterweight 12, and the Second counterweight 1
Holes 16 are provided in the housing 7 of the scintillation camera body 1 corresponding to the rods 15 so that the plurality of rods 15 on the opposite side to the scintillation camera body 1 protrude from the scintillation camera body 1. Further, the collimator 2 is provided with a recess 17 having a constant depth determined by the weight of the collimator 2, into which the rod 15 is inserted. The recess 17 is made shallower as the weight of the collimator 2 increases, and becomes deeper as the collimator 2 is lighter. The recess 17 balances the rotational moment about the center of rotation 5' due to the weight of the first counterweight, the sum of a similar rotational moment due to the weight of the second counterweight and a similar rotational moment due to the weight of the collimator. Thus, the second counterweight is moved along the center line l of the scintillation camera body 1.

As described above, in the scintillation camera according to the present invention, after selecting and installing a collimator appropriate for the type of radioisotope and the region to be inspected,
By moving one or more counterweights provided inside the scintillation camera by a certain amount with respect to the rotation center of the scintillation camera, balance with the collimator is maintained, and as a result, after the collimator is attached, The center of gravity of the scintillation camera and the center of rotation coincide with each other, so that the doctor who is the diagnostician can easily manually rotate the scintillation camera about the center of rotation. This makes it possible to perform delicate rotational operations as desired.

[Brief explanation of the drawing]

FIG. 1 is an external view of a scintillation camera, FIG. 2 is a sectional view of the main parts of an embodiment of the scintillation camera according to the invention, and FIG. 3 is a main part of the second embodiment of the scintillation camera according to the invention. FIG. 1...Scintillation camera body, 2...Collimator, 3...Strut, 4...Support arm, 5...Support shaft, 6...Balance weight, 7...Housing, 8...
...Spring, 9...Rod, 10...Screw, 11...
First counterweight, 12...Second counterweight, 13...Flange, 14...Spring, 15
...rod, 16...hole, 17...dent.

Claims (1)

[Claims] 1 A scintillation camera body that has a collimator that can be attached to the entrance port for detecting radiation, and that can be rotated around a support axis that is approximately parallel to the surface on which the collimator is attached, and that can be moved inside the scintillation camera body. a counterweight supported by the collimator to balance the collimator; and a mechanism for changing the position of the counterweight with respect to the rotation center of the scintillation camera body so that the center of gravity is located at the rotation center of the scintillation camera body. A scintillation camera characterized by being equipped with.